ok, simple questions here. new cam and lifters. install the cam, set the lash and that`s it? i mean tighten the push rods, 1/2 turn? i hear this stuff about "pump up"? can you install right out of the box? thanks.
ok, simple questions here. new cam and lifters. install the cam, set the lash and that`s it? i mean tighten the push rods, 1/2 turn? i hear this stuff about "pump up"? can you install right out of the box? thanks.
On a typical flat tappet cam, the rocker arm is adjusted when the lifter is on the bottom (heal) of the cam lobe. It's a common practice on with new lifters to soak them overnight in a bath of motor oil completely submerged. A liberal coating of cam lube should be smeared on the bottom of the lifter as well.
When the lifter is on the bottom of the cam lobe (lots of ways to establish this... an internet search will give you these options), the rocker arm is tightened down to first "0" lash. I roll the pushrod to just the point of resistance as the nut is tightened. When you are sure it's 0 lash, then give the nut about 1/2 to 3/4 turn more.
Last edited by 55mike; 02-12-2021 at 05:50 PM.
56-210, 283, 200-4R, Power steering, Power Brakes
thank you, gentlemen! a couple more questions to follow, as i put this together.
If it’s a hydraulic flat tappet make sure you use a high zinc break in oil and keep the rpm’s up for about 20 minutes or so.
Last edited by ykf7b0; 02-20-2021 at 03:10 PM.
Jesus is my pilot!
Didn't it come with any instructions?
i like info like from you guys who have done it, that`s all. thanx
If you had a more specific question I'm sure someone could help, but otherwise to try and explain the whole correct procedure for installing a cam would take forever. There are endless sites and videos on how it's done would be the best place to start.
I don't think Dave has clarified whether he's installing a hydraulic or a 'solid' lifter camshaft, but the suggestions of using a high zinc break in oil and keeping the rpms up for 20 min is a good one regardless. I usually run 2500-3000 rpm for close to 30 minutes. The rpm has to be kept high enough that the engine runs 'smoothly.. ie. doesn't try to slow down on it's own.
The comments about 'pump up' and adjusting for zero lash and then 1/2 turn are a mixture of suggestions and a little misleading. If you're talking about 'hydraulic lifters' and 'zero lash' (you have to be talking about when the inner spring is uncompressed. Then the 1/3 or 1/4 or 1/2 turn extra is 'into the spring' which is also the same as being 'into the hydraulic pressure' while running and the oil pressure will keep the lifter seated on the cam lobe.
For solid lifters you must maintain 'clearance' (not zero lash!)... the exact clearance a solid lifter requires is a function of the cam/lifter/engine specs, and temperature (hot or cold).
Follow your cam instructions for this, and if you have a detailed question(s), then tell us WHICH cam, which engine, and what your question is...
I've have always been trying to figure out what clearance to run in my original 1970 spec LT-1 11:1 crate engine with a solid lifter cam. I have been just setting them cold at .024 on the intake, and .026 on the exhaust. It seems fine, but even though it is difficult I want to do it on a hot engine sometime. I also started using the use the EOIC method when setting valve lash, and it works on any 4 cycle engine. Doing one cylinder at a time you just rotate the engine until the exhaust valve just starts to open, and then set the lash on the intake valve. Then you rotate until the intake valve just starts to close, and adjust the exhaust valve. Simplest method I've ever tried.
Last edited by 55 Rescue Dog; 02-21-2021 at 04:03 PM.