Update

[CDMA]

Guys,

So finally I have put Patience to bed for the winter. I know I have been quiet for the last few months but school is ridiculous. We finished mid terms this week and get this super nerd here is actually, get this, failing a class; only by three points but nonetheless still failing. So I have my work cut out for me but it is a great experience. So far the best class has to be Marine Engineering. I was insider a boiler the other day (not running of course), have disassembled a high pressure turbine and put a 8v92 connecting rod in a tensile machine and found out when it would break. So I like it. The work is like nothing I have ever seen before but it is doable. It is not the complexity but the magnitude. I am sad to say that so far we have lost 2 out of the original 22 and one more looks certain to go. One “stepped down “ (as he said) to MIT and the other one is on his way to Georgetown. Both report that the work at their new schools is considerably less…oh well. Other than that I spent the day today in our tow tank with a 44-foot Bruce King designed sport fish hull. We put the hull through a battery to tests and it did really well other than in a quartering sea where it had a disconcerting tendency to broach. Back to the drawing boards…

So the engine is out of Patience for a few reasons but primarily in search of more power. It is a stock 260 hp engine built to model a mercruiser’s specs…. so I am told. I pulled the heads and it looks almost too good to mess with. The bores look really clean with no scoring. It appears there is about 90% of the bores still have their crosshatching. Towards the bottom I see a little shine but only in a few places. There is no carbon or lip at the top of the cylinders. Now I need all your help. First of all I have little money. What I really want is a BB but unless Rick wants to give me his out of the 22 or one falls in my lap I am out of luck. But if anyone knows of anything please speak up. I am putting this together on a college budget and the money just is not there. I do not by any means want to do a half assed job but all unnecessary steps need to be skipped. The engine will retain stock exhaust, carb and a HEI ignition. Nothing to fancy but works. Now I, in retrospect, am kicking myself for not taking a compression test before I took it apart but I did not. I am running flat top 4 valve relief pistons that are supposed to be stock compression and 76 cc heads. What I was thinking is a combination of the following. To me it looks like I could leave the piston and bores alone and works from there but if this is a bad idea please yell now not later. I was thinking of going to 64 cc heads (Vortec most likely) for about $550 –600. They are supposed to add about 40 or so hp over stock. With that I was eyeing a Comp cams .470/. 480 lift, 224/230 duration @. 50 and 110 lobe separation. So that is what the basic idea. However I was thinking that if I am ambitious I could pick up a 383 kit. I see a few kits kicking around for about 700 or so with forged pistons. I know these may be discount kits but they are complete with balancer and so forth and might just work because I already know, like Jamesbon, that in the future I want a BB so this is only to keep my happy till I get more $. If I can only afford one, which is better, a 383 or the heads. Also keep in mind that whatever I put together has to stay together. I cannot afford the time or the money to keep rebuilding. If this motor blows up I am screwed.

Also could people with worked small blocks, Paul and Jamesbon, please post your specs of cams, heads and so forth.

Thanks
Chris

[GeneD]

You my boy, have a screw loose!
Take apart a perfectly fine running motor.
A head gasket is going to cost you $25.
I forget if you are running that Volvo drive still, but all the HP you put into that motor is going to be eaten up by the drive, but if you are still wanting to modify (cringe) that perfect engine, compression is what you need.
Of course a new cam couldn't hurt either.
The Vortec heads, while superior to stock chevy heads, will require a new intake manifold and valve covers.
Why not mill those heads, now that you have them off, to a respectable chamber cc, get yourself a new cam, one with the .480 lift and a decent duration would do wonders I'm sure, and call it a day?
Maybe if you get a few bucks in your pocket, get some roller rockers. You just aren't going to get a whole lot of HP improvement without spending some serious money. But the head thing and cam are pretty cheap. Gaskets are the one thing that drives me crazy. Everytime you go to do something, you have to buy a gasket. The $25 ea. for HG's pisses me off.
I've been investigating the HG's for the 400. Seems that the way to go is the copper gaskets. The deck surface must have o-ring grooves cut in them, but the HG's can be re-used up to 5 times before you have to throw them out.
Who out there has experience running domed pistons in a V-8 marine engine? This also sounds to me like a simple way to get HP Chris, though forged domed pistons are another money eater.
Easy big fella!
When I went to school, I didn't buy anything until I graduated. In fact, and I know you guys won't beleive it, I didn't even drink until the last semester of school.
Bad move.
Starting drinking I mean.

