valve springs

[mbruskin]

I know some people have used Isky 625/626 valve springs. They say to remove the bottom shim and retainer to get the 1.710 installed height. My machinist says that is not a good idea on an aluminum head, that it will gall into the head. The normal sources don't sell valve springs. Any opinions on the Isky valve springs? Any other good sources for valve springs?

Thanks,

Murray

 

[RootesRacer]

You want the shim on the bottom for heat transfer, springs get very hot during operation.

The easy fix is to have a deeper spring recess cut into the head.

Are the isky springs still available?

 

[mbruskin]

I talked to Isky today and the 625/626 valve springs are in stock.

Murray

 

[RootesRacer]

I talked to Isky today and the 625/626 valve springs are in stock.

Murray

I'll have to order something for my own motor as the valves readily float at 6200 RPM.

Are there any specs on those springs?

My last hipo head used crane cam springs, but the spring rate was rather high which puts too much load on the cam lobes.

 

[Tom H]

Jarrid, How do you know when the valves float? What is the indication?

Tom

 

[RootesRacer]

Jarrid, How do you know when the valves float? What is the indication?

Tom

Power hits a brick wall and sounds like there are elves banging on the valves with ball peen hammers.

When the valves are not returning due to the inertia of the valvetrain (float), the followers and cam are no longer running on each other and the follower crashes the cam further down the ramp. Sounds very ugly.

 

[Tom H]

I think I get the picture ( or sound!)

 

[RootesRacer]

In my own case, the clatter becomes louder than the induction roar, which itself is considerable.