F150 StrokerCobra

ok... on the PR's


here is the valve locks
http://store.summitracing.com/partde...art=CCA-611-16

retainers
http://store.summitracing.com/partde...art=CCA-740-16


are they a yes? will they work?

Joel5.0

Regarding the retainers, you need to have a shop make sure those will provide the required closed valve height for the springs specifications, if they don't, they might have to be exchanged by retainers with the correct offset.

5spd GT

Piston to valve clearance is not dictated by peak lift (rockers included) or peak lobe lift.

FivePointOhh

thats exactly what happened on my first dyno. typhoon intake, b cam, exhaust and stock valve springs. 198rwhp and after 4k rpms it just seemed to level off.

after the spring install, few more minor mods(electric fan, 73mm MAF) i was in the 230's with a nice upward slope, no flat spots.

FoxGT

I'm running an x303 on my stock pistons/springs/retainers/rockers @ 542 lift. I've been running it for probably 30k miles. I don't turn over 4600 rpm with it because I don't want this engine to see higher rpms until I can get around to replacing them.
I definitely wouldn't recommend it, i'd say get the springs to go with. It can be done though.

maroon89lsc

acually it depends on the heads you run if you have gt40 or gt40p heads you can run a cam with up to .550 a head with 2.02 valves you can run up to .500 lift just for your info so you dont tell people wrong.

Joel5.0

Negative..... GT40/GT40p heads (Explorer types) use a valve spring similar to the E7 heads, the only Gt40 heads that had better springs were the Cobra engine ones. Anything above .470" lift is a gamble however, it's not just the lift limitation, the stock springs do not have the spring rate to better control the valve train. Again, stock springs = stock cam. BTW..... total valve lift specs have nothing to do with PtV clearance issues..... with any intake valve diameter.