------------------
GeneD
007
Melbourne, Florida

[This message has been edited by GeneD (edited 10-19-2000).]

[GEOO]

Chris,
Sounds like school's a blast!! Keep up the studing so you can help us with all are future boat projects.
I ran a Crane Hydraulic Roller Cam in my 383ci. Part # 119631, Basic Rpm 2500-6000, Cruise 3000-3800, Rec. Comp. Ratio 9.5 to 10.75, Duration @ .050 222,230, Adv. Dur, 284,292, Deg. Lobe Sep. 112, Gross lift .509,.528. Great idle good power. This cam would act a little more radical in a smaller ci engine. I have the cam card if you need more info. If you call Crane they will help you select a cam for you marine application. GEOO

[rayjay]

CDMA,
Keep at it!! We need all the good engineers, marine or otherwise, we can get. Also as GeneD just said, why are you going to take apart a perfectly good running engine? But then I have done it, and so has probably everyone on this board who has ever dicked with engines. It may (have been) be running good, but we just want to make it run better! (lol) ;-)

As for your engine, please remember an engine is a system and as a system it has many points that control what and how much it can do. An engine is in reality just an air pump. It sucks air in and pushes the air out. At some point in the middle it combines the air with some sort of fuel, ignites the combustible mixture, and then, hopefully, converts the combustion energy into work part of which is to suck in more air and start the process all over again. At any time during this process you limit the engines ability to move the air or ignite the mixture you have created a control point and until you change that control you will limit what any other change will do, especially if you are concerned about bang for the buck and do not have any "rules" governing what you can (and cannot) do. The more air in and out, the more potential you have to produce power. Things that increase the BMEP through efficiency are different as they are not trying to move any more air through the engine, but just getting the same amount of air to give a bigger bang. You say you want to keep the stock exhaust, well you have just created a significant "control" point and have limited how much power the engine will make no matter what else you do. I have seen too many high performance engines; car, motorcycle, or boat; where someone puts on a big carb(s), big cam, and then forgets to upgrade the head and exhaust. Then they wonder why they didn't get the big power increase like they were told they were going to get. They cannot get past the limitation(s) the are leaving in their "system". If you are going to keep the stock exhaust, then keep everything else mild to match its limitations. Boat engines are like truck engines, they are almost always under load and as a result need a greater exhaust flow than we would normally think of in terms of a car or motorcycle.

Vortec heads have really good flow and add "swirl" for better combustion, but without an exhaust upgrade they will not make that much more power to compensate for the extra work and parts. Go back and read all the tests where the "magazines" say the Vortec heads added "X" number of horsepower. You will probably find they are using an "improved" exhaust system of some kind. Remember Vortec heads also they need a special intake manifold to work. The mounting bolt angles are slightly different, but the biggest change is on the floor of the manifold and the angles and shape it makes with the floor of the head. Just reuse your heads, maybe milled for a little more compression. March the compression ratio to the intake closing point of the cam. If you can afford it, get the valves "back cut", a good "full radius seat" valve job, and some bowl work with a little port matching to even out how each cylinder works. Too much compression will blow right past your old rings even if they look to be in good shape. Also without an intake upgrade the cam you are looking at will not produce all the power it is capable of producing. If you need help with the heads, let me know and I will be glad to see what I can do.

Hey BigG, any more to add before I loose everyone? rayjay

[This message has been edited by rayjay (edited 10-19-2000).]

[This message has been edited by rayjay (edited 10-19-2000).]

