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Who makes quality knucklehead tappets?

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framebuilder

Posts: 53

Joined: Fri Oct 14, 2005 2:21 am

Location: Australia

Post Wed Aug 01, 2012 2:59 am

Re: Who makes quality knucklehead tappets?

Hi. Thanks for all the replies and ideas.
I plan to work on the bike this weekend and will take some pictures of the holes in the lifter body tops and try and post them here.
During the last time I changed the pushrod corks, we found that the front exhaust lifter top had come loose in the body.
At first I didn't know why the top of the lifter was wobbling around when I was lowering the adjuster.
When the pushrod had been removed I pulled the lifter up as far as I could in the body to try and see what I could.
The adjusting top of the body came out in my fingers.
Since I did not know about any other problems with the Eastern lifters, I just assumed it was a fluke anomaly.
I removed the lifter block from the engine case and had a look at the lifter body.
Although the lifters were still nicely fitted in the lifter blocks, the top of the lifter had become a loose fit in the body. Also the top was not concentric with the body. If the top had vibrated around in the body, it would have jammed under the vacuum port in the side of the lifter block with some disastrous results.
I actualy know this could happen because I put it back in and gently rolled the engine over with the back wheel to back the next lifter down so i could take out the pushrod. At first I could not work out why the engine would not go through a revolution so I backed the wheel back a bit and gently came forward again and it came to a gentle solid stop. I rolled the wheel backwards and pulled the top of the lifter out and then rolled the engine through.
I cleaned up the loose lifter with acetone and used a loctight product that fills a gap of a few thousandths and lightly nipped it between the soft jaws of the vice for 24 hrs. It ran marvelous during a recent ride, but ,I am now feeling I might look for another set of lifter blocks and move to another brand of lifter. Iwill let you all know how it goes.

Regards Steve Little.
Race Frame Engineering.
Australia
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Early Iron Motorcycles

Posts: 144

Joined: Thu Feb 27, 2003 1:01 am

Location: De Soto WI.

Post Thu Aug 02, 2012 5:03 am

Re: Who makes quality knucklehead tappets?

Here's a pic. of the S&S lifters.
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amklyde

Posts: 624

Joined: Fri Dec 19, 2003 1:01 am

Location: Wisconsin, USA

Post Thu Aug 02, 2012 6:55 am

Re: Who makes quality knucklehead tappets?

It would be great if S&S would crank out a batch of .010 O/S lifters. A fair number of servicable blocks out there that just don't clean up at plus .005.
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Early Iron Motorcycles

Posts: 144

Joined: Thu Feb 27, 2003 1:01 am

Location: De Soto WI.

Post Thu Aug 02, 2012 7:49 am

Re: Who makes quality knucklehead tappets?

Hi amklyde, I'll talk to Eric and see if he can get some made up.
Mark.
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amklyde

Posts: 624

Joined: Fri Dec 19, 2003 1:01 am

Location: Wisconsin, USA

Post Fri Aug 10, 2012 11:51 am

Re: Who makes quality knucklehead tappets?

That would be great Mark. I haven't been able to log on for a while, got stuck in may of 2010 for some reason.
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framebuilder

Posts: 53

Joined: Fri Oct 14, 2005 2:21 am

Location: Australia

Post Fri Aug 10, 2012 1:22 pm

Re: Who makes quality knucklehead tappets?

I think they call that a flash back.
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amklyde

Posts: 624

Joined: Fri Dec 19, 2003 1:01 am

Location: Wisconsin, USA

Post Sat Aug 11, 2012 5:56 am

Re: Who makes quality knucklehead tappets?

Steve, You mean it wasn't the computer, it was me? Usually my flashbacks go to a time a few decades ago.
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fhsmith1

Posts: 200

Joined: Wed Jul 26, 2006 6:10 pm

Location: Georgia

Post Tue Aug 14, 2012 11:47 am

Re: Who makes quality knucklehead tappets?

framebuilder
I'd REALLY appreciate seeing some pictures of your Eastern tappets with the hole in them. I'm curious if that's what mine look like.
F
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framebuilder

Posts: 53

Joined: Fri Oct 14, 2005 2:21 am

Location: Australia

Post Sat Aug 25, 2012 7:45 pm

Re: Who makes quality knucklehead tappets?

