cylinder head help

R

Roy

Member
I just put a resurfaced head on my cub with a new gasket and torqued the bolts in the right sequence, but notice air bubbles coming from the gasket( from antifreeze I spilled). Now the tractor stalls under a load or if I throttle it too fast (loosing compression?). I first tightened up to 45 ft lbs, then went up to 50 ft lbs to see if that would stop it. Any suggestions to my next step?
Thanks
Roy
 
Did you torque the head in gradual steps or did you go straight to 45? I'd run it for 20-30 minutes and re-torque to spec. Then re- check after a couple or so hours of run time.
 
Roy,

Bigdog is right on. I wouldn't try any more torque on the bolts...some of the bolt holes in the block are weak and can be easily damaged by over-torqueing. Was the deck on the block in good condition? Have you ruled out cracks in either the head or block?
 
George,

I had the head magnafluxed when I resurfaced it, and it was fine. As far as the block I'm not sure about a crack. I was blowing white smoke and the oil dipstick had a milky deposit on it. I was told that meant antifreeze was getting in, so I changed the head gasket. Also, when I changed the oil, a small amount of antifreeze came out of the oil filter drain. After replacing everything I don't have anymore white smoke.( only ran 15 minutes)

Roy
 
George

As far as your other point, I didn't spend alot of time on the engine block surface. I did run a razor blade acrossed it and then went over it with a wire brush in my drill

Roy
 
John

I did not use anything as far as a sealer goes.

As far as the gasket, is there a right side up rule? I was told to keep the writing up when installing.

Thanks
Roy
 
Roy
When I put the head back on my cub it did the same thing, I used a sealer with the gasket and it stopped leaking.
Johnny
 
Well I ran my cub a little longer today and it is definitely leaking small bubbles of antifreeze around the gasket. It also blew some white smoke again. I guess I'll take it apart again and make sure the engine surface is OK and try sealer.
Will the gasket be OK to reuse, or should I get another?

Roy
 
I have never felt very comfortable reusing a head gasket, but I have known of quite a few people doing it and it working OK. One question though, if you add sealer to a used gasket and it still leaks, what do you do next? Do you have another problem to chase down or do you then try sealer on a new gasket?

I would suggest that if you want to reuse the gasket, remove the head by reversing the normal head tightening sequence. Just crack each bolt a little, then repeat the pattern going maybe a 1/4 turn at a time until the bolts are all loose. Otherwise, you will probably deform the gasket when you loosen the head bolts.
 
Jim

You make a good point about a used gasket. Ill get a new one tomorrow along with some sealer.
You mentioned taking off the gasket a 1/4 turn. How far do you turn to put one back on?

Roy
 
I’ll try to not start a war here… :D We have hashed over this a number of times on the ATIS tractor list over the years. Everybody has their own ways of doing things and that is as it should be. But… It is as simple as this… in my shop ALMOST NOTHING goes together dry. I have not done thousands and thousands of jobs but I have turned wrenches for $$$ in the past and still do now and then but I’m just a lot slower now. :D I have “never” had a head gasket fail that I installed. Never. I have also never put a head gasket on dry and have no plans to ever do so. I firmly believe that having something on there is generally more important than what is used. I do not like products that are like permanent glues like the old original Permatex products were. I am kind of partial to the copper-cote type of products but have used many other things including from Hi-tack type products all the way to a simple brushing with grease. I think it is important for the mating surfaces to slide against each other. As you tighten a head down for example that gasket has to move around a tiny bit as it is compressed. I believe that almost anything that provides a bit of lubrication to help it shift into place will help it form into the proper shape. You have to think like a molecule. :D
I never put bolts together dry, especially head bolts. I clean each bolt on a wire wheel and make sure the holes are clean. I dip the bolt in oil just before I put it in the hole and I want the bottom of the bolt head and the top of the cylinder head where the bolt head seats both lubed. When I torque a head down I do it in at least about 5 steps. On something like a #$%& CUB the first pass might only be 5 # of torque but always in the pattern. I wouldn’t dream of going to 45 # on the second or even third pass. Re-torquing after running enough to warm the engine up is just automatic.
I like to use a huge fine cut flat file to lightly draw-file both the head and the top of the block. Not to remove material but to be sure there are no unseen burrs or bumps that a visual inspection might miss.
Of course we are talking old tractors here. I realize that a lot of new cars and trucks call for a lot of special techniques and they should be observed in those applications.
 
Roy":3ok8cn8u said:
Jim
How far do you turn to put one back on?

