Scratching head over head gasket?

HOPPING DIESEL · Post by **HOPPING DIESEL** » Tue Sep 16, 2008 11:58 pm

Well... I think I have seen something new to me. I pulled the head off my 1.6 n/a and the head gasket looked rather odd. In several of the places where there should be cooling channels from the block to the head through the gasket (the triangular holes) there never was any triangular holes. Instead, they drilled maybe 3/16 size holes where the triangular holes would have been. A couple of them they drilled a bigger hole, but most are smaller. At first I thought it was corrosion, but scraping the buildup off, I still had a perfectly round hole through the steel. I always had a problem with it heating and I could never get heat in the car, always froze. Think I know why now. I will try to post some pictures. Also noticing the valves and pistons hit ever so slightly on a couple of cylinders. A couple of pistons are pitted on top, guessing from bad spray pattern. Back to the gasket... the pistons measure .75 mm at the highest which is a number 1 gasket. I do not see any notches or numbers on this gasket to give me any indication of what it is. To thicken the pot even more... there is a sticker on the side that says this is a VW remanufactured engine (canadian). It has been sleeved, standard pistons. I don't think VW would have cobbled this together, but I didn't realize someone else had messed with it before I got it.

I was hoping to clean this up, adjust the valves, and be able to put it back together and run with it but now I am starting to rethink my plans a little. I'll try to post some pictures I know it makes things easier. Any input would be much appreciated.

rsxsr · Post by **rsxsr** » Wed Sep 17, 2008 4:05 pm

Hello, not exactly sure what you are asking. In regards to the head gasket. Not all the coolant passages are the same size. This was done to control the circulation direction of the coolant through the head. So in answer to that question there were holes that were round say 3/16 to 1/4. As far as the valves hitting the pistons. The cam timing may be off. The gasket options were for piston to head clearance not valve to piston clearance. Not knowing the condition of the engine and wanting peice of mind, I would drop the pan and pull the pistons. You'll be able to inspect the rod bearings and the piston skirts. If the cylinder walls look good, you could deglaze the cylinder walls and replace the rings. Keep the bearings in order if they look good. They can be reused. If they look beat, you will want to drop the main caps and look at the main bearings. Hope that is a little help.

HOPPING DIESEL · Post by **HOPPING DIESEL** » Wed Sep 17, 2008 10:39 pm

I appreciate your input. Sorry... it was late and I really was not making sense.

I did not know they controlled flow that way. I have overhauled a lot of engines in my life but never seen that before. I will be curious to see the new gasket. I planned to pull the pan anyway so I will give it a good look.

Have no idea how long it went on that belt, so it could have stretched too in regards to the timing. What are the odds some of the valves got bent? Any good way to check that out?

Quantum-man · Post by **Quantum-man** » Thu Sep 18, 2008 4:08 am

I used to think that the small or non existant was down to sloppiness. As 'Fats' says it is probably coolant flow control. Note blanks coincide with inlet valves [on my gaskets at least] Even oil flow and return may have been considered and possibly gasket integrity

rsxsr · Post by **rsxsr** » Thu Sep 18, 2008 6:36 am

The valves if they touch hit very straight. This lessens the chance of the valves bending. Two ways to tell at this point. One would be to remove the valves and spin them in a drill. If they seem ok, you could then get some lapping compound and lap them back into the head. You will have a nice gray ring around the face and seat.

The diesel head does not have much of a combustion chamber, so you could test this way. Pull the cam out, mark you direction on the cam caps. Then with an syringe or oil can, with the head sitting upside up on a couple blocks of wood, put some atf into the intake and exhaust ports. On a used engine some seaping is normal. If you the atf flows out passed the closed valve you have a sealing problem. Diesel fuel wil also work since it evaporates slowly. One a head with the combustion chamber we flip the head upside down and fill the combustion chambers and see if they maintain their levels. At this point, a local machine shop could do a valve job for you. That way you would have a nice sealed up top end. They would also check the valve guides for wear and replace the valve stem seals which were prone to seap oil. Sorry for the ramble.

