Leaking Head Gasket.....I'm stumped

[Mike'sHorseBarn 2,942]

I have a head gasket on a k341 that refuses to stop leaking. I've had the head off and "planed" it on my piece of granite counter tip like I've done with many other heads. Has a new head gasket. I had the head off twice and tired a different gasket. Bolts are torqued to 30 ft lbs. I honestly don't know what else could be wrong. Any ideas or am I searching for a new head? Also I purchased this tractor at auction so I don't know it's history, but from what I can tell I guarantee this thing was run hot. I put a new exhaust valve in it to replace the burnt one that was in it. 

 

 

 

Edited July 25 by Mike'sHorseBarn

[oliver2-44 9,379]

What does the top of the cast iro cylinder look like? 
Ck this. Bolt the head on lightly snug with no head gasket. Go around with feeler gages and mark any gaps. (You could also use some machinery Blue). Now torq the head down and recheck your gaps. This should show you any trouble areas of the block surface. 

 Any pitted areas?

 

[Mike'sHorseBarn 2,942]

Top of the cast iron cylinder looks normal. No pits or anything. I'll have to bolt the head on with no gasket and check for gaps.

[RED-Z06 2,203]

361s were picky with the ohv head, had to use a kohler gasket, and copper sealer on both sides, lube the head bolts and torque in sequence, warm up, then retorque...never had one blow twice.

 

Edit- looks like a flathead in the pictures, 341?

[ri702bill 8,081]

6 hours ago, RED-Z06 said:

lube the head bolts and torque in sequence, warm up, then retorque.

Chase the threads  - by hand - in the block and wire wheel the head bolts. As I recall, there are hardened washers required under the hexheads on 3 of the bolts on large block Kohlers. Per the manual, torque the head in 10 ft/lb increments until reaching 30 ft/lbs and do one more pass.

Use a genuine Kohler head gasket that has the metal "fire ring" on the inside. Doing this helps prevent the compression blowing out the gasket, by necessitates retorquing - in the proper sequence cold several times. A cast iron block, aluminum head, steel head bolts and the gasket - all different materials that heat and expand at different rates.

Curious - did it seem too easy to unscrew the bolts with the bad gasket??? If so, they were not properly torqued.......

 

 

KohlerKseriesManual.pdf

[squonk 40,703]

New flange head bolts may help as well.

[953 nut 54,262]

Mike, did you warm the engine up and then retorque the head after it cools down?        Has the gasket blown out at the same point both times?

You could check the block surface by using some Prussian Blue (or a good old magic marker) on the mating surface of the block and adhere some sandpaper to your granite and gently sand the color away seeing if there is a low spot.

[Mike'sHorseBarn 2,942]

8 hours ago, RED-Z06 said:

361s were picky with the ohv head, had to use a kohler gasket, and copper sealer on both sides, lube the head bolts and torque in sequence, warm up, then retorque...never had one blow twice.

 

Edit- looks like a flathead in the pictures, 341?

 

It is a 341. My fat fingers typed 6 lol 

[Mike'sHorseBarn 2,942]

2 hours ago, ri702bill said:

Chase the threads  - by hand - in the block and wire wheel the head bolts. As I recall, there are hardened washers required under the hexheads on 3 of the bolts on large block Kohlers. Per the manual, torque the head in 10 ft/lb increments until reaching 30 ft/lbs and do one more pass.

Use a genuine Kohler head gasket that has the metal "fire ring" on the inside. Doing this helps prevent the compression blowing out the gasket, by necessitates retorquing - in the proper sequence cold several times. A cast iron block, aluminum head, steel head bolts and the gasket - all different materials that heat and expand at different rates.

Curious - did it seem too easy to unscrew the bolts with the bad gasket??? If so, they were not properly torqued.......

 

 

KohlerKseriesManual.pdf 14.16 MB · 1 download

 

It was definitely too easy to unbolt the head the first time. I'll try this sequence and see what happens. 

[Mike'sHorseBarn 2,942]

21 minutes ago, 953 nut said:

Mike, did you warm the engine up and then retorque the head after it cools down?        Has the gasket blown out at the same point both times?

