Mind you, English is my mechanic's 2nd language. He just installed a hughes airgap, and some 1.7 adjustable roller rockers. He said he couldn't get the truck to start with the roller rockers, and in his text read,
"The valves are very compressed".

I told him to ensure he soaked them in oil prior to (he did), and not to torque them over 20 ft/lbs. He said that is not the problem.

Any thoughts on what, "the valves are very compressed" could mean, and possible resolution?


I have the following in the moter:

Pushrods: Melling MPR-462
Mopar Performance Valve Springs DCC-5249464
Mopar Performance Valve springs retainers DCC-4452032
compcam 20-744-9

 

If he put on adjustable rollers rockers and just went and torqued them down,its very possible he might have damaged a spring or worse (valve) does he know how to adjust the rockers???

 

I don't think he did that. He told me he knows how, and I believe him. He is an extremely talented mechanic, I just wanted to get some ideas of what it could be before I went by the shop tonight to talk with him.

I'm wondering if something like the pushrods need to be changed. too long/ too short, etc.

 

If they are adjustable rockers, they just need to be adjusted. If they are not, then the pushrods are likely too long.

 

I just went by his shop. He didnt know how to describe what a pushrod is. in english.
He told me the valves remain open, even when he adjusts them. (They are adjustable).

Is it possible I need shorter pushrods with adjustable rockers? And how I know how short to get?

Also, with shorter pushrods, is there still an advantage of the H.S. roller rockers over the stock?

Thanks.

 

Go here for a photo of what a pushrod looks like:

http://www.jegs.com/p/COMP-Cams/Comp...47156/10002/-1

The pushrods he has are 6.931 inches long. If he can't adjust the rockers to allow for the valves to open and close properly, he will need shorter pushrods. If the engine block was decked or the cylinder heads shaved (or both), this could likely have caused this issue. Might want to measure the length of those pushrods to ensure that the length is accurate. You possibly may have been given the wrong length pushrods in that box.

 

You need to get your truck the F out of there ASAP and take it to someone whom knows what they are doing, you have to measure for pushrods...Did Juan do that?

 

That cam has valve lift of .480" with stock 1.6 rockers... with 1.7's you're at .512" valve lift.
Will those valve springs handle that much lift?
Do you need deeper pockets or beehive springs?

 

He needs someone who knows what he is doing, but those springs are good for .525 lift.

But....Springs and valves are only part of the equation. The reason for the lift limit is generally spring retainer to valve guide interference and coil bind, Magnum heads are limited because "truck motors".

I don't know what the limits of stock Magnum heads are, first mod I did was throw em in the trash.

 

Ha ha...I missed this.

I told him to ensure he soaked them in oil prior to (he did), and not to torque them over 20 ft/lbs. He said that is not the problem.


Classic example of blind leading the blind....Sorry.