[300kwv6]

Hi Guys,

I've had a ticking noise coming from the top end of my engine for a while. I originally thought it might be lifters, so these were replaced with a brand new set.

After I had the car on the dyno, the tuner said I may not have enough pre-load on the lifters. So I took a rocker cover off and had my mate take a closer inspection, he found some marks on the roller rockers and also skuff marks on the valve reatiner.

Roller rockers are YT 1:8.1, cam 225@50, 130lb double valve springs.

Here are some photos:





Is it safe to grind some material from the underside of the rocker??? I read somewhere you need approx 0.040" clearance.

What do you guys think??

Cheers

[delcowizzid]

i see no pics bumps for pics

[immortality]

can't see pics. may ahve to pack the rockers up and use longer pushrods. what is the installed height of the springs?

[300kwv6]

Originally Posted by delcowizzid

i see no pics bumps for pics

I fixed the link, so pics are now available

Originally Posted by immortality

can't see pics. may ahve to pack the rockers up and use longer pushrods. what is the installed height of the springs?

How can lifting to rockers help? Not sure of the installed height? Is it simple as measuring it?

Thanks

[vxcalais_01]

Wouldnt raising them alter the ratio ? Yella Terra should reply to this soon.

[300kwv6]

Originally Posted by vxcalais_01

Wouldnt raising them alter the ratio ? Yella Terra should reply to this soon.

Changing the height won't alter the ratio, as this is set by the piviot point where the pushrod meets the cup in the rocker. If the point moves closer to the centre the ratio will increase and the opposite occures if its moved further out.

Your comments are appreciated.

[delcowizzid]

i wouldnt be grinding them down it would weaken them a bit allso why do the springs hang out past the retainers

[300kwv6]

Originally Posted by delcowizzid

i wouldnt be grinding them down it would weaken them a bit allso why do the springs hang out past the retainers

I had the heads built by a bloke in QLD, so not sure why they stick out beyond the retainer. They are double valve springs so thay may explain it.

[delcowizzid]

ide allmost say they retainers are the main issue being dished like that

[chargedvx6]

Looks like the springs are shimmed on the base? The cheapest solution may be to install different spring retainers that sit below the valve head and remove or reduce the spring shims . This (in theory) should help retain the desired spring install height and improve rocker to retainer clearance.

If I'm wrong and there are no shims on the springs, a different set or retainers (about 0.120" lower install height) should still be able to be used even if it adds extra spring seat pressure. That is assuming the springs have enough travel in em

[immortality]

....or raise the rockers (shims, you can get special ones just for this purpose) and use longer pushrods. your only other option is to change the retainers but that will effect the installed height and seat pressures and possibly limit your lift (coil bind). unless you change the spring/retainers for a lower installed height items.

[ScoHar]

crazy subject to come up, huh immortality

[TappetHead]

Grinding clearance in the arms will weaken the rockers.
You need ro raise the rockers up with longer pushrods and taller pedestalls or shims under them.
You can see from the photo that the scallop is deep enoungh for the spring diameter but theres not enough valve protrusion from the retainer.
I would expect the geometry will be better when you do this but if not, you can use lash caps to get it back.
After you get the geometry right I suggest rubbing the damaged part of the rocker with fine emery paper to take the sharp edges off, or get the guys at YT to buff them out.
Call YT next week and see if there are taller pedestalls available.
Cheers.
Mark.

[300kwv6]

Rang YT today to find out what my options are and it looks like the shims are the only way to go. YT don't make a longer pedistal or a thicker guide palte.

The standard pushrods are 7.950" the next size I can get is 8.000" which is 0.050" longer, so if I get shims 0.050" in thickness it might come close to solving the problem.

What do you guys think??

[immortality]

get some different thickness washers and trial fit the rockers before deciding what you need.

[VNracer34G]

Originally Posted by delcowizzid

ide allmost say they retainers are the main issue being dished like that

Just confirmed out in the shed that S1 & S2 motors have flat topped retainers level with the keepers . S1 have a double spring stock, S2 a single with a smaller diameter retainer

[taztassio]

shouldnt have used double springs. you can get a single 130lb, which is apparently good for 700".

doubles seem to cause trouble on our heads

[taztassio]

Originally Posted by 300kwv6

Rang YT today to find out what my options are and it looks like the shims are the only way to go. YT don't make a longer pedistal or a thicker guide palte.

The standard pushrods are 7.950" the next size I can get is 8.000" which is 0.050" longer, so if I get shims 0.050" in thickness it might come close to solving the problem.

What do you guys think??

u sure on that length? i thought standard push rods were 7.05" or 7.10", and the VT rods are 7.27".

ls1 are like 7.40"

[300kwv6]

Originally Posted by taztassio

u sure on that length? i thought standard push rods were 7.05" or 7.10", and the VT rods are 7.27".

ls1 are like 7.40"

Yes, Stock pushrods are definatley 7.950". The Ecotec are 7.05". The earlier Buick has a taller deck height so that the reason for the longer pushrod. Not sure of the LS1.

[300kwv6]

Originally Posted by taztassio

shouldnt have used double springs. you can get a single 130lb, which is apparently good for 700".

doubles seem to cause trouble on our heads

I had the cylinder heads assembled in QLD, so the guy there did everything. I guess he could've used single springs, but I'm working with what I have.

Longer pushrods have arrived and have put shims under the pedistal, it looks like we are in business

[taztassio]

sorry, thought it was an ecotec

[VNracer34G]

Hey so how'd you get on mate?, this thread seems to have gone cold

[na3point8]

i had ticking from my lifters 231 cam found next to no pre load fitted Trend 8" pushrods (crow are made by trend) now quiet as a mouse they were 161buks from performance wholesale. I have 1.6 roller rockers and 125LB comp cams double springs and retainers they dont have the big dish like yours do.