1.6 TD rebuild questions

[Orb95]

I have discovered that my TD has developed some really bad blow by and am considering rebuilding the block. I had some questions about what route I should go. This being one of my first engine builds, I don't know if it is best to go one size up in pistons, or just hone the cylinders and re-ring the stock size. The motor still runs strong but the amount of oil and pressure being blown out of the valve cover, and crank case has me very concerned come winter time. I see the many rebuild kits Parts Place has for sale and was going to order one from them. Any input of piston sizes would be greatly appreciated.

Thanks,
     Owen

[ORCoaster]

The size you need depends on the current wear on the cylinders.  What you need to do is take it apart, measure the cylinders top and bottom at their widest points then decide on the size you will need for the round hole you need to make.  Pistons tend to wear more on one part than the other and can make the cylinder an oval and what you need to figure out is the size of the hole if round that would make the fit within specs.  Which by the way are pretty tight.  That is why we get the blow by in the first place.  23 to 1 compression remember.  Nearly 500 psi, it has to be a tight fit to hold it in place.

So before you buy parts and bore the cylinder to that size and spend your coin doing that. Make sure that the hole size you make is what it needs to be or you will be looking at blow by again well before you need to be. 

Just my thoughts for this glorious day in Sept.

[libbydiesel]

Does the blowby increase or decrease when you rev up the engine?  If you set the oil cap in place without tightening it, is there enough blowby to blow it off the engine?

I agree with taking it apart, or at least taking the head off.  Unless the ridge is really deep or there are deep grooves in the sides of the cyl, 0.5mm up from the current size will almost always clean it up.

Make sure whoever does the boring is well versed with VW diesels.  The spec piston to cyl clearance of 0.0012 is very tight and many machinists will bore it too large, essentially giving you a block that is already half worn out to the next piston size.

Before taking the pistons out, measure the piston protrusion of all four.  Make sure you clean the carbon off the tops of the pistons first as the carbon can easily be enough to go from 3-notch to 1 notch on the gasket.  When you get the new pistons, measure the wrist pin to crown height on the old and the new pistons (new German pistons usually move the pin bore up 0.010" with each oversize) you can then tell the machinist how much to take off the head gasket surface of the block to be in spec for the head gasket sizes.

[Dakotakid]

And, you can do a lot better simply buying parts individually than by getting "bent" from Parts Place.
German Auto Parts place is another seller which I can not understand why so many of these guys take a good "bending" there as well. I out-grew both of these sellers when they were no longer comparable to places like autohausaz.com and some other places.

Additionally, the heads on these cars/engines need thorough rebuilds just as much as the block. None of this is "cheap" (if done right), So, brace yourself.

You need to spend time reading through years of discussion of stuff exactly like you are asking. For a topic like this, I probably would not even use the "search" feature. I would just go back and look for the descriptors in the name of the thread. Knock yourself out.

[libbydiesel]

I agree on avoiding Parts Place.  Their prices are quite high AND a lot of their stuff is Chinese knock-off parts.

Autohaus has been a bit disappointing to me lately.  They seem to have dropped a lot of higher quality brands and are going with more Meyle and Uro, etc...  They have also dropped a fair amount of selection and increased their prices.  Heat shields are now over $6 each?  To top it off, they take at least one additional day to ship an order.  It used to be that if I placed an order before 11:00 a.m. I'd receive it the next afternoon.  Now it is usually two extra days on top of that.