PY Online Forums - Bringing the Pontiac Hobby Together

PY Online Forums - Bringing the Pontiac Hobby Together (https://forums.maxperformanceinc.com/forums/index.php)
-   Heating & Cooling TECH (https://forums.maxperformanceinc.com/forums/forumdisplay.php?f=420)
-   -   cam and A/C (https://forums.maxperformanceinc.com/forums/showthread.php?t=808768)

rad400 08-17-2017 12:16 PM

cam and A/C
 
Does anyone know what the biggest cam hyd. flat tappet cam you can run with factory A/C? ie. .229/.239/@.50 .480/.500 lift 108 lobe sep.
Thanks

70GS455 08-17-2017 02:15 PM

You are about as big as possible while still having enough vacuum to run vacuum accessories. You have 18 deg overlap at .050", which will work as long as it's a 455 and you have decent compression (9.5 or better). As much initial timing as you can get to work properly will also help vacuum.

Sent from my SM-T817V using Tapatalk

rad400 08-17-2017 02:26 PM

So if its a 400 it won't work.

ponyakr 08-17-2017 02:52 PM

Might wanna consider a Crower 60243 or a Crane 283951. I think Cliff has posted some good numbers for 400's with that Crower cam.

https://www.crower.com/camshafts/pon...m-284-hdp.html

https://www.summitracing.com/parts/c...IaAusEEALw_wcB

A Howards 410051-14 might even work, since it has a 114° LSA, and 285/295 adv duration.

https://www.summitracing.com/parts/h...w/make/pontiac

No, I've never used any of these 3 cams. I ran an 041 clone/Rhoads lifters in almost everything. But it seems that when I recommend that, most can't stand the ticking sound the Rhoads lifters make.

DOC 08-17-2017 06:51 PM

Last combo I had a 462/ 6X/ QJ/ T1 intake then cast intake/ XE 284 Cam and had no problem with the AC and still having Power Brakes..

ponyakr 08-17-2017 07:10 PM

But he has a 400. That cam would act much bigger in a 400, would it not ?

I suppose he might get by with a 268 Voodoo. Paul Carter can probably tell us more about using a Voodoo in a 400, than anybody else here.

http://www.lunatipower.com/Product.aspx?id=1776&gid=287

rad400 08-18-2017 10:12 AM

ponyakr would an 041 with rhoads be ok to Run A/c or would the 744 style cam be better?

ponyakr 08-18-2017 11:04 AM

Quote:

Originally Posted by rad400 (Post 5775743)
ponyakr would an 041 with rhoads be ok to Run A/c or would the 744 style cam be better?

The 041/Rhoads is great in a 455. But, Cliff Ruggles has posted that he has run across lots of guys who didn't like the 041, in their 400, at all.

The Summit 2802 is similar to a 744, but has more lift. Would probably be a better choice than the 041. For me, I'd also run Rhoads lifters, with the 2802, in a 400.

The 744 clone has barely over .400 lift. So, it wouldn't make as much power as the 2802. But, the lower lift also puts less strain on the valve train. Should be able to get by with less spring pressure.

The Melling SPC-3 is a 744 clone.

I'm aware of the question you asked, in post #1. But, FWIW, unless you plan to spend a lot of time over 5000 rpm, I'd drop back to a smaller cam, which will have better street manners from idle to 4000 rpm. The Lunati 10510312 & Crower 60916 are more cam than the 068 or Summit 2801, but less than the 2802. Either one should make a good streetable 400 cam, as would a Voodoo 262.

http://www.lunatipower.com/Product.aspx?id=1759&gid=278

https://www.summitracing.com/parts/c...xoCQqsQAvD_BwE

http://www.lunatipower.com/Product.aspx?id=1775

rad400 08-18-2017 11:07 AM

ok thanks.

64speed 08-18-2017 09:18 PM

Paul recommended to me a Lunati voodoo that I never would have picked for mine and he knew that I wanted streetability with good power. I guess the best of both worlds. Private message him tell him what you want to accomplish and he won't steer you wrong

69Farburd 08-23-2017 06:06 PM

I have a Summit 2802 in my 428 with lower compression heads (6 x 4). The AC controls and power brakes work great.


All times are GMT -4. The time now is 10:03 AM.