#1  
Old 09-23-2006, 11:05 PM
78 GHOST 78 GHOST is offline
Ultimate Warrior
 
Join Date: Feb 2001
Location: Houston, TX. USA
Posts: 2,354
Default

Jimmy, you might review the thread I started a while ago:

http://216.178.81.108/forums/showthread.php?t=489745

I was fortunate enough to have advice shared by members of this board who have a lifetime of experience with these engines. My car is a numbers matching frame off restoration with what I term "invisible upgrades" to enhance it's performance and drivability.

I have tried at each step of the project to throw the very best at this car. The engine is going to be 472 C.I. sporting an Eagle crank, Scat rod, Diamond forged and dished pistons (9.5:1 CR), new valves, springs, Harland Sharp 1.50 ratio full roller rockers, a Continental "tight" 10" converter, stock keepers and retainers, good valve job and very minor cleanup on the heads, intake and heads gasket matched, stock distributor curved and converted to "stock look" HEI, R.A.R.E. HO reproduction exhaust manifolds, Stock intake, Q-Jet, TH-400, 3.07, A/C, Power brakes, and Power steering.

After a lot of consideration, I chose a Summit 2801-K as the cam. This cam is a really mild cam compared to what a lot of other guys are running, or suggested. However, as Jim Hand pointed out, this cam is bigger than anything Pontiac used from the factory.

I don't like a really lumpy cam, just a noticable idle. The old cam was about the same specs using an UltraDyne cam on a tighter LSA of I think 108 or 110 which resulted in surging at a stop light. The wider 112 LSA of the Summit 2801 should result in an engine that produces MORE power and a smoother idle.

I know it's counter-intuitive to put a smaller cam in and go faster, but I think with 9.5 CR to protect against a bad load of fuel, and unported heads, you have to be realistic about the cam choice. Putting in a bigger cam, on this engine will probably sacrifice torque in the range I'll be using it. My opinion is to build as much torque as possible, I'm not really concerned with the HP number game. Torque is what you feel.

I can not take the credit for this cam, the 2801 was not even on my list until Jim Hand recommended it.

__________________
____________________________________
"I work in high speed aluminum tubing."
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 05:40 PM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 




Copyright © 2017