Tommu Engine Re-Re-Rebuild

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Jivermo
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Re: Tommu Engine Re-Re-Rebuild

Post by Jivermo » Sat Jul 21, 2018 4:13 am

Not catching many breaks here. How come it’s nearly always the people who brag about how good they are, and who they do work for, who perform the worst. Like the “stable genius”.

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Amskeptic
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Re: Tommu Engine Re-Re-Rebuild

Post by Amskeptic » Sat Jul 21, 2018 5:54 am

Jivermo wrote:
Sat Jul 21, 2018 4:13 am
Not catching many breaks here. How come it’s nearly always the people who brag about how good they are, and who they do work for, who perform the worst. Like the “stable genius”.
It is as clear as day. Insecurity is rampant. It causes an itch. The insecure are trying to scratch their itch. Same with the perverts who always blather about your lack of morals. Then they defend the indefensible (like now with the genius).

Tommu, make sure that the edge of the gallery hole is not raised. Is there a nick in the saddle? Make sure that is not raised anywhere.
I think your engine will be very kind to you, and long-lasting as long as your attention does not flag.
Colin
BobD - 1978 Bus . . . . . . . . . . . 111,155 miles
Chloe - 1970 bus . . . . . . . . . . . 206,820 miles
Naranja - 1977 Westfalia . . . . . 108,000 miles
Pluck - 1973 Squareback . . . . . . 55,570 miles
Alexus - 1991 Lexus LS400 . . . 78,885 miles

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Re: Tommu Engine Re-Re-Rebuild

Post by Pearl76 » Sat Jul 21, 2018 9:42 am

I think this engine case will be fine with respect to the stuck brush/repair issue. I am not a VW engine expert but have some aerospace experience with lubrication in very demanding applications (>20k rpm) with high loads and very poor lubricants (jet fuel). I expect that the oil gallery entry into the bearing is opposite the high load region so some minor discrepancies in this area are not fatal. In that case the journal (shaft) does not much care about that spot. Oil flow will be determined primarily by the bearing clearance. I may not be seeing the damage as you are but what I see does not look that bad. As Colin said make sure there is no raised material and get a good, proper match on clearance of bearing housing to journal. (Note: too fine of a finish on this type of bearing can result in difficulty in maintaining a fluid film that supports the load. Generally you want to avoid an extremely fine mirror finish.)

So sorry you have run into this series of challenges but your difficulties have been a very valuable learning experience for many. I believe you are on the right track and you will have a good engine as a result. Keep up the diligent effort. In the long run things will be fine.

An additional thought: In addition to thorough cleaning as Colin outlined, if you can have the bead blasted parts that you are reusing ultrasonically cleaned that might help ensure parts are as free of media blast particles as possible. Many machine shops should be able to offer that but get a feel that they know what they are doing, don't allow parts to contact others during cleaning and are using clean solution. (avoid ultrasonic cleaning of ball bearing assemblies)

Alan

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tommu
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Re: Tommu Engine Re-Re-Rebuild

Post by tommu » Sun Jul 22, 2018 5:47 pm

Pearl76 wrote:
Sat Jul 21, 2018 9:42 am
I think this engine case will be fine with respect to the stuck brush/repair issue. I am not a VW engine expert but have some aerospace experience with lubrication in very demanding applications (>20k rpm) with high loads and very poor lubricants (jet fuel). I expect that the oil gallery entry into the bearing is opposite the high load region so some minor discrepancies in this area are not fatal. In that case the journal (shaft) does not much care about that spot. Oil flow will be determined primarily by the bearing clearance. I may not be seeing the damage as you are but what I see does not look that bad. As Colin said make sure there is no raised material and get a good, proper match on clearance of bearing housing to journal. (Note: too fine of a finish on this type of bearing can result in difficulty in maintaining a fluid film that supports the load. Generally you want to avoid an extremely fine mirror finish.)

So sorry you have run into this series of challenges but your difficulties have been a very valuable learning experience for many. I believe you are on the right track and you will have a good engine as a result. Keep up the diligent effort. In the long run things will be fine.

