Quote from: 96_yota on September 07, 2015, 01:40:13 pmThe only reason I don't think all four pistons were replaced is because three (1,2, and 4) all have the same numbers on the 76.98mm and a few other numbers stamped into the tops where piston number 3 is completely flat with no numbers in it.Are you suggesting that the previous owner over-bored and replaced the pistons on only three of the four cylinders. I've never heard of such a thing. Yes, the three that are marked are oversize and so obviously not original. The one that does not have any markings is ALSO not original and I would be astounded to find that it was not the same diameter as the other three.
The only reason I don't think all four pistons were replaced is because three (1,2, and 4) all have the same numbers on the 76.98mm and a few other numbers stamped into the tops where piston number 3 is completely flat with no numbers in it.
I've never heard of a machine shop over-boring just some of the cylinders. I believe it would cause significant imbalance in the engine. You said the single piston is just flat, are you saying it doesn't have the cloverleaf cutout?
...BTW your Bieber avatar is awesome.-Malone
You will need to plug that 2nd oil hole as Dakotakid pointed out. That should have been done before. No CY should have been hydraulic, so you may have a mess there.
Your picture of the head clearly shows the oil hole between Cyl 1 and Cyl 2 which is only present on hydraulic heads. The solid lifter heads have a coolant channel there and a depression on the outside of the head rather than the extra bump...
Make sure you actually have a CY block. If you have a hydro block all is well, but CY was never a hydro. You could block that passage and run a mechanical head gasket as that is what I am doing right now on my CY engine, but if you have to go through the entire head and you could find a solid lifter head cheaper, do whatever. Someone may need a core hydro head and you could recoup some cost. Or do as I did, whatever works
This is a supplement to all the above. I never knew they made hydro "CY" blocks. I DO know that CY blocks appear to have a bit more nickel in the cast iron and that substantially helps with engine life (without making machining more difficult). The CY's actually physically feel heavier when you grunt the empty block around.Here is an additive to help you in the rebuild: do NOT fit crankshaft bearings with an integrated center main. THAT is all the parts places want to sell these days and it is NOT the hot ticket. Integrated center bearings are like "loaning" your girlfriend to the local biker gang.....NOT good!If you NEED crank bearings, buy a set to fit a 1997 AHU tdi diesel. Those are the IDENTICAL bearings the way they used to be sold for our little pea-shooter engines. If your engine is currently fitted with an integrated center, you will have to acquire the four thrust bearings (shims/inserts) to be fitted along-side the center bearing.Also, do not overlook wrist pin bushings as well.......a lot of these guys do.....don't you make that mistake.EDIT: Also, those rods will need a reconditioning or good check/measurement. You are going to be attempting to use this engine to pull a heavier vehicle than it's original purpose (unless it originally was in a vanagoon. Anyway, I personally would NOT take any shortcuts on the rebuild.
