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AIRGRADY
05-16-2001, 09:31 PM
As some of you may know I hurt the Hornet engine during the Sanford/Portofino Substitute weekend. I have pulled the motor and it now resides at the local machine shop. It was kinda funny when I dropped off the dismantled 25-year-old engine the guy chuckled and said, “Man I haven’t seen stuff like this in a long time”. He grabbed a pushrod and said, “They haven’t made these in years”. It appears my block and crank are the only salvageable pieces. Connecting rods are useable but he simply suggested I replace them. I am looking for 450 – 500 reliable, pump gas horsepower. He has worked up an estimate and I must say I am shocked at what this is gonna cost me. Bottom line it looks like I’m at about $6600 for machine work and parts! Keep in mind the estimate is using some high quality pieces. Assembled Merlin VR iron marine heads, Merlin alum intake with brass jackets, forged pistons, MSD Marine distributor and ignition w/ rev limiter, 9 quart oil pan, etc. etc. He built a pair of these motors two years ago and has parts list and dyno sheets 520 hp. I’m guessing $8500-9000 by the time I’m nickel and dimed to death. The estimate had no roller cam or oval port heads. As I understand it, oval ports create better torque for this type of mild marine engine and a roller cam is desirable for reliability.

There has to be an alternative to dropping all that cash. I have been surfing the web and found a GM crate motor. 454HO delivered for 4900 bucks. Engine is assembled and needs carb and ignition. Forged crank, pistons, rods, GM performance rectangular port cast iron heads, roller cam, lots of good guts to the engine. 425 horsepower, 500 lbs. torque. . Is this engine an option for me? Will it fit my application? Hell, I could buy the Merlin heads, Merlin intake and a fresh water cooling system and probably spend less money. Store the original block and crank for a spare motor if needed. Are there potential pitfalls if I buy this type of motor?

I AM SO CONFUSED

Any advice is appreciated.

Grady

GeneD
05-16-2001, 09:51 PM
Your first paragraph left me speachless...
I don't know what to say except there is no way that I would spend that type of money on any engine that wasn't running in the Indy 500. (wings at my house that day if anyone is interested...)
It just freaks me out, I guess the money level does it for me. I can see it costing that much, but man...
I would opt for the crate motor. And go for the relatively stock set up. Lots of times, we over do the engines that we build. Car engines, or should I say race motors, and lets group oval and drag, are a lot different than our boats that are supposed to get max HP at around 4800-5000 RPM.
Look, back when I was drag racing, 7000 RPM's was our magic number and anything I got over that, was gravy.
Am I making sense? Keep it relatively simple, and it will last for years.

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

BigGrizzly
05-16-2001, 09:52 PM
First, the oval port torque theory is not true. There are several oval port heats some good most poor in the flow area.Remember my Corsican. It has big port Clevland heads, their suppose to be poor in the marine application because they have poor low end tork. It is as good as any 350 out there. My Criterion has rectanular ports and it works fine. I would go with the Crate motor. Your hull and drive will have decreasing returns. John and Kathy have a blown 427 and it runs in the low 70's. This isn't slow the have reached the hull speed of that combo. Their boat is done right, by the way and beautiful. After you get the motor it would be cheeper modify at that point. Newer parts to start with. Its still better then what you had.

Randy

woodsy32
05-17-2001, 07:56 AM
Grady,
Check out this website. https://www.spoperformanceparts.com/ It shows you all of the GM Performance Crate engines. I did a lot of research, and its really the only way to go. Instead of rebuilding your old motor, for $5787.00 you can have a 502 ci, 502hp/567 ft-lbs monster motor. GM P/N 12496962, all you have to do is add your exhaust, carb and ignition. You can even buy what is essentiaslly an HP 500 FI motor for about $8100.00 They have a bunch of different options including a cast iron 502 with 450HP/550 torque. Check it out and let me know what you do. Next year I will be selling my 454 Mag MPI and upgrading to a 502. I would go crate and not worry about it.

Hope this helps!!

Dave

Jamesbon
05-17-2001, 09:18 AM
Woodsy32's idea looks good.

In comparison, I'm doing the following (which may make a crate motor more attractive)

502 short block 1200
heads 1500
roller cam, lifters 450
bearings 100
pistons 400
intake 250
misc. 500
machine work 400
labor 300 +\-

There's $5100.

Hmm, where's this crate motor place again? http://www.donzi.net/ubb/wink.gif

I opt for this solution for two reasons
1) I don't have 5K ready to burn up, however, with a little time, it's no problem to piece it together.
2) I can pick and choose each component myself. (I like the radical cams and higher compression)



[This message has been edited by Jamesbon (edited 05-17-2001).]

