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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50262
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Posted: Sun Jun 27, 2010 11:50 pm Post subject: Pushrod tube o-ring replacement |
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Seven or eight years ago I picked up an entire '74 VW 412 excepting the transmission. I stripped it for all it was worth, but really never looked at the 1800 engine except to note how dirty it was. I just dumped it in my junk pile. Last fall someone came by wanting an engine but having little cash available so I hauled this one out to have a look at it. A redneck compression test of turning the engine over by hand showed it had good compression and it turned smoothly so to me it looked like it had a good chance of being good. However the guy turned it down so it went back into its pile.
Needing an engine for my own 411 while I build up the one that is in there now using one of Jake's cam kits, I decided to give this dirty old thing a try. I bought myself a gasket kit and a set of seals and have been going at it in my spare time for the last few days, scraping off grime and swapping in new seals and gaskets. I decided to take a few pictures of the procedures I use to renew the pushrod tube seals as these kinds of things just get easier with the years.
Here is a picture of how dirty this engine was:
In order to remove the pushrod tubes I fold a shop rag over so that I have six to eight layers a cloth and then use the rag to pad a 23mm open end wrench which I slip over the pushrod tube. I then use a hammer to beat on the wrench to remove the tube. It took me about 1 minute to remove the four tubes on one side. (staged picture on a now clean engine )
Most tubes I have run into including about 1/2 the ones on this engine have been damage by rocks, sticks, or past removals, so I beat a socket down through the tubes to push out any dents. (Some tubes have factory detents in them and you can not easily repair them) My 13mm deep 3/8 drive socket just barely fits inside a good tube so will force out any dents from a damaged tube.
With the tubes out I pull each lifter and have a look see. They really don't look to bad, but are worn down to where the chamfer around the face is about gone and experience tells me that cam wear will soon be accelerating if I don't do anything. What I do is regrind the chamfer with my bench grinder. I grind it at about 20-25° to the face verses the original 45ish degrees, assuming it will cut into the cam lobe less at this lower angle.
If the heads have sharp edges in the pushrod tube bores, I round those edges with a round file so that the o-ring will not be cut when the tubes are pushed back into place. On this particular head the bores had be remachined for some previous owner and were nice and rounded, so no filing was necessary.
To install the tubes I build up this set up, a stepped 1/2 drive socket that will wedge itself pretty tightly into the large ends of the tubes.
Using this tool I can typically install the tube in just a couple of seconds using a twisting motion as I push in on the tube.
Removing and reinstalling the tubes is pretty easy doing it this way. I wish I had an easy way to clean all the gunk off the engine. Lots of elbow grease seems to be required no matter what kind of stuff I spray on there.
Last edited by Wildthings on Wed Jun 30, 2010 10:36 am; edited 1 time in total |
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poptop tom Samba Member
Joined: July 27, 2004 Posts: 1607 Location: The Hoosier State
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Posted: Mon Jun 28, 2010 3:21 am Post subject: |
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Very nice! Thanks for sharing! _________________ '76 Deluxe Campmobile |
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raygreenwood Samba Member
Joined: November 24, 2008 Posts: 21474 Location: Oklahoma City
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Posted: Mon Jun 28, 2010 6:10 am Post subject: |
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I have never in my life seen chamfered lifters in a 411/412.....at least nothing like that.
Most have a .020" to .030" max 45* bevel at the edge, but not a chamfer protruding into the contact area. Ray |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50262
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Posted: Mon Jun 28, 2010 9:41 am Post subject: |
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Ray
The chamfer is what I cut into a used lifter. As you are well aware T4 lifters and cams get a very funky wear pattern with age. It has been my experience that they run and wear fairly evenly for the first 100K miles or so and then begin to really dig at each other, cutting a groove in the center of the cam lobe and dishing the lifter badly, sometimes even leaving a weird little tit in the center of the lifter. The idea of recutting a chamfer at a lesser angle is to prevent the lifter from gouging the lope so badly. Even though there was the tiniest bit of the original chamfer left, the rim where the face and chamfer meets had a very sharp burr, I hope to reduce that burr and the cutting of the lopes by recutting the chamfer. I did this to my high mileage 1800 many years ago now and it still runs well at 225K, though I haven't pulled a lifter to look at it.
