Bill's T4 engine build

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wwebner
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Joined: Mon Dec 15, 2008 7:34 am

Re: Bill's T4 engine build

Post by wwebner » Mon Dec 30, 2019 12:02 pm

In my last post, I was a little vague on setting end play, and I had no pics of my build. So, I thought I would mock it up and provide a little more info. First, shims are sold in metric increments. So here's a little chart.
0.24mm= .0095in
0.30mm= .0118in
0.32mm= .0126in
0.34mm= .0134in
0.36mm= .0142in
0.38mm= .0150in
I doubt that any of us have a metric dial indicator or micrometer.
as mention prior, I pick 2 shims and measure them.
We'll call this one .013 (actually .0134)
end play 002.jpg
This one .014 (actually .0142)
end play 003.jpg
So, we have a 2 shim set of .027in
Install them on the crank.
end play 005.jpg
Before we install the flywheel, clean up the mating surfaces and remove the o ring if it is still there. ( don't forget to install the new o ring from the gasket set before final installation of the flywheel)
end play 008.jpg
clean well, both mating surfaces.
end play 011.jpg
A good time to clean up and polish the nose that sits in the oil seal. Some fine steel wool works.
end play 009.jpg
I like to polish this area. check for any grooves. Just make sure it's nice and smooth to avoid oil leaks.
end play 010.jpg
Install the flywheel and attempt to torque it. this can be difficult to get to 80 ft.lbs without a flywheel lock, A large flat blade screw driver in the flywheel teeth will work. Get the bolts as tight as you can. Even is more important than getting to actual torque spec. Getting a dial indicator mounted is also tricky when working with just the case half. So. we are going to use a feeler gauge here.
Here we have a nice tight .020in.
end play 007.jpg
Now for some math.
we want to get to .004in (+- .001) to be at spec.
We have .027in in shims. .020in gap. deduct the .004 from the .020in. that we want for our desired end play = .016 shim needed for the 3rd shim. there is no .016 shim, so we use .015 and should end up with .005in for our end play.
You can work various combinations for this. But, in searching various suppliers, they cost between $8-$10 each.so use what you have and determine the shim you need before dropping $'s on a bunch of sizes.

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wwebner
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Re: Bill's T4 engine build

Post by wwebner » Sat Jan 04, 2020 1:08 pm

OK. Back to getting the case have ready to assemble. NOTE: we will check end play after assembly again.
First, get all the case hardware together. There are 20 bolts/nuts, including the 6 long thru bolts around the crankshaft.
(you did set them aside ;) ) I had all mine plated, as a local plater will plate a hole bucket full of stuff for $50, and I had a bunch of other grungy stuff to plate. Nice part is, he has to bath them before plating, which saves the time ans mess of my doing it.
2L 118.jpg
2L 086.jpg
ALL the nuts and washers get a little Permatex to seal them up.
2L 119.jpg
Type 4 main thru bolts get this to hold them in place,the bolts install from the case half that is now on it's side.
2L 120.jpg
Don't forget the cam plug.Wipe the circumfrence with some Permatex 3H. One of the few places that RTV is acceptable,if you choose.
Smear some white grease on the gears. This helps cushion and lube things up until we get oil pressure when we first crank it over.
rods 024.jpg
Some cam lube on the cam lobes. In the "old days" we used STP for this.
2L 115.jpg
Wipe both case halves clean with a rag and brake cleaner.
Now we can apply the case parting line sealer. As Bruce mentioned, there are many and they all work, except, NO RTV here. It builds too thick and does not allow for proper bearing crush. I have been using Locktite 518. One case half only.
2L 131.jpg
You can smear it around.
Picture 040.jpg
Short break.

