Polo motor build for junkyard coupe 58367

[neilbardsley]

Nice work as always

[jjeffries]

So cool! So much work! Justin, you are surely one of the patron saints for these wonderful little cars. John

[JTR70]

Thanks Neil!

And thank you John! It pushes my patience alright, so much so that I have to walk away for a while to regroup. Which is why this next entry is a couple of months in the making.

Thanks again Guys!
Justin
8/11/18
Cam tower weld clean up and detail.

Time consuming job of opening and shaping all the ports and inner welds. All the non sealing and mating surfaces that don't require machine work.

Began with the die grinder to get the rough shape first. Then a paper template was made of the pristine mate and the high spots where outlined with marker. Then it was all hand filing and sand paper shaping from there.

This blob was next. Tried to get at least one aspect done a session but I got sidetracked as it slowly went.

Moved onto shaping the outer details as close as possible.


Slowly grinding and shaping out the lower fin details.

Wasn't just the port openings but also the underside the spine as seen through this hole.


This area was the most challenging and time consuming as most of it had to be done by hand all the while taking care not to bite into surrounding details around it.

Not perfect and I might chase it more later but good for now. The worst thing about all this work was that I had to do it ALL twice.

Took a while but I got them both to the point where I could drop them off with Bill to perform the required machining and hole drilling.

Another correction to make; the rocker won't slide in. Its a slip fit to begin with and we just missed it by a few thousands.

Red highlights are for Bill. You'll notice the outer shoulder for the rocker is red. Since everything on that side of the weld is what moved I figure if we get our needed clearance from over there all should work out fine in the end. We'll see when I get these back from Bill!
Thanks for looking!
Justin

[Blechquäler]

Regarding all that amazing detailwork you've already done and what's left over to do...
I think it's much easier (and faster) to build a house.

[JTR70]

Hey Gerd, Thanks!

Yes, I think I could have built a house twice over. I really have taken the very long and impractical road of building a POLO engine as I just could have run a 911 fan housing and lopped the end of the cam towers off as Dean does but I get obsessed and have to have things a certain way to ever be satisfied with it all.

As for what's left to do I am actually getting very close to being done with custom machining. I just got the block back from Bill again as he was boring the case through bolt holes to accept later 964 case through bolts and washers. Dean originally had it set up for the early style. Once I get the cam towers back the case has to go back to Bill one last time to machine it for the 964 chain boxes. All I can say is that I am crawling closer.
Justin

[roy mawbey]

Justin,

Sixty years a go I started my apprenticeship as a tool maker. My first two weeks were spent filing rough formed squares to a standard that I thought acceptable. The toolroom foreman had these ready for me from his stock of items to make me begin to realize, filing and shaping is important as back then so many jobs were manual.
Every now and then, he would turn up and inspect my work. After two weeks of this with instruction on how to use files, he then asked me to file a flat area that we would inspect. He used a vice along side me doing the same and together, we worked till I was satisfied. We then compared with a dial indicator set up on a surface plate, both his and my results.

Then I fully realized the importance of filing. His accuracy was amazing, mine was all over the place. Never ever forgotten him and I had huge respect for him till I left 5 years later on completion of my apprenticeship.

Your work with the file reminded me Justin very much of the effort required and the time involved to be happy with the result. You are doing well my friend.Your car will be that much different to anyone else's.

Roy

[Blechquäler]

about as, Roy?

[Tony G]

I am speechless Justin, I can't wait to catch up with you and the project. When you finally fire it up, you will probably be screaming like Doctor Victor Frankenstein---"It's alive, it's alive!".

[JTR70]

Thanks a lot you guys and wishing you all a Happy New Year!

With the site being down all this time some forward progress happened.


Bill had finished resurfacing for valve covers.


And the mounting face for the heads.

Redrilling for the dowel pin and bolts holes for the heads was next.

Also resurfacing the weld area on the inside for the head bolt as well.
A little closer with the final result cleaning up nice. More later and thanks for looking!
Justin

[JTR70]

Next round of machining,

Bolt and dowel holes opened up to mount the heads.
We'd have to surface the inner weld should a bit more to clear the eventual wave washers.

Edge details where also carved out as best as possible.

Top side also surfaced and ready to accept some closing tin.

Closer still but not out of the woods just yet .

Thanks for looking!
Justin

[JTR70]

Last major hurdle: Cam journal alignment

I was warned about and was expected but hope springs eternal.

