Looking for tips on a 525 project

[RockyS18]

I posted a thread a couple days ago and I wasn't thinking and deleted it when editing...

Anyway, in my quest for more power I've decided on a 525/XR package. I spoke to Carl C about it a while ago and read his build thread (thanks for your help!). My cousin's Cig is also in need of an engine, so we both saved some money by just dealing between us and he'll be getting my 496. I pulled my engine last week and got an opportunity to clean out my bilge (it looks great nice n shiny!).

If anyone has some advice for the project, I'd really appreciate it.

Sorry for the blurry pic I didn't realize it was blurry until now.

[Carl C]

Beware of the steering police! :smash::nilly::eek!::propeller::nuke::doh::bonk::l ightning:shocker::blub::uzi:

[gcarter]

Carl, I think it's the steering brigade!:banghead:

[roadtrip se]

But I'll give you a few pointers:

1) Beef up the pan with a coring layer. There is inherent flex in the tub and it is going to flex, then stress crack about half way down the bilge on the port side and around the stringers. The transom should be fine, but I would core to and cap the stringers. If interested, PM me, and I can provide you with the lay up I used.

2) Plan on solid, offshore mounts at the least. I have a modified engine cradle hard mounted to stringer mounts. The engine isn't going anywhere. Even with solid mounts, plan on tightening fairly regularly. Again PM me and I can provide pics.

3) Plan on a good twin ram hydraulic system to the helm. I can't tell from your pics, but if you have one, use this opportunity to put backing plates on the transom side for more strength on the transom. These boats will not need more glass work on the transom, but backing plates expand the load bearing surface.

4) I would look at replacing the transom assembly with an HD version. Get the one with the mechanical pivot and digital sender. Easier to do with engine out and a major safety factor. This is also a good time to check the alignment of the assembly, as Donzi got sloppy here on some 496 boats.

5) Carl can talk to you about trials with the differences on gauge senders and such when moving from the 496 to the 525. I didn't deal with this as I am still utilizing a set of 500EFI accessories and senders.

6) Think XR shaft IMCo shorty. Good for 3 to 5 and makes this platform so much more interesting to drive. The X dim is way too low on these boats and you won't be able to maximize the use if your new power with a stock leg. Plan on plenty of prop testing depending on the various conditions where you run your boat.

7) Replace crappy Springfield pot metal seat systems with Garelick Ezzee Sliders. The junk is going to break under the harder load, sooner than later. And at the worst time. The Garelicks are solid aluminum, and superior in every way.

8) Look at your wiring. Now is the time, while everything is apart, to heat wrap all open connections, check the support for the loom and install aircraft clamps every six inches or so. Also take a look at hanging wires in the bilge, and get them out of the way in the same fashion.

9) Take a look at a Hardin sea strainer with Y-valve to keep the water running to your new blue motor clean. Also makes it easier to run on the hose. Also, while you are shopping Hardin, take a look at their stainless water pump. It uses the same impeller, but with a superior body to the Mercury plastic junk.

10) Get rid of the exhaust cans on the transom. Also, chuck the Q&Q or plan on some significant tail work to get it to function. Remember, the 525 has reversion issues, so I would be sure to use very inch of real estate at the transom to get water out of that engine.

11) If you have Bennett's and use them, I would look at kplanes or an equivalent like Dana or Eddie Marine. The Bennett's are just too slow at 80+. Again, easier to do with the engine out. And use backing plates similar to the steering rams on the inside of the transom.

12) Look at the Livorsi or Uflex throttle unit. Still a single lever, but a much easier piece to work with. You are going to want this when funneling that power. Again at 80+, you will appreciate the reaction time to keep from blowing a drive. Some here also have had luck with the Dana controls. I don't like the stick systems, because they require a clumsy pod and poor positioning to make work with our boats.

This is a start. It can be done incrementally, but plan on doing it all eventually.

[Carl C]

http://www.donzi.net/forums/showthread.php?57025-Air-22-Dwight-Can-U-Help-Me-W-525-Install

I just re-read my repower thread. It starts out with pages of people telling me that I can't do this myself. Then when I said that I cruise at 70 mph, conditions permitting, more pages of criticism came. Most of that was deleted by Madpoodle. Then the steering police would just not give it up. That was cleaned up also. Twice I was ready to walk away from my thread. Twice it was cleaned up by Madpoodle. My results were fantastic. The boat has run great for 3 seasons now with no problems. Full Zeiger steering is on the boat now. Some people have wondered why there aren't more project threads. I know mine scared a few people away. I will offer Rocky help only through PMs or phone calls.

[Ghost]

(This is rhetorical.) If all the advice about external hydraulic steering was garbage, why spend the money?

I'm reminded of one of my favorite Steven Wright jokes. "I intend to live forever. So far, so good."

[roadtrip se]

Posted by Roadtrip SE on 4/15/2009...

