In the late 70s to early 80s GM had an optional 5.7 liter diesel available throughout it’s divisions.
The 5.7 diesel is NOT a converted gas engine (as is commonly believed) but IS built upon the olds smallblock architecture; apparently, some innovative hot rodders take the diesel olds and re-convert it into a high compression gasser for the strip by simply swapping gasser heads and intake manifolds.
Apparently, the 455 itself is also based on the smallblock…with 1.25 inched added to the deck height.
Is it (in theory) possible to take an olds 455 block and put 5.7 diesel heads on it?
I have no idea if everything lines up, but you will have a 30% higher compression ratio than you will with the 5.7. I suspect that you will get detonation with any common sort of pump gas or race fuel. Alcohol might work, but I really have no idea.
No.
I’m not seeing if I can create a super-high compression gasser, but a giant diesel out of spare parts.
The 350 Diesel used a stouter block than the gas version, this is the part the racers want. The 20:1 compression ratio is waaaaaay to much for any gas engine.
I don’t think BB and SB heads will swap out (not a chevy guy here), but even if they did, I doubt the intake setups would be the same, or if you could put glow plugs in the heads designed for spark plugs. Of course, if you have a machine shop and limitless budget, anything is possible.
Retterath
Proud(?) one time owner of an Olds Toronado diesel.
If I recall correctly, the crankshaft from the diesel was replaced with a gas engine’s crank to keep the compression workable in the conversion to gas.
But, back to your diesel idea-
Where are you going to get a crank and pistons and intake manifold to use with the 455 block? You’ll need around a 20:1 compression ratio. That can be achieved through either custom pistons or a custom crank or both, but you’re looking at major bucks there (455 block? Have you priced one of them lately?). A regular intake from the SB diesel wouldn’t work even if the heads do because of the different deck height. I also recall that the major problem with the P.O.S. Olds diesel (I owned one in a Coupe de Ville) was with the heads. I think it would be cheaper and better to just buy a good diesel drivetrain from a late-model diesel pickup truck.
I figure, mix-n-match the diesel heads and exhaust manifolds, the engine (minus heads) out of a 70s station wagon, remove the carb from the intake and plop an air cleaner in its place, and you have a mill as big as one in any commercial truck.
But of course, this is just an engineering exercise…or an exercise in field expediency.