No Compression

[hcrisp]

I get no compression on any cylinder when I hand crank my A4. This has been determined by holding my finger over the spark plug hole. At first I could not crank it at all. Now, after the application of MMO in the spark plug holes It turns easily with the hand crank. Maybe too easily? I'm not a mechanic but I can't understand what I am missing. The engine has been idle for the last five years - this will be the sixth if I don't get it started. PO states the engine ran fine when he put it on the hard. He drained all the water out of the block, and drained all the fuel lines and that is the way it has sat. I need to get this baby started! I have not tried the starter. No battery yet.
Thanks for any comments you can offer.
Howard

[JOHN COOKSON]

Is the engine harder to turn over when the sparks are in tight and sealing the cylinder?

TRUE GRIT

[CalebD]

Howard,

We recently lost compression in cylinders #3 & 4. Engine had been running on all 4 and it was a rather sudden loss of comp. in #3 & 4.
Turned out to be our head gasket which was easy enough to replace. A set of head gaskets is $36. Call Ken at MMI parts.

The other possibility is you may have stuck valves (intake/exhaust) which sounds fairly likely. If this is the case then you might as well remove the head so you can see if the valves open and close as you crank the engine. To access the valve seats and springs I believe you would need to remove the manifold - others know more about this than I do.

Don't give up.

[tenders]

It is encouraging that the MMO enabled the rings to unstick from the cylinder walls. Chances are good that the valves are stuck similarly, and a little bit of lotion and motion will free them. Highly likely that you can knock some or all of them loose through the spark plug holes with an allen wrench, a flashlight, and a moderate amount of pressure. There are descriptions of doing this on this site. I would at least attempt this before taking off the head, but it's true that the head isn't all that hard to get off.

When you're testing this I would suggest hooking up a plastic fuel tank into the system as close to the fuel pump as you can get it - don't fill up the boat's fuel tank, as that introduces another set of possible failure points.

[lat 64]

Don't panic and bring a towel

Don't panic about getting it started. just need to keep rolling it over every few days while you slobber in that "lotion" tenders was talking about.
The fact that you got it to turn over is super good. You can save this patient. The rest is just picking away at all the chores of restoring an engine.

I turn mine over by hand whenever I can get to the boat during the winter. I think it likes me for that.

Steady on old bean,

Russ

[hcrisp]

Frustrating

Steady on and don't give up are excellent words. I admit I was frustrated this afternoon but after listening to your advice and having a good dinner I am starting to come around. Little din din in the cockpit on the hard. More MMO tomorrow. The hours are building up fast with no reward other than I know the A4 enjoys the attention.
Later, Howard

[Laker]

You have stuck valves. (Stuck open is redundant ; if they were stuck closed the camshaft could not rotate past the valve stems...)

Buckle down and remove the head. Good access to the valve tops is what you need , then after you have worked those valves free you wind up with a nice new head gasket(s) from Moyer. It will be a great learning experience. CK

[hcrisp]

Clearance

The space between the top of the head and the underside of the cockpit sole is enough to raise the head above the studs. But not much more. If it comes to removing the head I am cutting an access hatch in the cabin sole. There are other reasons for cutting a hatch to get "back there"; stuffing box comes to mind, not to mention engine alignment and cutlass bearing. I have experience as a boat builder and have no doubt I can make the "hole" watertight. I have no experience, well, a little now, as a mechanic. Even Don says he wouldn't try removing an A4 head while the engine was in the boat. I know from reading this forum that a lot of you guys have removed the head while the engine was in the boat. It can be done, you say. Getting the thing is out is just the beginning, I have a feeling. Would you put the head back without grinding the mating surface?

[lat 64]

Grinding the block gasket surface is done only if it has warped or as part of a repair to cracks or such. I realy doubt that your engine has any problem with that. The head is thinner and is slightly more prone to warp. You can take this to a machine shop and have them check it.
When the head comes off, the studs can be removed and both gasket surfaces cleaned with a scraper and checked with a machinist's straight edge(not a carpenters level!). The old gasket material sticks to the iron and has to be GENTLY scraped off completely. Do not gouge the iron with your scraper.
Found a good pic here:

http://www.jalopyjournal.com/forum/showpost.php?p=3960945&postcount=16

It' a car engine, but the procedure is the same. The text has some general advice on torquing too.


As for the zen thing while scraping: Two or three cups of hot chocolate and a cd of all the Bach cello suites will make this go well.

Russ

[systemek]

I am a huge proponent of removal and accessibility creation. I have removed the head (with tight access) as well as a valve job, but there is investment and peace of mind when it comes to creating accessibility, as the need to get in there (like the stuffing box), will invariably arise again. It is especially worth while if you have experience in boat building and can make it structurally-sound and water tight.........

[wmmulvey]

Grinding the block gasket surface is done only if it has warped or as part of a repair to cracks or such. I realy doubt that your engine has any problem with that. The head is thinner and is slightly more prone to warp. You can take this to a machine shop and have them check it.
When the head comes off, the studs can be removed and both gasket surfaces cleaned with a scraper and checked with a machinist's straight edge(not a carpenters level!). The old gasket material sticks to the iron and has to be GENTLY scraped off completely. Do not gouge the iron with your scraper.
Found a good pic here:

http://www.jalopyjournal.com/forum/showpost.php?p=3960945&postcount=16

It' a car engine, but the procedure is the same. The text has some general advice on torquing too.


As for the zen thing while scraping: Two or three cups of hot chocolate and a cd of all the Bach cello suites will make this go well.

Russ

Thanks for the torque sequence. Surprised it isn’t in the maiintance & repair manual.

What is the Ft. Lbs. for the head.

Regards

Bill

[Carl-T705]

get a compression gauge.... and a battery! I don't think you are getting a good seal by holding your finger on the Spark plug hole and turning the engine over by hand. I doubt you can accurately say no compression with the way your testing.

[lat 64]

No!

Thanks for the torque sequence. Surprised it isn’t in the maiintance & repair manual.

What is the Ft. Lbs. for the head.

Regards

Bill

No bill. That's for a V8 flathead Ford
Sorry to confuse. It's just the method of surface checking I was trying to show.
My bad.

The Moyer manual I have says "The nuts should be torqued in at least three steps from the center outward using 25,30, and finally 35 foot pounds"

In general, when you have no torquing sequence illustration or instructions you can go in a circular pattern from the center nuts to the outers as Don says.
See my drawing of a very GENERIC pattern.

[hcrisp]

Speed of crank

Perhaps you are right, the starter motor may make a difference. But, air is air - where is it going to go? If not up, out. If the hand crank can start the engine I should be able to get a good compression. What do you think, Russ. No positive results as yet from the additional MMO. I can't get a mirror under there. Well, I could but I wouldn't be able to see anything. MMO first, head removal last. Isn't that sticking to the theory of starting simple?
Thanks guys,
Howard

[lat 64]

Yea, Start simple. I think they call it the low hanging fruit.
Read up on the head removal though. The valves seem to stick in these little engines quite easy, so It will probably come to that. You are still helping it by squirting lube in there and turning it over lots.
The water pump impellers will need something to keep them lubricated if you start to crank it a lot with the starter. I forget, did you look at them yet?
The manual and videos from Moyers will make you as smart as anyone. Think of an investment there. Definitely the manual

Cheers,

Russ