yedister

Got a call from the guy working on the Vette. He has it on the dyno, he said that after a few pulls on the dyno that the valves are getting noisy. Sounds like that they loosen up. Is that normal? I have a Jesel Shaft Rocker setup. The shaft assembly was removed back in January to change to the bushed lifters, new length pushrods were needed, went from a 6.8 to 8.6 inch, rocker arm alignment was checked. The changed was performed by a mechanic that is a serious racer. It has no run time on the motor after he adjusted the lash and drove out of the shop.

Thanks for your assistance

A Peter C4

After breakin of new parts lash should be checked

gerardvg

Check the valve springs and rocker arm geometry, and of course make sure the rocker does not bind with the valve retainers.

Usually after a run the valve lash should be checked, what brand lifters are they? were the primed in an oil bath before fitment?
Now that she has been run i would back of the adjustment screws and do the valve lash from scratch, what lift is the camshaft and valve spring rates? I am sure a experienced engine builder would check for coil binding spring rates and lifters, rocker geometry and pushrod length to keep everything within spec. If not you could have bent pushrods or rockers...

Good luck ...

C409

..... Who made the lifters ? Bushed lifter failures are documented ... even with famous name brands ... why the switch ? .....

yedister

Please see the answer to your questions below

Comp. Cams
Duration 252/258 @ .050, .682/.682 lift on 106 Lobe center  installed 102
Lobe lift .440 / .440
Valve lash .020 / .022
Valve Springs
Comp. Cams. Part # CC998
Installed height 1.950
Open pressure 646 lbs.
Closed 194 lbs.
Valve Train
Jesel 1.55 / 1.55 Shaft Roller Rockers
There's only one way to install the rockers and lifters. Shaft rockers and lifter are the same way - fool proof.
Lifters are Jones Cam Designs
Lifters were changed because the Bushed lifters are rated for a higher spring pressure. just wanted to worry less about the stress on the lifters with all of the street driving / long distance driving I will be doing.

billschroeder5842

No worries, I believe you are good. Pop the valve cover and re-tighten. Celebrate your success with a beer(s)

cv67

If lash is on bet its just your oil getting warm and thinning some so you hear more
Shaft rockers are great they never really go out of adjustment, really adds stability. Pricy but worth it 100%
Id never run a healthy spring with studs again

edit: thats a huge change in pushrod length is that correct?

C409

..... Any oil restrictors in the lifter galleys ? .....

yedister

# 7 intake and # 8 Exhaust needed adjustment. No other problems found with valve train
yes the engine has oil restrictors, it also has oil spray bar in the valve cover. Removed, smoothed out and enlarged a little bit the oil drain back path to the pan from the valley area in the rear of the block.

The oil pressure wasn't was it used to be, found that the mechanic used 10w40 instead of 20w50 like i told him.

yedister

I was shocked at the difference between them. First though was they sent me the wrong one because of the height. Found out the link bar location is the important thing. used the Jesel pushrod length tool to determine the length

C409

..... The lifters on the left (originals ?) have quite a bit of pushrod offset built into them and the roller wheels look a LOT bigger in diameter ... cannot tell if there is any offset on the ones to the right ... that could cause some geometry issues ... I'm told that the solid bushing lifters need more oil than the needle roller bearings ... you might need to remove the restrictors .....

yedister

The new one lifter have 180 offset. thsts wshat the Brodix -12 heads recommend. Back in 2002, I could only get 150 for the tsller lifter bore.

yedister

I will check about the bushed lifters oiling issue,thanks for the heads up

cv67

x2 those look way different, pull those restrictors out of there if its a st engine

yedister

Why would I pull the restrictors out? Here is an example where my restrictors are located, they don't keep oil from getting to the lifters or springs. Also the valve covers were built with spray bar. This is an example of my setup, I have a taller lifter bore block,

C409

..... Those are not restrictors , they are drain back stands to keep valley oil from raining down onto the cam and getting into the rotating assembly (windage) ... Lifter galley restrictors screw into the end(s) of the block's lifter oil passages to limit the amount of oil flowing to the lifters and ultimately to the rest of the valvetrain ... it is very common with aftermarket blocks to have restrictors in order to facilitate the priority main oiling feature that they promote ... whose block are you running ?

yedister

It a Chevy Bow Tie sportsman racing block from Scoggins-Dickey

C409

..... Just a side note ... a universal FYI so to speak ... roller lifters should be installed with oil only as a lubricant ... no assembly lube on the rollers (its OK on the lifter body) ... this goes for cam lobes also ... you can slather the high pressure lubes all you want on the cam journals just not on the lobes ... the roller wheels need to turn , and not slide on the lobes or they might score or flat spot ... Also , whenever possible with high pressure valve springs , break-in should be done with only the outer valve springs installed to limit the amount of spring pressure seen by the rotating cam and lifters until the surfaces have had an opportunity to "mate" and develop a wear pattern ... valve lash should be re-adjusted with the engine hot ... then measure the cold lash after cool down for future reference for your next cold adjustment .....

C409

..... Good luck with your build ! From the specs , it should be pretty stout ! What kind of numbers did the dyno session produce ? .....

cardo0

Well even with expensive valve train parts like shaft rockers you still need to verify enough clearance of the rocker arm to the valve spring retainer, the rocker arm on the stud and the p-rod in the guide plate. I dont know how many owners overlook this because they expect quality name brand parts to all fit and it's tedious enough to take a full days work to get it right. I read you verified p-rod length and valve tip pattern but the work doesn't stop there.

I hate to bear bad news but high valve lift and high pressure springs have a greatly reduced spring life. Yes even the good stuff. IMHO I wouldn't expect 30K mi life on your valve springs let alone 50K mi. I suggest you buy a valve spring pressure tester as some can even measure spring pressure while spring on the head.

Good luck please give us feedback on what you find.