Perfomance questions

[455ho]

I own a 71 T/A. I am considering removing the stock 197 heads and milling them ( only enough to increase the compression to about 9.5 to 1 ). I also want to do some other head work and maybe a cam. The car dynos now at 300 rear wheel h.p. @ 400 lbs. of torque. My question is what exactly should I do? I want to drive the car but also want to take it to the track and run consistent 12's. Any input would be appreciated.

[455ho]

I own a 71 T/A. I am considering removing the stock 197 heads and milling them ( only enough to increase the compression to about 9.5 to 1 ). I also want to do some other head work and maybe a cam. The car dynos now at 300 rear wheel h.p. @ 400 lbs. of torque. My question is what exactly should I do? I want to drive the car but also want to take it to the track and run consistent 12's. Any input would be appreciated.

[Dick Duclow]

A 71 T/A with 300 rear wheel HP should be making about 360-370 HP. Fill us in on what you've already done to the engine.

9.5-1 compression with a 224/234 @ .050 cam with 475-485 lift and a 112 LSA combined with a good exhaust system will get you the power you need. Is the car auto or 4 speed? If auto, use a 25600-2800 stall convertor and a 3:55 gear. If 4 speed use a 3:73 gear. Have fun

[bs78ta]

Dick, The cam specs you suggested are exactly what I am looking for. Where can I get that grind profile? Every one that I have found has a 110 LSA and my dyno program shows my combo will do better with the 112. Thanx for any info.

------------------
Butch

[Skip Fix]

Butch,
Quit looking in the cam catalogs and call any of the cam companies and they grind you whatever lobes on what lobe sep and what ground in advance. My current RAIV is running one with 242/236@ 0.050 on a 110. It liked more on the intake side. That isn't in any catalog.

Skip Fix

[Bob Dillon]

Skip, I'm curious. Do the cam companies make an extra charge for grinding a custom cam? If so, how much?

[KO]

Comp Cams is about $30 higher ($150 jobber)for a custom ground flat tappet cam vs. off the shelf. Solid rollers are the same price custom vs. shelf stock.

[Ron]

I built the motor you want. I used a 455 bored .060. The 197 heads were milled down to 100cc. The heads were ported to flow 270 CFM on the intake. I used a cam provided by HO Racing. It is their 03 cam. At the urging of Ken Crocie at HO Racing I also used Rhodes lifters. I topped it off with an Eldelbrock Performer RPM intake and a 800 CFM Q-Jet massaged by Brad Urban at The Carburetor Shop. I also installed an HEI distributor along with an MSD6AL ignition system. With 3.31:1 gears the car ran a very consistant 12.50 at 107 MPH. The car idled great, was perfect for street or strip.

Good luck with your project. IF you need any additional information, please feel free to e-mail me.

Ron

[Ccass]

There is another good posting on this topic in the 70-72 GTO Tech.

[bs78ta]

Does HO Enterprises grind their own cams or who are they using? He lists the profile I want - .465/.488 lift, 224/234 @.050 and 107/117 LSA for $150 including lifters. Has anyone used his cams and if so how are they? Any info will be helpful. Thanx

[JB]

Bs78ta I think you can find the cam with those spces at PAW. I ran that same cam about a year and a half ago and got the cam and lifters really cheap. I would give you more info on it but I tossed out a lot of that stuff when I moved. they have an ad in every magazine it seems like so you can find them with no problem. Just check everything you get from them. The first cam they sent me was for a 390 cid ford, so check everything right away. The cam cost me about $50, I don't remember what the lifters cost.

Sorry for deviating from original topic but having trouble with my Email today so I couldn't send this response direct.


[This message has been edited by JB (edited 01-02-2000).]

[77TA]

The cam Paw list is 224/234 on a 114 lobe seperation so its 2 degrees wider than the one you are talking about but it may be fine. I like to hear some talk on lobe seperation and what pontiacs like best ?

[Phil69GTO]

You might consider talking to the folks at Ultradyne cams. They really seem to know their stuff. Jim Butler also stocks Ultradyne cams and was very helpful in my cam selection. Just a thought...

[Rocky Rotella]

My dad and I are running Nunzi grinds in our cars. His is a 72 455HO T/A, with ported 7F6's and bored and stroked block. Mine is a 76 455 4 speed with ported 4X's and a bored and stroked block. We are both currently using the Nunzi 2041HL with is 222/232@.050 with .450/.470 lift @1.5 While we are both going to switch to Nunzi 1.6 full roller rockers (winter project), I have decided to switch cams as well. I am going to install his 2042HL which is 232/243@.050 with .460/.470 lift @1.5. Right now both cars run extremely well and pull hard to personal 5500rpm red line. Let me know if you need any more info.