Sparkplug didnt look good when pulled out, need help

Ok guys I need some help with this, I picked up a 216 motor , the guy said that the motor ran strong, cool.

When I got it to my shop and set it up to go over it , I seen that the #6 plug didnt look too good.








So I went ahead and compression test it. The #6 read





the #5 read




The rest read where they should be.

My question now is by the way the spark plug looks, is the problem the head gasket or bad head or burnt valve?

I checked the oil for water, it looked good , anyone got any ideas?

 

Pull the side covers off, check for valve movement. May just need a little Marvel's Mystery Oil to free things up.

 

I think the head gasket could be burnt right between # 5 and 6. If the damage isn´t right near a water passage, the only thing you are losing is cylinder pressure. I would pull the head and check it out later. At first I´d try and put a squirt of oil in those cylinders and see, it the compression comes up some. That would be the rings then.
Good luck!
Chris

 

Ok so it my be a valve sticking, I hope so. Ill check later. Thanks

 

water

 

OOOOOO, good luck , Im gonna need it. LOL

 

I used to unscrew the hose from the compression tester and connect it with suitable fittings to an airline (or weld an air chuck into an old spark plug shell). Remove the rad cap, the oil fill cap and put #6 at TDC on the compression stroke.Then air up that cylinder via the spark plug hole. If air comes out the tailpipe you have an exhaust valve problem; out the carb= intake valve; bubbles in rad= head gasket; blasting out the oil fill= get the cherry picker.

 

I hope all I need is a head gasket.

 

It looks well past needing changed but doesn't look that bad. Lots of crud/carbon on it.

If you don't have a leak down tester I'd knock the guts out of a plug that fit the head and weld a fitting to it to screw an air hose fitting in. Then bring one of the cylinders up on tdc with both valves closed and put the air to it and see where it is going. Then repeat on the other one. Refer to Deuceman 32's post that's easier.
You would piss off the nieghbors but you could also try running the engine and letting part of a jug of automatic trans fluid dribble down the carb while you keep the rpms up. I used to that to my grandfather's Dodge every couple of months when he got it so carboned up that it wouldn't run. It fills the whole neighborhood with smoke so it's best to do it a ways out of town and then put the air cleaner back on and take up off the road until the smoke clears and hopefully the engine runs smoother. I've done the same thing with a pop bottle of water as it will break the carbon loose too with the same method. If that doesn't work get ready to pull the head.

 

Your scaring me man, well as for the cherry picker, the motor hasn't made it into the car (yet) I made a motor dolly that I can start it up on and roll it around.


Im may have to try out your method.

 

I use to do the water down the carb method, thanks for the reply. Ill let everyone know what the out come is , let hope it is miner

 

i have seen this a few times, #6 cylinder when in the car is the lowest point on the intake manifold, condensation forms and travels back and into the engine through the intake valve. check that the valves are moving, oil up the cylinder and run it. then check the compression. i have found motors that have sat,had little or no compression in one or more cylinders, but when checked after running had good readings.

 

When doing a leak-down check,,after bringing the cylinder to TDC, you will need to hold the crankjshaft from turning. Either at the front pulley bolt or flywheel.

 

thats a good idea I hope I can remember that in the future

 

Ok heres an update,

I put oil in the # 6and 5 cylinders, the #6 stayed the same and the #5 pressured up .

Put air into the #6 and it came out the intake port.

Ok now lets take off the head then and see whats up.

After taking it off , the gasket looked in tack but the #6 valve area looked a little rusty.


Im thinking some water got in there or maybe like what was said (condensation forms )



So whats my next move guys, tell me something good.


Also the rest looked about right but whats with all this rest deposit and is there any kind of plugs need to be replaced there or do I just clean them the ports out?

 

Maybe the pics are misleading me, but the gasket area on the head between cylinders #5 and#6 looks shiney and clean compared to the sealing areas between the other cylinders. I think that is where the headgasket leaked. Too me it looks like the moving gases have polished the area a bit.

Now, I wouldd just clean everything up, maybe flush the cooling circuit, check if all the valves are moving freely and then stick it back together.
Just my 2 cents.

 

At minimum lap the valves or get them ground. Check the head and block with a straight edge to make sure they aren't warped or damaged. Clean up the gasket surfaces and put her back together.

You can check to see if the valves are sealing by turning the hed upside down so the combustion chambers are facing up. Then pour some kerosene in the combustion chambers, if the level of the kerosene drops in the chamber the valves aren't sealing right.

You can do a cooling system flush after it's back together, less chance of water and coolant getting into places it shouldn't be.

 

Your water passages are pretty well full of rust. I'd try getting as much of that out manually before buttoning the engine back up. I'm willing to bet the engine has been overheating (just a guess!) and that low cylinder is not the only problem you have with this 216.

 

Yea I notice that too but I wasnt sure if anything was wrong there, this picture is the head side of the gasket, you can bearly make out there is 3 places like that on there.



Also when I cranked the motor up before I took it a part, it made like a thump/ knock sound.

I though like the crank was slapping, but when took the head off and cranked the the block it was quiet. Dont know what it was.

 

what else do you see

 

I would pull the entire engine apart.

 

Clean the water passages and lap the valves as suggested before.

 

what is Lap the valves

 

This should give an idea of what lapping the valves mean. Basically you take some lapping compound, an abrasive paste, and put it on the valve and the seat. Rotate the valve back and forth, lifting occasionally until you get a uniform contact patch on the valve and the seat. Plenty of info online, just search for 'how to lap valves' and you should be good to go.

 

You use lapping compound and a tool that has a suction cup on the end of it that sucks onto the bottom of the valve. Put the compound on the seat part of the valve , put the valve back in the head and spin it to help reseat it without machining it. Look up lapping compound on the web. Shit beat me to it

 

Lapping the valves and getting it back together with a new head gasket, etc is about as far as you want to go. Unless you're into a full rebuild.

It may pay to have the head looked over by a machine shop to check for cracks and get their opinion as well.

Bob

 

Thats sound about right, didnt want to do a full rebuilt cause I had 2 other motors that I could have done it to.

I picked up this motor off another site and was hoped just to dress it up and drop it in. Ive contacted the previous owner and said to let hm know what I found out.

So lapping the valves sound like the best bet and I called one shop and the said 45$ to check it out.

 

If you had a "knock" when you turned it over, I would check for loose wrist pin while you have the head off. Just turn the motor over by hand and just when the piston is over TDC, push down on it with the end of a hammer. If there is play, you have a loose wrist pin. Do this for all 6 cylinders.

Carl

 

Thanks Ill check it out, I heard the knock when the head was on but I took it off and spun the motor by the starter , it spun fast and quiet, no slapping or knock.

If I have to Ill drop the pan and check from there i will but first thing first.

 

Between the help on here and You Tube Ive got valuable info , thanks everyone and Ill keep posted on the progress , hope the holidays don't take me away from this.