An additional thought: In addition to thorough cleaning as Colin outlined, if you can have the bead blasted parts that you are reusing ultrasonically cleaned that might help ensure parts are as free of media blast particles as possible. Many machine shops should be able to offer that but get a feel that they know what they are doing, don't allow parts to contact others during cleaning and are using clean solution. (avoid ultrasonic cleaning of ball bearing assemblies)

Alan
Thanks for the reassuring post. I was convinced that this build was cursed! I made the decision to not put anything back in thus engine that had been bead blasted. Those pushrods are going in a box in the attic but I do like the idea of finding a place that knows how to use an ultrasonic cleaner properly.

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tommu
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Re: Tommu Engine Re-Re-Rebuild

Post by tommu » Mon Aug 06, 2018 10:28 pm

Almost done with cleaning and collecting parts. Measured with plastigage all rods measure .002.
What I know to do now is:

1) Bolt the flywheel to the crank and check end play - without rods installed.
2) Check came gear lash and cam thrust bearing clearance
3) Install distributor drive and distributor
4) Rods on Crank
5) seal up Case and install pistons

What else should I do? Do I measure case clearances with plastigage with the case torqued together?


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SlowLane
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Re: Tommu Engine Re-Re-Rebuild

Post by SlowLane » Tue Aug 07, 2018 10:22 am

tommu wrote:
Mon Aug 06, 2018 10:28 pm
Almost done with cleaning and collecting parts. Measured with plastigage all rods measure .0002.
What I know to do now is:

1) Bolt the flywheel to the crank and check end play - without rods installed.
2) Check cam gear lash and cam thrust bearing clearance
3) Install distributor drive and distributor
4) Rods on Crank
5) seal up Case and install pistons

What else should I do? Do I measure case clearances with plastigage with the case torqued together?
1) I'm not sure if there is much value in setting end-play with the case "on a half-shell" so to speak, unless you are just doing a visual check to see how much of the end-play is actual bearing movement in the case saddle. The final end-play measurement needs to be done with the bottom end fully assembled so that you can check the play at several points in its rotation with all pertinent parts participating.

2a) If you are opting for a full-circle cam thrust bearing, read and follow Ray Greenwood's detailed advice on the topic in a recent post over on The Samba. You may have second thoughts about going for a full-circle thrust bearing after reading it.

2b) Test fit oil pump and check for adequate clearance between pump body and cam gear bolts/rivets throughout the full camshaft rotation.

5) I assume that implicit in this step are all the little details like fitting the oil pickup with a new o-ring and visually inspecting its seal, installing the little nylon guides for the case through-bolts, installing the cam-shaft end plug, applying the case sealant of your choice, etc.

One thing that I opted to do when I assembled my engine was to install the pistons into the cylinders before attaching the pistons to the con-rods, rather than fitting the pistons to the con-rods first. This allowed me to install the pistons into the top of the cylinders rather than the bottom, and I believe that this is easier on the piston rings, since they receive full circumferential support from the ring compressor as they transition into the cylinder, rather than have only partial support as they transition across the cut-out in the bottom of the cylinder.

To do this, you have to plan ahead a bit with installing piston circlips on the flywheel end of the pistons and ensuring the pistons are oriented the correct way in the cylinders. And then you need to install the cylinder/piston assemblies starting from the flywheel end (ie. cylinders 1 & 3 must be installed before cylinders 2 & 4), but if you are a puzzle-solver by nature it is quite satisfying to get this worked out.
'81 Canadian Westfalia (2.0L, manual), now Californiated

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Re: Tommu Engine Re-Re-Rebuild

Post by asiab3 » Tue Aug 07, 2018 11:29 am

Check your zeros on your rod clearance please! :pirate:

Excellent thoughts on installing the pistons top-down. I always feel uneasy when installing into the bottom chamfer. Lots of oil on the cylinder walls please! :)

Tom, do you have a snap gauge and caliper to measure the 1, 3, and 4 main bearing clearances? Absolutely plastiguage the split-shell #2 main bearing, but you'll need some fancy tools for #s 1/3/4. If not, PM me if you'll be assembling this weekend, I'll bring mine up when I head to the Pomona Swap Meet. Or just show up at the swap and look for me!

Check the distributor drive gear end play with the distributor you intend to use fully seated and bolted in. I aim for the tighter end of specified clearance to minimize timing scatter. Type 4 cases need one shim minimum, but two are fine if you require them.

Don't forget the second half of the cam bearings. Ask me about that one…

What else should you do? Wash your hands! :)

Robbie
1969 bus, "Buddy."
119k miles with me.
296k miles on Earth.

