Found the compression problem with the H...

Absent Minded Farmer · Oct 22, 2011

I think that bit of missing gasket has something to do with it. There was a bit of carbon built up where the missing piece of gasket had existed. It cleaned up with a blue shop towel, I couldn't believe it. I hope that piece of gasket isn't hiding somewhere it shouldn't. I checked the head & there was nothing to be found. The valves look great, springs too. I cleaned & wiped off the top of the block, put the new gasket in place & re-installed the head.
So far, so good. I would like to know how much torque to put on the bolts that hold the rocker assembly down. 70 ft-lbs? The shop manual does not say or, if it does, I missed it. A-hee yuk!

Thanks to all that responded to my earlier post about the ailling, wheezing H & I'm still waiting on a new coil-thingy for the light switch on the 400. should be in on Mon. or Tues.

Mike

rustred · Oct 22, 2011

might end up with the same problem if you did not check head for warpage, as i believe thats where your problem lies.

Janicholson · Oct 22, 2011

Slot machines are for Vegas! Jim

Absent Minded Farmer · Oct 22, 2011

%*#$^%!! That's not good! I forgot all about it. Ok, how can I check for warpage? I can't afford to/don't have the time to take anything in. I am thankful that I can afford to pay attention, here. No joke. Also, what else do I need to do or look for before reassembly?

Thanks,
Mike

Janicholson · Oct 22, 2011

With a real 2 foot straight edge (that could be put on a surface plate and not have a .001 feler gauge slip under it) and the head clean and shiny, lay the straight edge such that the bridge between the cylinders that had the gasket failure is in the middle of the tool's length.
Put feeler gauges under the edge while holding it down to check flatness. Repeat across, and diagonally. (and other places as well) If .003" blade will go under, I would machine it with a truing cut, not more than .010"
If between .002 and .001, and tapered across more than 6 inches, I would run it. Use coppercoat on the gasket, and torque it in 4 stages to full torque. Run it till at operating temp, then retorqur adjust the valves and be happy. Jim

Owen Aaland · Oct 22, 2011

Looking at the head gasket from front to back the only place it was not leaking from # 1 cylinder forward. You can see carbon between the other cylinders and out the back from # 4 cylinder. Maybe it was leaking from lack of tension on the head studs but if the gasket blows again you really need to take a look at both the block and the head for flatness.

Absent Minded Farmer · Oct 22, 2011

Ohhh boy! My smallest feeler gauge goes down to .003" & I would be happy to find 2" of straight anything around here. Uh, I might have to wait 'till Monday & take it in to my local dealer & have it looked over. They usually don't charge for that. I thank you guys for causing me to pause before I made a mess out of things.

Mike

Brownie 450 · Oct 22, 2011

The block & head surfaces should be clean enough to eat dinner off of--that's what I have been told.

Absent Minded Farmer · Oct 22, 2011

Now that you mention it, there were three or four nuts under the valve cover that didn't seem very tight. They didn't pop when I was breaking them free, anyhow. Honestly, I'm not sure now, what I'm going to do. My gut says the nuts were loose & the gasket will be fine, my detail addled head wants to check the head AND block for warping. Oh me, what to do. I guess I don't have anything left to do with the tractor that isn't light duty, this fall. Just have to move some things around with the loader & move a few machines around in the shed. I'll have all winter to work on the H, then. If you, or anyone else thinks I'm going to cause great harm to my tractor, lets hear it. Otherwise, I guess I'll put everything back together & get my work done so I can tear it all apart, again. *sigh*

Thanks,
Mike

Absent Minded Farmer · Oct 22, 2011

I made sure they were spotless. I wanted to scrape the little carbon chunks out of the exhaust ports, but I figured I can clean it good after my fall garage/property cleaning is done & I have the time.

Mike

mkirsch · Oct 22, 2011

Worst case it's just going to blow the head gasket again.

Only takes a few minutes with a straightedge to check for warpage. At least then you'll know what you need to do when you do take it apart again. Heck, you might find out everything's okay!

Tom Fleming · Oct 22, 2011

Warpage is one consideration. Also remember, if head is not evenly torqued down, it can cause the same symptom. check for warpage as has been indicated. if it is under .003 as others have indicated, put her on and torque as indicated.

what worries me is that uneven torquing of a head and then run, can also warp it. I hope that is not your case.

Absent Minded Farmer · Oct 22, 2011

Ok, I think I found something to use as a straightedge. It's my Port Austin level. There's a link below for reference. It's heavy duty cast aluminum, I should hope it's perfectly flat yet. I'll have to pull the head & see what's what. I'll post back, hopefully tonight yet.

