Im running the HKS 272 i/e cams right now..looking to upgrade to more aggresive cams when i build my motor,port head and get springs and retainers.i will most likely go with the 280s ,but from which company?ive heard great things about JUN..anyone want to chim in and let me know what would be best,running AMS 35R with built 2.0 soon.thanks in advance.

Justin

P.S. with me upgrading cams..HKS 272s will be for sale here shortly...

 

The jun 272 s have gotten great reviews

 

do a search on this topic tho, i think it has been addressed several times on this forum

 

You have to be careful when you say that you will go with 280's from X company. Cam maufacturers measure duration differently, so that one manufacturer's 260* duration camshaft may be much more agressive, or "radical", than another manufacturer's 280* offering. Thus, as a practical matter, a JUN 264 has about the same effective duration as an HKS 280* cam.

I probably got it all wrong, but I'm just trying to caution you, that you should not assume that a 280 HKS cam is gonna behave the same as a JUN 280 cam.

 

i never said a hks 280 will perform the same as jun 280s...actually jun 272 will perform better then hks 280s from what ive heard...i was just saying that with whatever company i do choose to go with out of those 3 it will most likely be 280s

 

Jun and Cosworth dont even make a 280 cam..

 

oh ok i figured they did,never really looked them up...probably gonna go with JUN 272s and springs and retainers as well when i do motor build soon

 

272- revolver has a bigger lift than jun, but either one is your best bet

 

The misinformation on this is terrible.

The cam sizes are:

Revolver Cams
Intake 262
Exhaust 264

HKS
Intake 280
Exhaust 280

JUN
Intake 272
Exhaust 272

And if you want Revolver good luck getting them.......

 

It becomes misinformation when one attempts to use solely advertised duration numbers (e.g. 280, 264, etc.) as a basis of comparison for different manufacturers' cams.

The fact of the matter is that duration @ 1mm (or 0.050") is effective duration, and is a more realistic indicator of cam behavior. In reality, the JUN 264 appears to have about the same effective duration as an HKS 280. He who ***umes that a JUN 264 behaves like an HKS 264 will find out otherwise.

Terms like "280" and "272" are almost meaningless when comparing cams from different manufacturers, and Sparky's post above is 100% correct.

 

My post was not directed at sparky. He was right on.

But when people say:I have to say something.....

 

Yes, well those are obvious blunders!

Here are relative effective duration figures for the cams in question. Note that my estimation for the JUN 264 (don't have the hard figure for that one) indicate it likely has more effective duration than HKS 280s or Revolvers.


HKS 264
Effective Duration 206 deg @ 1mm

HKS 272
Advertised Duration 214 deg @ 1mm

HKS 280
Advertised Duration 222 deg @ 1mm

Revolver
Effective Duration 222/223 deg @ 1mm

JUN 264
Effective Duration 228 deg @ 1mm (estimated)

JUN 272
Effective Duration 235 deg @ 1mm



Now, keep in mind these figures do NOT take into account lobe centerlines, which have a direct affect on power vs. rpm. With a set of cam gears however, that becomes a moot point, as one can set the lobe centerlines anywhere he likes.

They also do not take into account differences lift, which flow data indicates will have a greater effect on a properly ported head than a stock head (which is pretty much done by 10.2mm lift for both ports).

 

i needed help deciding on cams, and I went for Jun 264s based on Ted's recommendation!

 

I don't think PlayerZ was posting the "names" of the cams as a comparison of potential, but rather to inform the people who were talking about 280 Juns and 272 Revolvers and such that there is no such thing. Perhaps what he could have posted is this:

 

Please post a link to the review. I can't find them with the search

Thanks,
Maurice