Picking valve springs for my gt40p/N41 cam combo

StreetDreamsGT

New Member
Mar 6, 2003
449
0
0
New Jersey
So the last engine I built I used the crane springs and the crane 2030 cam, it seems like the crane springs aren't really available anymore... back order from summit says the earliest ship date would be June. So which springs do I use? Most people say to turn to the Trick flows but I read about there being problems with the valve stem seals on this thread over at corral GT40P heads - upgraded valve springs?? - Page 4 - Corral Forums.

It seemed like most of the guys were trying to run 1.7 rr's, would that cause the problem? I really dunno or understand the situation so I'm looking for a bit of an explanation if you guys don't mind breaking it down for me.

Also, IIRC, last time I just tossed on the valve springs without actually measuring anything (stupid I know), is there anywhere I can read up on how to properly install the valvtrain components? As far as measuring installed heights and seat pressures... like I said I'm really clueless about all of that :shrug:, but seeing how important it is I really want to learn.
 
I got springs from Thumper of orange park. I'll be running gt40p's with a n-412. specs are 590 lift/135lbs closed/360lbs open. More expensive than TFS springs but can handle more lift. No machining required.
 
I got springs from Thumper of orange park. I'll be running gt40p's with a n-412. specs are 590 lift/135lbs closed/360lbs open. More expensive than TFS springs but can handle more lift. No machining required.

Yea I read about them, I was thinking about going with them because I know Thumper would stand by his stuff... what did you have to do to install them, as far as measuring?
 
Technical Specs & Information

Ok so let me see if I understand this correctly, checking for coil bind basically means I need to measure to be sure that when the is completely open the coils of the spring aren't touching one another correct? Another important thing to check for is the clearance between the retainer and the rocker arm right? Comp cams has some good info on their site, correct me if I'm wrong with anything please let me know. The only thing I don't understand is why you would want the shortest possible installed height on all the valves...