John's t-4 engine rebuild

[wwebner]

Just spent an hour bringing this up to date. went to preview and it was gone Note to self,Don't forget to refresh every so often,or post and edit to continue

[toolbox]

Just spent an hour bringing this up to date. went to preview and it was gone Note to self,Don't forget to refresh every so often,or post and edit to continue

If you know the coding you can do it in word and then copy and paste it into the board...

[wwebner]

Just spent an hour bringing this up to date. went to preview and it was gone Note to self,Don't forget to refresh every so often,or post and edit to continue

If you know the coding you can do it in word and then copy and paste it into the board...

Thought about that,after the fact Post was getting picture heavy and time got away from me.

[wwebner]

OK,here we go again. Now that we have the crank and case oil passages cleaned and the case,including the mating surfaces. It's time to build the crank assembly. Chuck stopped by one day last week and when I turned my back,they had the crank built up.

T 4 crank build is the same as T 1 whith 2 exceptions. No oil slinger on the end of the crank and the rods are symetrical ie,there is no up and down. We put the rods on with the numbers on the cap and rod up,for no particular reason.
Bruce's crank build shows the pics That I missed.http://www.leakoil.net/forum/viewtopic.php?f=23&t=4227
We did set the crank bearings in the case halves and seated them on the dowels,then marked the center line. This makes it much easier to position the bearings when setting the crank in the case half and considerably lessens the chance of missing the dowel and ruining a bearing. This was done on all 3 main bearings that install on the crank.

Plugs installed where we tapped the main oil galleys

Center main bearings installed in both case halves,along with oil pick up with new o ring from gasket set.

Crank installed in left case half and ready to install cam bearings.

Rotate the crank assembly several times to make sure there are no clearance problems.
Now it's time to install the cam,aligning the timing marks.

This is where we ran into a small problem. The cam would not set down in the bearing at the gear end. This is why.

The outer diameter of the thrust bearing was about 1mm too wide,not allowing the cam to set down.
This was a Kolbenschmidt (Brazil) bearing. I had a German set in my stash,so,we could continue.
Like Art Brow used to say "I know it's a new part,but is it any good?" DON'T ASSUME THAT ANY PART IS CORRECT
With that issued solved,the cam setting like it should,and timing marks aligned,rotate the assembly several times to make sure every thing clears and there is no binding and the timing marks still line up. Now is a good time to install the distributor drive at TDC for #1 and hold it in with the distributor. Makes it easier to know where you are at as you continue with the build. Rotate a few more times.
Now install the oil pump (test fit) to check clearance.

Since we re used the cam gear and bolts from the cam that was in the motor on the new cam,we were fairly certain that there would be no problem. It is close,but no clearance issue.
Just a note here. ALL replacement cams come with bolt on gears. Most all replacement oil pumps will have clearance issues with the cam bolts and the pump. Note the low profile heads on the cam bolts. If you do not check this clearance,THIS WILL HAPPEN.

Now we are ready to stick the case halves together in the next installment

[John]

any updates?

[wwebner]

Takes longer to put together a comprehensive build thread than it does to build a motor

[wwebner]

Finally found some time to get back to this. BTW,John's motor is in and running

Now that we know that we can rotate the innards with no binding,we can go about sticking the 2 cse haves together.
I have used several different sealers for this and they all work. I have used Locktite 518 the last several times and so does Chuck.

a thin bead,then smear it with your finger.

Don't forget the cam plug. concave side faces the cam on all engines except T1 auto stick. we used permatex 3H around the outside of the cam plug.

Set the right case half over the studs.

There are 20 case bolts on the T4 motor along with washers.Three of them are easy to overlook.1 at the bottom front in the bell housing area,1 in the deep recess on the bottom,this is the 71mm one that holds the oil pick up,and one below the oil cooler in the left case half. the 6 main ones around the crank get torqued first ,from the center out.
It is best to give the engine a few revolutions at this time,to make sure there is no binding. Then the rest of the case hardware on the outer sides of the case. Wipe any excess sealer from the crank seal holes on both ends of the case. Also around the sump cover area and the oil pump area.

Before we install the flywheel seal,it's time to check the end play.
spec is .003-.005 We were at .005. Good to go.

a few more rotations,everything is looking good.

Install the front and rear crank seals. (T4 has one on the fan end also.)