"Let's just say somebody decided...
to hit the delete key on all of his posts, not realizing that somebody else might just have the un-delete key....The joys of insomnia....

I do think some of the posts were a little rough, some of which have been deleted, but you ask for advice on a public forum, and you will receive advice on a public forum. Some of it may not be what you like to hear.

I know, I have enjoyed it on occassion as much as the next guy, even when I didn't think I deserved the abuse. Part of the joy of a public chat board. A thick skin is a requirement...."

Your post above just looks like sour grapes at this point...

[Ghost]

Rocky, apologies if I missed this, but with your serendipitous game of pass-the-motor, will you be keeping your gimbal or buying new? If you're buying new, I'd definitely go with the HD. I don't really know whether the beefier gimbal is needed with the 525, but external steering has got to be the best thing in the world for a non-HD gimbal with a 525.

I totally dig your project, and I suppose you'll likely be the only 009 with a blue motor...

[undertaker]

Rocky your boat is gonna be a sweet set up with the new motor and upgrades, I wanna do the same thing to my boat some day (when I get my big boy pants :biggrin:)...I will be watching this thread very closely and hope to run with ya up at LG this summer....

As a side note I would listen to Todd very closely the guy knows his stuff, also contact Dr Dan, Bob Haver, Dwight Air22 they aren't rookies either...if you need any of there contact numbers shoot me a pm....


Man you are making it tough to not do this to my boat sooner rather than later...:yes::pimp::pimp:


Undertaker:wavey:

[RockyS18]

Ok, I don'y have a lot of time right now so this is going to be a rather short reply for all the information provided.

First of all, thanks to everyone who has provided advice so far. I absolutely do not want to open a can of worms in this thread, so please let's all put our differences of opinion aside and just peacefully discuss the subject.

My boat is already equipped with Zeiger full hydraulic steering and it has a high x dimension.

I'll post in-depth later.

[Pismo]

Make 110% sure your transom and/or stringers are not wet or rotting. Lots are. Fix it while you have it all apart. Lots easier to do it now if need be.

[DON N.]

Stop up to bolton and talk to jason @ performance marine.
Remember we chatted @ the boathouse.

[Pat McPherson]

If there is any question about the stringers, add reinforcement.
A "race" engine mount is a no brainer as it will tie the sringers together. You don't want the engine to move around at all.
K-planes are better than Bennetts but if you have the double pistons, I wouldn't bother.
No captain's call with a 525; use mufflers if you must.

[Pismo]

Carl I believe has switchable exhaust on his setup. Take a look.

[Carl C]

"Carl I believe has switchable exhaust on his setup. Take a look."

Yes. It requires special divertors and is only usable up to 2,500 rpm according to the Mercury 525 service manual. I only use mine off plane. I already told Rocky that one of his biggest expenses will be fitting the exhaust whether he goes with Q&Q or not. I also agree that the hull needs to be reinforced while the engine is out. If it were me I would do something like the factory reinforcement kit with a couple extra layers of stitchmat. It can be done in a couple of weeks.

[mike o]

Governor for EJ...........;)

[VetteLT193]

There are two ways to handle the exhaust issue. Carl did the move the tips method / fix the transom. You can also have the CMI's fitted to match your boat. With this method you stick the engine in, measure it all up, send the exhaust to CMI with the measurements and when they come back they should bolt in. The long tail headers are meant to be customized so you wouldn't be heading into unusual waters going with this method. At the very least it's worth doing a price comparison.

[RockyS18]

Roadtrip se, thanks for the thought out response. I will be beefing up the engine room floor, and I will be installing 280 k-planes.

I boat on Lake George so the sea strainer is not a necessity.

Undertaker, hopefully we will finally run together at lg this summer... And your boat will be even more badass when you upgrade the engine someday! I am in contact with Bob Haver and Dr Dan (cruised with them at the fall picnic) and I'll be sure to shoot air22 dwight a PM.

Pismo- I'll definitely check the transom and stringer condition, thanks.

Don N.- I'm good friends with Jason and Johnny, and I have spoken to them thanks. Yes I remember

Pat McPherson- a race engine mount has been the plan from the start since tying the stringers together will ensure rigidity as you said. Thanks for the reply

I don't have captain's call right now, I have the Quick n' Quiet II which means that there is no solenoid. At idle, some engine noise will exit through the drive while some will exit through the main exhaust pipes. At speed all engine noise exits from the main exhaust pipes. As far as I know this set up works with the 525..

Mike o- ha!

I'm not sure what to do for the exhaust issue. Having custom CMI's made is going to be much more expensive than moving the exhaust tips, however since my transom is black it will be permanently scarred from the exhaust tip relocation... Once I get the engine in I'll see what has to be done and get a quote from CMI.

Carl, how close are your headers to your hatch?

Thanks in general for all the replies, I really appreciate the help provided. :biggrin:

[Carl C]

"Carl, how close are your headers to your hatch?"

