Home Menu

Menu


          
PY Online Forums - Bringing the Pontiac Hobby Together > Search Forums > Search Results
Page 1 of 20 1 2311 Last »
Showing results 1 to 25 of 500
Search took 0.10 seconds. Search: Posts Made By: dmac
Forum: Pontiac - Street 03-28-2022, 06:03 PM
Replies: 47
Views: 3,534
Posted By dmac
Max potential for small valve heads

I have the original #15 small valve heads off the 455/467, and expect about 450HP around 5000 rpm, MAX. Cam will be done by right about that point in this low CR engine.

Lower rpm should be...
Forum: Pontiac - Street 01-27-2022, 08:40 PM
Replies: 71
Views: 9,032
Posted By dmac
Electronic stuff is great right until it fails....

Electronic stuff is great right until it fails. Mechanical stuff that electronics has replaced almost always gives you some notice it is going bad, when used as intended.
Forum: Pontiac - Street 01-19-2022, 10:07 PM
Replies: 35
Views: 5,628
Posted By dmac
Beefing up the transmissionisn't cheap either.

Beefing up the transmissionisn't cheap either.
Forum: Pontiac - Street 11-19-2021, 04:29 PM
Replies: 14
Views: 2,878
Posted By dmac
Watch the fan shroud

Watch the fan shroud
Forum: Pontiac - Street 11-15-2021, 05:50 PM
Replies: 50
Views: 7,055
Posted By dmac
In common language, when most of the auto parts...

In common language, when most of the auto parts store octane boosters say '2 point' increase, it really means .2 increase, as in going from 91 octane, to 91.2.

I don't know if saying 'two points'...
Forum: Pontiac - Street 10-18-2021, 07:36 PM
Replies: 48
Views: 5,524
Posted By dmac
I would simply spend a few dollars more to send...

I would simply spend a few dollars more to send the block and stroker kit to a shop that worked with lots of pontiacs.

The local shop didn't zero deck the block like I asked, and told me I could...
Forum: Pontiac - Street 10-14-2021, 01:17 PM
Replies: 40
Views: 3,361
Posted By dmac
For a street car running pump gas, getting the CR...

For a street car running pump gas, getting the CR right should top concerns over flow. I doubt that performance at street RPMs will vary much if at all, but 'street' use can mean different things to...
Forum: Pontiac - Street 09-14-2021, 04:05 PM
Replies: 21
Views: 3,361
Posted By dmac
Could oil pressure in the lifter bore slow the...

Could oil pressure in the lifter bore slow the 'leakage' some? I always assumed that the leakdown came out of the fill hole in the exterior shell? If the leakage occurs on top of the lifter, oil...
Forum: Pontiac - Street 09-14-2021, 03:53 PM
Replies: 56
Views: 13,041
Posted By dmac
Did you ever check the pushrods for straight?...

Did you ever check the pushrods for straight? Rolling them on a flat piece of glass will expose any that are bent. Looks like #4 exhaust is maybe hanging open letting exhaust in, blackening that...
Forum: Pontiac - Street 09-03-2021, 10:37 PM
Replies: 22
Views: 3,224
Posted By dmac
You could mill less than the total amount and...

You could mill less than the total amount and combine with a slightly thinner gasket. Going to a much thinner gasket could be an issue. The thinner gaskets I've see require a more perfect finish...
Forum: Pontiac - Street 08-27-2021, 08:07 AM
Replies: 60
Views: 12,561
Posted By dmac
Forgot all about the hr cam!. Now I am wondering...

Forgot all about the hr cam!. Now I am wondering if more lift would throw off your rocker geometry and mean you need new pushrods. .

A new cam could have a different base circle starting point...
Forum: Pontiac - Street 08-26-2021, 10:10 PM
Replies: 60
Views: 12,561
Posted By dmac
I just saw this and thought that maybe a gear...

I just saw this and thought that maybe a gear change might be easier like going to 3.23 or 3.08 if this is to be a street car you can afford to drive. If it is running great, I would hate to mess...
Forum: Pontiac - Street 06-29-2021, 05:15 PM
Replies: 53
Views: 10,143
Posted By dmac
Exactly this!!!!!! Cam change would be pretty...