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tommu
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Re: Tommu Engine Re-Re-Rebuild

Post by tommu » Tue Aug 07, 2018 12:14 pm

SlowLane wrote:
Tue Aug 07, 2018 10:22 am
1) I'm not sure if there is much value in setting end-play with the case "on a half-shell" so to speak, unless you are just doing a visual check to see how much of the end-play is actual bearing movement in the case saddle. The final end-play measurement needs to be done with the bottom end fully assembled so that you can check the play at several points in its rotation with all pertinent parts participating.
My understanding was that the play will be between Crank and number 1 bearing is the endplay and with the case separated and rods off - I can measure it most accurately. I'll go ahead and measure in the 'half shell' and then again when fully assembled. Will be interesting to see the difference.
SlowLane wrote: 2a) If you are opting for a full-circle cam thrust bearing, read and follow Ray Greenwood's detailed advice on the topic in a recent post over on The Samba. You may have second thoughts about going for a full-circle thrust bearing after reading it.
After reading that thread I bought a double-thrust kit from the type-4 store for my initial build. I think that's an expense too far for me this time. I have a KS and Mahle single thrust set. I'll use the one with the best clearance.
SlowLane wrote: 2b) Test fit oil pump and check for adequate clearance between pump body and cam gear bolts/rivets throughout the full camshaft rotation.
Good point!
SlowLane wrote: 5) I assume that implicit in this step are all the little details like fitting the oil pickup with a new o-ring and visually inspecting its seal, installing the little nylon guides for the case through-bolts, installing the cam-shaft end plug, applying the case sealant of your choice, etc.
Absolutely, I wonder if there would be value in detailing these point by point. It cannot replace Wilson, but it would be fantastically helpful to have an itinerantly approved step by step process. What do you think Colin?
SlowLane wrote: One thing that I opted to do when I assembled my engine was to install the pistons into the cylinders before attaching the pistons to the con-rods, rather than fitting the pistons to the con-rods first. This allowed me to install the pistons into the top of the cylinders rather than the bottom, and I believe that this is easier on the piston rings, since they receive full circumferential support from the ring compressor as they transition into the cylinder, rather than have only partial support as they transition across the cut-out in the bottom of the cylinder.

To do this, you have to plan ahead a bit with installing piston circlips on the flywheel end of the pistons and ensuring the pistons are oriented the correct way in the cylinders. And then you need to install the cylinder/piston assemblies starting from the flywheel end (ie. cylinders 1 & 3 must be installed before cylinders 2 & 4), but if you are a puzzle-solver by nature it is quite satisfying to get this worked out.
Yes - followed approach this on my first build and did indeed come a cropper with number 3!

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Re: Tommu Engine Re-Re-Rebuild

Post by tommu » Tue Aug 07, 2018 12:15 pm

asiab3 wrote:
Tue Aug 07, 2018 11:29 am
Check your zeros on your rod clearance please! :pirate:
Damn those imperial measurements! Edited for posterity!
asiab3 wrote: Excellent thoughts on installing the pistons top-down. I always feel uneasy when installing into the bottom chamfer. Lots of oil on the cylinder walls please! :)
Agree, I did this first time round and will do so again..
asiab3 wrote: Tom, do you have a snap gauge and caliper to measure the 1, 3, and 4 main bearing clearances? Absolutely plastiguage the split-shell #2 main bearing, but you'll need some fancy tools for #s 1/3/4. If not, PM me if you'll be assembling this weekend, I'll bring mine up when I head to the Pomona Swap Meet. Or just show up at the swap and look for me!
I do have a snap gauge and I need to get used to using it. European Motorworks down in Hawthorne measured these when I was there and discovered that RIMCO had not. But! Had I measured myself I may not be rebuilding now. So I will measure. Pomona sounds like fun. I might see you there - if not you're welcome for to drop in for beer pit stop.
asiab3 wrote: Check the distributor drive gear end play with the distributor you intend to use fully seated and bolted in. I aim for the tighter end of specified clearance to minimize timing scatter. Type 4 cases need one shim minimum, but two are fine if you require them.
This is a Type 4 sir. Although case wear may have occurred I don't believe I can control clearance here.
asiab3 wrote: Don't forget the second half of the cam bearings. Ask me about that one…

What else should you do? Wash your hands! :)

Robbie
I have been washing washing washing. I even bought a 15L ultrasonic cleaner to help. You're welcome to try it out..

