PY Online Forums - Bringing the Pontiac Hobby Together

PY Online Forums - Bringing the Pontiac Hobby Together (https://forums.maxperformanceinc.com/forums/index.php)
-   Pontiac - Street (https://forums.maxperformanceinc.com/forums/forumdisplay.php?f=418)
-   -   Anyone running this cam or suggest one. (https://forums.maxperformanceinc.com/forums/showthread.php?t=878501)

Dealerkiel 01-29-2025 09:59 PM

Anyone running this cam or suggest one.
 
New member. First post. Comp cams suggest this cam for my setup. Thoughts? Anyone running it. Magnum 224/224 110. HFT I want decent lope/chop but nothing outrageous. Car is a 1967 gto. Setup is
1968 400 .30 over 10.50:1ish compression 62 heads stock Rochester carb edelbrock intake. 2000 stall th400. HO exhaust. Msd dist 355 posi. Has a 204/214 112 cam in it now. I don’t want to change springs or go roller. So stock lift THANKS.

JB Eng Wis 01-29-2025 10:28 PM

Comp Cams Adv duration is 270* on that camshaft ..... Im guessing your CR is more around the 10.2 : 1
That cam will make to much cranking compression & Not run on todays Permium Pump Gas....IMO
Since your new here........ Read lots of info on this fourm...... Lots of Smart Poncho People here...
Others will chim in.....we love camshaft,,,,, stuff
I think you need to lower the compression ratio or a different camshaft....... I not sure if the 068 could handle 10.2 : 1 today....

67Lemons 01-29-2025 10:45 PM

Have you or the engine builder cc’d your heads & know for sure that you’re running 10:5ish compression because what Pontiac claimed for these engine stock was usually from everything that I’ve red been less than advertised compression by a point or so.

jamaca85 01-29-2025 11:14 PM

cam will work I had a 400 with 62s with that cam ran mid 13s in my firebird

RocktimusPryme 01-29-2025 11:15 PM

Im normally all for tinkering, but if the car runs well as is, I don't know that I would take the path you are taking.

If you are limiting your cam selection to stock lift, I just don't see that you would make a gain commensurate with both the amount of work required, and even more, the risk involved in breaking in a new HFT cam.

Again, Im all for a cam change, but maybe rethink the stock lift part of it, to make sure its going to give you what you want out of it.

steve25 01-30-2025 12:07 AM

Your cylinder pressure with #62 heads and that cam will not be an issue, but what might be an issue is the lift.

If I am not mistaken it’s .470” which will be pushing stock springs right to the limit or over seeing as you say there used and I would have to guess with over 50k miles in them.

Kenth 01-30-2025 07:02 AM

Melling SPC-7 (068) camshaft and Crower 68404-16 valve springs will make a nice combo.
No issues with compression or carb/ignition.

i82much 01-30-2025 08:34 AM

man doing all the work to change a cam and then being unwilling to change the springs is just a head-scratcher for me?

Dealerkiel 01-30-2025 10:05 AM

Only had the car a couple months but after driving, it’s leaking oil from the rear main and the oil pan and the valve covers, etc. so I’m pulling the engine and thought while it’s out put a little better cam in it. But trying to also avoid the rabbit hole of Changing this to change that to change this other thing and then all of a sudden I’ve got thousands more than what I originally just wanted to do.

Steve C. 01-30-2025 10:20 AM

This is not a race application, however to reflect on post #8 it will be of interest to note in a race application the most highly stressed engine part is typically the valvespring.


.

PontiacHO 01-30-2025 11:27 AM

I’ve ran the Comp 270 Magnum in a 402 big block Chevy. It didn’t have a lot of choppy lope but definitely could tell it was more than stock. The valve springs that Comp lists for this cam are too much. Used the 396 350 horsepower springs. It was right at 9.5 compression with no spark knock running premium fuel. Since this is a Pontiac, my opinion is stay with Pontiac profiles (lift, duration, and LSA). The Pontiac engineers got the most out of these engines without compromising reliability. The 068 should be a great cam. Use adjustable rocker nuts. If the plan is to use the tired/used valve springs………then just stay with the cam that’s currently in it. Just Another opinion….

Jim Moshier 01-30-2025 11:30 AM

The car is new to you and that cam is a little bit bigger than stock with the converter and gears should run pretty darn good. It sounds like a nice setup, enjoy it as is fix the oil leaks and cruise it! Change the mufflers to a nice free-flowing straight thru if you want to hear the engine more Should be a fun ride!

HWYSTR455 01-30-2025 01:48 PM

Quote:

Originally Posted by Dealerkiel (Post 6548511)
...But trying to also avoid the rabbit hole of Changing this to change that to change this other thing and then all of a sudden I’ve got thousands more than what I originally just wanted to do.

That would be called, as most car guys know, project creep.

First, in general, Pontiac heads tend to like a little more duration on the exhaust side, and with manifolds, I think it would be best to stick the a split-duration cam. So in that respect, the cam you have wouldn't be a first choice.

HFT cams are fairly inexpensive, all the gaskets probably cost as much. But if you're taking it out anyway, gaskets, timing cover seal, and potentially a rear main seal, is a standard approach. So swapping a cam isn't that big of a deal.

True, you should do the springs (could argue even if not changing the cam), or really, a 'top end' rebuild, like freshen the heads and valve train. A short block can go 200k plus miles, but the heads usually need to be freshened around 120k or so miles.

Having it out of the car, especially if you are doing a rear main seal, it would be good to inspect the short block. Aaaaand that would be the most likely area project creep could set in.

Talking about the rear main seal, if it's a rope seal, those have a tendency to leak after sitting for a while. They dry out and can get hard, which is when they start leaking. It is possible after 'regular' use, it could swell up enough to stop leaking.

I say just do the valve covers, timing cover seal, inspect the timing chain, drive it for a while, and if it still leaks at the rear main/pan area, then pull it. If you haven't had it long, enjoy it some.

During that time you can even save cash to cover any project creep when you do pull it.

Any idea how many miles are on the engine?



.


All times are GMT -4. The time now is 02:24 PM.