455 Crane High Intensity Lifters Part 2
455 Crane High Intensity Lifters Part 2
Apologize for my lack of education on Part 1 by not asking a complete question. Part two, what I omitted initially was that the rockers are not adjustable but the push rods are. Could I please ask how to get the correct adjustment with adjustable push rods or be pointed to a tech manual that will explain how to do this. This engine obviously had a complete rebuild sometimes in the past before I purchased the car. Unfortunately there are no records on the rebuild nor records on who did the rebuild. The block is out of a big car now with F casting heads, W-30 intake manifold, Crane high intensity lifters, Crane Cam to emulate W-30 cam and Edelbrock Quadrajet carb. Its a 442 cloned to W-30 appearance.
Why would you start another thread for essentially the same question?
https://classicoldsmobile.com/forums...ifters-153281/
Unlike Chevy, the Olds system doesn't change rocker geometry with changes in pushrod length. Assuming that these are hydraulic lifters, adjust 'em to get reasonable preload on the lifter plunger. It's not critical--as long as you have "some" but not "too much", the engine won't know the difference.
Some guys want the lifter plunger very near the top of it's travel, so it can't "pump up" and hold the valves open.
Some guys want the lifter plunger very near the bottom of it's travel, so it can't "leak down" and lose valve lift.
GM typically put the plunger .050--075 from the top of it's travel.
WHAT DOES THE LIFTER MANUFACTURER RECOMMEND?
If this was me, I'd use one of those adjustable pushrods to find the suitable length, (testing several intakes and exhausts, front and rear, from both banks) then order a set of non-adjustable pushrods the proper length to actually run the engine with. Make sure that YOU measure the pushrod length the same way your pushrod supplier does--there's at least three different ways to measure pushrods.
https://classicoldsmobile.com/forums...ifters-153281/
Unlike Chevy, the Olds system doesn't change rocker geometry with changes in pushrod length. Assuming that these are hydraulic lifters, adjust 'em to get reasonable preload on the lifter plunger. It's not critical--as long as you have "some" but not "too much", the engine won't know the difference.
Some guys want the lifter plunger very near the top of it's travel, so it can't "pump up" and hold the valves open.
Some guys want the lifter plunger very near the bottom of it's travel, so it can't "leak down" and lose valve lift.
GM typically put the plunger .050--075 from the top of it's travel.
WHAT DOES THE LIFTER MANUFACTURER RECOMMEND?
If this was me, I'd use one of those adjustable pushrods to find the suitable length, (testing several intakes and exhausts, front and rear, from both banks) then order a set of non-adjustable pushrods the proper length to actually run the engine with. Make sure that YOU measure the pushrod length the same way your pushrod supplier does--there's at least three different ways to measure pushrods.
Last edited by Schurkey; Feb 27, 2021 at 02:03 PM.
We did talk to the Crane tech department and they were not much help They seemed to be only able to speak Chevy and not Olds not to mention adjustable pushrods. Talking about 1/2 turn to 1 1/2 turns which of course means nothing when the rockers are not adjustable. I have fully admitted that I am a computer Neanderthal in previous posts and I'm dadgummed sure I'm no wrench with vast experience to draw on. Therefore I have asked questions.
Make sure the cam is on the base circle of the lobe. Install one pushrod, install the richer and bridge, slowly tighten the bolt while spinning the pushrod between your fingers. When you start to feel resistant turning the pushrod, stop tightening the bolt, that’s zero lash
Use feeler gauges, measure the distance between the cylinder head and the rocker bridge. If it measures around .030-.050, congratulations, your done. If not, you need to do some math to figure out how much longer/shorter the pushrods need to be.
Use feeler gauges, measure the distance between the cylinder head and the rocker bridge. If it measures around .030-.050, congratulations, your done. If not, you need to do some math to figure out how much longer/shorter the pushrods need to be.
Thread
Thread Starter
Forum
Replies
Last Post



