why not just reseal?

[77targa]

hello all i am in the process of a 2.7l reseal project engine is out i am at the point now of removing the timing chain and covers, anyways i am following the book how to rebuild and modify and i am scared to take the crankcase and pistons apart simply because the book states that there are different types of cylinders and one type u cannot hone or reuse. if the bearings and crank rings and valves are good why cant u just reseal the engine and put back together? i dont know its my first one so any pointers are appreciated thanks

[Dixie]

If it ain't broke, don't fix it.

If the only issue is leaks, then just reseal it. Did you get compression numbers before dropping the motor?

[T77911S]

i dont know how bad your leaks are, or the condition of the engine, but it sounds like a lot of work and money to stop oil leaks. if the seam is leaking, you will likely need to have the case machined to stop the leaks.
you may just want to replace the gaskets on the timing chain covers, put on the turbo valve covers, and if the front and/or rear seals are leaking, replace them.
are you familiar with timing the cams and do you have the tools to do it?

maybe a little more info as to the why's and how come for the rebuild.

[77targa]

well im not sure if the case was leaking or not but compression was good so what the hell ill just reseal the rest of it and leave the case for now im just used to the old american engines this porsche stuff if really neat but a little pricey in a sense any way to tell what cylinders i have without removing them? thanks for replys all.

[77targa]

howcome you recomend the turbo valve covers? as far as the tools go i will need to get them

[Superman]

Good question. I've been told there are differences in the number of fins on the two types of cylinders (Alusil v Nikasil).

FWIW, here is my personal experience:

I disassembled my engine because a Dilivar (exhaust side) heat stud had snapped. They do this. Corrosion.

It is nearly impossible to replace head studs without removing cylinders, so I removed them. In fact, I took the engine down to the cranks. I found valve stems that were fairly worn, so I replaced the valves, guides and seals. I found the rings were at the edge of spec, so I replaced them. I had Alusil cylinders, which are not hone-able. I cleaned them within an inch of their lives, virtually etching them. They changed color a bit. I believe this was the key to my success. The new rings seated fine on the Alusil cylinders. They might not have, if I had not cleaned the heck out of those cylinders. The pistons were well within spec, so I reused them too.

The rear main bearing was showing some brass (wear) as was the layshaft bearing. I replaced them. No biggie.

Aside from the cylinder re-use problem, your engine has additional needs. Mine was a 3L with the aluminum case. Yours (probably) has a magnesium case. Those cases can have their own issues, such as stripped stud threads and main bearing saddles that may have gotten out of alignment.

We don't know where your leaks are that you are trying to reseal, but a reasonable approach might be to not remove cylinders or open the case. There are seals between the chain housings and the cam housings. There are seals you can ADD to the rocker shafts, and if the engine is out and the chains are off, this would not be difficult. This would seal many of the common leak points. When you start taking heads and cylinders off, and case halves apart, you are likely adding a fair bit of money to your project.