My buddy just bought a 68SS (138 car) Chevelle Convertible with a 502 crate Marine motor in it. He wasn't thrilled with the fact that there was a marine motor in the car but didn't care because he has a 68 396 motor he just rebuilt sitting on an engine stand in his garage that he said he will put in the car anyway. He said he just couldn't live with the fact knowing there was a marine motor in his car. The motor only has about 1800 miles on it and sounds great and runs very, very strong. The guy selling the car said about 500 HP. Except for the obvious, (modifying the existing manifold or replacing to acccomodate heater hose)can you think of any draw back to this motor. I actually had heard that the marine motors were stronger and built to tighter tolerances. Anybody else hear that??? This motor runs so strong, I think he is crazy to pull it out and put the 396 in it. Any comments on this situation?

it`s the same block

The only problems that I can think of would be a looser piston to wall clearance (so maybe a little noisier on cold start), and if the block was ever used in a boat, the coolant passages will be corroded worse than one that never was, especially if it was used in salt water!

HTH

Blown is rite on the money...marine engines are built with greater piston clearancce because the water pickups deliver cooler water to the block than a radiator possibly can...
camming is variable ..some marine cams are also recommended for street use...look in the crane cams catalgue and you will see some cams listed under bothe marine and street applications..
marine engines MUST a a good idle so cam will not be very lopey...

i dont think i would think twice about running it..
what do the rest of you guys think???
in fact lemme know if he decides to sell it!!!!


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Rich
Cocoa Beach, Fla
Team Chevelle #380
wa3men@aol.com
www.chevelles.com/showroom/70_SS_454.jpg (http://www.chevelles.com/showroom/70_SS_454.jpg)


[This message has been edited by 70 SS 454 (edited 11-08-99).]

[This message has been edited by 70 SS 454 (edited 11-08-99).]

Never used in Boat. "Story" goes that the motor was bought and determined to have a cracked piston. Piston was replaced and a hotter cam was put in it while it was apart. 1800 street driven miles on it only. Idles smooth and sounds quiet at idle. 850 Holley provides the fuel. I wasn't in the car for test drive but my other freind was and he said it was very strong. Needs a tire swap that will give him better traction. I watched as they pulled away and put there foot into it a little and no smoke from the exhaust. I think he has got himself quite a rat motor in there but he hasn't decided what he will do yet

I think he has a piece of junk and needs to set it out at the curb for the DZAUTO junk man to come by and get rid of it for him. I will haul it off at no charge.
Would tonight be soon enough?

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Tom Parsons

I have a 502 that was a mercury marine warranty,it is a genvl motor.It is a standard 502 block,steel crank,7/16 rods with je pistons.It came with a hyd.roller cam,but was not gm it is a retro fit set-up.I believe the valvetrain is crane stuff but there is not the usual numbers in the usual spots.I figured the lift out with a dial indicator and it is right around .600/610.So if you can get a good price,you can definitely get some good hardware. John

DZ TOO LATE! I already hooked up with my bro-in-laws pickup AND I'M COMING TO GET IT!!!!

Don;t freak on the marine motor . My friend used a marine block to build up a 509. It is outragueous. ( Solid roller Crane, Dart heads and a ol chev tripower added for good measure!). The oil pan was tricky in his Camaro, (Gen6 block), but I would tell " my buddy" what a piece of manure these things are and get it cheap. RUN IT!

Then we can call you MYTRAT!

Thanks for all the help. He has decided for more originality with the car and is going to put the 396 in it.....but will not part with the 502. He has an extra engine stand and will be putting this motor off in the corner for another project down the road. I think he realizes what he's got and does not want to part with it....Sorry guys. Thanks for alll the feedback

P.S. Gene...I already can be called Myt(little)Rat because I have a matching numbers SS396 67 Chevelle to go along with my 68RS Z/28 ('69 302 motor). I like to keep all my rodents "covered" in my choice of toys...lol

[This message has been edited by Mytmouse (edited 11-10-99).]

So you are ratified, excellent! Your buds a smart man. A few mods to that mill will give you 600 solid ponies and GOBS of torque.

I recommend some nicely polished stainless propellers for the rear of the Chev. Quality always stands out.

I dont get it.. hes taking out the 502 to put in a non matching #'s 396 for originality?? I say dress the 502 up like the 396 and rule the streets.

Hell I think its sort of cool that its a marine motor.

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Mike Reeh
Gold #34
San Diego, CA

Mike & Gene

My sentiments exactly. If it were mine the 502 would not leave that engine compartment... except maybe to "dress" it up a little. 5-600 ponies and gobs of tourque would be just too much to pass on. But this is my freind and he has alway wanted an SS Convertible and built this 396 himself(which came out of his other 68 SS Coupe) for the day he found an SS Ragtop. He always expected to only ever be able to find a rolling project vehicle because there just ain't that many of the ragtops around and those that have em just don't want to part with em. By the way, I found this car for him in the classifieds on this web page and we traveled from Ohio to Wisconsin and trailered the car back last Saturday.

The other caviat to this story and the one that may make it more understandable as to why he would pull the 502 is that the he still has the gorgeous 68 SS coupe that the 396 came out of. This car has a crate LS6 that has been built up even more and dyno'd at 542HP. So when he wants the power and the torque he still has a choice. Pretty nice choice wouldn't you say??

Thanks again for the comments...it is always good to here the different views and ideas but I don't thinks you will see a stainless propeler JWagner but the idea did make me laugh

Mytmouse

It was always my understanding that marine engines were hand picked,with heavy duty parts.And they run the same clearances.Ask your self why would you run more clearance on an engine that runs cooler?In fact marine engines use thermostats just like cars most about 160 degrees...FRED

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