[CDMA]

Ok,

Yes I know I have a screw loose but you know what we all do. First of all thanks to a trusty work ethic and the forsite that people pay big bucks to have their boats detailed I am blessed with a few more bucks than the average college student. However what I have and what I can spend on a clean conscience are two different things. This has to be done responsibly. Also so many people out there say to buy a crate motor and so forth and I think they are wonderful things. However, I have never built an engine from the ground up and until I have, I know how it works and goes together. To me much of the Donzi fun is learning stuff I do not know and that is more or less why I am undertaking this project.

Gene,

I can stomach the bill for the Vortecs if need be. I have done a lot of reading about them and they appear to be a well thought out piece. Milling is nice but in the end you still have the crappy flowing GM heads. Also you can also now buy the Vortec heads drilled and tapped for the old style intake.

Geoo,

Is that a roller cam or a standard style cam? Also is that safe in terms of reversion with stock exhausts?


Chris

[woodsy32]

Chris,

Just be extremely careful with if you decide to rebuild. No matter how good the motor looks, if you tear it apart, Ie: take apart the lower end, you will need to double check all of the following items:
Main Bearing Clearances
Bore Diameter & Straightness
New Cam Bearings
Once you tear apart a motor, it will never go back together the exact same. You stated you cannot afford to have this motor grenade on you and to be truthful very few people can afford those types of mistakes. Thats why engine builders get sooo much $$$. Make sure you put the main bearing caps back onto the block in the same spot they came off of. I always number mine before dissassembly. You should bring your bare block to a reputable machine shop who can hot tank the block to remove all of the internal rust and scale. The shop can then then check your cylinder bores for wear and tear. I know you said it looks good crosshatch and all, but a little time and $$ spent here can save a lot of heartbreak later. They can also install the new cam bearings. If the bores are ok, You can reuse your old pistons and rods, but I suggest new rings. Rings are relatively cheap for a SBC. Who knows if you may have a stress crack in your old ones from removing the pistons from the bores. A broken ring can ruin your block. If you know how, you can use a micrometer to check your crankshaft for wear, but I would recommend having the machine shop check that for you also as well as out of round. You may be surpised that you have to have your crankshaft ground. They can then advise you on what main bearings to use ie: .010 under, .020 under etc. After you get the block back from the shop, run a tap down all of the threaded holes to remove any crap that could give you a false torque reading. Make sure you buy a good quality torque wrench and torque the bolts to the recommended torque in stages and follow the torque pattern. Put a new timing chain in when you install the new cam or even if you keep the old cam. I can guarantee your old one has stretched some. As far as cylinder heads go, I would be looking at the GM fastburn heads, but thats me. Roller rockers are nice if you have the $$. Of course, if you leave the lower end alone, disregard my post. Doing the top end is the cheapest way to boost the HP. A set of fast burns, a new intake, might have to recurve the distributor, and you are done. It won't make the most HP possible from the combo because of the exhaust bottleneck, but it will definitely make more HP. I might reconsider a crate motor if the cost of this comes to 1/2 the cost of a new crate motor. Only because of the reliability issue. You could always rebuild this one as time/money permit after installing the crate motor. Good Luck.

Dave

PS: For the record, my first rebuild engine grenaded... these are the lessons learned.

[MattM]

Good work Chris,
Now get an 18' in that tow tank and make a keel pad for it so us little water boaters can get a few more MPH!

On the small block. If those are the late 70s 76 cc heads they can work very well. If you spend money on new heads they won't work any better because of your stock exhaust. Better spend the money on a decent exhaust system and work the heads a little. Get your die grinder and port match the to your manifolds and grind off the boss in the exhaust port for the air injectors if they are there. These are probably the same heads that Edelbrock recommended for their Performer RPM package before they made their own head. Contact them and get the Performer RPM recipe which will include their manifold, Cam and how to rework the heads. It's not difficult. This package is worth 420 Hp at 5500 RPM. With marine exhaust you'll see at least 375. For your budjet, or for anyone looking for that kind of power I'd recommend it. If built one and loved it, great sounding idle, decent (stock type) low end, and great high end. Good luck.

