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Cal-look/High Performance => Technical stuff => Topic started by: Iryanu on May 10, 2017, 15:47:38 pm



Title: Bent Push Rod?
Post by: Iryanu on May 10, 2017, 15:47:38 pm
Ive been hearing a ticking now and then from about 1500rpm-2000rpm. It might be there higher up the rev range but it gets drowned out.

I had a strange experience last year setting my valve/rocker clearances. On cylinder 4 inlet pushrod I set it to loose zero as usual. And when I went to spin the pushrod it got tight then loose as I span it.

Thought it was odd, so took the rocker shafts off and checked the pushrod. In retrospect I should have checked it more intensively, it seemed fine though I did roll it along the work bench looked fine.

Put it all back. Adjusted up and left it. Fast forward this year and the ticking is here. Going to pull it apart again. Maybe swap the pushrod from inlet on number 3 to see if the problem moves with the pushrod. I'll check it properly for straightness first.

Manton pushrods by the way. Chromoly.

Am I barking up the right tree here? Is there another possibility other than a bent pushrod. And will I be able to straighten it myself. Can't buy singles. And a whole set is £100!

Cheers

Ryan


Title: Re: Bent Push Road?
Post by: richie on May 10, 2017, 16:55:48 pm
Yes good chance it is bent, also look at adjuster screw cup if its that type, might be worn funky

If you are stuck I might have some singles if they are 0.058 wall thick


Title: Re: Bent Push Road?
Post by: Rocket Ron on May 10, 2017, 17:24:44 pm
Hi I have single pushrod if you want

I bought a set minus one rod a while back. Lucky I did as I had a bent rod myself

Let me know if I can help

Ron


Title: Re: Bent Push Road?
Post by: Iryanu on May 10, 2017, 18:10:45 pm
That's what I'm talkin' about! VW dudes pulling together!

Thanks for that guys, I'll whip the rockers off over the weekend and see what I can see. I'll check the pushrod cup. The adjusters are the ball footed type. It's deffo something on the pushrod side of things. I was worrying it could be a lifter, have cb lightweight lifters which I know did have a bad batch moons ago.

Will keep you updated, with pictures of my findings.

All signs point to no on the "straightening attempt" then? Guess it will be a lesson in futility getting it to spin true, was going to get it in a 4 jaw with a DTI as a last resort, I just cannot stomach buying a set of 8, my moneys getting gobbled up by my 2 wheeled pursuits right now.

Ron, Richie, they are the 0.058 wall rods, got them from stateside. Will obviously pay for the going rate of the set divided by 8 plus postage, and a drink for the hassle of it all.

Ron, how did you bend yours out of curiosity?

Ryan


Title: Re: Bent Push Road?
Post by: Felix/DFL on May 10, 2017, 18:36:12 pm
Also check side play of the rocker, much sideplay even makes noise an give you variable valve lash.
Greetz


Title: Re: Bent Push Road?
Post by: Rocket Ron on May 10, 2017, 19:07:51 pm
That's what I'm talkin' about! VW dudes pulling together!

Thanks for that guys, I'll whip the rockers off over the weekend and see what I can see. I'll check the pushrod cup. The adjusters are the ball footed type. It's deffo something on the pushrod side of things. I was worrying it could be a lifter, have cb lightweight lifters which I know did have a bad batch moons ago.

Will keep you updated, with pictures of my findings.

All signs point to no on the "straightening attempt" then? Guess it will be a lesson in futility getting it to spin true, was going to get it in a 4 jaw with a DTI as a last resort, I just cannot stomach buying a set of 8, my moneys getting gobbled up by my 2 wheeled pursuits right now.

Ron, Richie, they are the 0.058 wall rods, got them from stateside. Will obviously pay for the going rate of the set divided by 8 plus postage, and a drink for the hassle of it all.

Ron, how did you bend yours out of curiosity?

Ryan

Sorry didn't see Richie had offered. Don't want to step on anyone's toes

My aren't manton


Title: Re: Bent Push Road?
Post by: richie on May 10, 2017, 19:29:39 pm
We are mid move and I don't know where anything is so please help if needed, saves me searching ;D


Title: Re: Bent Push Road?
Post by: Rocket Ron on May 10, 2017, 19:35:21 pm
Do have some others that are manton but are used so will need to know a length but unsure of wall thickness will have to look back on my records

Happy to help


Title: Re: Bent Push Road?
Post by: Iryanu on May 12, 2017, 17:50:34 pm
Well, was all a bit weird. Had the rockers all off. Checked the pushrod, if it's bent then it is very very slight. Here is a video (with slow mo) of rolling it on glass:

https://goo.gl/photos/mbUeRUJ7HEqh5Q3e9

Swapped inlet rods 3+4 after checking lengths were the same.

Bolted it all back up, set clearances and it's all fine, no binding. Will run it up tomorrow and see if the ticking starts again, and check them cold again Sunday for the binding problem.

Utterly bamboozled.  ??? Does it look bent in the video?


Title: Re: Bent Push Road?
Post by: richie on May 12, 2017, 18:26:39 pm
Looks ok to me