High compression?


Active Member
Oct 14, 2004
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Miami, Florida
What vehicle(s) do you drive?
1987 Cutlass Supreme 2 door with 500 Cad/Turbo 40
So I have this 87 Cutlass in my backyard which has a 500 under the hood I had the car built about 15 years ago. Its had 3 engines. The first was overheated immediately after installation when the a/c shop left it idling for an extended period while charging the a/c system. That cracked the block. I got another block and the machine shop sleeved the cracked block and pawned it off on some airboat owner. He built a lot of airboat 500s. That engine had 10:1 hypers and the VT10 cam. It knocked and pinged something awful. I used to put 100 octane avgas in it and with a tank of that it was driveable but still pinged when I got on it. I parked it a few years. My illegal alien who worked a local junkyard removing parts off cars for customers notified me there was a 75 or 76 EFI 500 in a smashed Sedan Deville (very sad, car was obviously well cared for until the accident which was severe) and I got that. I still have the EFI intake and throttle body. My machinist was shocked, he'd never seen one. I rebuilt that block and used 71-73 soap dish pistons with the early heads which I ported at home and had the shop use BBC rectangular port valves. So it was a low compression engine. I used the MT10 cam. I was very happy with it; it would break the tires loose up to 20 or 30 mph sometimes. I loved blowing past people trying to pass 'that junk old car' in their fancy BMWs etc. It would hit 100 like nothing. That stupid air pump belt arrangement killed me. The pump seized, lost my water pump belt, overheated, cracked the heads. I saved them, stripped them and got another set off Craigslist cheap but had to put a stock set on the car to get it back on the road. It was a little slower.
I got the air pump eliminator pulley set, well worth it. Fast forward a few years. Consistent fuel starvation problems never let me make even a full 1/8 mile pass even with a new 1/2 fuel line and an electric fuel pump It would get into 2nd gear before it ran out and the trans was set a little too high at 5400 shift point. You could feel the power fall off after 4800. Stock 35psi oil pump. I think I spun a bearing as now there is a rapping sound over 2000 rpm. Its been parked now a couple years.
I have some other projects to finish but I have the die grinder out and I'm thinking of getting the car back on the road. I have the old high compression shortblock or do I stick with low compression motor and replace the bad bearings? I was wondering if maybe a bigger cam, blocked heat crossover, cold air and a true zero decked block with really tight quench would allow me to use 93 and be happy with the 10:1 compression ratio. ? Somehow I doubt it.