DarkCrystal

Hi everyone,

Have installed comp cam LSR cam - 227/235 @ 0.050. 0.614 / 0.621 lift. On the card she's 109 + 4 LSA.

Have installed com cams timing set 3158KT.

She has 1 3/4 inch primary on the headers into dual 2.5 inch. No cats (legal in New Zealand).

At dot to dot I had 0.075 exhaust clearance and 0.09 intake clearance.
Advanced her 2 degrees and got 0.088 exhaust clearance and 0.066 intake clearance.
HavING spoken to a few a tuners and a lot of reading, my measurements when advanced 2 degrees will be okay as long as have good springs. I have installed comp cams duals 26926 (tool set retainers/comp seats/seals/locks).
The heads have never been off the car - stock 243's. Later down the track I'll purchase better heads to take advantage of this cam and roller rockers too as know that valve tips don't like these springs too much. The car is a weekender only. The car is actually a VZ HSV Clubsport (4 door version of your GTO) withe the LS2. She's 6 speed.
Just looking for opinions on running my PTV this close as I can't increase PTV without either changing head gaskets/fly cutting/new heads/new cam. I don't want to remove the heads though ha ha..
If this is too close, could I run a smaller cam with sam springs till I can afford less agressive springs?

Thanks
Matt

Neumonic2002

That cam should have 0 issues installed straight up in an LS2. I had the springs you chose and they are very aggressive regarding seat pressure so they will put a strain on your valves over a short period of time especially if you plan to run the car hard most of the time your out. Contact Brian Tooley Racing for a set of springs better suited for your combo and you will have a better more reliable combination.

DarkCrystal

Well after getting things right, I have found I have 0.066 exhaust clearance and 0.058 intake clearance at dot to dot. Little close for comfort that, so will pull the cam out maybe timorrow and get something smaller. Not overly keen to flycut/head gaskets etc..

Regardless of what cam I get next, will my 26926 comp duals be okay to use for a few months (weekender only) till i get less aggressive springs?

Thanks

Ragtop 99

I'm surprised that a 227 cam with 4 degrees of advance on a 109 LSA can have any issues on PTV. People run larger duration lobes with later IVC all the time on the LS2. The 4 degrees advance makes for a a pretty early IVC with that small an intake valve. I would think running it with 0 advance would give better overall balance.

I'd be ok with the dual springs for a while.

CMY SIX

I'd replace the stock lifters

DarkCrystal

Hi everyone,

Just a quick update.. I've now installed a VCM11 cam. 225/232 0.578/0.590 lift 112.5LSA. Now have 0.090 intake clearance and 0.095 exhaust clearance on check springs, so likely more with my dual springs due to deflection, and the less lift not so hard on the valve train with the comp dual springs. Finally will have this thing on the road soon.. it's been 6 weeks off the road!

DarkCrystal

Well started her his morning.. she's running!! Absolutely stoked. Just used stock ls2 pushrods for startup.. new pushrods will pick up this week and install... she was noisy for first 90 seconds while lifters pumped up, but after that she's as quiet as factory.. So dam nerve racking that first start up!! Will tune her in the next couple weeks and post my results!

DarkCrystal

Hi everyone,

Got her back from the tuner - 309rwkw (approx 420rwhp) at 6300rpm. 520nm torque at 4800rpm.. pretty happy with it!!