When to change valve springs?

[BullF-16]

Motor heads, need some good info.

I have just over 13k on these springs. HKE (Erik Koenig) hand built the motor. Mast BlackLabel LS7 305 heads, 6 bolt with Manley Nextec springs custom spec'd by HKE.

Not a 1320' warrior just a street car that has been way overbuilt. I have tapped the limiter at 7k a few times since traction is an issue.

Cam is a PatG spec .675" intake .652" exhaust with fairly aggressive lobes but not crazy.

So, when should these things be changed out. I have it on the schedule for Jan and HKE will send me new springs.

My question is.....is this too early, too late, or just about right.

I drive the car pretty aggressively on the back farm roads here in North Texas on the way to work a couple days a week.

Dont want to drop a valve on my coated Wisecos!!!!!!

[1FASTZ]

Has HKE or PatG recommended a time frame to replace them?

[BullF-16]

Originally Posted by 1FASTZ

Has HKE or PatG recommended a time frame to replace them?

Talked to Erik last night. He says they can easily go 30K based on how he installs them......he's a perfectionist.


Got a ton of money in the motor, and 3-400 bucks every 2-3 years seems reasonable.

My plan is to take the old springs to my local speed machine shop and have them see how they held up after 13k. Like i said, I have bumped the limiter numerous times. Kind of easy to do at 1000whp and above.

[DrkPhx]

That's a lot of lift so they have to be aggressive lobes. The only way to really know is to take them off to test the pressure and compare it to the original pressure rating. Most machine shops have a tester. It's pita, but a piece of mind. Maybe take off a couple to check for consistency. My .02

[BullF-16]

Originally Posted by DrkPhx

That's a lot of lift so they have to be aggressive lobes. The only way to really know is to take them off to test the pressure and compare it to the original pressure rating. Most machine shops have a tester. It's pita, but a piece of mind. Maybe take off a couple to check for consistency. My .02

Yep, this is my first foray into high performance.....at least on the ground. I plan to change all the springs in January. I will take the old springs and have them tested by a local machine shop. Though in Wichita Falls, Tx, there are not a ton of shops to do this.

The lobes from PatG were pretty agressive. As a matter of fact, Erik at HKE did not like how the beat the crap out of stuff on opening and closing and they made no more power than less agressive lobes.


Bottom line, i have not been gentle with these springs. The oil has never gone more than 2500 miles.

I dread dropping a valve into this "work of art motor" .

[cmracing]

Originally Posted by DrkPhx

That's a lot of lift so they have to be aggressive lobes. The only way to really know is to take them off to test the pressure and compare it to the original pressure rating. Most machine shops have a tester. It's pita, but a piece of mind. Maybe take off a couple to check for consistency. My .02

Do this!

I made a BIG mess in my race engine from not checking the springs. Had been running prefect, put it off for too long. Probably about $4000 mistake. Block was good, had to bore it and do new pistons. Only had 250 passes on the brand new block, glad it was still good. Heads were repaired, again, not cheap, but neither were these heads.

If you don't remove a set of springs, at least check them on the engine. I had the tools to do both, but never got around to it. Will never make that mistake again. I do bring it to 8200 every pass (drag race only) so the fault is all mine.

[DrkPhx]

If you don't race at the track I would also consider going to a different cam with less lift for better valve train durability. Once again, my 02. Make sure to check the new springs pressure and weigh them before you install them. You would be surprised at the variance even in a set. That in itself can cause problems.