Exactly this!!!!!! Cam change would be pretty simple with engine already out. Cam/lifters for under $400 would still be a great deal, but you would still want to know whether it is stroked, but that...
Forum: Pontiac - Street 06-24-2021, 08:44 PM
Replies: 45
Views: 6,382
Posted By dmac
Going from a 26" tall tire to a 28" tire changes...

Going from a 26" tall tire to a 28" tire changes gear ratio from 3.55 to 3.30 according to Wallace racing Chart. Going from a 3.55 to a 3.36 AND getting slightly taller tires could get you pretty...
Forum: Pontiac - Street 06-14-2021, 06:18 PM
Replies: 12
Views: 1,728
Posted By dmac
That exact issue happened to me in a brand new...

That exact issue happened to me in a brand new car with electronic ignition in an 83(?) chevy I had bought specifically to make a cross country trip in. It happened 3 times at highways speeds.

...
Forum: Pontiac - Street 05-24-2021, 04:20 PM
Replies: 79
Views: 13,237
Posted By dmac
If you already have all the parts, you couls mill...

If you already have all the parts, you couls mill the heads some for more compression if you have good gas available. And you mentioned something about wanting to keep rpms down, so you would need a...
Forum: Pontiac - Street 04-13-2021, 04:38 PM
Replies: 92
Views: 8,139
Posted By dmac
It is nice to see how simulations can be very...

It is nice to see how simulations can be very close to real world results.

I should have said that Lee ran simulations of about 4-5 stock cams from various manufacturers and several different...
Forum: Pontiac - Street 04-11-2021, 09:35 PM
Replies: 92
Views: 8,139
Posted By dmac
And everyone's goals are different. And low CR...

And everyone's goals are different. And low CR like 7.7: and 9.5: will change which cam is 'best' as will heads, rocker ratio, lifter choice, spring choice. There isn't enough time to test all the...
Forum: Pontiac - Street 04-11-2021, 09:22 PM
Replies: 92
Views: 8,139
Posted By dmac
Lee is the one who ran the dyno sims for me. And...

Lee is the one who ran the dyno sims for me. And he did need the intake closing info, and head flow etc. Funny that after multiple testing, the cam he came up with for a low CR/pump gas cam for...
Forum: Pontiac - Street 04-09-2021, 03:51 PM
Replies: 92
Views: 8,139
Posted By dmac
A member here ran quite a few simulations for a...

A member here ran quite a few simulations for a low CR, low rpm , high torque and came up with using the ultradyne H5 and H15 lobes on a 115 LSA advanced 8* and it had almost 500 ft/lbs of torque at...
Forum: Pontiac - Street 04-07-2021, 04:43 PM
Replies: 6
Views: 1,374
Posted By dmac
Just read in a post yesterday that if you use a...

Just read in a post yesterday that if you use a shallow chamber high compression head with dished pistons to lower the compression, at higher lifts they will have less valve shrouding than some of...
Forum: Pontiac - Street 03-24-2021, 06:53 PM
Replies: 65
Views: 8,038
Posted By dmac
I have wondered for years about how high you can...

I have wondered for years about how high you can go with rocker ratio to 'soften' the lobe on the cam. I once had some 1.7 ratio rockers combined with Rhoads lifters on a cam similar to a Summit...
Forum: Pontiac - Street 03-02-2021, 04:48 AM
Replies: 19
Views: 2,763
Posted By dmac
In California, it might be worth $5-6000 or even...

In California, it might be worth $5-6000 or even more due to the pre 1975 cars never needing to pass smog tests and there are so few of them.. The difference between a 1975 model and a 1976 model of...
Forum: Pontiac - Street 01-07-2021, 08:07 PM
Replies: 53
Views: 3,049
Posted By dmac
Just a suggestion that has worked for me. turn...

Just a suggestion that has worked for me. turn the engine over without any stepping on the gas allowing the carb to fill. Then, before trying to turn over, pump pedal once to the floor, hold open and...
Forum: Pontiac - Street 01-07-2021, 05:06 AM
Replies: 25
Views: 2,129
Posted By dmac
Just curious, but where is the piston when max...

Just curious, but where is the piston when max lift is reached with the came timing advanced or retarded? Would that few degrees add the max cam lift, or could you advance the cam more to allow more...
Showing results 1 to 25 of 500
Page 1 of 20 1 2311 Last »

 
Forum Jump

All times are GMT -4. The time now is 11:49 AM.

 

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.

 




Contact Us Home
Copyright © 2017