IDK. My exhaust was the only part of my swap that I paid to have done. Brian Orlandi did it. The parts and labor was around $3,000 and I kept Q&Q for idle use only. The new diverters retail for $1,000 each. It also prevents waves from washing up the exhaust if a baffle should stick open. If any water gets up in there it will run down the Y pipe and not over the hump into the engine. Custom tails will probably be close in price. You cannot tell that my tips were relocated. Brian did an excellent job. I'll try to think of a way to measure the header clearance short of laying in the engine room and closing the hatch! I'll look for a picture too.
http://i763.photobucket.com/albums/xx275/CARLC222/Pics312Medium.jpg

[Ghost]

Playing around (fore and aft as well as side to side) with a good straight-edge on the frame of the hatch opening, and the hatch bottom, should give a decent idea of clearance.

Or maybe put a glob of Play-dough on the top of the headers and close gently.

[Carl C]

My guesstimate is 1 1/2" clearance between header and hatch. If you need a precise measurement I will climb in there with a flashlight and ruler and close the hatch. The store is out of 2" plasti-gauge.......... :)

[VetteLT193]

The raised X on the 009 will be really similar to my Brother's old '87 22. His CMI's rubbed the hatch a little... He had E tops not the 525 style full header. Of course, CMI doesn't list the dimensions on the standard E top so it will be hard to tell. Based on the pics the E top and the 525 header seem similar in height except the peak height on the E top is farther back.

So... if the engine is sitting even it might just fit. If the engine is tilted back at all it probably won't fit. DonziDirect sells the Shelby style hatch for about $900 so that could be an option. Or if you go the custom route CMI should be able to fit you height and on the exhaust center.

FWIW I had contacted Stainless Marine about custom fitment and the prices seemed far cheaper than glass work / paint.

[JayZ]

Looking forward to watching the build. Good luck!

[roadtrip se]

What Jay Z said, plus some... Just remember it never ends...

[Carl C]

Nope, it never ends. I've been drooling over this more and more. Especially with some local guys running over 90 now. It adds 50% more hp which should get me up to 750-800 hp and maybe near triple digits :). $9,000 + a Teague style raised hood scoop and a new prop. Just need business to pick up a bit. :)
http://i763.photobucket.com/albums/xx275/CARLC222/whipple525.jpg

[MDonziM]

I have a 540 ci motor in my 94' 22 that I put in 4yrs ago. Glasswork in the eng compartment is really important imo. There are plenty of threads on this but since your hull is an 09 I would assume that you should just need to stiffen the bottom either with additional stringers or added layers of glass. We also replaced the "shelfs" with thicker core and ran the tabbing further up the topsides than the factory. With the new stringers tied into a new sistered bulkhead and longer 1/2" aluminum eng mounts the compartment is real solid.
Everything RT listed is valid in my book. I have a Dana side mount 2 lever throttle that I love.( no pod)
As to exaust, I kept my old gil risers and fitted Hardin "shorty headers" to them which perform great and retain all the original exaust alignment. With a dart intake, 1"spacer and 3" flame arrestor I'm just under the hatch but my exaust has at least 1" clearence.( 94' X is 2" lower I think) A lot of info on 525 exaust as there were issues years back. You didn't say if your power was new/used.

- Marshall

[roadtrip se]

I agree with all that Marshall said here...

A couple of more thoughts...

- To clarify, when I criticized the "single stick" systems, I was referencing the ones that do require a pod like the offshore style versions available from Livorsi or Gaffrig. Ted actually used a Dana set in the Ilmor boat and it looked like it was mounted in a manner where it would be comfortable to use. Looks like a good choice. I have been very happy with the Uflex-based unit from Livorsi. I can't imagine going back to the stock Mercury stick.

- Also, Marshall mentioned coring in his recipe and tying in the shelves and transom. While we didn't do the transom, we did utilize a significant amount of coring across the pan. This is critical from my view, as it adds even strength across one of the thinnest and most highly stressed areas of the boat. Just adding fiberglass weave isn't enough to really stop the flexing, and subsequent cracking down the road.

- As for the mounts, I wanted the full monty with an offshore cradle. Most should be able to do what Marshall did by improving the stringer mounts and going to solids. I wanted the cradle, because of the conditons we boat in here in Michigan. Nothing is moving or flexing back there now.

- Q&Q. I ran Corsa Q&Q on the 500EFI for a lot of years. I have also had a chance to look at what Brian did for Carl at the shop. That was some engineering and finagling. Potter was adamant about getting it off the boat with the 540 project, due to possible reversion issues. Some days I do miss it with as loud as this thing is now. I'm not sneaking up on anybody!

[RockyS18]

I guess it's either:
a) custom CMI's
or
b) Shelby hatch, relocate exhaust
I suppose whichever one is less expensive is the way to go. No real performance difference either way.

Carl, your boat would be a monster with a supercharged 525! That should get your triple digits, right?

I actually like my current Mercury shifter... :outtahere: Oh, and the 525 is new.

