Another Head Gasket

[mt4x4]

I Started Pulling things apart yesterday. I have a leak between the heads. It does not seem that bad but its on its way now. I ordered the head gasket from Big Mike's http://www.bigmikesmotorpool.com/co.../head-gasket-set-for-multifuel-engine-5702678 So far i got the injectors off and in the shop to be tested. I took them to Oregon Fuel Injection. I ordered the injector return line fitting from here http://www.supplyhouse.com/Jones-Stephens-C74-158LF-1-4-Lead-Free-OD-Brass-Pilot-Line-Breakaway-Nut per the sticky. I just about got the heads off. Maybe tonight. I plan to have the heads looked at. I keep finding some people say shave some off no matter what and others say if you don't need to than don't. I have done some searching and keep finding posts with links that don't work to other posts. Seems like we should have a sticky for changing the head gasket. Does anyone know of a shop in Oregon that knows what they are doing with these heads? Do most people send them off or just take them to a local shop?

 

[clinto]

http://www.steelsoldiers.com/showthread.php?11295-All-this-for-a-freeze-plug-!

Any machine shop can do the heads.

There is a difference between "shaving" and "resurfacing".

Shaving is taking material off the entire bottom face of the head, in order to reduce to capacity of the combustion chamber. This is done in order to raise compression ratios without having to buy new pistons. I would not allow anyone to shave a multifuel head because the combustion chamber is basically in the cylinder and so any small amount you remove will make a big difference.

Resurfacing is when the machine shop puts a machinists edge on the head to ensure it's straight and then they clean it with something that is abrasive enough to remove carbon, old gasket material, etc., but is not abrasive enough to remove actual material, like the iron the head is made out of (or aluminum if you're fancy). If the head is warped, then a few thousandths will be removed in order to get the head straight. I rarely encounter heads that are warped unless there was significant overheating occurring. The '05 Civic below got hot enough to blow the head gasket but the head wasn't warped.

If you have a straight edge that you trust and your head is perfectly flat, then you can clean it with whatever you wish, as long as it leaves the surface clean and smooth. I use 3M pads on a die grinder. I've done it for 20 years and never had an issue but I'm sure someone out there will scream about how it is removing material. The Honda Civic engine deck below is one of a hundred I've done this way.

 

[snowtrac nome]

ive used scotch brite for years also 220 on a da sander works well but you must be careful the gasket needs a certain amount of roughness in both surfaces to grab on too.

 

[mt4x4]

Ya resurface is what i was thinking not shaved. I will probably replace the freeze plugs too.

 

[mt4x4]

How about having the heads tested for cracks? Do you guys normally do this? Does the m35a2 normally have cracks that need to be fixed?

 

[snowtrac nome]

it's a steel head and crack check should be in order it can be magnafluxed most guys use dye glow now instead because its cheep and works with aluminum parts too. if I can get a dye kit here in nome I would expect you can get one there too

 

[mt4x4]

I got the back head off tonight. I have the new style gasket and there was nothing wrong with it. I thought for sure it was number 4 but it must be 3. I decided the head gasket needed to be replaced because it was making a tick noise. just like in this video https://www.youtube.com/watch?v=qEIHjNoIeNU. I did not see anything coming out of the head gasket so i sprayed some water in between the heads and the tick went away for a second or two as the water was blown back out. It also leaks oil along the right side. Is there anyway this could not be a blown head gasket? Can a head gasket leak compression without it being blown out?

 

[rustystud]

Your head gasket is leaking pretty bad there coming out of number one !

 

[mt4x4]

Sorry i should of explained more. This is not my video or truck. My truck just sounds like this one. My truck was not blowing out number one like this one.

 

[snowtrac nome]

funny I have seen this twice this year one on a mistsubisi engine in a forklift and the second time on a 3306 cat both engines needed head replacements the 3306 had bad valve guides and seale the mits engine was eroded from driving it too long like that. in this case I would certainly have the head resurfaced just incase there is some erosion there you might not see.

 

[mt4x4]

I got the front head off this morning. Looks like it was number 3. There is a crack in the ring. I'm going to try to attach a picture.

 

[mt4x4]

The heads are at the machine shop. I printed off the pages in the tm about the heads and gave that to the guy for any info he might need. He told me he has not got to them yet so he is not sure what all needs to be done but he did not see any info on the minimum valve recession. He explained to me that its ok to take off more than .005 if needed as long as he sets the valves the same. I keep reading on here not to take off more than .005. Is this guy correct? Should i find a new shop? Is there something i need to explain to him before he starts working on them?

 

[mt4x4]

The shop just got back to me. No cracks. Both heads are flat until the front edge which is .007 to .01 low. This is the same on both heads. He says it looks like it was machineed this way. What do I do now?

 

[rustystud]

The heads are at the machine shop. I printed off the pages in the tm about the heads and gave that to the guy for any info he might need. He told me he has not got to them yet so he is not sure what all needs to be done but he did not see any info on the minimum valve recession. He explained to me that its ok to take off more than .005 if needed as long as he sets the valves the same. I keep reading on here not to take off more than .005. Is this guy correct? Should i find a new shop? Is there something i need to explain to him before he starts working on them?

He's correct and not correct. The normal head can take up to about .020" off with no harm as long as you reset the valves that same amount. The problem is the heads on the multifuel. The amount of material available to take off is not as much as more modern heads. Since the compression ratio is so high (22:1 ) you need more material to safely operate. I would stay with the TM's recommendation.

 

[rustystud]

The shop just got back to me. No cracks. Both heads are flat until the front edge which is .007 to .01 low. This is the same on both heads. He says it looks like it was machineed this way. What do I do now?

I would just run the heads with the newer style head gaskets and see what happens. Make sure your head "studs" are in good condition though. It wouldn't hurt to remove them all and run a tap down each hole and thoroughly clean the studs before reinstalling them. New "grade 8" nuts wouldn't hurt either.

 

[mt4x4]

Thanks for the reply. I need to go look at them in the shop to see just where they are low. The leak was on the back of the front head and the shop says they are low on the front of the heads. Seems my problem should of been a leak on the front of the head. I want to make sure one of us is not confused. I'm also wondering how far past the edge are they low. If it's half way through the cylinder that seems like a problem. If it's only leading up to but not including the ring seems like I might be OK. Keep it coming I want to know what everyone thinks.

 

[mt4x4]

I looked at the heads today and the low spot is where the gasket leaks. The shop talk me in to letting them fix it. looks like my truck will be a Guinea pig for removing more than .005.

 

[cheepsk8]

Did the heads turn out ok?

 

[mt4x4]

The shop fixed one head. They found that on the other head something with the valves would of been too thin. I don't remember now. I bought a NOS head as a replacement. As i look back i wish i had just replaced both heads but so far i have had no problems. The truck seems to run good as far as the heads go.

 

[cattlerepairman]

I straight-edged the thoroughly cleaned deck and replaced both heads with OEM heads, used new style gasket. Result: it oozes here and there. Re-torqued heads. Result: It still oozes here and there. I could get really angry about this - but since it starts as soon as you think about touching the button and runs like a scalded rat, I decide to smile instead and enjoy the drive. What's a little bit of brake cleaner to wash off oil traces.