Don't know much of anything about the history of this particular engine. Way dirtier than you would expect for an engine out of a passenger car, and it has obviously been seeping oil for a long time. Lots of varnish built up inside the engine, but it doesn't look like it has been too badly over heated. The valves were all set correctly when I first pulled the covers and from the crud level it was obvious the covers hadn't been off in a while.
I have hope this engine may have a lot of life left in it and will have been worth the effort to clean up and reseal. |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50262
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Posted: Wed Jun 30, 2010 10:42 am Post subject: |
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Another thing I do to make dealing with this job easier is to insert 1/4 inch diameter bolts into the holes in the rocker shafts while I have the rockers off the engine. Keeps the all the pieces of the rockers from falling a part and getting intermingled with other stuff in the parts bucket.
Here is the much cleaner engine with all the tubes installed.
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raygreenwood Samba Member
Joined: November 24, 2008 Posts: 21474 Location: Oklahoma City
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Posted: Wed Jun 30, 2010 2:27 pm Post subject: |
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Wildthings wrote: |
Ray
The chamfer is what I cut into a used lifter. As you are well aware T4 lifters and cams get a very funky wear pattern with age. It has been my experience that they run and wear fairly evenly for the first 100K miles or so and then begin to really dig at each other, cutting a groove in the center of the cam lobe and dishing the lifter badly, sometimes even leaving a weird little tit in the center of the lifter. The idea of recutting a chamfer at a lesser angle is to prevent the lifter from gouging the lope so badly. Even though there was the tiniest bit of the original chamfer left, the rim where the face and chamfer meets had a very sharp burr, I hope to reduce that burr and the cutting of the lopes by recutting the chamfer. I did this to my high mileage 1800 many years ago now and it still runs well at 225K, though I haven't pulled a lifter to look at it.
Don't know much of anything about the history of this particular engine. Way dirtier than you would expect for an engine out of a passenger car, and it has obviously been seeping oil for a long time. Lots of varnish built up inside the engine, but it doesn't look like it has been too badly over heated. The valves were all set correctly when I first pulled the covers and from the crud level it was obvious the covers hadn't been off in a while.
I have hope this engine may have a lot of life left in it and will have been worth the effort to clean up and reseal. |
Ah...yes....that chamfer would cut down on the center divot. I know exactly the ragged ....sharp edge on the lifter scenario you are speaking of.
But also what I have found....is that only "some" of the type 4's wore to leave a ragged edge on the lifters. I just don't know the rhyme or reason. They will all wear that divot in the center just due to the flat face, tapered lobe and offset contact.
But.....I have had factory engines that got the ragged lifter edge syndrome at moderate to high miles....and others that ran really high miles but never wore the ragged sharp edge on the lifters.
But what I did also find is the on those that did wear the lifter edge ragged....replacing the lifters with even new OEM's....also wore the new lifters ragged in a relative short time.
This is why a few years back when everyone...owners, builders, Jake, Webcam and others really started talking about the wear issues ...and failures with type 4 lifters.....I kind of confirmed my suspicion that here were differences in hardening and geometry over the years.
That heavy chamfer trick might very well give some added life to an engine before actually needing to tear it down, clean out the metal and put in a properly matched cam and lifters. Ray |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50262
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Posted: Wed Jun 30, 2010 9:41 pm Post subject: |
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Ceramics someday again, ceramics.
Quote: |
But what I did also find is the on those that did wear the lifter edge ragged....replacing the lifters with even new OEM's....also wore the new lifters ragged in a relative short time. |
My idea has been that keeping with the used matched lifters should cut down on this kind of rapid wear. Don't have much of a sampling to choose from with regrinding the chamfer, but I have done this to a hand full of engines over the last two decades and have had no bad reports. |
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raygreenwood Samba Member
Joined: November 24, 2008 Posts: 21474 Location: Oklahoma City
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Posted: Thu Jul 01, 2010 5:56 am Post subject: |
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I do know that my last web # 73...with Johnson lifters.....did fantastic. Not a mark or divot on it or ragged edge of lifters in 89k miles......and it all died from an oil pump nut that came loose ....but the cam is still pristine. Ray |
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GusC2it Samba Member
Joined: June 23, 2005 Posts: 1376 Location: Orlando, Florida, USA
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Posted: Thu Apr 14, 2011 8:04 pm Post subject: |
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raygreenwood wrote: |
Wildthings wrote: |
Ray
The chamfer is what I cut into a used lifter. As you are well aware T4 lifters and cams get a very funky wear pattern with age. It has been my experience that they run and wear fairly evenly for the first 100K miles or so and then begin to really dig at each other, cutting a groove in the center of the cam lobe and dishing the lifter badly, sometimes even leaving a weird little tit in the center of the lifter. The idea of recutting a chamfer at a lesser angle is to prevent the lifter from gouging the lope so badly. Even though there was the tiniest bit of the original chamfer left, the rim where the face and chamfer meets had a very sharp burr, I hope to reduce that burr and the cutting of the lopes by recutting the chamfer. I did this to my high mileage 1800 many years ago now and it still runs well at 225K, though I haven't pulled a lifter to look at it.
