Topic: Rebuild Ideas

[Kevin]

Kevin,
How's your hunt for new heads going?

Geno

Finalizing a deal on #62's.

[72blackbird]

Kevin,
Make sure to run dished pistons. I know it's been beat to death but who needs to go back into a freshly rebuilt engine only to find your bearings hammered out by detonation?

Geno

[Kevin]

I'll make sure.

[Kevin]

Kevin,
How's your hunt for new heads going?

Geno

I have these bad boys now...






Whats the horsepower prediction so far with these heads? Any guesses/recommendations?

[kjkjkcjkcj]

i have a set of 62 heads on my car with a very mild cam and i am putting out 267hp and 387 torque to the rear wheels.  i am hoping to put a more agressive cam in my car like the xe274 or xe262.  so it should liven my car up but she moves pretty well.  oh my heads have some porting done to them and i have a holley 650 on it which the guy who tuned my car said was a great choice.  other than that the car is pretty much stock with .030 bored.  and i can run it on premium.

[Rick]

I have these bad boys now...

Just don't forget to figure out your accessories mounting (PS pump, alternator, etc.), because those heads don't have the bosses or the holes on them to match up exactly with second generation heads.

[Kevin]

i have a set of 62 heads on my car with a very mild cam and i am putting out 267hp and 387 torque to the rear wheels.  i am hoping to put a more agressive cam in my car like the xe274 or xe262.  so it should liven my car up but she moves pretty well.  oh my heads have some porting done to them and i have a holley 650 on it which the guy who tuned my car said was a great choice.  other than that the car is pretty much stock with .030 bored.  and i can run it on premium.

My machinist is telling me that 400 horse shouldn't be hard to achieve with this build..

[kjkjkcjkcj]

yeah i gotta get a new cam. and talk to mr p body. about why im not gettin the right power.

[72blackbird]

kj,
What kind of gearing are you running? cam and exhaust?

Geno

[kjkjkcjkcj]

stock gearing i belive like 3.23 and my cam is like an xe234 or something low like that. my exhaust is 2 1/4 pip all the way to some flowmasters and i have hooker headers.  idk why my power is so low.  and the port work was done by this guy who knows pontiacs very well.  and he put all new stainless valves in them.

[72blackbird]

Alot of it has to do w/ the cam- you need about a minimum of .480" lift and 225-230 duration @.050 (around 280 degrees adv.) to get that porting to move more air/ fuel mix and fill those cylinders. In addition to a hotter ignition coil, you also need a stronger ignition - a CD ignition to hit that charge in the combustion chamber at TDC w/ multiple sparks at lower rpms and longer hotter spark at high rpms.

The 2 1/4" pipe will also limit exhaust flow and constrict the motor a little, compared to a 2 1/2" pipe. I also run a Holley (750 vac. sec.) on an e-performer- 400's can use more carb.

I would be surprised if you couldn't make at least 325 hp/ 425 ft-lbs. with those changes.

Geno

[Rick]

Kevin, you have a PM.  Pics to follow.

[kjkjkcjkcj]

Hmm thanks I'll take that into consideration. I finally got a job so I'll be able to put money into the car now

[72blackbird]

Anyone running a 72cc head w/ flattops should be well advised to take the advice engine builders like Jim, Rick and myself give about this combo- we talk about it over and over, but it seems like few heed the warning about detonation and what it can do your your engine.

When I pull the 400 w/ ported no. 48's out of my 'Bird this spring I will document the teardown of this motor and show what happens to your bearings when detonation hammers away at them.

Geno

[Rick]

I wouldn't put me into the class with Jim!  I was a "forensics engineer" in one of my past lives.  I've seen the results of several engine failures and figured out how they happen.  Holding the ruined pieces in your hand kind of focuses the memory...