Put a little lubricant around the inside of the seals,install the oil pump. Installing the flywheel now makes it easier to turn the engine over for the installation of the pistons.
Next up will be prepping the pistons and cylinders and the heads.

[wwebner]

Now it's time to prep the pistons. Don't be temped to skip this part.even if you bought new P&C's. these parts are coated with oil to keep them from rusting while waiting for you to buy them. This oil probably collected some dirt since manufacture,plus your rings may never seat. Take the pistons out of the cylinders and remove the rings and pins. Keep the rings in order as the middle and top can look similar. Clean the hell out of them. soap and water and brake cleaner.
We are using the pistons and cylinders that were in the engine. the cylinders were honed,pistons soda blasted, and we are installing new rings. Grant rings on the Mahle pistons. Clean the ring grooves. A old piston ring works well (break it to get into the grooves). Spray the grooves with break cleaner.
Now we are going to check the ring gap. Nor a bad idea to do this even with NEW pistons,remember,we have been seeing incorrect or bad parts even from "NAME" manufactures.
Install the top ring in the cylinder and square it using the piston to push it down.

spec is .014-.022 we are at .015
Now the side clearance.

spec is .0023-.0035 We have a TIGHT .003
You can now install the rings on the pistons. Note the top and middle (don't mix them up) are marked with "Top" on the side that faces up.

You can do this carefully with your fingers or use a ring spreader. Do this carefully,don't want to break one. follow the instruction that come with the ring set,or refer to "How to rebuild your Volkswagen air-cooled engine, by Tom Wilson.
Prior to installing the pistons in the cylinders,we are going to take one more step. We are going to "seat" the cylinders in the head. Apply some valve grinding compound on the mating surface of the cylinder.

Lap the cylinder into the head. Be sure to take a minute and mark which cylinder goes in which head chamber.

This is just an extra step to ensure that the cylinder seals in the head. (more on that when we get to the heads)
Clean the tops of the cylinders and the head surface thouroughly.
Now install the pistons in the cylinders. I did not get a pic of this,but,using a ring compressor install the piston from the top and push it down until the pin bore is accessible. Prior to this, you need to stare at things and determine which piston/cylinder is going on which rod. There is an arrow on the top of the piston. This arrow MUST point towards the flywheel. You also need to determine which direction that the pin will install from. On the T4 engine #4 has to be installed first with the pin installed from the #3 side. (the oil cooler boss prevents the pin from being installed from the other direction). Stare at it awhile and have a sequence planned.

Now before installing all 4, we will install one in order to measure deck ht. I did not get a pic of this process so I mocked up a Piston and cylinder. With the piston and cylinder installed on the rod. Check deck ht.

We measured .045in. write this down on you build sheet along with the head vol (cc's) the you did a while back.
More in a bit. I just got called to dinner
OK,I'm back
I need to back up a bit here. Normally there is a gasket or "shim" at the base of the cylinder where it meets the case.
I measure the deck ht. WITHOUT THIS shim/gasket. THEN, figure the compression ratio. With a stock or NON STEPPED head, you do this,substituting various shim thicknesses to get to the comp ratio desired. 7.1:1 was the stock ratio. This is a bit low,but VW was trying to meet emission standards and lowering the comp ratio was what they did to do so. I shoot for 7.6:1. This is the comp ratio for U.S. spec 2L Porsche 914's. Euro spec (flat top pistons) were 8:1
I knew that with the AMC stepped combustion chamber we would probably not get to 7.1:1. I was correct. With a 60cc chamber and .045 deck ht on a 2L (1971cc) engine we were at 6.8:1. If we were off 3cc on our head cc measurement (possible), we would be at 7.1:1. So,that's what we have. No way around it other than taking the heads to the machine shop and have them mill the step out. The good news is that the previous builder had a .030in shim at the cylinder base,which made John's previous comp ratio 6.4;1. So,we are still better than it was.
Since we left out the bottom "shim" we used Loctite 518 around the base of the cylinder. Even with a shim or gasket,this mating surface needs a sealer. (NOT RTV SILICONE). Some builders use this,but you need to be carefull and use it sparingly as it builds thick and you run the risk of it getting into the sump and possibly clogging things up,which is what had happened to this engine.
Next up. prepping and installing the cylinder heads.

[Josh]

Impressive Bill!

[Kooper271]

This is the thread that brought me here. Planning to have my heads done at Delzani's.

Teach me your ways!