I just put a Craigslist 283 in my 57 chevy pickup and all is well while its not under load, first it wouldn't idle at all under load but ran great in park then I mess with the timing and got it drivable but it bogs way down and sort of chugs in gear at the light (only when warm) I have replaced the carb Holley 1850, new torque converter 2500 stall new fuel pump and filters manual, ran new gas line away from everything, and curved the distributer and deleted the vacuum advance. It has a mild cam from what I hear I don't know the size exactly but I can't figure it out please help!!!
I am thinking about putting a 4 speed in it as that would essentially eliminate the problem because it runs fine in neutral don't know where to start with the clutch pedal assembly as it has a 76 camaro front clip I barely have enough room to run my headers my steering arm rubs any thoughts?
If it bogs under load with an automatic, it would probably bog under load with a manual tranny. Better to find the problem and fix it. Did you actually set the timing or just mess with it? Could be ignition breakdown, any age on the plug wires and spark plugs?
Changing the gear only makes you happy, not the engine, unless the weight of the converter is wrong for your set up. But I Think you are barking up the wrong tree. This much I do know, most people over here don't look much on relationship between converter and cam. Because we only Think the converter has to match the trans. Can it be that your converter "catches" before the cam starts to deliver? Since I'm not up to up to speed on bogg is? Is it like nothing happens and then alot happens? Do you know how much unburned fuel you have in you're exhaust?
A 283 is as simple as it gets. Like others have said,start with the basics. Timing and ignition, carb settings, valve adj. then compression test and leak down test. Doing one thing at a time is a good habit to get into unless your really good with motors. Good luck
Vacuum test should show up a rounded exhaust lobe. Could also pull the valve covers, crank engine over without ignition and observe rocker arm activity. Have you checked for faulty ignition wires for "opens" or leakage to ground? Faulty wires work reasonably well at idle, but fail when cylinder pressure rises under acceleration or load.
What heads, what cam, what compression? A Big Cam in a 283, with big chamber 350 heads, (no compression)and an automatic will cause similar problems. The first engine I built as a kid was like this.
You said you have a Holley carb on the 283. What manifold are you using? If you are using an iron Chevy part are you using and adapter? Some HP aftermarket manifolds on 283 heads may have ports that don't match up with enough material to seal the gaskets fully. Also using a carb adapter on a 283 manifold with heat riser passages don't always seal the exhaust from intake charge. Also don't forget about checking the power valve in the carb for leaking or shrunken cork gaskets in older Holleys.
Also check that the timing tab matches the balancer- with a 50 year old engine who knows what has been changed. Mismatched timing tabs/ balancer marks are common on small block chevys.
I would set the valves to see if the exhaust seats are going away. If the heads don't have hard seats the unleaded fuel will wear them away. If the exhaust valves are more then 1 turn out of adjustment you will need to pull the heads and replace the valves and exhaust seats.
So am I the only one that sees that it is indeed drivable? I must be the only one that sees the problem arises at low rpm in gear? There's a lot of guesses here that skip the basics of trouble shooting and go right to rebuild type repairs, its Like keyboard Tourette syndrome.
Too many possibilities to list. That 600cfm Holley might be the problem. I tried one on my 283 and experienced similar problems. It was just too much carb. I went down to a 425cfm edelbrock. 500cfm max. Posted using the Full Custom H.A.M.B. App!
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