Thanks for the info on hull reinforcement. I'll be doing some coring as recommended.

RT, I'm surprised that Q&Q would add to reversion issues versus helping. Any water that got past the flaps would exit down the Y pipe instead of going in the engine.

[Ghost]

Best I understand it, reversion is a fascinatingly complex subject with lots of factors involved.

The vertical drop to the y-pipe in a switchable system may well help stop reversion in some instances, such as water sloshing from the sea into the exhaust. And I won't say it can't have some beneficial effect to stop reversion of cooling water that mixes in the risers. But my guess is the negatives outweigh the positives where that cooling water is concerned.

I also suspect some of the big negatives with switchable exhaust are only correlated to reversion, not causal. Nearly all such systems require relatively short risers before the water is mixed in, which makes reversion eaiser. They also may have relatively little drop angle, likely with the same effect.

All that said, I think one of the wackiest and most vexing problems with any system is lack of a vacuum break. And while there seems clearly to be a reduction in reversion risk with less valve overlap (less agressive cams), what isn't clear to me is just how much the lack of a vacuum break may a factor in ANY system, even with a mild cam.

Meaning, if a system resonates the right way to break the surface tension of the water (which apparently they do, allowing it to flow well back uphill), and it operates with the pulses of intake strokes creating an effective net suction back up the exhaust passage, just how much riser length and/or drop is needed to stop reversion from happening? The tales I read qutoing Mac Privott of Carolina Classic (who had MAJOR reversion issues in his line for years) include making a transparent exhaust, and watching the water "walk" right back up the pipes. If so, then the question is how far and how steeply can it walk, for a given setup?

As for the solution, short version is, I bet vacuum breaks are a very good idea. (Best I can tell, they squeeze the flow down a bit within the exhaust, and maybe also act as a mechanical dam to stop water moving back up in the system.)

If the study below is correct, the technology simply got lost. Way back, someone discovered the need and invented them and they became part of the standard riser molds. Time passed, new manifold designs came along, and nobody making those knew about the vacuum breaks and what they did, so they disappeared. Only to see lots of motors damaged, and requiring re-invention.

Recommend anyone read this study: http://www.michel-christen.com/ExhaustElbows.pdf
(http://www.michel-christen.com/ExhaustElbows.pdf)
I hope this is helpful.

Mike

[Carl C]

Mr. X (Ted) Ran 104 in his Ilmor 22. IDK how much hp he was making though. Also he probably could have squeezed a little more out of it. The 525 makes about 540 hp. Whipple's claim is that their kit boosts hp & torque 50%. That would put me at 810 hp. I think that is triple digit potential. Does anyone know how much hp Ted's boat was making?

Rocky, what you will get here is a collection of advice from people who know a thing or two about this. You have to weigh everything out and decide on your plan of action. I did not core mine because I did not want to trap water in the front of the hull and also because my hull had already been significantly strengthened with a Donzi engineered kit. Ted cored and vacuum bagged his and Todd cored his. Others have added power and done nothing. Exhaust is your call but the Q&Q with proper diverters is safe up to 2,500 RPM. Did your engine come with headers? If so, I would pressure test and use them.

Let me know when you want to talk about getting analog gauges to work with a smartcraft set-up. That will be your other big headache.

I found this post from Mr. X. Looks like he was running a 710 hp Ilmor? This is the trickest 22 Classic I know of and it's top secret who owns it now.

"Looks like 103 MPH is all she's got.
I need to post some pictures of the finished product.
It is rock solid stable at all speeds, has a cruising speed 70 MPH.
Can't name any names, but the man who has driven more
Donzi's than anyone else on the planet, (only guy to have driven more than me) said " this is the best and fastest 22 classic I have ever driven!" He literally let go of the wheel at wide open throttle.
No porpoising issues, no chine walk......just rock solid and fly’s straight and level. The acceleration is phenomenal! The entire hull running surface was cored with 3/4" corecell and then vacuum bagged. Then 5 layers of 1808 X and S
glass laid over it all, including the huge stringers. All of this was done to accommodate the over powering of the Ilmor 710. The boat was literally built around the engine. So many things had to be taken into consideration as far as engine fit and clearances. It uses a custom fabricated solid engine mount system, metal fuel tank with a fuel return and tons of other engineering challenges I can't go into. Please keep in mind this was a 2 year project and everything was a challenge.

I did not build it to be the fastest 22, but more of a custom concept boat with emphasis on fit and finish.
In the engine room all you see is custom Viper blue diamond plate and engine.
No wires, hoses or cables.....there all hidden.
I had the best of the best people in the industry help me with this project.
From lay up to paint to upholstery to rigging.....it is super trick and custom.
I hope to get it out where you all can see it in person soon.
I have to state that this entire project was a private endeavour and no company had any direct involvement. http://www.donzi.net/ubb/wink.gif
Thanks for the interest."

