85 Cutlass with a 455

[blk74nova]

I just picked up an 85 with a 455 in it. Its seems to have a few issues. It seems down on low end torque. I'm not real familiar with olds motors, but I would think it would be a torque monster. I don't know alot about the motor yet. No idea what year or what heads but it has an Edelbrock intake and carb with dual exhausts. The carb is a 750 but looks a little old and may need rebuilding. I may slap a good 600 Edelbrock thats in the garage on it just to check. I pulled the cap and rotor on the hei and there was a little rust on the advance plates not letting them slide freely. I swaped for a lighter set of springs and cleaned up the plates so they move better. The vacuum advance can isn't working either. I may order 1 from autozone for $40.00 or get a good one from the speed show in town. Anyone have any other suggestions? Whats a good initial and total timing to start for a mostly stock 455? I know I'll have to fine tune for this motor so I'm just looking for a starting point. I know it depends on year but any estimates on what torque and hp a stock 455 has? Thanks in advance, Neil.

 

[jordanfr13]

That really depends...it could have between 250 and 375 hp and somewhere around 400 ft/lbs of torq

 

[88hurstolds]

Is the trans toast?
You could have a bad timing chain, a buddy of mine had a 455 in a T/A and it had the same problem with low end torque. Turned out to be the timing chain.
600cfm is way too little for that motor, find a carb from a 73-76 Olds 455, they are 800CFM.
I might have a spare that needs rebuilding if interested or rebuild your 750, it should do just fine.
Clean up the HEI and get new plugs and wires.
That's about all I can tell you without seeing the car run :|
Good Luck

 

[svltrack]

Yeh, go over the basics & that carb is too small for sure.

 

[blk74nova]

The trans works great, shifts firm. I had a timing light on it and the mark wasn't jumping around at 700 rpm so I'll hope its not the timing chain for now. A new hei from autozone was 40, without cap,rotor,and coil but I have all that stuff (Mallory coil, cap etc). I am leaning more towards the distributor as it got alot better after I changed springs. I'll pull the plugs and check but they look new. Its got some Accel wires on it and may swap them out too. It should be able to turn the tires over no problem even with crappy rear gears. I'll grab the 750 off my monte to check if its the carb.Thanks guys

 

[olds307 and 403]

Try anywhere from 16-23, depending on your advance curve. My 403 easily burns both tires with 2.56 gears, low compression crap rebuild.

 

[82cutty]

Dust is normal for an HEI.... They all do it, all mine have it and my cars are tuned up every 2 yrs regardless of the miles put on. Most Q-jets are a 738 cfm and the newer ones of the late 70's are around 800 cfm. Most big bodied cars have them, de tuned to meet emmisions. I would guess 76 and up, alot on Deltas and Pontiacs. When I had a bone stock 71 455, I did a few things and she ran very well. I had a 250 hp motor as a base starting point. The single exhaust cars had 270 hp in 71-72. I put in the lighest springs in the HEI and kept the original weights, did some minor linkage bending to the Q-jet, some bigger jets and secondary rods and hanger. I also played with the secondary flaps to get a bit more air. I ran headers and 3.73's gears with a 28 inch tall tire. I timed it a 9 degrees initial on a 76 HEI. The distributers will have different curves depending on the yrs. The engine was a work horse, blew it up 2x and she still ticked like clock work. That engine would spin both rear tires like nothing else, I had a buddy once measure the "signature" I left and it was well beyond 275 ft from a single track tire fryer.... Go to www.442.com and browse the tech section and look up the engine numbers and get your specs. This will get you the timing numbers and you can go from there. Then play with the timing by a degree here and there to get the most out of it. My 455 like 9 degrees and a stock vacumm advance curve with the stock weights and the lightest springs. My 432 I have now likes medium springs with NO vacumm advance timed at 5 degrees mechanical timing.
Good Luck!!!
Steve

 

[blk74nova]

Hey I got it figured out. Thanks for the link. Car had a few things wrong. First it didnt have a thermostat, it needed an adapter plate for the carb(huge vacuum leak). It had the vacuum advance can locked out. The biggest problem was the number 2 and 6 plug wires were crossed . I'm the 3rd owner in 2 months, wanna bet the other guys got rid of it because it didnt run right? Thanks for the suggestions

 

[gbodyaddict]

good job finding that out....now go burn some rubber

 

[Blake442]

Now post some pics!