[rayjay]

CDMA,

Okay, I am going to treat you just like one of my customers who has just come in looking to make his or her motorcycle go faster. First decide on your budget and what you want to accomplish, like what power or speed are you looking for and how much you have to spend at this time. Be realistic about both. Horsepower costs money, and not just for the original buildup. High power brings out the inadequacy (BREAKS in some cases) in other things like i/o's, cooling systems (GEOO), props, steering, trim, etc.... Have I left anything out? And most power producing things have a fixed HP x time relationship. More power means it will last for less time. And also, where you want to go in the future. If you want to go to a big block, then don't put much into anything you are going to have to get rid of, like your small block. You have to make this decision first before it is worth getting into specifics of what to do. Then make sure you leave a portion of you budget over to fix the "inadequacies".

Your heads are perfectly good with just a little work. They are worth replacing if you are thinking about "heavily" reworking them to fit your plans. You are not racing in a class where you can't change heads. There are some very good SBC heads out there, and are almost always cheaper in the long run than reworking the stockers to get to that point. But don't discount the performance abilities of your stock heads if new heads are not in the budget. Also from a money saving point of view, unless you have a lot of experience do NOT get into doing a lot of "grinding" in your heads. You will almost always ruin the first few heads you try to modify, that's how you learn. And in porting, the metal you leave is more important than the metal you remove. Plus it is very hard (read that as expen$ive) to fix mistakes like building up the floor or filling in the pushrod hole after you have ground too much away. Another thing, "fast burn" are the better heads but they are AL and will require a closed cooling system. AFR makes some very good FE heads. They should have a "vortec" intake, raised exhaust, and "fast burn" combustion chamber head very soon that will not need to have the bolt holes moved. They will also be able to tell you what manifolds will line up (floor and port) with the intake. There is a lot of "efficiency" power to be gained there by having the metal in the right place. I learned about heads from playing with broken.blown up heads that couldn't be salvaged. So I had a number of ports to play with, under the tutelage of some good "head" people, and put on the flow bench without worrying about going too far in grinding away metal. I was very lucky!

Come back with your budget and where you want to get to, and there are many people on this board who can help you. rayjay

[This message has been edited by rayjay (edited 10-19-2000).]

[GEOO]

Chris, Not sure on the stock exhaust? May be marginal?? Read a good book and try porting your heads. By the time you add up the cost of a cam,heads, gaskets ect...and the fact that you can sell your motor; a new Chevy crate motor doesn't look too expensive. GEOO

[BigGrizzly]

Chris, there are only teo ways to make horse power and that MORE BANGS or BIGGER BANGS. this is what RayJay is telling you. Yes you should have left the heads on, but then you would have wondered all winter about it. Well now your there! Forget about the out drive merc volvo omc the difference is small on stock units. Three to four horse power will cure that. This is a constant get over it. If you put in a big block you can keep the Volvo.

Here is what I would do. Crane cam, there better in boats then Comp cams, who are really good with cars. Then Stanles marine exhausts. Heads, don't get fancy, do it cheep but good. How about 2.02 intake valves, three angle valve job match ports(you have a good intake? ). Remember you are not pulling 6000 rpms on your budet! Good heads are a waste of money without top dollar every thing else. Do this in this order and prop it right and many people will be looking at your stern. I like the Crane that Forest uses good acceleration ramps on the lobes, or we could ask Babe Erson to see if he would make you up a Max 1DPH.

Don't spend money for a 383 if you really want a big block--just a waste! By the time you get done with it, it has $5 and $50 you broke, its like dope, once you start you can't stop till are #1 bad ass, which will last untill you see Geoo the folowing weekend.

I love closed colling systems, because you can run the engine at 180-190 and still run the exhaust cool to prevent salt crystalizing in it. By the way extra heat is horsepower, and reduces whear. There is a GM service bulletin that proves this with a graph.

[This message has been edited by BigGrizzly (edited 10-19-2000).]