[Ghost]

Exhaust is your call but the Q&Q with proper diverters is safe up to 2,500 RPM.

Just to be clear, I think what's key here is the definition of "safe." In the context of Carl's note above, as I understand it, "safe" means it won't create too much backpressure by making the motor try to drive too much through too small of a pipe. But it has nothing to do with safety from the sort of resonance reversion that I discussed in my prior post. The sort of reversion I was discussing is an issue down around idle RPM, and the "up to 2,500 RPM" rating is clearly not speaking to that subject at all.

[Carl C]

Ghost, if that were an issue then I think it would be addressed in the service manual and Brian Orlandi, who did my exhaust, knows what he is doing. And I have 3 trouble free seasons on the 525 now. Just don't use the 496 diverters!

[VetteLT193]

There might be a performance benefit to the Shelby style hatch because of the air flow increase. Emphasis on might. I heard through the grape vine that one 22 owner switched to a shelby hatch for styling purposes only and picked up some top end speed.

My thoughts supporting the theory is the engine room is kept cooler and more flowing with air with the much larger and forward facing vents. Another thought is the older 22's, when they came out with the 4 small vents, didn't have a firewall like the newer 22's do. Basically the engine area was vented all the way through to the bow. The newer ones get any air from the vents.

My thoughts against the theory... It's a through the grape vine unproven rumor and mathematically the 4 vents should be enough to support the power.

Donzidirect I think is the only place that sells the hatches so DonziJosh should be able to confirm or deny the performance upgrade of the extra air.

[katanna]

My "opinion" would be that any benifet from the air increase would be offset by the huge drag of all that air going in with no way to get out. The carb can only flow so much air, any more wont help unless it is sealed to the carb such as a procharger. I would be intested to see what the air temp difference is when actually running at speed. Just to be clear I do love the look of the shelby hatch.

[VetteLT193]

I forgot it's a 009 boat (brain fart). It's already got a scoop so changing to a shelby would only be for header clearance. :embarasse

[Carl C]

I wonder if any air actually gets rammed into the Shelby style scoop given that the windscreen and lip directly in front of the hatch direct airflow up and over the hatch. I like the Teague scoop and my boat may be getting one. Now if we are talking just about header clearance then that's a whole different story.
http://i763.photobucket.com/albums/xx275/CARLC222/shelbyDonzi.jpg
http://i763.photobucket.com/albums/xx275/CARLC222/teaguescoop.jpg

[Ghost]

Ghost, if that were an issue then I think it would be addressed in the service manual [emphasis added] and Brian Orlandi, who did my exhaust, knows what he is doing. And I have 3 trouble free seasons on the 525 now.

Right, that is what you think, I disagree, and that is why I mentioned it. I mean absolutely no offense, I just think you are just wrong about the statement I bolded above and I'd caution everyone not to make such assumptions. Contrary to your assumption, I think it's very likely reversion wouldn't make it into a service manual at all. Because it's been such a sneaky and poorly-understood phenomenon where for a while, nobody had all the answers or "knew what he was doing." That's not a knock on anybody, just the reality of a very sneaky problem. Over time, people are learning more and more.

The research study I cited indicates that the understanding of the resonance reversion issue itself, and the technlcal solution to that issue, appear to have been lost even among the absolute best and brightest in the industry. It just eroded from the knowledge base. Merc made engines that had problems. Volvo made engines that had problems. Virtually every maker did. And no reason to think Corsa, or OSCO, or any aftermarket vendor magically understood and tested and solved everything either. There is no shame in not fully understanding it, and we're not sure anyone can yet claim he fully understands it. If one looks at all the combinations of cams, head geometries, riser lengths, riser angles, installation angles, heights above waterline, exhaust output locations, flappers versus not, sea conditions, etc...it's a potentially a huge mess of complexity. Exhaustive testing (pun not intended, but I'm going with it) might be REALLY hard. With a set of answers that might be like dive tables to prevent the bends--not cut and dried but just probability-based. Take a look at the Merc drive/motor installation PDFs sometime. It takes them a whole book to outline their specs.

That said, what is extremely useful is to compile empirical data, such as your experience. I put INFINITELY more stock in the real-world experience and observation of installations like yours, examined closerly over significant time, than I would put into an assumption about what Corsa knew (or didn't know) or tested (or didn't test) based on the fact that they DON'T mention reversion in their service manual.

The perhaps sad but true reality is, when a sneaky problem like this gets noticed, vendors almost never do anything except duck and hope that their stuff isn't the problem and/or that they don't get blamed. But the last thing their lawyers will ever let them do is make explicit quality/safety claims when the problem isn't very well understood. That just invites added liability to buy you a new blue motor. What they do is NOT TALK about it publicly. Hence, their omission of a subject in the service manual is the LAST thing upon which I'd base an assumption about their product in a particular application.

