Cam questions.

[rlaman821]

Hi everybody. 1st question: Does any body know the specs of the purple shaft 509 cam. I am making comparisons to the 484/284 that I have in another small block on my Desk Top Dyno. I bought a small block with what I think is the 509 and we are looking for a little more low end.
2nd question: One of you guys explaned this to me before. I should have wrote it down, but how do I figure the cam lift if the cam is out of the car?
Thanks in advance, Bob

[fox]

Answer to the 2nd question.
Using a mic or dial caliper, measure total hight of the lobe. Now measure the base circle. Subract the base from the lift measurement and you have cam lift.

[te.ringer]

It's been my exp.do not use the mopar engine book or there cam charts for street stock engines with cast iron exhaust manifolds and restricted carbs,so what is your engine set up?

[rlaman821]

We are running a stock 360 crank with 11/1 cast pistons and Summitt headers. I think the cam is the 509 purple shaft. At least it sounds like other 509s I've heard. Also a 750 Holley. Using it for the 8th mile drags with a manual 727 and 456 rear. Slicks are 9.5 and the car is a '71 scamp.
Oh, we are using a dual plane also. Had a single when we bought the car but the dual helped with the launch. Heads are iron with 1.88s that we cleaned up as best we could. Best time so far is 7.8 @ 86 mph.

[rlaman821]

Fox, thanks for the cam info...

[DartGT66]

292 an 284 mopar cams have a similar nature, they are "hot" hydraulic cams with a tight lobe separation angle and a big overlap. The 280/.474" cam is way smaller in practice, and if you really like to make a difference, i would use that one. Except, that I would use a more modern grind like comp cams XE 275.

[te.ringer]

looking at your spects every thing looks good ,if your too rich on the carb or weak on the ign. /timming in will make the bottom end flat (too rich of a carb at lower rpms)
but a cam with a tight lobe center with shorter dur. will help as dartgt66 said.I also used that cam in a stock car with 14/1 comp 360 x cylinderheads 202/160 valves with no porting.and it was to big .on a 3/8 mile track/7200rpms.

[rlaman821]

These are some interesting ideas. I was unaware that a fat carb would hold you back down low. I will need to look at that. And the Comp xe cam is new to me. I will check that also. We are running the timing @ 36 using the mopar silver box for now. Seems to be ok but a hotter coil may be in the works. Thanks for the info guys. I will keep you posted of future results and time slips.

[rapidtransitnj]

Originally Posted by rlaman821

Hi everybody. 1st question: Does any body know the specs of the purple shaft 509 cam. I am making comparisons to the 484/284 that I have in another small block on my Desk Top Dyno. I bought a small block with what I think is the 509 and we are looking for a little more low end.
2nd question: One of you guys explaned this to me before. I should have wrote it down, but how do I figure the cam lift if the cam is out of the car?
Thanks in advance, Bob

multiply the lobe lift x the rocker ratio

[Mopard]

Dont mean to hijack the thread here, but since we are on the subject about cams, i have a quick question. What would be the best set up for a Lunati Bracket Master II Cam & Lifter Kit
Advertised Duration: 292°/292°
Gross Lift: .480''/.480''
lobe seperation 109