Hi F.
I have a picture of the Eastern lifter with the hole and a original unit.
But I can't work out how to load it up from a iPad?
Anyone got a tip.
Or a tip to post a picture from a laptop will do.
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framebuilder

Posts: 53

Joined: Fri Oct 14, 2005 2:21 am

Location: Australia

Post Sun Aug 26, 2012 12:28 am

Re: Who makes quality knucklehead tappets?

After reading the FAQ,s about this site, it would seem that I haven't qualified to the level of posting a picture.
I will explain it as best I can.
If you use the S&S picture above as a guide, the adjuster is at the top, then a narrow straight shank which then has a small radius to the top of the cylinder body of the lifter.
A 1/8" hole is drilled into the corner of this radius at the bottom of the straight shank that the adjuster sits atop.
If it still confuses you, send me an email, and I will send the picture.
steve@raceframe.com.au

Steve Little
Race Frame Engineering.
Australia
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fhsmith1

Posts: 200

Joined: Wed Jul 26, 2006 6:10 pm

Location: Georgia

Post Tue Aug 28, 2012 6:05 am

Re: Who makes quality knucklehead tappets?

Steve
Thanks for the picture. Here's my attempt to post a picture.
F
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framebuilder

Posts: 53

Joined: Fri Oct 14, 2005 2:21 am

Location: Australia

Post Tue Aug 28, 2012 3:39 pm

Re: Who makes quality knucklehead tappets?

The hole is 1/8 inch. 4 holes = 1/2 inch hole to lose vacuum. I have bought a vacuum/ pressure gauge and plan to remove the tanks from the bike and start it up to measure the readings before I block the holes and then do the same thing after I block the holes. I suspect that there could also be a pressure charge coming through these holes as well.
Has anyone got a vacuum reading at the nipples on a rocker box?
Regards Steve
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fhsmith1

Posts: 200

Joined: Wed Jul 26, 2006 6:10 pm

Location: Georgia

Post Wed Aug 29, 2012 5:10 am

Re: Who makes quality knucklehead tappets?

Steve
I tried to measure vacuum but it was very minimal on a gauge. I did test it's ability to suck oil. I used a hose from 1 disconnected rocker box fitting to a small cup filled with oil sitting on the floor below the engine. At idle it sucked the cup dry in less time than I expected. Don't remember how long but seemes quickly to me.

I saw a picture of someone else on here that had a lower pushrod tube rigged with a vacuum fitting on it. Don't remember his results.

F
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Saintly

Posts: 4

Joined: Mon Aug 06, 2012 5:43 am

Post Thu Aug 30, 2012 7:32 pm

Re: Who makes quality knucklehead tappets?

I saw this thread and decided to check my tappets.
Both of my front tappets are fine (no hole).

However, my rear exhaust tappet has the small hole just like in the photo above.
Furthermore, my rear intake tappet has a hole AND a cocked top.

I know, I need to plug the hole on the rear ex. , but I'm not keen on trying epoxy.
I tried tapping threads in it and it's way too hard. It's chipping and destroying
a good Irwin/Hansen tap. Also the hole is too damn close to the edge of the
tappet body, so I'm thinking that mig weld will warp or "out of round" it.

I definitely don't want to score or ruin my tappet block. Has anyone tried soldering
the hole closed?

Also, any suggestions on where to buy just a single rear intake tappet (preferably
without a hole), I don't want to blow $300 beans on a full set of lifters if I only
need one.

Thanks
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fhsmith1

Posts: 200

Joined: Wed Jul 26, 2006 6:10 pm

Location: Georgia

Post Fri Aug 31, 2012 7:49 am

Re: Who makes quality knucklehead tappets?

Saintly
There are very small cup plugs available. Some are used in automotive carburetors. If you could get 1 fit tightly it may work.
F
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framebuilder

Posts: 53

Joined: Fri Oct 14, 2005 2:21 am

Location: Australia

Post Mon Sep 03, 2012 6:27 am

Re: Who makes quality knucklehead tappets?

