geezel

I recently installed a TPIS cam, springs and lifters in my '86. I previously had installed Crane Gold roller rockers. The first time out, there was some valve train clatter that wasn't present prior to the cam change. I readjusted the valves, too tight I think, the clatter was nearly gone but she ran like crap. Readjusted valves again, real careful this time, clatter is back but runs great. No clatter upon start-up, gets louder as car warms up. I'm adjusting to zero lash plus one full turn, without engine running. Should I be concerned? Anything I should do?

CAJUN C4

If you run a Roller Cam & Self-Alligning Roller Rockers your gonna get a slight metallic sound.It's normal..And quite frankly, sounds good as well.

geezel

I run a flat tappet cam.

CAJUN C4

Are the Crane Rockers self-alligning?

geezel

Yes they are. JEG's P/N 270-11750-16. I was able to use the old guide plates.

CAJUN C4

Phil..So do I & Mine does the exact same thing.Thought it was valves needing adjustment. Everyone on this forum who runs self alligning rockers told me it's normal..and not to worry about it.Kinda sounds like a solid Roller Cam does.
Hope this helps.

Dennis

geezel

O.K. I won't worry. It just seemed a little wierd that the roller rockers made no noise with stock cam & lifters but noisy with new cam & lifters.
Thanks

autotech

I have the same thing with roller lifters, (stock setup), with a mild comp cam and stock stamped rockers. I cant get rid of it, but the car runs great. If you figure it out, let me know... :thumbs:

CFI-EFI

Chevy has three methods of retaining rocker to valve stem alignment. Self-aligning rocker arms, push rod guide holes in the head casting, and stamped steel guide plates. Although many people employ multiple alignment methods, It is reccommended that only one be used to prevent one fighting the other and binding up.

I find that the most accurate way to adjust the valves, and allow you to really tell where you've ended up, is to do it with the engine running. Running, there is no question on when zero lash is reached. Also, personally, I feel that one turn down is a little tight, but it IS the spec. Good luck, and...

RACE ON!!!


[EDIT] In response to the question, "are they self aligning rockers?", you answered, "Yes they are. JEG's P/N 270-11750-16. I was able to use the old guide plates." After I posted this, I went to Jegs website and checked out the part number you gave. That part number is for NON-self aligning rockers. Therefore, my caution, above, concerning two or more methods of maintaining alignment doesn't apply here.

Further checking tells me that the iron headed L98s have press in rocker studs and no guide plates. With the iron heads, the rocker alignment is controlled by the guide hole cast into the heads. The aluminum heads use guide plates. If you have the stock, iron heads, you may still be employing multiple alignment methods. With aluminum, you should be fine.


[Modified by CFI-EFI, 6:16 PM 11/12/2003]

autotech

I have an 88 with the same problem. I have aluminum heads. Is the supposed to pushrod guide plates in there, because I don't have em?

CFI-EFI

If you have self-aligning rocker arms, you should NOT use guide plates. I presume that you MUST have self-aligning rockers, because you would be having bigger problems than just a little noise, with no alignment device. Good luck, and...

RACE ON!!!

geezel

I'm still confused.. Do I have self-aligning rockers or not? When I ordered rockers from JEG's and told them I had an 1986L with aluminum heads and guide plates, which I do, they told me to use P/N 270-10750-16. The description of this series rockers in the JEG's catalog claims them to be "The only aluminum rocker available for GM self-aligning". Like I said before, with the stock cam and new rockers, no noise. When I added the TPIS cam P/N 700-135, I've got clatter. Do you think I've got a problem?

scorp508

I put that 270-10750-16 P/N into summit and it didn't come back with anything. Is that the right number?

geezel

It's a JEG's part number. Do they have their own numbering system?

scorp508

Yes, sorry I don't know why I tried Summit.

scorp508

Ok I just looked them up and it sure looks like you need to get a set of hardened pushrods and guideplates for them. I don't see any alignment tabs on this thing....


http://www.jegs.com/cgi-bin/ncommerc...64&prmenbr=361

270-10750-16
1.50 Ratio; 3/8''
Stud; LT-1 & LT-4
Non-Self Aligning

Stock 1.50 ratio with a standard 3/8'' stud diameter. These are narrow body rocker arms for centerbolt valve cover heads. These are sold as a set of 16.

Applications:

Chevy V8 305-350 LT-1, LT-4 1988-95
Chevy 90° V6 4.3L 1987-91

Note: 1988 and later engines equipped with self aligning rocker arms require the installation of pushrod guidplates and appropriate heat treated pushrods in order for these rocker arms to function properly. Valve clearance must also be checked in late model applications.

geezel

I just confirmed w / JEG's these lifters are not self-guided so I should be good with my present set-up. Right?

scorp508

I just went through this whole thread again and noticed some major things.

1) 1 full turn is far too much for roller rockers. Try more like 1/4 to 1/2 turn after 0 lash.

2) The plates that came on the aluminum heads from the factory were for assembly purposes to hold the pushrods in place when the rockers were bolted on. They are not true guide plates.

I would suggest picking up some hardened pushrods and guideplates and installing them along with going less of a turn on the rockers. The pushrods should run around $35 and the plates about $25.

geezel

Somewhere along the line, I thought I had learned these were true guide plates as evidenced by the extremely tight clearance between push rods & plates. Hardened push rods were used with guide plates. I think I was told this when researching the purchase of the roller rockers. Are you sure I don't have true guide plates and hardened push rods?