And in this specific case, look at Corsa's position. They aren't the deciding factor anyway. Why get involved? Just like Trident wouldn't try to say whether using their exhaust hose risks or protects against reversion. Whereas the 2500 RPM number, if I understand it, is something much simpler, about volume of exhaust flow through the y-pipe versus flow out the transom, and the associated backpressure. And it is more cautious than what I recall from Merc in their install docs.

Proabably worth some summary, for clarity:

I think highly of Corsa (and am a customer) though I don't expect they have all the answers on reversion (nobody does)
I think VERY highly of Orlandi Performance (and am a significant repeat customer), but I don't expect they have all the answers either (nobody does)
I would place a HUGE bet on Corsa's non-mention of reversion in the service manual NOT meaning they guarantee it won't be a problem
I'd base any exhaust design on all the info I could gather from real-world experience observed over significant time, info like Carl's


The other thing I'd do (in fact, I just did it last year) is not stick my jewels in anybody's vice if I don't have to. More and more laws are showing up that (outrageously) ban ANY SWITCHABLE SYSTEM regardless of how much noise comes out of it. This is stupid, offensive, wrong, and yet very real. So far, enforcement is spotty, and lax overall. So far. Full-time muffling is also getting added to more laws. I designed my custom exhaust last year based on all these factors. (Ironically, while it was being fabbed, my home state passed a ban on switchables, and I think a requirement for full-time mufflers.) Glad I did it the way I did, even if the likelihood of being stopped is low.

Hope this is useful for some,

Mike

P.S. Quick aside, one of the really cool things about Brian Orlandi is the progression of learning. He'll tell you that they never stop learning new stuff, that "we know A," we've never done that before but others do and we're willing to learn it" and "we're doing C now which nobody understood and was unthinkable just 5 years ago."

[roadtrip se]

FWIW, I have run without the stock hatch with the current power pack, and it did make a huge difference.
The primary improvement was on the mid-range snap and acceleration. I didn't have enough time to really explore the
impact on top end, as I was out on Lake Erie on a fairly bumpy day, with a wide open engine bay and I really wanted
to come back to the docks. We ran out of time before the season began last year, but the idea is to install
an Aronow/GT hatch on the Flowerpot this year.

[Carl C]

Ghost, please stop being so argumentative with your epic posts. What I quoted about Q&Q being safe up to 2,500 came from the HP525 EFI Mercury Racing Service Manual; Not a Corsa manual. Page 7A-2 Exhaust System Requirements: "A boat with a hi-performance engine(s) that offers through the prop or through the transom options (i.e., Silent Choice), must not be operated above 2,500 RPM without the exhaust going through the transom or severe engine damage may result."

[mike o]

Mike's epic pontifications.......;)

[Ghost]

LOL, Carl, honestly dude, I just think you gave a mix of good and bad advice.

I explained my agreement with part of what you said, and also where I differed. BTW, you then said I was full of it, and gave your rationale (which by your own admission is pure assumption). I took the time to explain why I didn't buy into that assumption, giving information I'd want I were trying to sort out the best answer.

Which manual it comes from doesn't change my point one bit. I believe if you understood my point, you'd know why. (Further BTW, Merc is the OEM company in the study whose manifolds once had vacuum breaks, and later didn't. Take a look through all the manuals of engines which have had reversion issues with spec setups, and let me know how much they talked about reversion and what guarantees they gave about how to avoid it.)

Yes, Merc says what you cited about not running more than 2500 RPM through the y-pipe, and the damage that can result. The manual also probably says don't operate the boat when you're hammered, and change the oil every so often. What do any of them have to do with risks of resonance reversion at idle?

As for 'argumentative,' too funny. Pot, this is Kettle...

As for 'epic,' I do feel your pain there. It's tough finding time not to read stuff. I could show you stacks of letters I've written to people who destroy my life by writing so much that I don't read. Dostoyevsky, the Enquirer, Penthouse forum...don't get me started on those Britannica people.

[BUIZILLA]

As for 'epic,' I do feel your pain there. It's tough finding time not to read stuff. I could show you stacks of letters I've written to people who destroy my life by writing so much that I don't read. Dostoyevsky, the Enquirer, Penthouse forum...don't get me started on those Britannica people. absofrickinhilarious :tooth: :jestera: :jester:

[Phil S]

...I've actually found & read that article from your link before. I think it was during the time I was having overheating issues, and was suspecting clogged risers / elbows, which Poodle told me to check at AOTH. It's probably the best article I found that shows you the inside of elbows and completely explains "resonance reversion". :yes:

The "vacuum break" casting makes perfect sense to me, and if the inside diameter of the elbow were to be sized properly to include the additional lip, it doesn't seem as though it would restrict the exhaust flow.

Phil S.

[roadtrip se]

I kind of like Ghost's epic posts, too. Even then, some folks will read and comprehend them eight different ways until Sunday...sometimes intentional, sometimes not.

