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Valve pads...

Posted: Sun Aug 30, 2015 8:17 pm
by Witchboard
I tore down my engine and installed new piston rings. 3 were seized on two different pistons. Anyway, I didn't realize there were pads inside the lifters until I opened up the container I had put them in during the reassembly process. The pads have different numbers which I'm presuming means they are different thicknesses. How would I determine where the pads go after the fact? If I would have known, I would have put the lifters in order, but I thought they were all the same. I looked in the manual and didn't see anything about it.

Re: Valve pads...

Posted: Mon Aug 31, 2015 11:04 am
by willandrip
The shims are used to alter the valve clearance and there are many sizes.

The usual procedure is the bucket and the shim is bagged and tagged with location.
This makes for a much easier rebuild.

Each bucket is more than likely a different "height" and will have worn somewhat to the recess in the head.

Never mind, these things happen !

What you need to do is to reassemble the engine keeping note of shim location and size.
Keep the etched number face to the bucket so it is not worn away at a later date.
The shim size is pretty accurate.... a micrometer can be used to check if available.

When rebuilt, check the valve clearances.
There is a table in the manual.
Your going to find them all or most at least, out of spec.

Using your notes with your shim sizes and location and the spec table work out where you can swap shims to get the correct clearance.

You have to restrip the cams out and swap the shims....not the buckets though..rebuild and remeasure the clearances.
It will take a few attempts to get all the clearances correct again.
If you have stripped the valves out of the head and done work on either or the clearances were incorrect before you stripped the motor ..you will require additional shims.

Some old school shops have a shim swap programme if budget is tight.

If you have the cash ...buy an aftermarket shim kit.
They have 3x of each shim size...you will never use them all ...ever ...but it will save numerous cams in/out/measuring.swapping/remeasuring......rinse and repeat.

http://www.ebay.co.uk/itm/Hotcams-Valve ... 2a50fb33dc

As always ; do an update.

If you pull it all apart and get the valve clearances spot on at the first attempt....go straight out and buy a lottery ticket.
Send half of the money you win to me !

Re: Valve pads...

Posted: Mon Aug 31, 2015 1:18 pm
by Witchboard
Thanks. Sounds like I have quite a bit of trial and error ahead of me.

Re: Valve pads...

Posted: Tue Sep 01, 2015 7:42 am
by Evilchicken0
The valve train is a pain but it's fairly straight forward once you get the hang of it.
The thinner shims tend to go on the intake vales, they tend to stretch a bit more than the exhausts. Pay very strict attention to the cam journals and the moulded spots to get the cams to line up. Remember the assembly paste on the cams and the intake cam will slightly towards the carbs when the chain tensioner is fitted.

Re: Valve pads...

Posted: Tue Sep 01, 2015 7:50 am
by Evilchicken0
Cam journal positions

Image

Image

Re: Valve pads...

Posted: Tue Sep 01, 2015 9:46 am
by Witchboard
Thanks for the additional information. The more I have before I start, hopefully the less likelihood that I'll screw something up... well, more than I already have. ^_^

Re: Valve pads...

Posted: Tue Sep 01, 2015 10:08 am
by willandrip
Do not force the cam caps down....many have snapped them.

There is a sequence to be followed to prevent this .

Re: Valve pads...

Posted: Tue Sep 01, 2015 11:36 am
by Evilchicken0
willandrip wrote:Do not force the cam caps down....many have snapped them.

There is a sequence to be followed to prevent this .
Use a torque wrench.
It's only a low torque because you're really pushing against the valve springs, which are pushing up on the cams. Follow the manual step by step and you'll be fine

Re: Valve pads...

Posted: Wed Sep 02, 2015 5:12 pm
by Witchboard
Will do. Thanks guys.

Re: Valve pads...

Posted: Thu Sep 10, 2015 3:19 pm
by Witchboard
Took a couple of times, but I've got them all back. Thanks for the assist guys.