RickSE
05-17-2001, 11:53 AM
FYI, Jegs is now selling GM Crate Motors, at reasonable prices.

AIRGRADY
05-17-2001, 10:11 PM
OK, OK…. Geeze guys I guess a crate motor is in my future, but nobody has answered my questions. What has to be done to a crate motor to make it qualify for a marine application? Head gaskets? Freeze plugs? Any freaky clearance issues? Automotive cam OK? I am just apprehensive because this is looking too easy! I am leaning towards a fresh water cooling system for the block since I will run in salt water 90% of the time. Let me know what mistakes NOT to make. I need all those years of experience everybody has here on the board. I understand the Hornet will never be an 80 mph boat, I knew that when I bought the gem. However, if I’m gonna shoot the lock off my wallet and step up to the plate and build an engine I want everybody to know when I fire up my boat that, “ITS NOT STOCK”. I like the idea of a lumpy idle, and a big cam. If speed were the issue I would have never bought the Hornet, I would have bought a 22 like TOMAHAWK! (gotta love that boat!)

In a nutshell, I want a pump gas motor that sounds NASTY! The hornet may pick up a few MPH and that is simply a bonus for me. SPEED ISN’T THE CONCERN. Pump gas, lumpy idle, and reliability are my concerns.

Help me out!
Grady

P.S. JAMESBON

Your estimate forgot to mention

ARP big block bolt kit = 65.00
Connecting rods = 350.00
Roller rockers = 275.00
Good head bolts = 45.00
Pushrods = 100.00
Decent timing set = 80.00
Harmonic Balancer = 95.00
Rings = 60.00
Good marine oil pan = 450.00
Good marine ignition and distributor = 500.00

Add about two grand to your $5100 estimate. And you might want to add a grand or so to the misc line

Puts you around the $8100.00 mark! That hurts, doesn’t it?

Jamesbon
05-17-2001, 10:23 PM
No. "short block" includes my pan, bolts, and harmonic balancer. Any Chevrolet distributor will work. (we both have'em) Rings included with pistons. Pushrods and rockers included in "misc."

AIRGRADY
05-17-2001, 10:29 PM
JAMESBON

OK, do me a favor, build and sell me your engine!!!!!!!!!!!!!!!!!!
If it performs like your small block, I'M IN!

Grady

Jamesbon
05-17-2001, 10:42 PM
Now, I like that! http://www.donzi.net/ubb/wink.gif

One would need the following for a salt water cooled motor
Stainless head gaskets
brass freeze plugs
non aluminum heads (in my opinion)
intake with bronz crossover


Clearance, well, I don't think so.
I guess an automotive cam would work, but most use one designed for marine use. A marine cam reduces the risk of reversion. (or when the engine ingests raw water through the exhaust) Using long tube or dry headers eliminates the risk of reversion with BIG cams)

"Bulletprof method" of creating mega, reliable horsepower on pump gas is cubic inches.



[This message has been edited by Jamesbon (edited 05-17-2001).]

Scott Pearson
05-18-2001, 05:47 AM
That sounds like a lot of money! I have a Big Block in my 1965 GTO. This motor was a spare from another Donzi that I owned. It was a 420 Merc. Motor. I had Nick at NICKS MACHINE SHOP do all the work. He is known very well for his perfection. He has built all my motors in the past. Any hooo...My 454 Dyno'd 539hp. It had alot of good parts from Merc. Crane roller rockers, Rectangular heads, Weiand manifold, Dimple 5/16 rods...etc...etc.

There wasnt a hell of alot of work that went into this thing. New pistons 11:1. Valves, L-88 cam.

To make a long story short I have owned this car for 17 years and havent drove it for 5. It lays in the garage with stuff piled all over it. But, when I did drive it I ran it one night at the track. The car weighs in at 3,800lbs, I had 9 inch slicks on the back, Thru exhaust, 410 posi, 4 speed 264 first gear. I ran a 12.37 at 110 mph. Didnt power shift it and only came out of the hole about 3,500 rpm's. I shifted the motor at 6,800 rpm's.

Not bad for a heavy old boat of a car. Im sure if I uncorked the thing and hammerd the hell out of it I would have no problem going in the mid 11's.

So....what the hell am I getting at? I had about $1800.00 in machine work on this motor and about $1600.00 in parts. Thats $2400.
Plus the $1000.00 I paid for the motor $3400.00 aint bad. Ohhhh and the best thing is it runs on pump gas all day long!

Did you have that guy take a drug test when he gave you that price...Cause he has to be on some good S**T.

My 2 cents...for what its worth.

