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Topic Review (Newest First)
06-23-2013 07:42 AM
LATECH
Quote:
Originally Posted by techinspector1 View Post
Just curious, I have not seen anywhere in this thread where the static compression ratio of the motor has been addressed. That's why I'm curious that you can tell the OP that it's too much cam. Not saying you're wrong, just curious.
You know I realized that last night after reading back through this thread.
I checked on a pontiac head chart somewhere and went with a stock 69 head chamber size when I originally made my statements. My Bad I should have asked him.
Maybe the OP will post his chamber volume and I can have a second chance here.
If his chamber size is about 72 CCs , the cam he has would be pretty good.
Maybe he will post the casting number.
#47 heads show to be 72 CCs
#48 heads were 64 CCs with press in studs (350) and were 72 CCs with screw in studs (400 ci)
Both head volumes would be Fine with his cam, of course the 64 CC heads would be real good. 93 octane would be needed as well.
06-22-2013 08:38 PM
techinspector1
Quote:
Originally Posted by LATECH View Post
Better put a 2500 or 3000 stall in that bad boy if youre gonna run that cam.
You wont like it trust us. We arent a saleperson trying to sell you something. All of the guys here have built engines (especially P Body ) and we know what works.
You want to take a step backwards..put that cam in . Big step backwards next.
Do what you want. Easy to change the cam now...later...not so much
Just curious, I have not seen anywhere in this thread where the static compression ratio of the motor has been addressed. That's why I'm curious that you can tell the OP that it's too much cam. Not saying you're wrong, just curious.
06-22-2013 04:54 PM
LATECH Ok. Well get it running and greak in the cam. See what you have at this point.
If youre dissapointed in the low end /take off performance , that big cam will be to blame.
Like I said you could put a higher RPM stall converter in it. Which would be a quick round trip , pull the trans, swap converter and reinstall.
See what you get. Let us know how she turns out.
06-22-2013 04:29 PM
off2wildblue I guess it is too late now. The motor is in the car. Everything engine and transmission related is complete and working good. I just don't have a windshield or top and interior. So to change the cam now has got to be expensive. That is why I was curious on what it would cost.

SAM
06-22-2013 04:25 PM
LATECH Better put a 2500 or 3000 stall in that bad boy if youre gonna run that cam.
You wont like it trust us. We arent a saleperson trying to sell you something. All of the guys here have built engines (especially P Body ) and we know what works.
You want to take a step backwards..put that cam in . Big step backwards next.
Do what you want. Easy to change the cam now...later...not so much
06-22-2013 01:51 PM
off2wildblue Well, we will have to see how it all works out. The engine is built and installed. I only have the top and interior left to do. I have done everything on the car except the motor. I was recommended this cam by Summit Racing. I live North of Atlanta and that is what they recommended. I bought everything at one time and figured it would work because they deal in this everyday and I don't.

Any idea on what it costs to change out a cam if everything else is newly built?

I really hate taking steps backwards in a build. So I may just have to see how it all works out.

SAM
06-22-2013 10:46 AM
Mr. P-Body I agree with Lynn. XE256H is a very good cam for both 326 and 350. Building a 326 right now using that one. Will also use Performer and a 650 E-carb. Figures to make around 300 HP and 400 lb. ft.

The old Magnum grinds (what you list) are basically similar to Chevy small block grinds popular in the '80s. They've been obsolete for some time now. Pontiacs ALWAYS "like" a dual-pattern grind (more duration and/or lift on the exhaust side).

Jim
06-22-2013 07:44 AM
LATECH You would be better off to run the 51-221-4 .
It would keep your dynamic CR down enough to run 87 In My Honest Opinion.
It is about the biggest you can run with catt wizz gas,tall gears, stock converter and 350 cubes .
Bigger cubic inches need bigger cams. Dont over do it on cam choice.
I agonized over my cam choice for almost 9 months before I finally chose th exact one. I had originally 3 different ones in mind.
06-21-2013 10:31 PM
off2wildblue
Quote:
Originally Posted by LATECH View Post
Comp Cams 51-221-4 would be a much better and more optimum choice for your 350.
It would do well on 89 octane and probably just as well on 87 with that cam and the rest of your build recipie.
Which cam are you saying would do well on 89 octane?
06-21-2013 07:20 PM
LATECH Comp Cams 51-221-4 would be a much better and more optimum choice for your 350.
It would do well on 89 octane and probably just as well on 87 with that cam and the rest of your build recipie.
06-21-2013 07:16 PM
LATECH That cam is way too big on duration for the 350. You are gonna hate it.
It will be a dog getting off the line.
You need more cubic inches, more compression, a stall converter and most likely some more rear end gear.
06-21-2013 05:56 PM
off2wildblue I am not sure what Information you need but here is what came with the camshaft. Also, my Carb is a Edelbrock 600 cfm.
06-20-2013 06:10 PM
Mr. P-Body In fact, the RPM is not well-suited to the 350 Pontiac. Performer is much better. RPM is the "red-headed stepchild" of Edelbrock intakes for Pontiac. The 400 is about the only engine size that really benefits from it. The runners are too large for the smaller bore 350, and the low-end "rush" is too much with the longer strokes. This is one of the many differences in how to approach a Pontiac versus a small or big Chevy.

Conversely, Performer is no better than the cast intakes Pontiac put on there in '69, as Bill and Lynn have pointed out. But the factory intake requires the use of Q-Jet or a really good "spread bore". Adapters on these intakes are verboten. Performer will work well with your 650 E-carb.

It would be really helpful if you elaborate on the cam. "Mild" is not a good description. Numbers, please.

350 Chevy will rev to the moon. 350 Pontiac makes significantly more torque at lower RPM. 350 Pontiac is not a good revver. That's what 400s are for... (:-

Jim
06-20-2013 07:58 AM
MouseFink The difference between the Edelbrock Performer RPM and the Performer manifold on a 350 CI Pontiac engine will not make any significant difference in overall performance. What little difference in performance that you will notice with a 350 CI Pontiac engine above 3,000 RPM is not worth the effort and cost it will take to change manifolds.

A Performer manifold is a replacement for a stock manifold. The Performer RPM manifold is more suited for a 400 CI Pontiac engine that has a better bore/stroke ratio and can take advantage of the short runners and larger plenum area at high RPM, as the name suggests. However, it will not operate as well at low RPM and in normal driving.
06-20-2013 05:17 AM
astroracer How does it drive? Pontiacs produce a bit more low end torque then a same size Chevrolet engine. Bleeding off a little low end torque usually isn't an issue with these motors if they are built right. Just helps them hook better...
Mark
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