stuck valves

[2dogsnight]

Hello,

trying to start the engine that was sitting for many years...got new spark plugs, cap, rotor, condenser.......turning over nicely, spark like lightning......after going trough the motions with no positive results, found no compression....and valves all stuck in open position.
Will be taking head off trying to free the valves to move again....
The question is: are there some gravely reasons for the valves to not work properly??

Sail On

Wojo

[Mo]

welcome

It is not uncommon for valves to be stuck on an engine that was laying up. The boat I currently own was on the hard 2 years and 4 valves were stuck on that.

Since you may not know much about the history of the engine it might be a good idea to pressure test the block and manifold. I've never done this, however there are a few on here that could walk you through that. This would let you know if you have a good block, no cracks or water leaks.

Same with the manifold, there is divider between the wet side of it and the dry side of it...if there is a crack it can put water into the combustion chamber...this is where my problem originated from. It must have frozen, cracked, and then water trickled into the combustion chamber got around the valves and seized them.

I know what I have written sounds overwhelming but it is not. If the valves seized is the only issue it's a matter of cleaning them and reseating them, new head-gasket, torque it back on. If the manifold is cracked it's a matter of putting on a new one. If the block integrity is not there this is the point to consider weather or not to continue with that particular engine.

Lots of sharp guys on here. Don't be intimidated...and once brought back around and maintained these engines are like the energizer bunny...they go on and on.

[Dave Neptune]

Sticking valves

Wojo, what Mo said was good info and I'm gonna'add a bit more.The valves stick on these beasties due to moisture invading the combustion chamber. A tiny bit of moisture is all it takes. When left to sit any moisture in the exhaust can get back through an open valve and any that condenses in the crankcase can eventuaqlly evaporate and recondence in the chamber and cause a bit of rust. It is a good idea to spray a bit of WD-40, a lubricating or penerrating oil in to the cylinders through the spark plug holes and give the engine a 2~3 second spin when leavingtosit for a while This gets the spray of choice all around the cylinder and valve stems. The valve stems on a flathead don't oil very well and a bit of moisture getting to the stem/guide will cause it to stick. These engines have VERY LITTLE valve spring preassure and stick easily. To that point they usually come unstuck fairly easy too. They can often be pushed back down with an allen wrench or something similar. Many on this site pour oil (MMO) directly into the cylinder but that does not cover like a spray does however it does help the rings, so doing both will not hurt!
Be sure that the water is OFF when tinkering it can back up in the exhaust and get in because it was not blown out. If your on the hard don't hook up water unless she starts then get it to her.

Dave Neptune

[2dogsnight]

thank you Mo and Dave,

I did put some oil into cylinders ...I sprayed head nuts with WD40 this morning and will give it some time before I start trying to take the head off......I think I will get some penetrating oil too.....can I check the block for cracks with the head off??

Wojo

posted 9 sec video on youtube

http://youtu.be/a1lTRLNKRwo

[Al Schober]

Wojo,
Welcome the the group!
Wow! What great engine access - even better than my Tartan 30.
You may want to remove the valve cover (behind the carburetor) and try freeing up the valves from that end. If it works, fine. If it doesn't, no labor lost as you'll have to open it up anyway to remove the valves.
As for cracks in the block, you may see something with the head off. If so, take pictures - we like pictures. Once the valves are out, you can also assess the condition of the valve seats. Intake seats you can probably lap by hand. Exhaust seats tend to take a beating, and the last engine I did I took the block to a shop to have them grind the exhaust seats. When I got the block back, I found they had installed hardened inserts - no extra charge. Oh yeah, they also included a magnaflux of the block in the price. I'd also recommend you have the shop do the valves, and if it's an old engine, ream the valve guides for the late model clearance.
Moral of the story: Working with a good shop can help you and save you money in both the short and long run. If you don't know a machine shop, ask your favorite auto mechanic where they send their heads for work.
Final tip: buy the Moyer Service and Overhaul Manual.
Best..

Al Schober

[romantic comedy]

It would be great to get those valves loose without taking the head off. If you get it running, you can see what else is going on. Hopefully you would only have to remove the head one time this way.

Even if it runs on 2 or 3, give it a try.

[2dogsnight]

....have to go to Home depot and get a can of penetrating lubricant....and attack the valves...took off the valve cover and I can move one of the valves...good sign :-)

thank you for all help

Wojo

[ndutton]

We recently had a thread on penetrating oils. A home brew of 50-50 ATF and acetone was superior by far.

[Laker]

The audio in your vid sounds exactly like an A-4 turning over with valves open alright.

My money is on the head coming off. May as well go ahead with that - then you can clean the carbon out of the combustion chambers , free the valves for sure , and install new head gasket(s). Your access is amazing - I had to look twice as I initially thought the engine was sitting on a shop floor.

Free those valves and get a compression test , hopefully after running the engine a bit. If the numbers are ok you are practically done , barring any unpleasant discoveries.

What kind of boat ? CK

[2dogsnight]

this motor powers 18', home build in 1956, plywood motorboat.....I should probably take the whole motor apart, since is so old......I expect lots of head bolts breaking during process..I will try this group recipe for penetrating oil today.
.....yes, the access is great...boat practically has noting inside other than motor and 2 gas tanks...if the motor works , I will have to build seats etc.
My sailboat is 1978 Boalboa 23'......with an outboard

Wojo

[sastanley]

Wojo...good luck with the head removal. Since you are digging into it this deep, be sure to pick up the A-4 overhaul manual when you make your parts order if you don't already have it & keep asking Q's & sending up pics & videos...

[Sony2000]

Since the valve cover is off, make sure the lifters rotate easily (1/2" spanner), are oiled by you and if they are sitting on the cam shaft then you will you see a space between, them and the stuck valves .
Since it is still in the boat, don't open it up yet, but check every system first.

[2dogsnight]

thanks Shown
going to Home depot to get some aceton.....have I mentioned that my Atomic has 6V electrical system?
......still having problems with making pictures small enough to fit the message

Wojo

[sastanley]

Easy as pie! Mmmmm....pie.

what PC operating system are you using?

I like a program for windows called paint.NET..it is a free & does all kinds of stuff, but it is real easy to do simple things like re-size images with it too. Paint.NET is a freeware download you can google search.

If you have windows 7, the built-in version of "Paint" that comes with the OS has an easy re-sizing option too. Right click on an image and "open", which should open Paint automatically..Right on the "home" tab there is a resize option. I check the "maintain aspect ratio" checkbox, so when you change either a horizontal or vertical dimension it changes the other one for you. Play with those settings until you get it to work & save the image..

[2dogsnight]

have Windows7...it's just the saving the pictures and making them smaller, and making sure that they are small enough etc etc etc....spending lots of time playing with that....just annoying ......I was looking for easy way out
.......made penetrating cocktail...I think is working...tried to undo few head nuts and they seems to be giving up....
Here is a picture of valves...I think i will go ahead and take the head off....I want to see what the cylinders looks like....if they are in good shape, I will put new gasket and call it good.....I need easy access to valves too...need to see seats etc.....can't really try to free them from side window....tried to press them up, and some are moving, some are not
I think since the motor was sitting for years, I need to do at least that....and carburetor needs cleaning etc etc
I will post pictures as I go

thank you for your help!

thank you for your help!

Wojo