Thread: Mixed up 350 GMC in a 21' boat

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I suppose this is a bit different talking about a boat engine on this forum. I picked up a 1989 Reinell OMC 350 that had the "long block replaced 250 hrs ago" I guess that many hours would equate to approx 15000 miles on a car.

Problem is, while working on timing etc. on this engine, I checked on the 4 barrel Q-jet numbers (17059286) and it appears to be from a 1979 engine. The distributer has points and condensor and not a vacuum hose in sight. Now I'm trying to find out what the heck I have here. Sales papers have only a Motor serial #T1066852 and the intake manifold has the #14096244GM.

Can anyone help me identify what I have? This thing is just quitting on me at about 3800 RPM where the boat motor should run strong up to 4800 RPM.

Any input very much appreciated.

BigD

Check on the block deck at the front of the passenger side just in front of the head and see if there is a stamped number. I ran a check on the manifold but couldn't find the number listed. The motor laying down at 3,800 could be any number of things, including tired valve springs.

"Long block replaced 250 hours ago" could also mean "boneyard 267 or 305".

Points distributor could mean any small block before 1975 except maybe 265, because of front motor mount. Could be a 283, 302, 327, 350, 400 with points originally or a 262, 267, 305, 350 or 400 with the HEI replaced with points.

I've been checking every freakin' number I can find on this engine. It is a GM 5.7 appears to be 1987 block with a 1977 Q-Jet carb and distributer with points and no vacuum hose?? The stamped engine ID # on the front of the engine is V1117PHD. The first part is ok but I can't find a PHD suffix anywhere. What I can get off the back of the engine is K077, GM 5.7, and 093638 which must have a 14 in front of it that I can't see. I'm having a real hard time reading the very lightly stamped VIN.

I need to find out the stock HP and max RPM. Hopefully someone can come up with a link to a torque curve.

Any crystal ballers out there?? Any help muchly appreciated.

BigD

BigD, you're not listening. There is no stock horsepower rating on this motor because it's not stock. It's an abortion that someone has cobbled together from different parts that were collecting dust under the shelf. From what you've said, you've already found the max rpm of this motor, 3,800.

Bite the bullet, pull this turd out and build yourself a 383 or 400 small block 2-bolt main that will have enough torque to haul this boat. Look at combinations 15 and 16 of these dyno-proven 383 builds and pay attention to the torque figures.

http://www.ryanscarpage.50megs.com/combos2.html

The compression ratios will also be "marina-gas friendly".

You are indeed correct. I guess you just have to hit me over the head with a pile of numbers to get my attention. Some pretty awesome engines on that list.

However, even if I don't have a clue as to what this concoction of mine should be turning, I still think it is laying down on me at WOT. I had it out on Friday and it sounded as if I was losing a cylinder at top end. Dragging one piston should cost me a bit of power. Guess I'll just go through the motions of an extreme tune up with everything new and call it good for now.

Thanks for the patience!

BigD

OK guys ....... I've been chasing numbers, ideas, skiers and fish with this boat for a month now. All numbers (aside from the 1979 carbeurator) trace to a 1988 engine. Block, heads, intake, distributer etc. etc. say this is a 1988 5.7 350 chevy marine long block engine. However it is still running with the HP of a six cylinder.

If, during the rebuild, the cam chain had been retarded one tooth this would seem to have intake valves partially open during the compression stroke. This would seem to not only lose power without a backfire, but also show low compression across the board when tested ....... nicht war??

Just a hypothesis fellers before I start throwing wrenchs in all directions. Would an engine set up in such a way still start with one or two pumps of the throttle?

Hopefully this will be a stimulating thought and not a waste of time.