[quote="Saintly"]
However, my rear exhaust tappet has the small hole just like in the photo above.
Furthermore, my rear intake tappet has a hole AND a cocked top.

I know, I need to plug the hole on the rear ex. , but I'm not keen on trying epoxy.
I tried tapping threads in it and it's way too hard. It's chipping and destroying
a good Irwin/Hansen tap. Also the hole is too damn close to the edge of the
tappet body, so I'm thinking that mig weld will warp or "out of round" it.

I definitely don't want to score or ruin my tappet block. Has anyone tried soldering
the hole closed?


Hi Saintly.
I think either lead solder or welsh plug and solder is the safest.
I believe the reason they make these in two parts is that the cylinder part of the lifter body is normalized steel so that it wears.
The adjusting cap and stem at the top is hardened.
If welding or brazing heat is applied to this top section of the lifter it will likely become normalized and soft.
The top section is fitted into the the cylinder section of the lifter by interference fit
The heat would shrink the top section when it cools, and become loose in the body....a problem they already suffer.
You go first and let me know how it goes :D
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framebuilder

Posts: 53

Joined: Fri Oct 14, 2005 2:21 am

Location: Australia

Post Tue Oct 02, 2012 3:34 am

Re: Who makes quality knucklehead tappets?

I recently fixed the leaking rocker tin problem that I have listed above.
I blocked the holes in the 2 front lifters and then rode the bike around the block.
Oil still dripped out past the front exhaust tin rocker gasket.
I then removed the rear lifter block and plugged the holes in lifters.
I rode it around the block and no leaks.
I then rode 3 hrs into Melbourne and back and not one drop of oil leaked out.
Note that I did not change the rocker tin gaskets, that had previously leaked. All I did was block the 4 holes in the lifters.
This proves without a doubt that the holes in the top of the lifters is the problem. Even 2 lifters with holes is enough to drop all vacuum away for a EL and cause oil leaks on the heads.
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Lee W

Posts: 137

Joined: Sat Sep 23, 2006 8:58 pm

Location: Carver, MN

Post Tue Oct 02, 2012 6:46 am

Re: Who makes quality knucklehead tappets?

Thanks for going to the trouble to test this. I think we all kind of assumed that to be the case, but you have provided some evidence! It is especially interesting that a vacuum leak at the rear tappets would still cause problems on the front head.
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framebuilder

Posts: 53

Joined: Fri Oct 14, 2005 2:21 am

Location: Australia

Post Wed Oct 03, 2012 4:58 pm

Re: Who makes quality knucklehead tappets?

I should mention that I did not weld the holes closed.
This brand of lifter is prone to the ( top) adjuster section coming loose from the body of the lifter.
I used of a bit of steel from a welding electrode as it measured .002 over the hole diam.
I cut a section 3/16" long and ground a lead chamfer on one end. Cleaned the hole and the dowel with acetone, then a light amount of loctite, and drove it into place with a pin punch.
.002 interference fit will hold the dowel in place, but I thought I would add loctite just to so I can say I did.
It is important that the dowel only be 3/16" long, because the bottom of the pushrod adjuster could foul on it when fully recessed into the stem when removing a pushrod.
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Saintly

Posts: 4

Joined: Mon Aug 06, 2012 5:43 am

Post Sun Nov 11, 2012 6:09 pm

Re: Who makes quality knucklehead tappets?

I also fixed my "eastern hole" recently, but I went a completely different route than frambuilder did.

I decided to plug the hole on the bottom of the tappet body where the steel is not hardened.

Photos of the hole before (with roller wheel removed):
Image
Image

I removed the tappet roller, cleaned thoroughly with mineral spirits, dried good with compressed air, and then zapped the hole closed with my mig welder.

Pic of welded shut hole:
Image

Finally, I re-installed the roller and staked the pin.

Saved the exhaust tappet, but I still need an intake tappet due to the fact that the top is cocked on the body.
Anybody got an intake tappet they want to part with?
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