Instead of rebuilding my original A4, I bought a spare one!

[southcoasting]

Yesterday, I picked up a used A4 from the next town over...Mainly, I did this for several reasons with number being that this A4, from the outside at least, is in much better shape than mine...It was started and ran for a while before I bought it and came with the engine bed.

I am excited to get this as it gives me an opportunity to get it ready easily with paint, FWC, etc.

I first want to check compression on 4 cylinders...If all is good, I plan on just removing the head and side jackets to make sure cooling passages are clean and clear...while at it, I will paint all major pieces separately using the por15 engine paint kit in Pontiac light blue.

Looking forward to it! I still have major work going on my Tartan 34 including removal of all deck hardware, rot removal, etc...so this will probably be done little by little...I plan on providing updates on this project as things get done on this thread.

[ndutton]

Looks like a good score and a fine example of the strategy of choosing one's battles.

[southcoasting]

BTW: I have a small oil leak in the two area below...I assume there are seals that need to be addressed. Input?

[ndutton]

The leak at the flywheel is due to lifting and shipping. There is no seal at that end. The leak from the rear is in fact a rear seal that needs replacement. Easy job out of the boat.

[BunnyPlanet169]

Southcoasting:

I went through exactly the same process and found it extremely satisfying - I trust you will too. http://www.moyermarine.com/forums/album.php?albumid=150

The por15 black primer is really good - pay attention to the warning about sticking to skin - it won't come off for days if not a week or more.

It looks like the PO paid some attention to the engine - that's a nice find!

[southcoasting]

Southcoasting:

I went through exactly the same process and found it extremely satisfying - I trust you will too. http://www.moyermarine.com/forums/album.php?albumid=150

The por15 black primer is really good - pay attention to the warning about sticking to skin - it won't come off for days if not a week or more.

It looks like the PO paid some attention to the engine - that's a nice find!

WOW! looks great! Interesting things you did...Why the 3 hoses going into side plate? Better flow?

The home made electrolysis, can you explain more? Was this used for rust removal or paint removal? How did you remove paint from block?

I was planning on aircraft paint remover...but if you have a better alternative, I'd love to know about it...

[southcoasting]

The leak at the flywheel is due to lifting and shipping. There is no seal at that end. The leak from the rear is in fact a rear seal that needs replacement. Easy job out of the boat.

Got it...thank you! Will order new seal soon.

[BunnyPlanet169]

WOW! looks great! Interesting things you did...Why the 3 hoses going into side plate? Better flow?

Thanks! Yes, described previously in this thread. http://www.moyermarine.com/forums/showthread.php?t=8979
Have to be honest and say it was a completely irrational PTSD response to a bad cooling experience. The A4 can and will live with less, but I wanted to try and replicate something like the original side jacket casting. I'm not sure I'd do this again.

The home made electrolysis, can you explain more? Was this used for rust removal or paint removal? How did you remove paint from block? I was planning on aircraft paint remover...but if you have a better alternative, I'd love to know about it...

Removes rust and (loosens) paint - the bond fails and the paint falls off. Described previously in this thread. http://www.moyermarine.com/forums/showthread.php?t=8526 As I mention in the thread, this is not my original idea, but something common in the old tools / old iron community.

After I found my block had been recently rebuilt (that was a really good day), I took a calculated risk and didn't separate the main castings (rear housing, block, and oil pan). I cleaned them with solvents and wipes, and did some sanding/wire brushing to make the surfaces as friendly as possible for the primer. I used the POR spray acid etch to prevent surface rust and add 'tooth' on bare metal.

It really depends on how far you're planning on / need to disassemble. If I had fully disassembled, I would have taken the big parts to get hot tanked and started from bare metal. My tub was big enough for the flywheel housing and everything else.

[southcoasting]

Ran compression test today. Ran engine until warm btw...

3 of the 4 cylinders came back at 100...One came back at 80. Poured a little oil and it jumped to 90.

I assume piston ring is in question?

[southcoasting]

Just finished adjusting all valves and poured more mmo into all cylinders to run the engine for a bit again...Mainly trying to see if valve adjustment would fix the cylinder #2 compression to make it match the others...

I bought a vintage set of a Sears/Craftsman Tap & Die set...ordered from ebay. Figured the steel is prob better than new sets made in China today...

I realized the other valve cover bolt was broken when I took the valve cover off and my attempt to extract it created a new hole there that is a bit off center...Should have been more careful...

So I got the new thread in and put it back together and report on the compression...

So after valve adjustment twice and more mmo, I am still getting about 80 psi at most from cylinder 2 and it won't hold the pressure...

My question then is, I suppose something is wrong with the piston rings or at worst, needs cylinder honing.

I think the carb is due for an overhaul...I am learning as I go and have learned a ton from reading on this forum. I went and started her yesterday and let it run for about 15 mins...One thing I noticed was when I open the throttle, it bogs and at one point, it died...I assume this has something to do with carb adjustment...Also ran a little crappy after...

Any suggestions?

I really did not want to do a full rebuild of this engine but seeing what others think when one cylinder is like this...All others are at 100 psi.

[JOHN COOKSON]

Just finished adjusting all valves and poured more mmo into all cylinders to run the engine for a bit again...Mainly trying to see if valve adjustment would fix the cylinder #2 compression to make it match the others...
So after valve adjustment twice and more mmo, I am still getting about 80 psi at most from cylinder 2 and it won't hold the pressure...
My question then is, I suppose something is wrong with the piston rings or at worst, needs cylinder honing.
I think the carb is due for an overhaul...I am learning as I go and have learned a ton from reading on this forum. I went and started her yesterday and let it run for about 15 mins...One thing I noticed was when I open the throttle, it bogs and at one point, it died...I assume this has something to do with carb adjustment...Also ran a little crappy after...
.

If you want to do the full on service: (It sounds like you do)
Hopefully it's just a valve hanging up or the seat is pitted or something similar that is causing the low compression. Remove the head and have a look see. While the head is off you can get the cooling jacket and water passages pristine clean. You will be ready to go with FWC then.
The carb main jet is probably blocked. If you rebuild the carb you will know there are no carb problems with the new engine - sort of like starting from zero again.

TRUE GRIT

[southcoasting]

A4 Teardown Begins!

All,
I have finally gotten a chance to start taking apart my replacement spare engine so that I can figure out why one cylinder was around 80 psi and not holding the pressure.

I'd like to avoid going any further than this in the tear down or rebuild since other cylinders came in at 100psi when warm.

Of course, I will be taking off some other parts as I will be stripping paint and repainting but would like to figure out the cylinder number 2 issue as it seems this engine is perfectly fine aside from that...

First thing I noticed was one gasket was used instead of two. Could that be a reason?

What else am I looking for here? I realized I had not removed the gasket from mating surfaces to closely inspect but will be doing so today and posting those pics for your inspection.

As far as valves, what am I looking for to see if they are the culprit?

[southcoasting]

I just poured a couple ounces of mmo on top of cylinder 2 and it slowly drained in about a half hour. Will piston rings let oil go by like that or are the supposed to let some air by?

[joe_db]

I just poured a couple ounces of mmo on top of cylinder 2 and it slowly drained in about a half hour. Will piston rings let oil go by like that or are the supposed to let some air by?

Try putting some in the other 3 and comparing

[southcoasting]

Try putting some in the other 3 and comparing

Thanks Joe.

Well, I decided I am just going to drop this off at the machine shop to have them take a look as I have noticed the pistons are not installed with the arrow pointing correctly anyways...So I'd rather get this right while I have it out and make sure they hot tank, etc...

I will report more info soon.