Getting a rebuilt 5.7

[ChrisCraftFan]

I am looking for a rebuilt long block for my 2000 VP 5.7GSi. I found a guy fairly close. He has said that the Volvo Penta 5.7 came as a 2 bolt main with a cast crankshaft. I had a 1972 Chris Craft that had a 350Q in it. That was a 4 bolt main with a forged crank. (I have a block for that in the shed but its a 2 piece main seal not a 1 piece) Just wondering if the 2 bolt with cast crank is okay to use for my 5.7GSi?? I do not want to do this again soon.

 

[Bondo]

Just wondering if the 2 bolt with cast crank is okay to use for my 5.7GSi??

Ayuh,..... No problem at all,.... Go for it,......

 

[Lou C]

I’m willing to bet that 99% of inboard/sterndrive engines OE from GM marine are no different. The main things are RV/marine cam, brass core plugs & marine head gaskets...if you
want your inboard to REALLY last, install a half closed cooling system (can’t do full with Volvo exhaust manifolds), and make sure the engine is properly propped. These 2 factors with regular maintenance of the cooling system and lubrication system are what will make the most difference. You do not need a 4 bolt main engine for it to last. Closed cooling helps because it avoids hot spots and corrosion; these engines were designed by GM to have pressurized cooling systems not raw water cooling low pressure systems. Raw water cooling allows localized hot spots and the build up of corrosion. The corrosion causes poor heat transfer and eventual overheating around the valve seats in the cyl heads.

 

[ChrisCraftFan]

Thanks! I have the closed cooling system that was used on my 1972 Chris Craft 350Q and was considering adapting it to work. it's bornze and has a heavy cast iron tank to go with it but in great shape. I was worried about the raw water intake though. Its the raw water pump on the front of the engine but pulls from the outdrive and through the Power steering cooler. Is that enough flow? Not sure how i would reroute or change that. any other issues from anyone that has converted?

 

[Lou C]

I believe that is how VP engines from the factory are set up so go look up in their parts diagrams how tiger have it set up. There is a link to the VP catalog right here on iBoats I think.
one detail difference but it’s important is that the Vortec engines require a bypass hose from the thermostat housing to the front circulation pump. The pre Vortec engines have the bypass in the block but even so most aftermarket closed kits have the bypass hose.

 

[alldodge]

Your going from a vortec to a non-vortec

 

[Scott Danforth]

VP's only ran half systems.

 

[ChrisCraftFan]

Yes I am planning the half system. Wish I could do the full and include the EM but i just got new exhaust manifolds and risers. I am not planning to change any of that. Hopefully they last 4-5 years (i do flush after use)

I am sticking with the vortec. Did not mean to give you the impression I was not. I am just planning to use the Heat exchanger from the old 350. Need to figure out the bypass but I think i have an idea for that. Something like the picture below. some other plumbing as well. There is also a bypass hose on the expansion tank. I will probably "T" those together into the circulation pump.
But after digging around I am planing to stick with the raw water intake where it is.

 

[Scott Danforth]

with a half system, you plumb it like a radiator in your truck. motor and heat exhanger glycol loop. the sea water comes in, and then the sea-water discharge tee-s off and goes to the exhaust manifolds.