Roy
Click to expand...

You reinstall by torque, not amount turned. I think Farmer covered that quite well, probably with more attention to detail than done by most.
 
If the head bolt holes pass through to the water jacket, instead of oil use teflon pipe dope (liquid - not tape!) on the threads. I've rebuilt a few engines, and I was given this tip by an auto mechanic friend. You'll never have a problem with fluid leaking into the head, and the threads don't get crusty & come out nicely if you ever have to take it apart again.

I coat all my gaskets with anti-seize. Messy, but they seal fine & don't stick when you take things apart.

Never re-use a head gasket. (my $0.02) I would also recommend using new bolts every time you bolt the head on. Torque in steps. 15, then 30, then 40, then 45 ft/lbs. Follow the same pattern each time.

Poor-man's magnaflux leak/crack checker:

- Clean block surface with brake cleaner

- Spray with #2 fuel oil (diesel works but fuel oil has red dye in it)

- Allow to soak for a while.

- Wipe clean w/rag dampened with brake cleaner

- put some corn starch in a piece of cheese cloth, and pat over surface. Coat with a thin layer of corn starch.

If you have a crack, the corn starch will pull the fuel oil out of the crack, and it will turn it red.

Hhmm, come to think of it I can't remember - was it corn starch, or talcum powder? :? Anyway, I suppose either would work.
 
I went back to the shop where I had my cylinder head resurfaced to get a new gasket and I explained my situation. He reinerated alot of what you all told me. He had a gasket, but suggested that I try some things first. He said to take out one bolt at a time(in order), wire brush it, soak it in oil, put oil on the top surface of the head where the bolt head seats, retorque it to 45 ft lbs, then do another until all 15 are done. Also anywhere a bolts hits water (#5 bolt) use a silicone thread sealer. He also said he retorques many times before he sends his engines out and even when he uses a copper sealer sometimes it bubbles the first time.
I followed this procedure and ran my cub. I had a little bubbling but only a fraction of the previous time. I let it run a while and retorqued (45) and it sealed. I let it cool down, ran it hot again then checked the torque a couple more times and everything is fine.
Thank you all for your knowledge to get me through this unfamiliar task. Now George, I have something just after I needed it - experience !

Roy
 
I have been watching this thread but nowhere has any body said anynthing about checking the deck of it for flatness.
I have seen & so have some of you other guys when the head is warped the block sometimes does to.

As for putting somthing on the head gasket (antisez.) (grease)
I worked in a garage for 12 years & the only head gasket you put any thing on was some of the mopars.

If I hired you to put a engine to gether for me & you put somthing on the head gasket you would get to do it again for free witth nothing on it .
Between I and my father we have over 75 years of rebuilding motors and
as I stated earler we only put a sealer on those that stated to do so.

One last thing on this tread how much did you have the head milled &
did you cmpensate for it in the head gasket.
In a l block valves are in the block if you remove to much off the head & don't replace it with somthing you will bend valve.

Sorry I don't mean to preach but why spend money if you don't have to on a 2nd rebuild.

Rule #1 on a rebuild check everything out then check it again.
replaceing a head or head gasket rule #1 still applies
Dale51
 
Roy":l149ahoq said:
I went back to the shop where I had my cylinder head resurfaced to get a new gasket and I explained my situation. He reinerated alot of what you all told me. He had a gasket, but suggested that I try some things first. He said to take out one bolt at a time(in order), wire brush it, soak it in oil, put oil on the top surface of the head where the bolt head seats, retorque it to 45 ft lbs, then do another until all 15 are done. Also anywhere a bolts hits water (#5 bolt) use a silicone thread sealer. He also said he retorques many times before he sends his engines out and even when he uses a copper sealer sometimes it bubbles the first time.
Roy
Click to expand...

Roy,

Your mechanic may not be aware of it, but ALL the head bolts enter the water jacket :!: I prefer to coat all the threads and the under side of the bolt head with plumber's teflon pipe dope. While others may disagree, I recommend you do the same... one bolt at a time. You decide.

I have been watching this thread but nowhere has any body said anynthing about checking the deck of it for flatness.
I have seen & so have some of you other guys when the head is warped the block sometimes does to.
Click to expand...

Dale,

You may have forgotten, but the Cub has a flat head engine. Both surfaces should be checked for damage, but neither can possibly warp enough to matter. That thin little head will conform to the block like it was made of rubber :!: Valve clearance is not affected by decking or milling on a flat head. :lol: :lol:
 
You must log in or register to reply here.
Back
Top