Buick 231 V6

[Misiti1973]

I have a 1980 Oldsmobile cutlass supreme with a buick 231 v6 and I'm looking to upgrade this motor and was wondering what can I do internally to get some more HP. This is not the original motor. Was thinking cam, lifters, valves and rebuild lower half. Wasn't sure on intake and carb. This car has no computer and emissions have been removed.

Thanks,

Chris

 

[King_V]

1) MOST IMPORTANT - dual exhaust. That factory single exhaust is restrictive even for the little V6! If not true duals, maybe a big single system, but duals are probably easier.

2) I would actually NOT recommend removing the EGR - it'll help with cruising MPG, while not detracting from full-throttle power. Use of EGR also allows for more aggressive timing.

3) If you have to get inspection,I'd leave the cats - or get some high-flow catalytic converters. Catalysts today are NOT restrictive like they were in the late 70s.

4) 4-bbl carb. Even with the stock cam, I'm told that going to a 4-bbl helps. On the cheap, using the 4-bbl intake (say from a 4.1L/252ci Buick V6 from the early 80s) helps. I think the carbs from those cars are all electronic-controlled, though, so an aftermarket carb, or maybe a retuned carb off a small V8 from the 70s, should do the trick.

5) If going inside - cams are as mild or wild as you want, and I don't really have experience with choosing a cam.

6) If rebuilding, I imagine that it's safe to go a little higher than the stock 8.0:1 and still be able to use 87 octane. I don't know how detonation sensitive the 231 is, though.


That's all I can come up with offhand. This is all "in theory" - I do NOT . . repeat, do NOT, have practical, hands-on experience in this. But I think the theory is sound. Well, with the exception of the dual exhaust - Uncorking the exhaust, I felt a real, noticeable seat of the pants difference despite the rest of the engine being 100% factory (on an ECU-controlled 1984 Regal 4-door)

 

[lilbowtie]

Chris
I have a new set of headers that I can give you a good deal on if you are interested.

 

[Clone TIE Pilot]

I did the 4bbl swap, wasn't worth it. The 231 is such a dog it would take a complete rebuild to better specs to get it past 120 HP. Crappy heads, crappy cam, and low CR.

 

[YGspider]

This topic has come up so many time from new Gbody owners. And most of the time the real answer is upgrading to a 350 Chevy or a Buick 350. If you want just a little extra power then maybe true dual exhaust and some headers but as stated to see anything more then the 80 HP you will need to tear into that motor and spend some cash. You just might be better of buying the 295 HP GM small block for 1500 or what ever it costs. I think the TH200 Would hold up and with highway gears the car would have some nice getup and go on the highway.

Or plan B Do what I did and sell what ever Gbody you have now and find a Regal T or Grand national with a already fast 231 with a Turbo. This plan may cost the most and give the most headaches though. :lol:

 

[Clone TIE Pilot]

The 1996-02 truck crate 350 is a really nice motor for the price. 4 bolt mains, 1 piece rear seal, roller cam, 9.4:1 CR, and vortec heads. It probably makes more usable power in the normal driving RPM band than the 290 HP 350 with better MPGs.

 

[spidereyes455]

I did the 4bbl swap, wasn't worth it. The 231 is such a dog it would take a complete rebuild to better specs to get it past 120 HP. Crappy heads, crappy cam, and low CR.

I did the same thing to a stock 3.8 in an 80 cutlass years ago and I agree it wasnt worth the effort , I think it actually made the car slower. But on the plus side it did have a unique sound when the secondaries opened i've never heard anything like it before or since.

 

[86cuttycustom]

Im just about done building my 3.8 . Doing 9:1 compression motor with comp cams kit, .060 overbore ,ported heads, edelbrock carb/ manifold with headers and and a 200r4 for the low first gear and od. Ive been told im wasting my money but everyone still agrees these are great motors .This car is just a cruiser anyways. They sound cool at low rpms and mine will have lots of low rpm tq. Of all the research ive done i think the biggest milestone is the 2 series gears ine the tear end. 2:42s will be a slug. I look forward to the before and after . Should be 2/3 more wks

 

[rustyroger]

If you can't find a turbo engine you could use an H body supercharged unit, or even a N/A engine. You will need the computer and bits and pieces to complete the swap, but you will have a noticeably more powerful and efficient engine for your trouble. The computer controlled engines are remarkably long lived as well, easy to find and cheap to buy.
Just another approach to your question.

Roger.

 

[jetsetw31]

If you can't find a turbo engine you could use an H body supercharged unit, or even a N/A engine. You will need the computer and bits and pieces to complete the swap, but you will have a noticeably more powerful and efficient engine for your trouble. The computer controlled engines are remarkably long lived as well, easy to find and cheap to buy.
Just another approach to your question.

Roger.

X2 on the N/A Fuel injected system from the FWD cars.
FIRST THING, IF YOU ARE NOT COMFORTABLE SPLICING WIRES AND READING WIRE DIAGRAMS, DO NOT TAKE THIS ROUTE.
1985 is the only year you can use the parts from. You will be looking for the '85 Buick Electra/ Park Ave and Century, '85 Olds 98 and Cutlass Ciera, You can use the parts from the 3.0 and 3.8 motors. Intakes, throttle bodies, injector and fuel rails, harnesses, The 85 cars have the standard V6 distributor but you may want to use the coil pack system with the 85 intake. I did it that way. The 86 up have the harnesses for the coil pack system. Also you'll need the crank sensor and harmonic balancer that triggers the coils.
My car ran great. Enough torque to fry one tire 50 feet. A big seat of the pants feel.