First Overhaul (so far)

[MarkH]

Cam Shaft Removal

Here we are. Oil pan is removed and the block is on its face on a towel on the bench. Don says the next step is to remove the cam shaft by first "removing the 7/16 bolts behind the big gear on the flywheel end." That will be a problem because this baby is frozen solid. So, no movie-movie of the crank to rotate the gear so that I can get to the bolts.

Time to ask a question: What is my next step? Do I remove the crank shaft to allow me to turn the cam gear so that I can then remove the cam shaft. Is there some tribal law that I will break or unintended consequence for the approach? ...and go.

[MarkH]

Cam Shaft Removal

One more thing...
I want to make sure that I can e-assemble this once I am done. How am I going to make sure the cam is in the right position relative to the crank on re-assembly. I know that is a rookie question, but I have to ask. If its in Don's bible, I might not have read that far...

[MarkH]

Crank Removal

Answer: Yes, remove the Crank first. No problems...

[MarkH]

Piston Removal

This is a bit uncharted for me, but I think I can make this work. I removed the crank bearing studs on each end... no problem, then turned the block back over and placed it on a couple of 2x’s to keep the piston rods off the bench. Then with a large wooden dowel and hammer I negotiated with the easiest one…#1. Just a few taps and it was free. The others may take some soaking and tapping. Any guidance on this is appreciated. I know enough to tap and not bang... being mindful of the pistons.

[Nanook]

When everything is cleaned up, you'll see the timing marks on the main crank and cam gears. The other stuff doesn't matter as long as they mate up.

[sastanley]

A lot of people on the internet have found a 50/50 mix of ATF and acetone to be an excellent penetrating oil..I might mix up a small batch and let it soak into the piston rings and see if they'll come loose...there seems to be no reason to unnecessarily score the cylinder walls at this stage.

[Al Schober]

Mark,
You've got some serious pitting on the deck of the block, which will need some grinding. Have the shop try to keep track of how much they grind off - you may need a third head gasket! The original head gaskets were a copper/asbestos sandwich, which compressed to about 1/16". The current crop of gaskets are about 1/32", hence two needed to limit compression to original. If your shop grinds off .020 or more, you may need 3 gaskets - I think I'd go with two gaskets and a shim plate.
Cooling passages look good. Often those passages outboard of the valves get limed up.

[MarkH]

Pision Removal Complete 3/6/17

Well, here is how all this went. After removing #1, the other three pistons were not going to be so easy. At the advice of a gear-head friend, I turned-over the block and filled the cylinders to just above each piston with transmission oil. I scrubbed a bit with a small wire brush around inside the bottom of each piston to loosen any corrosion that might keep the oil from leeching into the cylinder around each piston. I let this set up overnight. I came back and extracted the tranny oil with a large syringe, turned over the head and tapped out each piston with a wooden dowel. Not too difficult after all.
Here is the result:
The cylinders look to have some corrosion (surface) but no visible cracks or holes. The pistons look pretty bad, but can likely be cleaned up. Please comment if you believe otherwise. The head has some work to be done: magna flux, water jacket stud extraction, one bolt extraction on the rear where the coil mounts. If it passes the magna flux, then I am on to refurbishing the block and will build this out to completion. I will of course need a #1 exhaust valve, will replace all bearings and freeze plugs and then breathe new life into this 43 year old work horse.

[MarkH]

To the Machine Shop

Next stop is the machine shop. Any pointers to dealing with these guys would be great, I am basically going in with only this job under my belt. I think the following is a complete list of what I need done:
1. Crank shaft polishing
2. Cam shaft polishing
3. Tappet polishing
4. Piston polishing
5. Valve grinding and re-seat
6. Head ground (if necessary)
7. Block ground
8. Cylinders honed
9. Remove broken studs (8) total
10. Repair (weld and re-tap) one exhaust stud hole on the block
11. Sand blast and final clean up
12. New valve
13. New bearings

Let me know what I left out…

[Tim]

If the cylinders have any corrosion, they will likely need more than just honing. The A4 I rebuilt had what I thought was just "surface corrosion" in one cylinder - that cylinder needed to be bored +.020. I had all four cylinder bored so that they matched and had to buy 4 new +.020 pistons.

[MarkH]

Thanks Tim, I know that is always a possibility. These pistons look pretty bad anyway. So, I will wait to see what the machinist says and go from there.

[Administrator]

Suggest you take the time to price-shop the various Moyer Marine rebuild options versus the quote from your machinist.

Bill

[2dogsnight]

Suggest you take the time to price-shop the various Moyer Marine rebuild options versus the quote from your machinist.

Bill

Looks like your motor is going to need a lot of machining work. I wander about the number$$ myself......

Wojo

[MarkH]

I plan to buy and install all replacement parts from our host.
Shop work is not that much IMHO. This motor was free and the actual repair work is a dime sized ding on the exhaust side of the block. The rest of the stuff is just stuff.