Always something - valve spring retainers

[five7kid]

I put Comp 924 springs on the 396 heads when I ported them 4 years ago. Well, the engine builder put them on when he went through the heads after I ported them. We just reused the stock retainers - I didn't much like the look of them because they didn't completely cover the springs, but the builder thought they were okay.

Last year I put in the XS282S solid lifter cam, which is supposed to have a 2400-6800 RPM power band. They recommend the 924 springs for this cam. However, I shift at 6200 because it really falls off above that. I'm wondering if the valves are floating because of the retainers - everything else on the engine should support 6800 RPM - so I picked up some Comp 741 retainers, which is what their on-line catalog says to use with the 924 springs.

I finally got out to the garage last night to start the change process, and realized when checking the installed height that I need different keepers - for some reason that "10 degree" thing went right over my head.

So, now I've got the new 10 degree keepers. I hope that's the end of the "surprises" for this little project.

Would really like to go beehive, but that's a $300 or so proposition. And Pro Magnum rockers, $300. Retrofit roller, $mega. . .

[five7kid]

Well, there is something else.

It would appear it wasn't the retainers causing problems, but the spring shims were cut to shreds by the springs, a piece for each inner spring. Like cutting cookies.

I'll be having a talk with the engine builder tomorrow.

[five7kid]

Well, the engine builder said, "Looks like you've had valve float."

With the new & proper retainers, and adding another .030"-worth of shim, we'll see what it does.

[MaDmaXXX]

hopefully it wont put the seat pressure over the nose! did you put lash caps on the valves to prevent mushrooming? Are you able to test seat pressure with your new .030 shims? Hopefully it wont overpower your lifters and cause some cam wear.What are your lash settings cold.what type/weight oil are you using.

[five7kid]

He checked seat pressure, I wasn't back there when he did that. He was happy with it. I did see him run the external spring & damper only (he didn't like the look of the damper in the free state), that was 130 lb at installed height. The extra .030" squeeze puts the damper in play better.

I'm not using caps, I am using Magnum roller tip rockers.

I've only checked lash hot, which is what Comp recommended. Their baseline is .016" I/E, for the altitude they recommended .016"I/.018"E.

I'm using AMSOIL 5W-30 Heavy Duty Diesel synthetic oil (also gasoline engine rated). Excellent shear protection with the zinc and phosphorous they aren't allowed to put in GF-4 oils.

I had only done one cylinder when I wrote the previous (and talked to the assembler). I've since finished one bank, and it's the intake valves that all show spring shim damage. The exhaust aren't "pristine", but not chopped up, either.

[MaDmaXXX]

hopefully all will be well. good oil! ZDDP is your friend in mechanical camshafts. good luck and run her out the back door once for me!

[five7kid]

Got it back together, took it out for some on-ramp T&T, still not good. Float at about 6400. I'm convinced now it's a geometry problem.

I used Elgin lifters when I put the cam in, the cup is down farther than the hydraulics were. This puts the rocker down more, so I need to get that rocker back up.

In the mean time, I'm lowering my shift point to 6000. Pulls fine up to that.

[MaDmaXXX]

comp makes a really nice pushrod lenghth checker.install and twist till geometry is correct then take the measurement off of the rod and order the proper lenghth rods. Are your existing rocker nuts really far down on the studs? thats an easy way to tell if the rods are too short. good luck getting it all buttoned up and proper.

[five7kid]

Without doubt they are farther down than they were with the hydraulics.

[MaDmaXXX]

is that cam a solid roller or solid mechanical? do you have clearance issues with the rocker hitting the valve retainers? if it was that far down and geometry that far off i would really be worried about rocker to retainer contact! even worse possibility of rocker rolling off valve stem and pushing on retainer. definitely wouldnt wanna twist that motor up until you get it all right.big blocks are a lot of fun but no motor likes metal in the oil!

[five7kid]

It's a solid flat-tappet set-up. There is daylight between the rocker (Comp Magnums) and retainers, but not much. No danger of the rocker pushing on the retainer.

Looks like I'm going to need some longer pushrods.