real simple question. Will I be ok using the same dual valve springs if I swap out for a bigger cam? (blower cam to something similar to EPP cam 232/240 .595/xxx lift 115 LSA). is there anything I need to upgrade for this swap? going into a forged 347 8.7:1 CR set-up for turbo... but it will be NA for quite a while.

 

It depends on how many miles are on them. Check the spring pressure to be safe.

 

not sure on mileage. I would assume less than 8 thousand. Precision dual springs.

current cam is a 220/224, .551/.551, 114. thinking I'm going to buy a 23x/23x, .59x/.60x, 114-115 LSA cam. I just don't know if these springs are going to be too weak or not. what's the easiest way to check the spring pressure?

and with the lower compression I wonder if I will benefit more power being NA with the bigger cam?

 

im REALLY curious about this as well! BUMP for ya

 

lets say 10,000 miles

 

Valve spring pressure testers range in price from about $80-$650. You should be able to take them to a local cylinder head shop and have them test them for you. It shouldn't cost much.

Why are you putting a low compression ratio build in your car now with out the turbo? If you don't need it for the car to move I'd just wait until you have the money to put it in there.

 

Make sure the new cam doesn't have too much over-lap with that low comp. ratio

 

I would check the spring but the PRC springs are good for .660 lift and your running a .595 and moving up to a .60X lift. I would thing you would be fine, I have the same springs on my engine and usually change them out a round 20000 mile or when i notice early valve float, I shift at 7400 rpms.

 

Holy piston speed batman! It is VERY ill advised to run that high of an rpm with a 4.1" stroke, and to top it off with Eagle rods! Man, post up pics when that baby goes KABOOM! You gotta remember that the pin end of the rod stretches with high rpm loads (such as those high piston speeds), if it stretches too much, look out!

 

Ive been running this motor for two years now with no problems at all, I build my own engines. I ve had the rotation assemble balanced to the tee. The crank and rods and pistions has been matched and the rods have ARP L19 rod bolts. Ive put over 15 grand in this engine. It had alot of wot runs with a 300 shot of nitrous. Im going to use the same rods and crank in my new 434cid. next spring. 4.100 stroke with 4.100" bore.