Greatful as always!!,
Mike

P.S. I'm very surprised to see they are still in buisness. There's going to be a 48" Port Austin cast level & a 72" extruded aluminum red-colored level with the numbers on top, on my Christmas list this year.
On the level...

sflem849 · Oct 22, 2011

I would run it if you already have the head on and torqued once. The H gaskets are cheap and pretty simple to replace if you run into problems again. Those nuts being pretty loose and the ease and cost of doing it again all weigh into my decision. (Not to mention you sound like you already put the head back on. Some wouldn't reuse that head gasket now.)

If you had enough money for the gasket you have enough to get the head flattened out. IIRC my MD and WD-9 heads were $35. Not too bad IMO.

Absent Minded Farmer · Oct 22, 2011

What's with the light grey valves? Might that be an indication as to what happened to the head gasket? Cylinders are #1-4, left to right in the picture.

Mike

Absent Minded Farmer · Oct 22, 2011

Yeah, the head was on. No, I wasn't familiar with the fact that you can only use a fresh head gasket once. Ach, fiddle! I guess I should have just stayed in bed today.

Mike

sflem849 · Oct 22, 2011

(quoted from post at 18:22:35 10/22/11) Yeah, the head was on. No, I wasn't familiar with the fact that you can only use a fresh head gasket once. Ach, fiddle! I guess I should have just stayed in bed today.

Mike

It's all good. I'm going to reuse a frest head gasket on my WD-9, but that is a $175 head gasket. :shock:

Absent Minded Farmer · Oct 22, 2011

Whew! A certain relief! Yeah, $175 is a bit steep for a head gasket, in my book. I can't wait to find/pay for one for my Gehl chopper. It's powered by a very large Waukesha 6 cyl. engine. What's worse is, there are very few original parts left for the Waukesha 135. At least with the few months that I've been searching, anyhow.

Thanks for the gasket info. I promise to only squeeze head gaskets down once, from now on. ;v)

Mike

Absent Minded Farmer · Oct 22, 2011

I found two spots on the head that are questionable. The first is the space between the very front of the head & cyl. #1. I can fit the .002" but not the .0025" in there. The second spot is between cyl's 2 & 3. I can fit the .002" gauge in there. The spot where the blow-out was, I can fit no larger than the .0015" gauge. There does not seem to be a taper there. However, the spot between 2 & 3 has a slight taper. I could move the .001" gauge about 2" from side to side, between the coolant holes. I went over the head & top of the block, again, to get a cleaner surface. I would assume it is good to go, for now?

Mike

Absent Minded Farmer · Oct 22, 2011

Ooops, scratch that. The feeler gauge does go down to .001", in .0005" incriments from .004". The paper thin feelers were stuck together with oil. Lol!

Mike

Maxx · Oct 22, 2011

[b:55db8024ba]It really needs to be done with a machinists straight edge.
I doubt your level has a perfect edge on it.

Maxx[/b:55db8024ba]

Janicholson · Oct 23, 2011

Stuff on the valve heads can be ignored. The far cylinders were not running correctly. The gasket blew when they were running, then the combustion temps went wrong (less). I assume the valves are not leaking. (Filling the combustion chambers with water when turned upside down {with sparkplugs in} will tell if they leak.) Jim

JRSutton · Oct 23, 2011

instead of water in the combustion chamber - I like turning the head on its side, and filling the ports up with kerosene. Then you can see exactly how well your valves are sealing, and which ones may not be.

Just watch the valves for seepage, very easy to see.

Tom Fleming · Oct 23, 2011

and re-using a head gasket is only a No-no if you ran it and got it up to temp. if all you did was torque it down, and didn't run it, you will be just fine.

Absent Minded Farmer · Oct 23, 2011

Nope, the gasket hasn't passed room temperature yet. The way my back has been today, might be a day or two before it sees operating temp's. I think the head gained weight over the last 6 years. ;v)

Thanks,
Mike

Mike Bock · Oct 23, 2011

i reuse head gaskets all the time on my pulling tractors never had a problem with them use lots of copper coat and torque properly good to go even put used gasket off of different motor on it holds 250 psi of cranking pressure

M Diesel · Oct 26, 2011

(quoted from post at 19:15:56 10/23/11) i reuse head gaskets all the time on my pulling tractors never had a problem with them use lots of copper coat and torque properly good to go even put used gasket off of different motor on it holds 250 psi of cranking pressure

I pretty much do the same, especially on the same engine with a recent gasket. I have to reuse them on my old large IH gas start diesels. At $300 apiece "IF" you can get them it isn't a real hard decision. Granted they use fire rings but they work fine. And I use anti seize. Copper coat isn't about being sticky. It is about being a grease during the critical time when the gasket is settling in.

That H head has been loose for a long time. Not warped. Loose. With sloppy bolting those surfaces are probably warped by now too, but a new gasket will likely seal it up anyways. It's just an H.

That missing piece basically went out the exhaust quite a while go.

Found the compression problem with the H...

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