PRC 255 Heads question

[H4rm0n1'c]

Dears,

I already purchased prc 255 heads with 65cc chambers

the car already cammed with LG g6x3

I have 2 questions that I need your help in

1- I already have 0.045" head gasket is it will be fine to install it and there will be no ptv clearance issue ?

2- what kind of lifters, rockers and pushrods length I have to put in ?

thanks

[christianchevell]

The correct response would be for a person to say always check your PTV clearance, many places use clay.... like playdoh, some just measure.... Use stock rockers upgrading the trunions optional, stock ls3/ls7 lifters with the same part number .... should be fine, and can be upgraded on too but should be fine..., and measure to determine the correct length with a pushrod length checker for pushrod size as its off your base circle size of your cam, and the manufacturer can recommend the most common length ...for the engine. With your lift you may want it really dialed in with the timing absolutely perfect or your eating valves.....

[Bodywerks]

What he said, and what I said in my PM to you.

[BlaqWhole]

I don't know.

[Jason 98 TA]

I expect you'll be fine but should always check. The head has just about stock p/v before your gaskets are introduced into the equation. Maybe check how much pv it has with stock heads from LG!

Jason
Texas Speed
www.texas-speed.com

[Anthony @ LG Motorsports]

Originally Posted by H4rm0n1'c

Dears,

I already purchased prc 255 heads with 65cc chambers

the car already cammed with LG g6x3

I have 2 questions that I need your help in

1- I already have 0.045" head gasket is it will be fine to install it and there will be no ptv clearance issue ?

2- what kind of lifters, rockers and pushrods length I have to put in ?

thanks

If you can do a valve drop test I can tell you if you are ok or not.

Need to bolt the head down with piston at TDC, remove a valve spring and measure the distance with the valve fully closed and again touching the piston. You need approx 0.200" clearance for it not to hit.

We have not had issues with the LS7 lifters and you should be fine with those.

Ran stock rocker arms with the trunion upgrade on all of the race cars without issues

Pushrod length you are going to have to measure.

[Jason 98 TA]

I'm confused on the math on this one Anthony.

I think the LS3 head has .138" valve drop. Add .051" for gasket -.006" for piston out of the hole & a stock motor is less than .200"

Do you know what p/v is on a stock motor? On Intake he's down a little bit because of gaskets, but on exhaust he's ahead p/v.

Jason
Texas Speed

[Bodywerks]

That sounds like a lot of clearance! Is that what is needed for the g6x3? Because I believe stock ptv on an ls3 is .075 intake and .125 exhaust. On my prc heads with 65cc chambers and stock .055 gaskets and my cam(listed in my sig) I get almost exactly stock ptv.
If a guy needs .200 for the g6x3 then you either have a very small base circle on that cam or fly cutting is needed. One of the two has to be the case, correct?

[H4rm0n1'c]

thanks guys

but really I'm totally confused with those maths