A puzzle, finishing someone else's rebuild

[ronstory]

All--

I bought a old A4 build-in-process from a guy that ended up going diesel. So it basically came as a partially assembled short block and a bin of parts. Basically, I got an A4-in-box and now trying to figure out what been done and what needs redoing.

As a bit of foreshadowing, the bores were not cross-hone, the numbered pistons are all in the right holes, but the arrows are all pointing towards the flywheel. (sigh) And half of numbers on the connecting rod/caps are on the side with the cam.

The block has been stripped of paint, but water jacket cover looked like it had never been removed... and that was true. I broke 4 of the bolts removing the cover and it was full of scale.

So I just pulled the piston/rod assemblies and found a bit of good news. The crank was ground and rod bearings are new. Also, the piston rings are new as well.

Since I don't have any docs on the what he bought and some of the assembly has been incorrect, how do I determine if the rings are installed correctly?

[ronstory]

Ok, got the crank out and main bearings are new as well.

Now i'm starting to second guess whether the rings are new. They seem sharp and I can't seem to find any vertical wear but after removing them, the inside of the rings seem dirty, and it also looks like the piston ring groove was not cleaned out.

These piston rings have very small square 'step' taken out of the inside end of the ring, and both the top and bottom rings look identical. I could not find any markings to denote an up side the ring.

Also, if there a trick to removing the camshaft gear? Mine is on really tight, even after I bent back the retaining tab.

Can I just leave the gear on the camshaft when I remove it? I know I will need to reuse the retention plate/seal.

[Al Schober]

If you don't have one, get yourself a copy of the Moyer Manual. Covers all the neat stuff like numbering & orientation of the pistons, rods & caps, etc. As I recall, 'front' of an engine is defined by the location of the timing gears.
Rings can easily be checked for fit by removing them from the pistons and putting them into the bore. Use a piston (upside down) to push them to the bottom of the bore. Then measure the end gap of the ring. A good ring will have an end gap of less than .010". I did one engine where the old lower rings had a gap of over .100" - they were just along for the ride! PO did mention that the engine was smoking a bit..
Yes, the upper rings are the same.
Checking piston clearance is a bit trickier. Don't know your 'shop' capabilities. I think I satisfied myself that piston fit was OK using feeler gauges, but don't recall the details.

[ronstory]

Al--

Thank-you. I have the MM manual... two actually. One for the boat and one at home.

The trouble is the moyer manual is well organized, the box of parts I bought is not.

After looking at the pics posted on the forum, I've come to the conclusion that I don't have have hastings rings. So one more thing to order from Ken.

My shop capabilities are pretty good, but waiting on a friend who is a machinist since he has all the cool Mitutoyo toys. ;^)

I also want to send the oil pump to MM for testing. It would be my luck that I would spend all the time get all the specs right only to find out that the very inconveniently located oil pump was marginal.

[lat 64]

Ron,
I used to be an auto machinist sort-of. But I had a learning curve on specifics to this motor.
Awesome that you can get help from a machinist, but a cautionary note: some things on th A-4 are particular to that engine, ie. Piston orientation.
Sounds like it was put together wrong, so take it apart and reasemble as per the manual.
Re-reading different sections of it again, more stuff becomes clearer as you dig in.

Good luck, keep calm, and carry on,

Russ

[ronstory]

Thank Lat! I read it cover to cover on a week-long biz tip a couple weeks back. I just wish they had a electronic copy so you could search by keyword, but still... it's all in there.

Now just waiting on the spring compressor to arrive from Amazon today to get the lifters and valves and cam out.

I also dug into the giant bin of parts got to bottom and emptied it. We now have now confirmed that piston rings are original. Included at the bottom was the piston ring installer tool that was used and setup for the 2 9/16" bore size... plus a pristine and up-opened piston ring installer tool. ;^)

This is going to be a detective-based rebuild. lol