(NJ)Scott

woodsy32
05-18-2001, 08:10 AM
Grady,

If you use fresh water cooling... AND YOU SHOULD, especially if a lot of saltwater running is involved, you do not have to change a thing in these crate motors. Aluminum heads will be fine. Don't forget the cooling system will have an antifreeze solution running thru the engine. So internal corrosion will not be an issue. If you look on the website, you can buy an HP500 for about 8100.00 That's what mercruiser does, then paints it blue. It even uses the same MEFI 3 computer. The 502HO is the standard merc 502. As far as the camshafts go, they are the same cams that are in production mercruiser blocks. THERE IS NO DIFFERENCE. Look at the HP figures. Mercruiser rates the HP 500 @ 470hp. If you take the GM rating and subtract 30hp for turning the drive you get the same ratings. Many years ago there used to be a difference between a marine engine and a automotive engine, but its too costly to produce that way. As far as building your own goes, great high hp motors usually cost big $$$. it is extremely tough to build a durable high hp motor. That's why guys like Paul Pfaff and all the rest get serious money for their motors. Scott, you spent $3400 how many years ago? You gotta factor in inflation etc, I'll bet it would be a lot closer to $5000 to recreate that engine today. The reason they sell these crate motors is because it is comparable/preferable to rebuilding. I am not ranting, I just spent hours of research on this subject before I ended up selling my 18 and picking up the 22. For the record, I have built several high HP motors for my various project cars. Believe it or not, crate motors are the most economical way out. Just my .05 cents worth! I think I went way past .02 cents!! http://www.donzi.net/ubb/biggrin.gif

Dave

Looped
05-18-2001, 10:39 AM
Scott,
I dug around to see if I still had the pic of the Mer-Goat, but with no luck. Do you still have it?

Craig

BERTRAM BOY
05-18-2001, 03:29 PM
Hey Scott,
How did you run on pump gas at 11:1?
BERTRAM BOY

Scott Pearson
05-18-2001, 04:37 PM
Ok...I have to tell you that as long as you have a GREAT ignition system you can burn pump gas on 11:1 no problem. I have a MSD with a MSD dist. The dist. cap is set-up like the old Fords. It has ALOT of spacing between the wire connections. This is so the spark doesnt jump to the wrong cyl.

Quick story...when I started the motor to brake it in I couldnt shut it off (thats another story) but anyway, We pulled the coil wire off at the coil with a stick. A spark shot out and buried itself against the under side of the hood. And NO this is not a FISH story.

Good wire's, plugs, timing, Ignition system...no problem. I could probably burn water if I had to...(Laughing)

(NJ)Scott

BERTRAM BOY
05-18-2001, 05:40 PM
Wow, I always thought that 10:1 was the outer limits for pump gas......
BERTRAM BOY

GEOO
05-18-2001, 09:41 PM
Nate,

It sound's like you've been doing some research!!! HUM??? How many ponies?? GEOO

BigGrizzly
05-19-2001, 12:07 PM
BB you road in a 11:1 compression boat at Sanford. It was blue and white and seats 4 and sounda great. http://www.donzi.net/ubb/biggrin.gif

Randy

Forrest
05-19-2001, 08:12 PM
. . . and remember too, using a cam with a lot of duration bleeds-off a fair amount of that compression while the engine is running - static compression vs. dynamic compression. Also there are some other factors that will help let you run lots of static comression as well, such as cylinder head temp, quench, and piston dwell at TDC.

------------------
Forrest

Jamesbon
05-19-2001, 09:24 PM
Thanks for taking note GEOO!

When you're on a "white collar" budget, as I am, every PENNY is accounted for...

509 ci., 10:1 compresion, aluminum heads, roller cam....humm http://www.donzi.net/ubb/eek.gif

Oh, and an Arneson drive....

I love you guys!

GEOO
05-20-2001, 09:01 PM
Nate,

Sound FUN!!!!!! GEOO

Looped
05-21-2001, 02:04 PM
Ah ha, here it is. Scott P's Merc-Goat:
http://albums.photopoint.com/j/View?u=1399308&a=11451597&p=48907883&Sequence=0

Craig

BERTRAM BOY
05-21-2001, 02:18 PM
Those Mercruiser valve covers look really cool in a vintage Goat. Nice touch Scott.....
BERTRAM BOY

Scott Pearson
05-21-2001, 03:19 PM
Craig,
Thats kool you posted that picture...Gotta love it. I haven't seen that motor or car uncovered in about 5 years. Its sitting in my garage covered in Donzi stuff.

Thats a True Merc Cruser 420...ummm with lots of work done to her. I forgot I left the lifting rings on that motor.

(NJ)Scott