I missed Carl's coring feedback, yesterday. Ted is the one that strongly suggested the coring application I ended up utilizing. I even used his lay-up recipe.
I figured he should know, based on having fairly decent knowledge of what Donzi Custom was doing at the time to beef up the ZR boats. And, my boat is always stored dry, period.

As for the reversion issue, my opinion is that you are on the border line with a 525. They do have a dubious history of reversion issues that nobody, including Mercury, really wants to take responsibility for, and this is beyond the cracked header issue. On the other side, I ran Corsa Q&Q on the 500EFI for a decade and had no issues at all. We checked when we started tearing it down for rebuild. Hard choice.

[Carl C]

I missed Carl's coring feedback, yesterday. Ted is the one that strongly suggested the coring application I ended up utilizing. I even used his lay-up recipe.
I figured he should know, based on having fairly decent knowledge of what Donzi Custom was doing at the time to beef up the ZR boats. And, my boat is always stored dry, period.


This is a test to see if quoting works now :)! Yes, coring with a non-wood product would be best. Ted did recommend that. I guess you could notch it at the drain plug and get the bilge water to flow OK. Mine would have been a little harder to core with the mini "stringers" and filets in place. I put together a different plan. I believe that Ted pulled his boat apart and cored and vacuum bagged the entire hull. My boat is also always stored dry.

[Pat McPherson]

I would not ever run a captain's call/Q&Q type exhaust system on an engine with as large a cam as the Merc 525. Personally, I’d only run a Y-Pipe with the diverters on a stock/mild engine.

I've read a few articles regarding reversion and many of the exhaust manufacturers state 224 degrees of cam duration max with their diverter systems. I believe the 525 cam has something in the neighborhood of 236 degrees.

My best boating friend has a 525 in his 29 Fountain. He’s lost 2 engines in the past 6 years, both times failures in the top end and there have been signs of corrosion from water ingestion. The exhaust system has been checked for leaks and it’s OK, so where’s the water coming from? He’s planning to keep the diverters but will probably rely on mufflers to take the edge off more often this go around.

Here in CT switch able systems are suppose to be illegal but the intent is that mufflers are required. I plan to just add mufflers to my Donzi as I have to my previous 3 boats. Yes, I get more ugly looks from the people at our marina than my bud, but hey…

[VetteLT193]

It's not just duration but also LSA. The 525 is ground to a 114 LSA. Another factor is how the boat sits. The 22 Donzi sits quite high in the stern relative to the exhaust height. My brother ran his with no flappers for over 1000 hours, most of which was in the ocean, and never had issues with waves or anything else running into the engine backwards.

On other boats though the water level will be quite high relative to the exhaust. I'd say different story there. The 29 fountain for example sits like my 28 does, the exhaust tips are just above the water line and dip in and out of the water with waves, etc. That also means that the water line is in the Y pipe very high compared to the 22.

[BUIZILLA]

being on a 114 LSA is a good news band aid as illustrated below >

http://auto.howstuffworks.com/camshaft.htm

click around, and an understanding may be easier to focus on

in my mind, the MOST important valve event is the intake closing number

but then again, the intake opening event starts the overlap process

overlap can be your best friend, or your worst enemy...

[VetteLT193]

Right... It's the time the intake and exhaust arw open at the same time, plus the flow of air (easier flowing exhaust works BOTH ways), plus the distance to the water in the exhaust, plus the angle of incline. Oh yeah, and idle, slower being worse

I'll say there is a reason there is no formula to plug in on this reversion sonnofabiatch. OOF. Makes dry pipes look good:-)

[RockyS18]

Thanks for the research study on vacuum breaks, it really expanded my knowledge on the matter. Vacuum breaks seem like a good idea at the right price. I hope what I'm saying here is somewhat accurate because I'm imagining the whole set-up, but what if I did this: At the end of the headers (where the four pipes bridge into one) I cut off a small portion of the pipe. To avoid cutting off too much from that single pipe, in return I will cut off a small amount of the y-pipe for the Q&Q2. In this small section I created I can install the vacuum break with the "hook" inside of it to prevent resonance reversion. Where can I find these vacuum break units?

I have no diverter in my exhaust. It's just a Y-pipe. I can't switch between the two. At idle, some exhaust/noise is exiting out both parts of the y pipe due to there being no substantial force to make the exhaust go either way. When I am on plane and my RPMs are up however, there is more exhaust force and all the exhaust/noise is exiting out as if I had straight pipes. Aside from the reversion issues discussion, I can't see how this current system is bad for the 525. I'm using both pipes at idle and when I'm on plane (ie. above 2500rpm) I'm not utilizing the lower exhaust pipe so there is no strain/back-pressure on the engine.

I'm not sure whether or not my exhaust system is illegal, but it doesn't matter to me. I'll be passing the Db tests so law enforcement will have no idea about the y-pipe. I know that switchable exhaust is illegal in my area, but as long as you don't get caught switching it you are in the clear. Several of my friends have switchable exhaust on LG and none have ever had a problem.

