2.4 cams. shims for the lifter.

[srt4special]

when using a reground cam the lifter has to be shimmed. anyone done this.

[pobort]

Quote:

Originally Posted by srt4special when using a reground cam the lifter has to be shimmed. anyone done this.

when you grind a cam to create more lift, you have to make the base circle smaller. this inturn effects lash. so to make up for the base circle being smaller, you need to raise the follower. what i do is use longer valves so the tip is higher. (lash caps do the same thing). there's quite a bit of geometry considerations to take into account. just throwing some washers under the lash adjusters, can cause the follower to spit out at high rpm due to the more severe angle being put on the follower. it kinda hard for me to explain this but here's some links to kinda address it.


http://www.cranecams.com/pdf/273wc.pdf

[srt4special]

thanks. i have custom cams. not taking the head off. installed new springs. measured the preload of the stock srt4 cam at the lifter end of the follower. used a dial indicator. got .006 preload. i set the cam in. set the indicator to 0 and then tightened the cam down.

[srt4special]

Going to install cam today. Use shim on the two intake followers. Will use dial indicator to check preload. Think it should be .020. Any thoughts out there.

[srt4special]

installed .042 shims. measured preload. cam in place. set dial indicator and waited for lifter to set. unloaded cam. .016 preload. goiing to install cams. anyone had any trouble with this level of preload or have any thoughts on proload. thanks

[john doe]

Did you take into account that the lash adjuster are hydraulic and require oil pressure to be at the correct running height? I have heard that when guys degree their cams in a DOHC they fab up some solid lifters to use.

[srt4special]

Thanks. Have a solid lifter for center line and degree install. Looking for thoughts on preload of the lifters when installed and some known starting points for advance retard of cams. Using adjustable gears.

[pobort]

I haven't done this exact engine, but on other overhead cam follower type heads, what I was looking for when it came to preload on the lifter is I would collapse the lifter and see how much lash I would have between the follower and the cam base circle. I would like to see .030" clearance. be aware that if you shim the lash adjuster, you raise the back of the follower which increases angle on the follower when the valve is open. when i used reground cams, lift is increased by reducing base circle... this causes clearance between follower and cam (lash), to properly correct this and have correct follower geometery, I needed to use a longer valve and shim the lash adjuster. basically i was raising the follower the same amount on both ends.

[srt4special]

thanks for the info. was trying not to take the head off at this time. so shimming the lifter was the opp.