Hydraulic Lifter Preload Excessive?

[lewtot184]

Yes, I would estimate the open/closed pressures to be 314/141 lb, respectively - using 1.85" installed height. Looking at the Crane 99839 spring, I compute open/closed pressures to be 307/103 lb. I called Crane to chat with them, and they also recommended this spring. They indicated it would work with stock retainers and no head machining required.

If I use the Crane springs, do I need to shim them to bring up the closed pressure at all? Is 103 lb high enough?

Thanks.

last time i checked those crane springs i got [email protected]", [email protected]". springs do vary some.

 

[EngineerDoug]

Roger that - I have an adjustable pushrod checker on order to double-check my estimated length.
Rough measurements appear below:

Stock pushrod = 8.55"
Lifter preload with 0.020" head gasket = 0.110"

So if these figures are accurate - soon to be verified - I have a choice between an 8.450" and an 8.500" pushrod. Lifter preload will be either 0.060" or 0.060". Would you shoot for the low end or the high end of the preload range?

Thanks!

 

[lewtot184]

with a stock set-up i wouldn't be afraid of .110". taking .010" out of that wouldn't hurt anything for sure. i just put a stock valvetrain/camshaft in one of my 440's and believe it or not the tappets aren't quiet at .070"-.080" preload.

 

[dvw]

A couple things I see. First as long as the lifter piston doesn't bottom out in the lifter body, preload won't matter. Second, has anyone who commented on rocker scrub pattern ever done the math to see what the cage is when the shaft height is changed? I have, .060" makes a very small change in the overall scrub distance. I also agree that 105-110 on the seat is plenty. With all the flat tappet cam failures now a days I'd be leary to add too much spring pressure
Doug

 

[EngineerDoug]

Thanks for the guidance; I am returning the 911 springs today, and have the Crane 99839 springs on order. Once I get the heads mocked again I will use a checking pushrod and then I'll know where I have to go with the new pushrods.

BTW I got real tired of using my overhead valve spring compressor, so I modified it per the photo below. Now I can use a ratchet instead of turning that infernal wheel. Soo much easier - I just welded a cheap socket onto the hand wheel.

 

[khryslerkid]

They make this style too for head on valve spring removal. Spring manufacturers don't recommend scratching the spring. (The pic is Comp Cams)

This one is cheaper
http://www.jegs.com/i/Proform/778/6...176563173431&gclid=COHQxOeLvdECFQxYDQodsIMM-w

 

[nodust]

I have a 440 with shims under the rocker arm shaft, On one side the rocker hold down bolts came loose and the rocker shaft broke in 2 places. Can I run new stock rocker shafts with out shims using the original stock hdraulic lifters. Valve grind and pushrods are stock. Cam is a 284 484 Purple Shaft

 

[khryslerkid]

I have a 440 with shims under the rocker arm shaft, On one side the rocker hold down bolts came loose and the rocker shaft broke in 2 places. Can I run new stock rocker shafts with out shims using the original stock hdraulic lifters. Valve grind and pushrods are stock. Cam is a 284 484 Purple Shaft

Try it without shims and check your preload in the lifters.

 

[beanhead]

Thanks for the guidance; I am returning the 911 springs today, and have the Crane 99839 springs on order. Once I get the heads mocked again I will use a checking pushrod and then I'll know where I have to go with the new pushrods.

BTW I got real tired of using my overhead valve spring compressor, so I modified it per the photo below. Now I can use a ratchet instead of turning that infernal wheel. Soo much easier - I just welded a cheap socket onto the hand wheel.
View attachment 387068

I did this exact thing 4 years ago! I used a 1/2" drive socket and I can use a ratchet or (more often) my cordless drill with a socket adapter set on "1" for slow-rotating high-torque...works great when the head is on the car..

**Oh boy old thread got me again