Leakdown test on Cheetah PV

[hercalmighty]

Hey guys. Sort of have a multiple part question to ask.

 

First, when doing a leakdown test on a Cheetah PV motor, do you do it with the powervalves installed or do you run the test with the block offs?

 

Second, if you do the leakdown with the powervalves installed and they leak air, will this cause an issue with melting down the motor?

 

Third, if the powervalves are leaking air and it will cause a problem, how do you fix them? (Mostly concerned with air leaking through the PV and out the jet)

 

Thanks in advance

[trickedcarbine]

Now that is a good question! I remember a guy with a 250r doing leak down tests with a little block off plate he made.

[hercalmighty]

This is why im asking this question.

So, anybody have any info on this?

[Colby]

Camatv should be giving some advice on this soon ..  hes the powervalve junkie

[camatv]

if you can  source some small plugs for the release jets in the pv's  the pv casings should all seal up and that way you can pressure it up and check the rest of the motor.

 

they need the "controled leak" to let the pressure out of the valves.  this "leak" wont cause any issues as its mostly a oli dump and a way to kinda tune the pv's also.  

 

using blockoffs if there is an excessive leak in the gasket area on the block or the tops of the valves ( common on trinity's crap design) its good to fix that.  the pressure has to be there to open the valve or the top end performance will be lost..  you can look at that as if you were using flat plates on the intakes and then install the actual intakes you are going to use the potential to have a leak at the intake can arise.  then its all kinda problems!

[hercalmighty]

Ok. Sounds good. I kind of had the idea of plugging the jet some how. I was mostly concerned with it leaking air and causing issues with the motor.

 

On a side note, what size jets would you recommend for the powervalves? I figure the smaller the jet the slower the valves open and the bigger the jet the faster. Right now it has 230's. Is that a good starting point?

[mike0chek]

what was your previous motor to the PV your building??

[hercalmighty]

My old banshee was a stock cylinder dune port 4 mil. It was ported by hjr. I had 23cc domes to get me about 160~165 psi. +6 timing. Vf3 cages. 35mm Airstrikers. The thing ran hard.

[LowlyOilBurner]

Is there an alternative replacement for the Trinty pv's? Mine leaked, I took them apart and put a thin coat of yamabond on both sides of the gaskets. It worked, but if there's something better out there, I'd be interested I suppose.

[10milmike]

Frist off WNY sucks.. lol No there is not a replacement for the PV's  unless u run block off plates. You are shit out of luck.

[LowlyOilBurner]

Lol, yeah, wny does suck a fair amount of cock.

[trickedcarbine]

There have been a few different folks who've had their hands in making new power valves. Can't remember who off the top of my head though. I don't think it was ever a major production either.

[10milmike]

I was born there, and grow up in that shit hole.

[Wildcardracing]

I do the same as Cam. I took a set of Keihin jets and tapped them. I intalled a screw in the end with some sealant and am able to seal the PV's off for leakdown that way. I much prefer doing the leakdown test as the motor will be run, rather than using a blockoff to seal it.

 

-Brandon

[hercalmighty]

Little up date. I tried doing the leak down with the pv installed. Didnt work out very well. I sealed the hell out of them and was still getting air leaks out of them. So I ended up putting the block offs in to run the test. I did take the pv back apart and resealing them but haven't tried doing another leak down with them installed.

 

Also, I havent heard any feed back on a good size jet to run in the pv. I have 230s in now.