OK.. i know I'm not in the right form.. but maybe you guys can help me out here. I was looking at a 8 cylinder GMC marine Diesel today.. just trying too find some info on it, the guy that has it says as far as he knows it's a 1964 454 gas, converted over too a diesel. I took down some #'s on the block and front off the engine, is there any place on here where i can get them decoded. Now this Engine was used by the coast guard supply boats.. he said that it revs 2800 at max rpm.. just curious too what the HP would be. thanks.

 

i would just google it personally. if you posted this in the bomb shelter section of the website you will get responces. to figure out power we need a little more info. what injection pump does it use? is it idi or direct injection? is it turboed? i would check the rotating assembly for cracks. in my opinion i dont think gas to diesel is the best thing because you need some heavy duty stuff to survive what the diesel will do

 

My guess would be it is a 6.2. They never converted any of the gas engines to diesel it's just a mistake a lot of people make. Does it have a turbo? If it does it might be a 6.5. Most the 6.2's came out with about 140 hp in trucks and I don't think they changed much in the boats. The military uses a lot of the 6.2 and 6.5's.

 

No it doesn't have a turbo, it could be a 6.2 or 6.5 cause it doesn't have the wide valve covers like the 454 , it has the narrow chrome covers on there.

 

This might be a little late, but I don't think the 454 gas was ever converted to diesel. That said, GM converted the 350 CID V-8 to diesel and put it in early 1980s Oldsmobiles, Cadillacs and possibly some other brands. A few years later, owners mounted a class action lawsuit against GM for false and misleading representation, and they were successful! GM had to pay out millions in settlement of the claims.

Hope this helps.
JT

 

no they were not converted. the 5.7 liter diesel and 5.7 liter gas engine are seperate engine designs

 

here is a good bit of info i bet many of you young guys never heard of.

GMC Diesel Engines

 

...having just had my 60th birthday, I wouldn't say I was young - but I do appreciate the gesture...

Thanks for the link to GMC Engines. You're right - I didn't know about the V6 gas to diesel conversion. How about these obscure variations: I had twin 6-71s in my powerboat - WWII vintage, aluminum blocks, hydro-starters, pyrometer on all 12 cylinders - and both were connected to a single Allison hydraulic 2:1 reduction/reverse gear turning a single 38" propeller. I could run port engine or starboard engine as a stand-alone engine or both together for main propulsion, or alternatively, use one for propulsion and the other for pumping (bilge or firefighting) or PTO or whatever. GM made various configurations for different applications (marine, Sherman tank, industrial, genset) but all engines were connected to a single PTO or shaft: single 6-71; twin 6-71s (side by side); tandem 6-71s (end to end); quad 6-71s (side by side AND end to end). Very versatile power!

JT

 

thanks for the info