What Cam?

Posted By: TW69bee

What Cam? - 01/01/09 09:09 PM

This is what I have
I have a 383HP .040 over
Eagle H-beam Rods
Keith black pistons
Stock Forge crank
906 Heads cleanded up and polished.
I want to run a cam that I don't need to run adjustable rockers.
I have had adjustable on order with Comp cams since 9-10-08.
The cam I have in the car is XE268 H.If anyone can tell me a cam that is as good or better than that one and I can run Stock rockers.Please help me out.
Thanks Tom

Posted By: forphorty

Re: What Cam? - 01/01/09 09:21 PM

you left out a few details like intake,carb, headers,stall speed, gears. if this is a mild street type 383 , the cam you have now is a good one.if this is a heavy car with a 3 series gear and less than 3000 stall, i would stick with what you have now. i have run stock rockers on a comp 292 for 20 years.

Posted By: TW69bee

Re: What Cam? - 01/01/09 10:00 PM

1969 RR
Stock intake
stock hp manifolds
2.5 exhaust with H-Pipe
4 speed
3:55 sure-grip 489 case.
750 Edelbrock
It is a numbers matching car, thats why it is not an aggressive build.
I was running the stock rockers and shafts. Car never would run right on low end. It would foul plugs,I check timing, replaced carbs, Change jets.ran with vacuum advance without vacuum advance.
Finally I pulled the cam and did the math,and came to find out the valves weren't closing all the way.

Posted By: gch

Re: What Cam? - 01/01/09 10:39 PM

Call me stupid but unless the cam lobes were wiped it doesent have anything to do with the exhaust valves not closing.

The cam you have is a good one.With the 4 speed you could go up one size to the xe274 or the xe 275hl if your heads have better than stock flow.
Anything under .510 lift you don't need adjustable rockers.Some may have run more lift with stockers but the largest I have run is the .509 cam with stock non-adjustable rockers.

Posted By: Mr.Yuck

Re: What Cam? - 01/02/09 12:01 AM

Quote:

Call me stupid but unless the cam lobes were wiped it doesent have anything to do with the exhaust valves not closing.
The cam you have is a good one.With the 4 speed you could go up one size to the xe274 or the xe 275hl if your heads have better than stock flow.
Anything under .510 lift you don't need adjustable rockers.Some may have run more lift with stockers but the largest I have run is the .509 cam with stock non-adjustable rockers.

yeah..why weren't the valves closing??? heads milled and your push rods too long hanging the valves open? Sounds like an odd problem. You could fix it but shimming the rocker shafts up. They make shim kits for that reason.

Posted By: Pacnorthcuda

Re: What Cam? - 01/02/09 12:08 AM

Quote:

Anything under .510 lift you don't need adjustable rockers.Some may have run more lift with stockers but the largest I have run is the .509 cam with stock non-adjustable rockers.

I ran a .522 with stock rockers (and p-rods) and currently run a Voodoo .494/.513 with same.

ANY size aftermarket cam is a potential problem with non-adjustable rockers if the cam base circle is ground too small. Many of the larger cams are that way. I had a General Kinetics cam that offered very little lifter preload with stock parts.

Posted By: TW69bee

Re: What Cam? - 01/02/09 01:39 AM

Heads could have been milled?
Didn't look to be
Machine shop put harden seats,guides and new valves and springs on.
I Mic the cam and it's .002-.003 to grind specs.
Push tubes measure 8.570 just measured them.
Comp Cams, Talking to their tech said I need to run adjustable rockers on that cam.
the problem I have running adjustable rockers is this,Don't want to the valve covers off every couple months to check,a pain with hp manifolds.
also have a GF and Daughter going to drive every once in a while,They would not know if the was something wrong and would probably keep driving the car.also I have been waiting on these rockers since Sept 08
So any suggestion would be greatly appreciated
Tom

Posted By: gch

Re: What Cam? - 01/02/09 01:53 AM

Try Mancini,summit,jegs,or some of the board members who sell parts.Someone other than comp has something in stock.With a hyd cam you won't need to adjust valves often.Set them once and forget.Just use some quality adjuster screws and nuts.
If the heads had been milled excessively you would have intake alignment issues.
Get an adjustable pushrod and measure the length you need and compare to what you have.
With the proper pushrods you should'nt need adjustable rockers.