BillK

j,
If those are the correct pressures, then the springs "rate" is 323 lbs per inch. So if you set it up at 1.780, the seat pressure should be around 150 The open pressure at .615 lift will be around 348 or so. That will also compress the spring to about 1.165" ... what is the solid hgt of the spring ?

Personally, most of the hydraulic rollers we have used like about 150 lbs seat pressure but are closer to 420 open or more. 348 is kind of low in my opinion for that cam.

I have never liked fooling around with springs, removing inners etc. Valve springs are generally designed as a package deal. All of the components of the spring have to work together to control harmonics while they keep the lifter on the camshaft lobe.

What you really need to do is ask the camshaft manufacturer what pressures the cam needs to have when run in your particular application.

As far as machining the heads goes, if they are disassembling them, machining the guides, cleaning them and putting them back together, then I would say $200 is a reasonable price. I would get the heads machined for the good seals now no matter what. Even if you dont use them, if you decide to go with a double spring, you will have no choice. For some reason the number .725" is what I want to remember for how far I cut down the guides to on the last couple of sets I did, but .600 should not hurt anything as long as it leaves enough room on the guide for a spring seat, or shims as needed.

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

BillK

J,
Something does not make any sense here ???? I just looked at the Isky catalog on line and they show that spring as only being good for .525 lift. And that is when it is set up at 1.850 It coil binds at 1.120" Which means you are dangerously close to that figure at .615 lift I wonder if the damper is starting to cave in and that is what split the seals ?

Bottom line is, if you have the heads off, now is the time to put a good set of the correct springs on them so you dont have to worry about them for a while.

....... I just looked at the Isky catalog and found the cam you are running. It definitely calls for the 8005A springs and with the 1.7 rockers. You need the double springs, period !

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

jackhammer

Thanks again Bill... this is a lot of good info I hope someone else finds useful during their own engine build. This mistake is fairly small. I was lucky enough to catch it while the engines are in my garage! but, I still have to buy 4 new head gaskets @$50/ea. Int/Exh gaskets, machine shop, and I'm getting new head bolts because I lost count how many times I torqued these... easily pissed away a grand

jackhammer

Here we go again!!

This machine shop is saying the last machine shop didn't do it right (cut for new valves) and it needs to be done again. This link shows pictures of where the valve meets the head (lap ring). This new shop is saying I should have a lap ring on the exhaust nearly as wide as the flat part on the valve to keep it cool. It's not the money, it's the aggravation of getting different opinions about everything!

They did say the open pressure was about 100lbs low and needed the inner springs (which made me feel better)

http://www.offshoreonly.com/forums/g...valve-job.html

BillK

Are these the same heads from 07' ???? Like I said at that time, the exhaust seat could stand to be a little wider and more centered on the valve. Should be about .080" wide for proper heat transfer.

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

jackhammer

Yes, unfortunately I had to put the project on hold (to build a house).

The good news is you (Bill) and Wayne Calvert do both have the same opinion on seat width. So I take it back, I was referring to Anderson Engines and Wayne Calvert Engines. I'm basically getting a second valve job without ever stabbing the engines in a boat thanks to Anderson. But I won't give up!

jackhammer

Oh, he did say the seat pressure was 'close' but the open pressure was about 100lbs light. I forgot to ask what he thought they should be and I never heard back from Isky tech support

BillK

All you need to do is go to thier web site and look at the specs for the dual springs that they call for with your camshaft. That is all you need to know.

jackhammer

They cut the seats in better so now the geometry has changed a bit. I could probably get shorter push rods, but I don't want to if it isn't absolutely necessary. What do you think?