piston rings, cylinders, heads

[BusBerd]

I am in the midst of reassembling my engine. slowly.

I have been researching about how to check my deck height and CCing the heads and such to find the best compression ratio. few questions:

1. When installing the cylinders, do you use permatex on both sides of the gasket/spacer for the cylinder to case juncture? If so, doesn't that effect the carefully calculated deck height?? If not, doesn't that leave you (more likely) open to leaks??

2. (stupid question but here goes) while CCing the heads, do you simply plug the spark plug hole with a spark plug?(this will effect the displacement of the fluid effecting the reading)

3. I have new piston rings en route from BD. Will I need to gap the piston rings or are they all pre-gapped nowadays?

thats all for now. I'll keep it simple. Thanks!!!
_________________
"The large print giveth and the small print taketh away."
1977 Westfalia Camper Bus 2.0L Fuel Injected Engine, Manual Transmission

[SGKent]

you use RTV to seal the barrels, both sides of shims. That is the equal of the part number VW used. I use red RTV, some folks use black and some copper. I tried copper but it was too gummy for me and never hardened. It doesn't mess with your numbers enough to worry.

You use spark plugs screwed all the way in

you need to gap the rings and when done wash and dry them before using them. Most likely the book shows a 2 piece oil ring and you will get a 3 piece. The gap will be much larger. You put the rings in the cylinders and use a piston upside down to push the rings into the cylinders. Measure one ring and use it in EACH cylinder. Find out which cylinder is the biggest (widest gap). Then measure each ring and find which ring is the narrowest gap and widest gap. Be sure you don't start gapping rings in a way that the one left is too wide for the widest cylinder. Also measure the side gap. It is important. Do not swap pistons and cylinders around. Same piston in same cylinder.
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[WI sportmobile]

[BusBerd]

[BusBerd]

Also, In computing my compression ratio, how do i find the stroke of my engine? Are they all standard? do i need to measure it somehow?

I am assuming it is 71mm.

I have a 1977 bus, 2.0L engine with 94mm cylinders.


thanks!
_________________
"The large print giveth and the small print taketh away."
1977 Westfalia Camper Bus 2.0L Fuel Injected Engine, Manual Transmission

[Hoody]

No rings for the cylinders, They need to be lapped, go to Jakes site and the type4rum

[BusBerd]

[guitarman63mm]

[BusBerd]

[SGKent]

yes you can use valve lapping compound. That is what I used. Just look for an even lap. I roll the cylinder a couple of times, maybe 4 then lift a tiny bit and rotate it maybe 1/7 or 1/8 the way around and do it again. After you have gone about all the way around 1 time clean it up and look at the head and cylinder to see if the lapping mark is even and in contact all the way around. If it is you are done. If there are spots that have not touched then you have to deal with that. You can use a very light coating of copper coat on the top of the cylinder to help it create a carbon seal. Just shake the can really well and use a small paint bush like for a model to paint it on the top of the cylinder. A really tiny amount is all you need. The cylinder will seal metal to metal but the copper coat will ooze out a tiny amount and help start the process where carbon builds up around that seam and finishes sealing any small microscopic gaps.
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[BusBerd]

[guitarman63mm]

[williamM]

we used it on outboard cylinderheads when in west flordia as the salt content was so high. Have also used silver/aluminum paint in the same process.

As far as clean up from lapping compound-- most I've used is water based, so spit down the cylinder to make it flow and use a tooth brush and soapy water to scrub the chamber clean.
_________________
some days I get up and just sit and think. Some days I just sit.

opinion untempered by fact is ignorance.

Don't step in any!

[SGKent]

[BusBerd]

(apologies ahead of time if I don't know the technical identifier for each characteristic on a given part)
I tried laying the cylinders into the head and the outside diameter lip of the cylinder (not a cooling fin) comes VERY close to resting on the head. Which means that the inside (intended) mating surface of the cylinder and head would be gapped in the combustion chamber! I tried sliding an .004 feeler gauge under this outside diameter lip of the cylinder and felt drag against the head in a few spots.
So, I am concerned with lapping the cylinders to the heads now, which would even lessen that gap. Could I use the grinding compound on both the outside diameter step surface and the intended mating surface (between the head and the cylinder) just incase there is contact to the head from that outside diameter step on the cylinder?
I hope I am explaining this clearly enough...
_________________
"The large print giveth and the small print taketh away."
1977 Westfalia Camper Bus 2.0L Fuel Injected Engine, Manual Transmission

[Wildthings]

Have your heads be flycut since they were last installed? If so you can skip lapping the jugs to the heads. If your jugs are used then just lap them against a piece of window glass, if new they too shouldn't need lapping at all.

[BusBerd]

[Hoody]

Pay close attention to what Steve said....but after your cylinders are lapped I am a fan of the copper. Always tape it off and use it sparingly. The rest will burn off. It makes for the best seal when done properly. Gotta love dueling Gurus. I am not one of them.