After all the jigging and large centering dowel I thought we might get away with just a quick hone. ...but no The reattached end's journal was about a thousandth out to one side from the other two. Above is a shot and is about as far as I could go before it bound up. In this photo the cam has been inserted on the welded side and it did make it through the center journal but the third journal was a bridge too far. I almost got away with it.

Initial idea was a full line bore and to slightly over size all the journals for true center. I Thought I might be able to order special cams with oversize races to match the new journal size. After speaking with Dean it wasn't going to be a viable option as the raw billets available most likely would not have enough meat on them to work. The viable option now was to keep the journals stock.

So... I had my buddy Rick TIG the end bores.

Now it was onto getting them machined to true center with the two stock journals behind them.

This phase was really touch and go for a few weeks. My machinist really isn't set up for line boring but he knew of another shop that was. He inquired for me and they were not interested in taking the project on. They recommended we just get new ones. Not really an over the counter item at this point. Bill, didn't want to leave me high and dry so he said he'd come up with a plan. A few weeks later he certainly did. He built a new holding fixture for his lathe that held this part at true center with the two stock journals. His set up had the work turning(towers) while the cutter stayed stationary. He still wasn't sure if this was going to work as he was concerned about "tool flex" I believe he called it as the cutting and leverage was way out at the end but he'd know the minute the cutter engaged.
As you can see above it worked and both cams spin in there beautifully! It was close, for a while there even Bill didn't think these where going to be savable. You can imagine my fear and frustration level with all the time, planning, welding and machine shop expense I already had in them. Failure really wasn't an option for me. Anyway, we pulled it off in the end and they finally a usable pair of cam towers.
More later...
Thanks for looking!
Justin

[JTR70]

Oil feeder tube reinstallation.

At long last with all welding and machine work completed I can finally reassemble the cam towers.

Original feeder tube cut down to length. Fortunately all the holes lined up. I'll take the win no matter how small at this point.

Bill machined me a new set of end caps and holding dowels to place the ones that where lost when the tubes were removed. Even made me this great locating and depth tool for the dowels since its a blind operation.

Machined slightly thinner for a slip in fit to both locate the tube and confirm how far the dowel needs to be driven in with that scribe line.

This was a shot I provided Bill of a lopped off tower to show him how far the dowel protrudes into the tube.

Tube inserted with locating tool doing its thing. This really helped things along; Bill sure took care of me.

[JTR70]

Locking dowel pin in. The original was flush but this shank does not interfere with the cover or the seal so I'll leave it.

Finished the install off with the new end cap.

And lastly the valve cover studs.

A very long and expensive road but...

But I finally have a usable pair of bolt-on ready cam towers for this motor. Would I recommending going this route? NO! Would I do it again? HELL NO!
Dean's way is the smartest; lop off the end, weld up the corners and be done with it. Live and learn... Onto the next deal.
Thanks for looking!
Justin

[JTR70]

Cam tower full mock up:

A few last shots of the welded up journals. Resurfaced nicely and as you can see plenty of heat penetration as it began bubbling the outside of the casting.

Not as much heat thrown at this side.

Cam spins in there beautifully.

Rocker arms and shafts fit and operate equally as nice.

Both towers officially ready for final assembly.

Thanks for looking!
Justin

[JTR70]

964 oil conduit conversion.

This case was set up by Dean to run the earlier chain boxes with the external oil feed tube lines. 964&993 chain boxes have cast in oil conduit that takes the soft lines' place. Some of Dean's blocks had the provision casted in for this 964 option but as you can see this one does not as oil conduit is peeking just over that milled shoulder.

The final solution was a slip in stainless steel cylinder. Original gasket made for the perfect locating template.

Case through bolt here also doubles as the oil galley so Bill came in through the top at an angle to plumb it into the new oil sleeve.

My original thought was pressed in alloy sleeve but Bill didn't think a perfect leak proof fit could be had due the galling upon insertion. His idea was this removable stainless steel sleeve with an O-ring on either side of the galley. The sleeve is marked for orientation with the new hole in the case but I also had him add in that relief in the event this tube ever rotates slightly. So now there's no chance of the cam on this side being starved for oil. Notice too the welded over soft line port above the case through bolt.

Another shot of the angle Bill came in at to plumb the new feed tube. He's made me a cap to plug this tap hole off with. Another one down.

Thanks for looking!
Justin