You could check the block surface by using some Prussian Blue (or a good old magic marker) on the mating surface of the block and adhere some sandpaper to your granite and gently sand the color away seeing if there is a low spot.

 

These are new spots from when I first took it off. I had put sandpaper on my granite and you could definitely see that the head was warped. I sanded and sanded until I got it flat.

[Keaton 370]

im, no expert on this by any means, but what about a thick copper head gasket, or do they make those anymore, or are they available, I would stack mabye 2 dpepending on the thickness, again I'm not every experienced compared to any of you either

[Keaton 370]

23 hours ago, RED-Z06 said:

and copper sealer on both sides

that also would do it I'm guessing because copper should show you the problem

[953 nut 54,262]

22 hours ago, Mike'sHorseBarn said:

I had put sandpaper on my granite and you could definitely see that the head was warped.

How about the engine block?  You did say it had been run hot before you got it, could be some deformation of the mating surface of the block.

[squonk 40,703]

1 hour ago, 953 nut said:

How about the engine block?  You did say it had been run hot before you got it, could be some deformation of the mating surface of the block.

I agree. That leak is right at the exhaust area

[Mike'sHorseBarn 2,942]

I'm thinking of trying some copper gasket spray. I just want to get it through until it comes time to fix it up. It could very well be that the mating surface is warped. When I paint this one, I'll tear the engine down and get everything planed 

[Joe Shmo 157]

That second picture sure looks like it has a huge gap in the head.

[sqrlgtr 549]

13 hours ago, Joe Shmo said:

That second picture sure looks like it has a huge gap in the head.

Agree looks like a big gap, If it was me, I would be looking for another head. Looks like time you got that one flat there might be clearance issues. Just my  though..

[Mike'sHorseBarn 2,942]

So I messed with this this morning. I have gaps as big as .006 with the head laid on the bare block, no gasket and the heads been planed. So the mating surface has to be warped. I have a pretty good gouge in the bore as well. This engine will definitely need a total rebuild bu I put a gasket on with copper spray on it to see if I can keep it sealed until thay day comes. I have too many other irons in the fire to send an engine off for a $1,000 rebuild. It'll have to wait a year or two.

[Mike'sHorseBarn 2,942]

Update: that didn't work either, just blew out the sealer.

[RED-Z06 2,203]

38 minutes ago, Mike'sHorseBarn said:

Update: that didn't work either, just blew out the sealer.

Might try the planing again, periodically turn the head for even pressure.

[lynnmor 7,229]

17 minutes ago, RED-Z06 said:

Might try the planing again, periodically turn the head for even pressure.

We still don’t know if the head is warped or the block needs flattened.

[RED-Z06 2,203]

9 minutes ago, lynnmor said:

We still don’t know if the head is warped or the block needs flattened.

A warped deck is definitely possible but usually the thinner aluminum part will warp before the much thicker cast iron.  Ive had K/M heads so warped they split during torquing.  

[ranger 1,714]

One thing that I’ve done before with warped pressure washer heads is to carefully’press’ them back into a semblance of flatness using a hydraulic press. If you have a decent gas torch, you could try loosely fitting the head to the block, without a gasket. Then gently heat the whole of the head with the torch, and tighten the head bolts fully. Keeping the head nice and hot for a few minutes afterwards. After it cools right down, it may then be ‘flatter’, and need less ‘planing’ to get a seal? Providing of course, the block is not distorted? The idea of thicker, or fitting two gaskets is not usually a good idea, it can cause more distortion!

[lynnmor 7,229]

1 hour ago, RED-Z06 said:

A warped deck is definitely possible but usually the thinner aluminum part will warp before the much thicker cast iron.  Ive had K/M heads so warped they split during torquing.  

In post #18 he basically said it was the block, but apparently nothing was done.

[RED-Z06 2,203]

43 minutes ago, lynnmor said:

In post #18 he basically said it was the block, but apparently nothing was done.

Assuming the head is planed flat, doesn't take alot to shadetree plane a head uneven.  I wish i had access to a bridgeport, ive got 3 or 4 heads that need it but are holding for now.