Coming To A Conclusion Slow But Sure...

Finally received my head for my KZ-1000 back from APE yesterday. It looks like they did a very nice job, but I elected not to fix the crack in the exhaust stud boss while they had the head. The cost of the repair would have been quite expensive and there would have been no guarantee it wouldn't crack again. It was a real Catch 22 for me, fix it and put a ton of money into something that may go bad again or find a new old head and have it refurbished or have my head gone over and leave the crack alone and see what happens. With $80.00 into the head just shipping it to APE I thought the best bet was to leave the crack as is and repair the other issues with it. Hopefully I will try and avoid stressing the bolt that sits in the cracked boss too much and it will survive. I think in order to avoid turning the stud into the head too far I am going to put some permanent thread lock compound on it and leave it setup. Then I will just use due caution when torqueing down the exhaust manifold nuts on that #1 pipe.

APE replaced all the guides and seals and installed 4 new exhaust valves. I believe they replaced all the intake valves also with good used ones they had in stock as two of mine were bent. They did a complete valve grind on it and surfaced the head then sent it back to me. I noticed that there is very little intake valve stem tip protrusion from the top of each valve spring retainer which concerns me a little. There is a great deal more valve stem tip protrusion from each of the exhaust valves. I am not sure if this is normal or not, as I don't want the tappet block to come in contact with the valve stem keepers and/or the valve spring retainer. Thankfully there is a center section protrusion on the inside of the tappet block that rides on the valve stem itself. This protrusion inside the tappet block seems to be about .015" and helps keep the block off anything but the valve stem. I even went as far as putting some machinists dye on the inside of each tappet block and each valve stem to make sure there was no interference with other parts and there's no evidence of any.

I have the cylinder block out having the bores resized to accept larger pistons. The size of the pistons will be determined on how much material must be removed to eliminate the pitting that took place within two cylinders. I am hoping to go to 1045 cc, but we will see. Once the size is determined then I can order my piston kit from Wiseco. I do have a question for the membership here, in the factory service manual it talks about putting some liquid sealer around the four center studs on the rear of the engine block and then wipe off any excess. Do they just want the counterbored hole around each stud, where they meet the block, filled with sealer? The picture and explanation isn't very clear on this. Thanks for any help on this.

Rick H.