Try turning down the idle screw before you tamper with the air fuel mixture screws. If it has a tach make note of where its idling now and how low it goes before it seems troublesome
My First Project Ever- 84 Regal Limited w/ Pontiac 400
- Thread starter CoelacanthsKill
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Try turning down the idle screw before you tamper with the air fuel mixture screws. If it has a tach make note of where its idling now and how low it goes before it seems troublesome
If you have a vacuum gauge- use it. If not- get one. As you adjust the idle watch the gauge. Normal idle vacuum is 20" or better. If vacuum drops drastically as you lower the idle then that is why the idle is so high. To cover up a big cam that wants high rpm. There are ways to get a big cam to idle decently but first lets see what you have.
I have cracked 2 Pontiac cranks when I was young.
It is common when you rev them high.
Most people say don't rev a Pontiac......
But then most people don't know how to build a Pontiac
Built correctly that 400 could be a Boulevard Dominator!!!!!!
It is common when you rev them high.
Most people say don't rev a Pontiac......
But then most people don't know how to build a Pontiac
Built correctly that 400 could be a Boulevard Dominator!!!!!!
It was funny driving home going 45 in 2nd and the tach was flashing at me. Was only turning 3-3.5k rpm. They must have set the light trigger low from previous experiences, lol.
Pontiac's don't need to rev high to make power.
But built right you can shift them all day at 6-6500
But built right you can shift them all day at 6-6500
Actually the way 265/301 and the rest of Pontiac motors are almost like SBO and BBO's, just tall and short deck versions of each other. People have used the Turbo 301 block with a 350 crank, normal and a custom intake to make a decent stroker motor. Aren't even the small journal Pontiac's still
3" main journals? That is big for high rpms and don't forget the cast connecting rods. Pontiac, like Cadillac, Olds and Buick V8's all have better torque curves than brand C.
3" main journals? That is big for high rpms and don't forget the cast connecting rods. Pontiac, like Cadillac, Olds and Buick V8's all have better torque curves than brand C.
Wow. Worst I have done is spin rod bearings. That usually happens long before anything actually breaks and what usually does break is the rods. And even with broken rods the crank held up. That is why in their infinite wisdom- the factory outfitted a motor with just the right parts so it can only operate within it's limits. If you put a brick on the gas pedal it would run at WOT until the gas ran out- without breaking. When we change things it is on us to also upgrade the limits.
Good news: Transmission that's in the car is a 350, fixed timing, replaced body to block ground cable that went under valve cover, crossmember was chopped up and is being welded back together so I can fit dual exhaust, buying header wrap soon™ so I don't have to heat the oil filter and brake lines with exhaust.
Bad news: smacked crusty original "fuel line" when taking the crossmember out and then gas seeped out after awhile. It was on drivers side, and I've read many threads that say vapor return is on driver side... wouldn't be surprised if previous guys put the fuel pump on the vapor line. A rubber hose comes out of the frame on the driver side and that's where fuel comes out for the engine. Is it possible to feed a new 3/8" steel fuel line all the way back without unbolting the body?
Bad news: smacked crusty original "fuel line" when taking the crossmember out and then gas seeped out after awhile. It was on drivers side, and I've read many threads that say vapor return is on driver side... wouldn't be surprised if previous guys put the fuel pump on the vapor line. A rubber hose comes out of the frame on the driver side and that's where fuel comes out for the engine. Is it possible to feed a new 3/8" steel fuel line all the way back without unbolting the body?
Good news: T-350 is common, strong, available, fixable. Bad news: it is almost impossible to feed a one-piece fuel line from the motor to the fuel tank with the body on the frame- and that's how the factory did it. Better news: I ran brand new fuel line by NOT routing it exactly like the factory did. I just went around the obvious impossible road blocks and I used five foot double flared sections connected with proper unions. I know- double flaring is for brake lines. True. So I'm a belt-and-braces kind of guy. Since fuel supply line operates under suction you can get away with straight cut lines connected with compression fittings. The return line is very low pressure too. Either way works. On another wagon I used the one piece fuel line that came in a big roll. I still had to cut it to get around the road blocks. I double flared that too and used unions.
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