OK Racers, (especially Doug)
I would like to get your input on the size (lift and Duration) cam you would recommend for the following car. Since my sons car got my new cam when his oil pump gear failed I will need to get a new one and would like to get one best suited to what I need. Here is what I know and what I would like to achieve:

Car is a 65 valiant, Race car only
approx. weight 2600#
running a 4-speed with inline shifter ( Gotta have a 4-speed)
8 3/4 rear ( Gears not purchased yet / 4.30?? 4.56??)
Ported big valve head / Full length Clifford Headers
Hyper-pak / One of Doug's original Fat Paks (Gotta love the look)
225 with 198 rods and lightweight pistons / at least .060 oversize

Wishes:
I'd like to run mid 12's or faster
I don't want to turn more than 6-6200 RPM / I know what lies out there
I'd like recommendations on the cam? And manufacturer?
Size carb to run?
I dont want to go with the roller cams because of the $$$$
Not interested in Nitrous or turbo now. Perhaps a little shot down the road

Thanks for all your input,
Rick

Well,
Since no one replied I guess I'll just have to install a 360 in my car?
( Just Kidding !!!)

However I would still like some guidance? Unless this fall into the category of, "If I told you I have to kill you"

Thanks,
Rick

Rick,

I was waiting to see if some drag heavies replied, but I will throw in my 2 bits.

I'd say to run mid 12s on gas (I assume?), and stay under 6000, you will want about 0.600" lift and about 260-270 @ 0.050" duration. Ultradyne, Hughes, Reed or others should be able to set you up (I know those have websites with cam specs like these on them). I run a 250 @0.050" with 0.540" in my road/street Dart and with some head porting and a lighter car like yours I know my motor would do low 13s. It pulls well up to 6000, starts ripping around 32-3400, so you should go a step or two bigger.

Better than nothing, eh?

Lou

_________________
Home of Slant6-powered fun machines since 1988

Thanks Lou,
What is a rough estimate on the cost of a custom grind cam if you don't mind my asking?


Rick

Rick,
I'm doing some "homework" on this, you got a nice plan but I'm missing a piece of info.

Do you have a target compression ratio in mind? You can get 12 to 13 to 1 with a flattop piston 2.2 combo or around 10 to 1 if you go with the big dish turbo pistons and no head milling.

Compression will have a big influence on how much cam you will want to run. (mostly lift and lobe separation changes)
Cam selection is always a tough call, I have yet to find the "perfect" cam.
DD

As for the compression ratio. I would prefer to be able to run on high test pump gas so that would mean the 10 to 1 ratio. However, since for now it is going to be a race car only, if the C.R. of 12 to 1 is going to make signifacantly more horse power, then I could use to higher one.
Also, if I do decide I want to use a shot of Nitrous, wouldn't the lower C.R. be safer?

Thanks again for the info,

Rick

Rick,

If you run a big enough cam, then you will probably want the 12:1 comp, and it will probably be fine on pump gas too! I am running 11:1 with my 250 @0.050" cam on 91 octane with no pinging. The longer the duration, the more comp you want (and can tolerate). Distributor advance curve comes into play as well, of course.

I think most places will do a custom grind on your core for like $75-100, or you can buy a custom grind on a new core from Isky or Ultradyne or whoever (about $150-200). From my limited knowledge, nitrous will put more stress on a higher-comp motor, but as long as you stay away from detonation you are fine.

Lou

_________________
Home of Slant6-powered fun machines since 1988

Rick you want to build an engine that is siminalr to what Gary Bruner is building for me. So i will try to help. My engine is bored 100 thousands over with custom pistons from the Cox Bros. Custom Venoila pistons on balenced and shot peened 198 rods. We are going for 11.8 to 12.00 compresson with machine work on the head and block. The camshaft is a Ultradyne and i cannot tell you the specs. because that mean ole Bagel bomber might look. But the boys at Ultradyne can fix you up. Gary is porting and putting in the big vavles in the head, all i told Gary is i want a race head. The Clifford intake and exaust header will be port mached. The carb is going to be a Profuel 750 c.f.m. double pumper. The tourque conveter is going to be a P.T.C. 4500 stall conveter with 4.30 gears on a Richmond gear liteweight spool. Rick this is on a 2400 lb car so we hope we can go down in the 12 rear good. If any body can advise me please help because i am going to beat the Bagel out of that Bagel bomber this year. Thanks Ron Parker