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SlowLane
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Re: Tommu Engine Re-Re-Rebuild

Post by SlowLane » Tue Aug 07, 2018 3:50 pm

Have you "notched" the big ends of your rods as per VW bulletin somethingsomethingsomething to provide oil-spray cooling to the undersides of your pistons?

Also, consider treating your cylinder walls, wrist pins, lifter bores and valve guides with Techline PKSX. It's inexpensive enough, and the application doesn't require any baking of the treated parts. You just burnish it into the metal surface.
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
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Amskeptic
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Re: Tommu Engine Re-Re-Rebuild

Post by Amskeptic » Tue Aug 07, 2018 8:09 pm

tommu wrote:
Tue Aug 07, 2018 12:14 pm
SlowLane wrote: 2b) Test fit oil pump and check for adequate clearance between pump body and cam gear bolts/rivets throughout the full camshaft rotation.
Good point!
But wait! There's more! Your minimum acceptable clearance between the pump and the camshaft bolt heads *must* include the maximum allowable camshaft thrust. If minimum clearance is .010" let's say, you need to add the full .006" endplay allowed by the factory so that you don't get unfortunate contact in the future as the thrust bearing wears.
Colin
BobD - 1978 Bus . . . . . . . . . . . 111,155 miles
Chloe - 1970 bus . . . . . . . . . . . 206,820 miles
Naranja - 1977 Westfalia . . . . . 108,000 miles
Pluck - 1973 Squareback . . . . . . 55,570 miles
Alexus - 1991 Lexus LS400 . . . 78,885 miles

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tommu
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Re: Tommu Engine Re-Re-Rebuild

Post by tommu » Tue Aug 07, 2018 10:19 pm

SlowLane wrote:
Tue Aug 07, 2018 3:50 pm
Have you "notched" the big ends of your rods as per VW bulletin somethingsomethingsomething to provide oil-spray cooling to the undersides of your pistons?

Also, consider treating your cylinder walls, wrist pins, lifter bores and valve guides with Techline PKSX. It's inexpensive enough, and the application doesn't require any baking of the treated parts. You just burnish it into the metal surface.
Yes sir. Techline looks really interesting - not heard mention of it before.

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tommu
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Re: Tommu Engine Re-Re-Rebuild

Post by tommu » Tue Aug 07, 2018 10:20 pm

Amskeptic wrote:
Tue Aug 07, 2018 8:09 pm
tommu wrote:
Tue Aug 07, 2018 12:14 pm
SlowLane wrote: 2b) Test fit oil pump and check for adequate clearance between pump body and cam gear bolts/rivets throughout the full camshaft rotation.
Good point!
But wait! There's more! Your minimum acceptable clearance between the pump and the camshaft bolt heads *must* include the maximum allowable camshaft thrust. If minimum clearance is .010" let's say, you need to add the full .006" endplay allowed by the factory so that you don't get unfortunate contact in the future as the thrust bearing wears.
Colin
I have had my cam gear countersunk and I have some nice slim bolts from webcam. Wondering whether to use the start washers or not. I think I might if clearance is good enough.

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SlowLane
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Re: Tommu Engine Re-Re-Rebuild

Post by SlowLane » Tue Aug 07, 2018 11:11 pm

tommu wrote:
Tue Aug 07, 2018 10:20 pm
I have had my cam gear countersunk and I have some nice slim bolts from webcam. Wondering whether to use the starred washers or not. I think I might if clearance is good enough.
I would recommend Nord-Lock washers instead of starred washers if you have enough clearance.

A single Nord-Lock consists of a pair of matching "ramped" washers, so it's probably unlikely that you do have enough clearance. It is an interesting technology, though, and one worth knowing about for cases where it would be applicable.
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An endplay question.

Post by tommu » Wed Aug 22, 2018 10:01 pm

My endplay is very tight. If I push the flywheel in firmly and zero my depth gauge, then gently but firmly pry the flywheel back - the dial gauge (reading from the the fan hub) just makes .003. If I push back on force by hand (no prying) I make .002.

Is a firm pry to just make .003 a dangerous place to be?

I'm using three ,24mm shims. Using a micrometer I see that two sourced from Bus Lab (Porsche branded) are accurate enough - both read .242mm shims. and one from CSP - is a more inaccurate .26mm. I'm feeling that one more expensive Bus Lab .24mm shim is the safest way to go.

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