Don't know much of anything about the history of this particular engine. Way dirtier than you would expect for an engine out of a passenger car, and it has obviously been seeping oil for a long time. Lots of varnish built up inside the engine, but it doesn't look like it has been too badly over heated. The valves were all set correctly when I first pulled the covers and from the crud level it was obvious the covers hadn't been off in a while.
I have hope this engine may have a lot of life left in it and will have been worth the effort to clean up and reseal. |
Ah...yes....that chamfer would cut down on the center divot. I know exactly the ragged ....sharp edge on the lifter scenario you are speaking of.
But also what I have found....is that only "some" of the type 4's wore to leave a ragged edge on the lifters. I just don't know the rhyme or reason. They will all wear that divot in the center just due to the flat face, tapered lobe and offset contact.
But.....I have had factory engines that got the ragged lifter edge syndrome at moderate to high miles....and others that ran really high miles but never wore the ragged sharp edge on the lifters.
But what I did also find is the on those that did wear the lifter edge ragged....replacing the lifters with even new OEM's....also wore the new lifters ragged in a relative short time.
This is why a few years back when everyone...owners, builders, Jake, Webcam and others really started talking about the wear issues ...and failures with type 4 lifters.....I kind of confirmed my suspicion that here were differences in hardening and geometry over the years.
That heavy chamfer trick might very well give some added life to an engine before actually needing to tear it down, clean out the metal and put in a properly matched cam and lifters. Ray |
If you have access to a valve grinder, a better idea is to resurface the lifter with a slight convex surface, just like new ones. But nothing beats a new cam and lifters. _________________ 75 type 2 http://gusc1.tripod.com/1975vwtype2
Old vices have now been upgraded to bad habits.
http://www.facebook.com/pages/VW-Wild-Weekend-2011-St-Pete-Fl/197064760336111 |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50262
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Posted: Thu Apr 14, 2011 9:25 pm Post subject: |
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I think that is a yes and no answer. Doing it the way I did means the lifters are still matched to their lobe so there should be no break in wear, but you are still dealing with an "old" lifter with a slightly concave wear pattern. If you do a convex grind you will be dealing with an essentially new lifter which will have to rebreak in the cam. Which is best? Not sure, but as I can do the one at home and am sure it works I will probably stick with it for now. |
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GusC2it Samba Member
Joined: June 23, 2005 Posts: 1376 Location: Orlando, Florida, USA
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fifteenduth Samba Member
Joined: April 06, 2010 Posts: 73 Location: Ontario, Canada
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Posted: Fri Jun 03, 2011 11:00 am Post subject: push tube seals DONE!! |
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just finished doing this job using the helpful hints provided here and some from Muir. I was able to actually remove all the tubes by hand, likely due to the seals being flattened, dried out etc. I used the light pressure with vice grip as described in Muir to re-install. Oil on the seals seems important to make install easier. Not a bad job at all and I got to clean everything while it was apart and found some other leak sources too incl. oil pressure sender. Changed oil cooler seals while I was at it as well as crankcase seal at flywheel end. Did flywheel o-ring last year.
Thanks for the useful tips!! |
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Westfabulous Samba Member
Joined: January 07, 2007 Posts: 4207 Location: The tropic of Canada, dodging the giant flying moose of Surrey!
