I was wondering if this cam would fit with my stock heads....they have been milled but just for the heads being warped so im not sure how much that would be and do you gotta have the rev 921 springs on there or would a diff type of dual spring work cause I have a 918 springs on it right now.

 

definetly check the PTV clearance with your heads. you can use the PRC valvespring kit, its a great deal. you're also gonna need pushrods.

i got my PRC dual golds from terry @ racetech, you can get them from him and a few other sponsors.

 

well I got a valve spring kit with the 918s from tsp already on it and I got tsp hardened push rods so all I need to do is swap out springs and im set but how do I check the clearance?

 

do a search for piston to valve clearance, basically you just use clay with oil on it so it doesnt get stuck to the valves. then you measure the thickness of the depressed clay.

 

Just run the 918 spring it will be fine. A motor I built run's the 918 spring with this type of cam. 408 stroker 454 rear 461 ft/lbs....554 rear 709 ft/lbs on 100shot..daily driven.

 

i would not reccomend 918's on a cam with over 600 lift. they arent even rated for that.

 

Uh why risk running lift OVER what the springs are advised to handle. Its kind of silly taking short cuts when the risk is so extreme. The G5X3 clears on a 114, but 112 brings up issues. Get the PRC kit for $299 and sleep at night.

Brandon

 

still at the 1.800 installed height?

 

Yeah..maybe a little shorter. Most have no idea what that spring is capable of. Max safe lift is .655" Spring performance wise the 918 will kick the @ss of any dual spring on the market due to harmonics and the light weight of the spring. It's not a short cut it's a good decision..I guarentee it.

 

Yes strange how many people don't know this. Chalk it up to internet miss-information I guess. Bigger is not always better, and heavier is almost always a bad thing in racing.

 

how much shorter; whats it put the open and seat pressure at? i'd love to run a 918 in my setup for the light weight and harmonics but im looking for ~145 seat 380 open.

 

wow thats the first time i've seen 918's recommended for g5x3 cam.. or any cam over 600 lift.

 

Thank You...there is a higher power!

well "we"(j read between the lines) like to run our dyno sessions with the springs .050" before coil bind. These spring actually work better the closer you run them to coil bind. I think I installed those springs between 1.750"-1.775"

 

I was also wondering if 918's would go with a G5x3. I guess not, right? I guess it would be wiser to just go ahead and get the PP golds.

 

interesting.

in what instance would you recommend the 921's over the 918's?

 

You..knowing who I am... I'd probably say when it's pushing to the 250 duration mark and probably lifts over .630" I run 918's on EVERYTHING! My own motor has them and 3/8" pushrods..promag 1.75 rockers cam is well....custom

 

sorry for disagreeing with you above, im new with ls1's

great info, now i dont have to put these PRC's on my motor, ( it already has 918's) awesome.

 

hmm, depending how things look on the dyno i may have to give you a call

 

Feel free to put people in my direction and let them know that I know the facts. You know my situation.

 

ok well I guess I can run these with this cam but would there not be a slight chance the spring would collapse at high rpms? Also I still would like to know if this cam would fit with my stock heads since they were milled for warpage. Im guessing it would be an even tighter fit?