Sounds like some smart folks out there. Can anyone give me some advice. I have a pair of HP500's that were just pulled to do the springs. The leak down test netted over 20% on alll cylinders, one had 30% another was at 40%. Given the motors are out should I be doing the whole refresh or wait another 200 hrs. Hate to spend the cash if I don't need to . They ran fine last summer, they top out at 5050 rpm with 30" props and don't use any oil between changes. They have 270 hrs now. :confused:

if ya got em out.. might as well slap on some 14- 71's blowers :D

Sterling Performance uses Isky. Enough said?

pmary

the leakdown should have indicated WHERE the leaks were (intake, exhaust, or rings). If your leaks are in the heads, then you MUST do the heads while the motors are out. If it is the rings (which would be odd) then your motors have been run hard into detonation or stored improperly...

Does anyone know the correct replacement springs (in ISKY and COMP) for a Gen VI 454 Mag MPI? I would have a stock cam but I will be upgrading to 1.8 roller rockers.

For what it's worth, the shop manual shows:

Inner and outer spring assembled
Free length = 2.15 in
Installed ht = 1.88 in
Pressure at 1.88in = 110 lbs
Pressure at 1.34 in = 316 lbs

Stock lift is .483/.483 w/ 1.7 rockers; .512/.512 w/ 1.8 rockers.

Thanks

Traviss,
If you are going to replace the retainers, go as light as you can. Any weight you can remove from the valve side of the fulcrum is a plus especially at the lift and RPMs you plan on running.
Ric,
Ill check.
Bob

Can anyone recommend which Titanium retainers to use with the ISKY 8205-SP springs and which locks (at the standard height)? Isky's are $180 which is a little steep but if I have to, I have to...


Thanks

F

Hey Dave, it's been 5+ years since this post on springs; how did they work out? Any problems I can avoid? Thanks for your insight:drink:

We replaced those about 1.5 years ago and after 300+ hours thay had only lost 10 lbs.
I'm now running the 9005PLUS springs on my twin setup as I'm running 170 lbs. on the seat with the new high rpm Morel lifters and .670 lift.
RMBuilder can get you hooked up on all of your valve train stuff. Money well spent when considering the technical assistance he offers.
Dave

X2 for Bob, I use the Isky 8205 plus, Moral lifters.