About2Bite

I know it's not required but some people have had to flycut with this cam from what I've heard. Just trying to see what the guys on here did who are running the T-Rex.

So... If you're running the T-Rex, did you flycut?

Thanks,

Josh

NHRA4MULA

iTrader: (29)

I just got a TRex cam and what Thunder Racing told me was that if the engine over revs it will hit the pistons and thats with a stock engine un milled heads ect... but if everything is stock you can run the cam with no problem just dont over rev it ... for me Im building the bottom end and going to put in a set of pistons that have been fly cut ... I tried to get a fly cutter here on LS1 but didnt have any luck ...call Thunder Racing and they will tell you all about it

DietCoke

iTrader: (18)

All this really means is the PTV is very close. Invest in a proper valvetrain with springs that can handle the extreme lobes on the TRex and you wont have much issue.

dhpewterz

iTrader: (2)

No fly cut and motor has seen 7200rpm

01wssick

iTrader: (27)

I never had to fly cut with stock bottom/heads.

BennyB

iTrader: (12)

no fly cutting here. just make sure you have the right springs for the aggressive lobes of this cam

About2Bite

What springs are you guys running?

vettenuts

iTrader: (4)

I think the question that should be asked is who measured and what was PTV. Most don't measure and have no clue how close the clearances are.

SSPerformance

iTrader: (76)

We have a T-Rex and we did not have to fly cut we have plenty of ptv clearance... What it comes down to is how the cam is installed.

Nitroused383

iTrader: (10)

My friend with a 04 GTO had a Trex in his car with a D1SC procharger. He just sold the car after he returned it to stock. Anyways, he swapped the heads and every piston had marks from the valves making contact with the piston. Unless you degree the cam and measure piston to valve clearance you have no way of knowing if you have proper clearance.

vettenuts

iTrader: (4)

What were the intake and exhaust PTV values?

SSPerformance

iTrader: (76)

I dont remember off the top off my head but it was over .100 on the intake an exhaust... the motor has turned 7500 with ZERO issues

BaddBird

iTrader: (6)

Is this with a stock short block? Never heard of that much clearance with a Trex.

KevinR

I haven't either. I didn't have much luck with my trex. Had to take it out and go a bit smaller.

SSPerformance

iTrader: (76)

bone stock long block... Like i said it all depends on how the cam is installed

studderin

iTrader: (28)

I dont have the sheet in front on me, but it was somthing like .065-.070 @ 12-13* it dose clear, has more room then some of the other big cam only cams guys run. .05x
But I think every time I've taken the heads off a good running big cam only car it had marks from the intake valve making contact at one time. The motors run fine, and for what its worth years ago when I 1st took my stock heads off, my car at 55-60K with the stock cam it had intake contact marks from over revs.

BaddBird

iTrader: (6)

I was thinking I read Thunder said somewhere around .060" with a stock long block.

SSPerformance

iTrader: (76)

well im telling u we have a hair over .100 on the intake. Like i said we have spun it to 7500 with ZERO PTV issues