HOPPING DIESEL · Post by **HOPPING DIESEL** » Thu Sep 18, 2008 11:47 pm

While I am gathering information, does anyone have the part number for a 12mm stud kit?

libbybapa · Post by **libbybapa** » Fri Sep 19, 2008 12:21 am

The sizing of the coolant holes was done to the extent that the proper headgaskets for the diesel vanagon were different part numbers than any of the other diesel headgaskets. The only difference was the sizing of the various holes to compensate for the vanagon engine being tipped an extra 35Â° on it's side.

Andrew

HOPPING DIESEL · Post by **HOPPING DIESEL** » Fri Sep 19, 2008 11:35 pm

Quite interesting fellows, thank you for the info. Did not realize they compensated for vanagon engines in that manner. Quite ingenious. Thanks for the info Andrew. RSXSR thank you for your suggestions for checking the head.

I just have the bottom end to pull out and check over and then get the rest of the parts ordered. I think I am going to get the block cleaned up while it is stripped down. Solvent boiling is okay correct?

My other question is about replacing a piston or 2. I have a couple that might be questionable. Do I need to worry about throwing the engine out of balance? My thought is... I can take them to work and weigh them on an analytical balance and then match them up. Grind a little off the heavy ones if needed. I have done this to balance new hammers in a hammermill that were supposedly balanced. Made a HUGE difference. Does anyone know how much weight variance you can have across piston/rod assemblies?

Is there somewhere I can get valve springs? Jack is sold out

Thank for the help fellows!!!

tylernt · Post by **tylernt** » Sat Sep 20, 2008 12:08 am

HOPPING DIESEL wrote:I just have the bottom end to pull out and check over and then get the rest of the parts ordered. I think I am going to get the block cleaned up while it is stripped down. Solvent boiling is okay correct?

Well, I had mine hot dipped so I hope it's ok!

My other question is about replacing a piston or 2. I have a couple that might be questionable. Do I need to worry about throwing the engine out of balance? My thought is... I can take them to work and weigh them on an analytical balance and then match them up. Grind a little off the heavy ones if needed.

I read through the book but it didn't say anything about weight tolerance unless I missed it. It goes without saying that a weight variance will increase engine vibration though, and these things vibrate enough already. So yeah, I would balance them as well as I could. Not sure where it's safest to remove material though...

82vdub · Post by **82vdub** » Sat Sep 20, 2008 10:08 am

I did a google search for balancing an assembly and one website said to balance the pistons to within .5 grams of each other, and another one (Ford engine) said to balance to within .05 grams of each other. I wonder if this last one is a typo, as it doesn't take much to equal .05 grams of weight.

I would first start with using the same manufacturer and part number piston, then clean the old one as best you can (you don't want to balance the new pistons to the weight of an old piston with carbon on it). I would then try to get the new pistons to within a gram of the old one's. You may find that they are very close to the old pistons and no work would be needed (hopefully).

On the hot tanking, ask the machinist how much needs to be removed before tanking. Some tank solutions will eat the intermediate shaft bearings.

HOPPING DIESEL · Post by **HOPPING DIESEL** » Sat Sep 20, 2008 12:30 pm

Thank you for the piston info guys. I will get them cleaned up, weighed, and let you know what I find out. In some of Hagars writings he mentioned to never boil the block in caustic because it would either weaken the special metal cast alloy the block is made from or eat off some interior coating. Not quite sure, but I don't want to take a chance. I am going to replace the intermediate shaft bearings (thanks for the heads up fatmobile) just a little too much play for me.

tylernt · Post by **tylernt** » Sat Sep 20, 2008 12:36 pm

Our aluminum alloy cylinder heads would be damaged, but I've never heard about our blocks. I thought they were just standard cast iron?

libbybapa · Post by **libbybapa** » Sat Sep 20, 2008 5:33 pm

I would imagine that both intermediate shaft bearings and the oil pump bushings would need to be replaced if hot tanked.

Andrew

HOPPING DIESEL · Post by **HOPPING DIESEL** » Wed Oct 08, 2008 8:51 pm

I measured the piston cleaeance on the highest piston to be .07. But I got my old head gasket cleaned up and it is a 3 notch.

Any advice? I assume it would be best to go with a one notch unless there is some other reason they would have put a 3 notch in there. TO my knowledge, VW did the last rebuild.

HOPPING DIESEL · Post by **HOPPING DIESEL** » Sat Oct 11, 2008 11:08 pm

How much pitting is acceptable?