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Posted: Fri Jun 03, 2011 11:08 am Post subject: |
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Hey Wildthings, thanks for taking the time to post this tutorial. It is excellent, and I firmly believe that more follow-up and follow through on posts would benefit the entire community. I find it frustrating when I see a post of a problem that I can relate to, and suddenly it ends with no conclusion or follow through by the OP. Posts like this are so helpful. _________________ *****************
"I will gladly pay you Tuesday for a hamburger today." |
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Colonel_Mustard Samba Member
Joined: May 02, 2010 Posts: 400 Location: Newfoundland
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porschpow Samba Member
Joined: May 21, 2005 Posts: 1256 Location: Hamilton, NJ / Flanders, NJ
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Posted: Tue May 22, 2012 3:37 pm Post subject: |
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This is awesome. Pix help out sooo much! _________________ -1973 Volkswagen Bus Westy (Weekender)
1.8 liter from 1.7(original)
-2011 Subaru Outback
-1986 Honda Magna |
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relaxedryan Samba Member
Joined: August 11, 2011 Posts: 38 Location: Hawaii
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Posted: Sat Sep 29, 2012 10:36 pm Post subject: |
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Going through this process now cause of a stuck lifter.. HUGE HELP! Thank you! _________________ Chillaxin, Duct tape, Beer. |
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fleff Samba Member
Joined: November 25, 2007 Posts: 119 Location: Texas
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Posted: Tue Nov 19, 2013 7:38 am Post subject: |
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Bump.
I'm about to do this job as soon as the new seals arrive. It looks like some advocate using thread sealer and some don't. What the consensus? From the OP's pics, it doesn't look like any sealant was used.
Frank _________________ '76 VW Campmobile
'98 VW Passat
'69 Piper Comanche |
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Bleyseng Samba Member
Joined: July 03, 2005 Posts: 4752 Location: Seattle
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Posted: Tue Nov 19, 2013 7:53 am Post subject: |
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A tiny bit of Teflon sealer helps to seal the O rings better and they slip in better. The OEM method of a coating of 30wt oil works too "If" everything is brand-new. _________________ 70 Ghia Black convert-9/69 build date-stock w/133k 1600 SP-barn find now with a rebuilt tranny and engine
77 Westy 2.0L w/Ljet, Camper Special engine-95hp and with LSD!(sold)
76 Porsche 914 2.1L L20c, 120hp Djet (sold)
87 Syncro Westy Titan Red 2.1L 2 knob 100k miles |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50262
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Posted: Tue Nov 19, 2013 10:57 am Post subject: |
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fleff wrote: |
Bump.
I'm about to do this job as soon as the new seals arrive. It looks like some advocate using thread sealer and some don't. What the consensus? From the OP's pics, it doesn't look like any sealant was used.
Frank |
The one thing I do is ever so slightly bevel the bores in the heads with a round file so that one is less apt to pinch and thus risk cutting the o-ring during installation. Just file enough off to round the sharp edge on the entrance to the bore. That combined with a twisting motion as you push the tube into place seems to do the job well.
Last edited by Wildthings on Tue Nov 19, 2013 11:23 am; edited 1 time in total |
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udidwht Samba Member
Joined: March 06, 2005 Posts: 3777 Location: Seattle, WA./ HB, Ca./ Shizuoka, Japan
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Posted: Tue Nov 19, 2013 11:17 am Post subject: |
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fleff wrote: |
Bump.
I'm about to do this job as soon as the new seals arrive. It looks like some advocate using thread sealer and some don't. What the consensus? From the OP's pics, it doesn't look like any sealant was used.
Frank |
Yes on the 'Thread sealant' aka Teflon seal. _________________ 1972 Westy Hardtop/Type-4 2056cc
96mm Biral AA P/C's~7.8:1CR
Headflow Masters New AMC 42x36mm heads w/Porsche swivel adjusters
71mm Stroke
73 Web Cam w/Web solids
Dual 40mm IDF Webers - LM-2 - 47.5 idles/125 mains/190 air corr./F11 tubes/28mm Vents - Float height 10.45mm/Drop 32mm
Bosch SVDA w/Pertronix module (7.5 initial 28 total @ 3400rpm)
Bosch W8CC plugs
Pertronix Flamethrower 40K coil
S&S 4-1 w/Walker QP 17862
3 rib 002 Trans
185R14 Hankook tires |
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