[PaulO]

Grizz,
Good advice! And you are right, it never ends. The other thing is that you never get what you think your going to get as far as speed gains. Tell yourself that up front and you will be happy. Now, here is my question: With all the various work I have done on engines, I have never done port matching. It always seems to me that the intake gaskets are too big, too small, or off-center and that the intake manifold can be moved around too much so that you never get it in the exact postion anyhow. What is the proper procedure for this?
Thanks,
Paulo

[CDMA]

The wealth of information always amazes me. I appreciate all your time and effort in helping me.

I understand the idea that an engine is an air pump. So right now I am torn in so many different directions . For now I am just going to keep collecting ideas, thoughts, and information. I am off today to go do my favorite thing in the world....boat yard hunting. I think you are right. I want a BB and I know it now. I am going to see what I can come up with. I have Jan and Feb off from school and am working at Derector Shipyards in Ny so I will have a few bucks. Keep you ears and eyes open for BB's for me. I figure if I can get some kind of BB in there then I can work from there without throwing money away.

I just could not stomach the money for exhausts and so forth if I was going to eventually get rid of the SB. The the other problem is hatch clearance but for a BB who cares....


Chris

[RickR]

CDMA
Since the engine still runs good, put it back in, finish detailing your 18 out, spend this winter and spring STUDYING and next summer go BOATING! Spend some hours behind the wheel, get the feel of her and some experience on the water in different conditions.

Save your pennies and get the engine you want next winter.

I'll keep an eye out for BB parts.



------------------
RICKR
mailto:riggerb@aol.comriggerb@aol.com</A>

[CDMA]

As usual you guys are right. The money in the SB seems to be the wrong idea. I understand know I am biting off a lot but even with school my projects are what helps me make it through the day, week and semester. I mean this week I had 22 hrs of class and easily doubled that in study time. I generally sit down at my desk Monday and other than sleeping and eating that is all folks till Friday. What helps me make it through are the daydreams of my boat and the fun I have working on it and playing with it.

I put a solid 100 hrs or so on it this year and am absolutely comfortable with it. I have been driving boats since I was able to walk. My first boat was a Achilles 8' 6" inflatable with a 3 hp Yamaha. Then I went to an 8. After that went through a couple 13 whalers, an 18 whaler an 18 foot ski boat and a handful of sailboats. I am not very good at a lot of things. I get the grades I do because of effort not gift. I have no athletic talent and my artistic ability is non-existent. The one thing I have always been able to do well with out a challenge is drive. Cars boats and so forth. Sometimes it takes a week, other times longer. I do drive the Donzi hard but I know its limits and am responsible with them. I want to learn I am not often challenged and the Donzi has been a learning experience for me and building an engine would be an extension of that experience.

As it stands now I realize that a SB would be throwing money away. So I begin a quest to find a BB. I will consider anything from a core with marine parts, running package, to the ideal a Rick R motor but unless he wants to do monthly installments that is not happening. I spent all day combing boat yards today looking for used, abused and so forth. Found little but making some headway. Some guy emailed me he had a BB with all marine parts but a cracked block for $100. I almost flipped. So I am chasing him down and we will see about that. My guess is a 0 is missing off of 100. Tomorrow after playing with my dad and cool cars I am off to Moriches to try to track down this marine junkyard I know of. We will see what I turn up. Even if I only get a stock BB in this year I will be happy. Then at least I have a base to work from for exhaust and so forth. Well please keep your ears open.

Also what parts are interchangeable? I believe stuff such as the RW pump and the dist are the same. Anyone want a really nice stock SB in great shape....

Chris

[Len]

Could've used the small block two days ago in my delivery van... Do you have to change out your hatch configuration or drive height (x-factor) to accomplish a BB in the 18'?

[Looped]

Chris,
Keep checking in on the engine section in the Boattraderonline 7.4's (http://www.dibit.com/browse.stuff/Marine/Engines/)
http://www.donzi.net/ubb/eek.gif http://www.donzi.net/ubb/eek.gif
http://www.brucebullockmarine.com/mercury/images/454mag.jpg

You may find something?

Craig

[GEOO]

Chris, Get your sb running for next summer. Then spend your monies next winter for the Big Block. GEOO

[This message has been edited by GEOO (edited 10-21-2000).]