Ghost, nice "exhaustive testing" pun.

[VetteLT193]

If memory serves correct (i.e., check me) there are reversion cones in the 525 headers. Basically a 360 degree version of the 'hook' that was in the article.

Personally, I Think you'll be fine. Merc has built a ton of 525's and many of them have quick and quiet. The issues seem to be boat specific. Either with the angle they are at, that exact exhaust setup, or otherwise. The fact that Carl has no issues and heck, I haven't heard of any actual issues with water on 22 Classics in general, it's mainly fear of what might happen.

Don't forget the one guy that happens to have a reversion problem will sound 1000 times louder than the 1000 guys that don't have problems. If you look into the number of people that have actually had a reversion issue it appears to be a very low number.

[joseph m. hahnl]

I wonder if any air actually gets rammed into the Shelby style scoop given that the windscreen and lip directly in front of the hatch direct airflow up and over the hatch. I like the Teague scoop and my boat may be getting one. Now if we are talking just about header clearance then that's a whole different story.
http://i763.photobucket.com/albums/xx275/CARLC222/shelbyDonzi.jpg
http://i763.photobucket.com/albums/xx275/CARLC222/teaguescoop.jpg






time que 1:47 Donzi engineered for more flow and raised X



http://www.youtube.com/watch?v=JiDcf-H98Bg

[Carl C]

I doubt that they did any wind tunnel testing. I have a feeling that air flows right up and over that scoop and there may even be a low pressure area in front of it.

[Ghost]

A handful of suction-cup telltales would answer most of this in a hurry. Who knows, we might well find the backwards-scoop on some of the X-18s actually works better.

[Carl C]

A handful of suction-cup telltales would answer most of this in a hurry. Who knows, we might well find the backwards-scoop on some of the X-18s actually works better.

Interesting story: I have a 1982 Mustang GT with a factory hood scoop similar in configuration to the Shelby Donzi one. One day after washing it there was a small thread stuck to the front of the scoop. I watched in amazement how that thread blew forward while driving! There is a case for cowl induction scoops and I believe that a forward facing one needs to be elevated into undisturbed air. The Shelby scoop will definitely help provide ventilation but I think it was mostly designed to provide engine clearance.

[RockyS18]

Interesting story: I have a 1982 Mustang GT with a factory hood scoop similar in configuration to the Shelby Donzi one. One day after washing it there was a small thread stuck to the front of the scoop. I watched in amazement how that thread blew forward while driving! There is a case for cowl induction scoops and I believe that a forward facing one needs to be elevated into undisturbed air. The Shelby scoop will definitely help provide ventilation but I think it was mostly designed to provide engine clearance.

I don't think engine clearance was an issue for Shelby's. I have the same X dimension and my scoop is unnecessary for engine clearance.

I think the primary reason for this unique hatch was styling to separate it from other Donzi's. As a byproduct, there might be slightly increased air flow.

[VetteLT193]

Interesting story: I have a 1982 Mustang GT with a factory hood scoop similar in configuration to the Shelby Donzi one. One day after washing it there was a small thread stuck to the front of the scoop. I watched in amazement how that thread blew forward while driving! There is a case for cowl induction scoops and I believe that a forward facing one needs to be elevated into undisturbed air. The Shelby scoop will definitely help provide ventilation but I think it was mostly designed to provide engine clearance.

In a car the air enters from the front grill and the scoop unless the scoop is sealed to the intake. The grill on an older mustang is probably 50 times the size of the scoop so it is simple math why air exits the scoop vs enters it. For a 22 Shelby there are no clam shells so the only intake air is from the scoop. I doubt there is a ramming effect but there won't be regardless unless the scoop is integrated to the air intake. The size is what matters. My eyeball measurement says the Shelby hatch is probably 10 times the stock 2 intake clamshells. The aronow/009 hatch is probably 5 times bigger.

The net result is the stock hatch is like the engine is sucking through a cocktail straw vs the Shelby hatch through a McDonalds straw

[RockyS18]

For some reason my most recent post had to be approved by a moderator, weird...

[Ghost]

Rocky, I've had that happen on and off over the last week. No clear pattern.bbbb

[VetteLT193]

Rocky, I've had that happen on and off over the last week. No clear pattern.bbbb

I think it might have something to do with posting replies to a thread you started. I just got it on a thread I started but haven't on threads I haven't started (except for the for sale section of course)

[roadtrip se]

Happened to me too on George's offshore cradle post. I had to recreate a post twice. I have just started copying my posts before hitting the button now.

[Ghost]

I think it might have something to do with posting replies to a thread you started. I just got it on a thread I started but haven't on threads I haven't started (except for the for sale section of course)

Good idea, though mine didn't fit this pattern. Definitely not threads I started, and not always with replies. I did some testing, looking for a rule, and didn't find it. Replies, quotes, message length, certain words, never isolated anything. And I bombarded Scot with near-duplicate messages to approve. :) Still wondering...