Guys in an effort to understand why revolver cams are hit or miss i went ahead and purchased 2 sets.

***************The cams where never put on a Car************

I had all 4 cams Cam Doctored to find the following
lntake centerline (ICL),
Exhaust Centerline (ECL),
Lobe Seperation Angle (LSA),
Duration @ .200 (lobe agressiveness),
Duration .050 lift
Tappet Lift @ TDC

Good thing All Cams where within .005 of advertised

Next came test 32 valve Springs.......

Here is where the problem lies

32 Springs tested...... only 12 springs where within 5 lbs of the 95 seat 225lb open pressure standard to keep the vlaves from floating....

the other 20 springs tested between 80-87 seat and 180-200 open.

I believe the Problems people are having is with a quality control problem with the Springs supplied by Revolver.

I would recomend everyone have the springs tested before they are installed to see what you are getting. Improper Spring Pressures will kill power!

 

how in the world did you happen across 2 unused sets?

 

Please keep this on topic, but i ordered along time ago and waited.
I'm now waiting on a set of Piper Drag Cams from the Dentistmapped in the UK

 

good stuff!!!

 

eeewwwhh....guess i should have tested mine before the install...nice find. DEF good info here... for you sir...

 

Nice find & documentation

IMO:

the varience between spring pressure has zero to do with a power discrepancy, unless your talking about 8k & above.

people have power down issues @ lower revs & I highly doubt that the valve is leaping off the rocker or bouncing off the seat @ lower revs with ~180 lbs of nose pressure.

in saying all that, as you noted yourself, when getting your cyl head serviced, have your cyl. head done right & all the spring to spring variences will be taken up with spring shim to set the proper full lift spring pressure.

 

Wow, I wonder what would happen if you used a different set of springs and retainers on the cams. Would be a good move for the people with bad experiences.

Want to sell the good set Noogles?

 

that was nice

 

what installed height dimension did you use?

did you just go "X" amount of lift from your installed height to establish your open seat pressure?

how much more spring compression was left before coil bind?

i am not a revolver rep or have any ties to them, but some fitting is required to get your seat & open pressures perfect, regardless of spring manufacturer.

now if your saying only 180 lbs was achievable before coil bind, then that is a problem.

 

This is good to know.
Did you report this info to them?

 

wow......good find! This needs to be brought to the attention of the manufacturer for sure!

Good luck guys!

CJ

 

Good luck with that. The manufacturer up and vanished like a fart in the wind.



Noogles, while I commend you for the test, I wonder how many people actually used the springs supplied by Revolver? If they're still "hit or miss" without that variable then what? Pd1 is the most infamous example of Revolvers not wanting to play nice. I don't remember if he used their springs in the first place. Nevertheless, solid work.

I wish you could throw some Tomei 260/270/280 Procams on the cam doctor. A little birdie told me that Revolvers, Pipers, and Tomeis share DNA...

 

Noogles, awesome job testing this out to find the problem. Springs can definitely have an effect on power. This is no suprise to me as it seems the Revolvers were a complete hit or miss.

 

Install height was set a 30.6mm
All springs where tested to 13mm coil bind at 11.4

Between 18mm and 13mm there was not much of a change, i believe the in-consistency in spring pressure through out the valve event is leading to horrible harmonics that could possibly be bleeding down the lifters.

I have no actual information to prove that other than a Degree in Mechanical Engineering

 

What is this Cam Doctor? I have a set of Revolvers that I will bet money are out of spec. Comparing my car with a similar car with Revolvers he made 50whp more than me, but I made full boost and peak TQ 1000 RPMS sooner. Same tuner. My car with Revolvers made 340TQ on a mustang dyno @ 3000 RPMS. Never seen another 2.0L EVO come close to that. Weird thing is that my power capped @ 370whp. We could run more boost, more timing, a bigger turbo, etc. and it would not make any more power on the top end. It would gain some TQ and midrange, but peak HP stayed the same.

Let me know. The Revolvers are coming out of the car as we speak and I need to have them tested before I ask for a refund (if they are bad) or sell them (if they are good).

EVOlutionary