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wwebner
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Joined: Mon Dec 15, 2008 7:34 am

Re: Bill's T4 engine build

Post by wwebner » Sat Jan 04, 2020 2:30 pm

Now we are ready to mate the case halves. Before we do, this thread is not meant to be a step by step instruction. Just a guide. You do need a manual or two. The Robert Bentley, and Tom Wilson's " How to rebuild your Aircooled VW engine are excellent.
Now, an extra pair of hands helps. You need tho get the 6 main case bolts aligned in the other case half, while holding the 1 & 2 connecting rods up. I tied the rods after getting the thru bolts inserted in the other case half.
2L 132.jpg
When you get the case halves seated, coat the washers and threads with some Permatex 3H.
2L 133.jpg
I like to snug these up and rotate the assembly before going any further. You can bolt the flywheel on to help rotate.
rotate several times. If all is good, install the rest of the case parting hardware. There are wavy washers on all of them,bolt heads and nuts. I still like to put a little 3H on them.
Don't miss this one.
2L 137.jpg
Or this one. I like to get this one first (after the 6 main), just to be sure the pick up tube is aligned. Sealer here,along with the wavy washer is important, as it sits in the sump area.
2L 134.jpg
Torque them all according to sequence in the manual. Rotate the assembly often to be sure nothing is binding.
Once you are satisfied that all is good, wipe excess sealer from the oil pump area, and both crank seal areas.
Picture 048.jpg
2L 138.jpg
Whoo Hoo.
2L 136.jpg

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wwebner
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Re: Bill's T4 engine build

Post by wwebner » Thu Jan 30, 2020 12:18 pm

Sorry for the delay in continuing. Got a little busy. I'm going to back up a bit. Since I did not take pics and document the modified type 3 oil pump from European Motorworks, I'll explain a little now.
Jorge modifies the type 3 pump shaft to work with type 4 cam gear.
As you can see, the flange on the type 3 pump is considerably thicker than the stock type 4 pump. This requires installing longer studs.
type 3 oil pump 006.jpg
type 3 oil pump.jpg
Installation is the same as type 1. A thin coat of permatex 3H on the gaskets, or if you choose,or hi tack, or gasket shellac. Just a thin coat. Be careful to not get sealer in the oil groove in the pump or the holes in the gasket.
type 3 oil pump 008.jpg
type 3 oil pump 009.jpg
Also, a thin bead of Yamabond around where the pump body to ensure no leaks.
type 3 oil pump 007.jpg
Pack the gears and the pump body with white grease. This helps priming the pump to get oil pressure quickly. I also pump some oil down the oil pressure switch hole prior to initial turn over.
Install the cover gasket and cover and coat the stud threads with permatex. I also like to use a sealing nut.
type 3 oil pump 004.jpg

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wwebner
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Re: Bill's T4 engine build

Post by wwebner » Thu Jan 30, 2020 3:45 pm

Moving on. I will spend a minute on the heads, which we will get back to later. I acquired these heads 15 or 20 years ago
and set the aside for this future build. Short story, they were part of a gift to me from a customer. They came from Mark Stephens High performance around the time they were closing the shop. the first thing I noticed, along with the port and polish work, was the chamber work AND, the head cc. 61cc as opposed to the stock of around 55cc.
Stock 2 liter head.
2L 006.jpg
My head.
2L 007.jpg
My original intent was to use stock 94mm 2L pistons which have a 7cc dish. plugging the 61cc head chamber volume along with my desired deck ht. of .035 to .40, I realized that my comp ration would be too low, under 7:1
So, while the heads were sent off to Delzani's to install my new stainless steel valves and the valve springs supplied by the cam manufacture, I explored my options.
Option 1 was to use 914 Euro spec 94mm flat top pistons.
2L 155.jpg
This pic is not the 94mm flat top but shows the deck ht. .001 not clamped down. .000 was the measurement clamped.
2L 148.jpg
This was an unintended result of decking the case. But worked, as I could now choose the appropriate shim to get my desired deck ht. and comp ratio.Assuming a .030 deck shim. I came up with 8.4:1 comp ratio. acceptable, but I tend to be conservative when it comes to comp ratio for a bus. .040 deck shim got me 8.2:1. Again acceptable but I was shooting for under 8:1
Option 2 was to use 96mm NPR dished pistons. Using a .040 shim, for .040 deck ht( The max I would accept), I ended up at 7.72:1 comp ratio. Larger displacement 2.1 liter and a comp ratio I can live with.

Just a word on deck ht. In addition to being part of the comp ratio formula, There is a happy number. Too low deck ht and you run into the problem of the piston hitting the bottom of the combustion camber, BAD. Too much deck ht and you have an issue with "squish" The goal is to have the combustion energy directed to the center of the combustion camber and the center of the piston. Too much deck ht and too much of this energy extends to the outer area of the chamber and the pistons putting more stress on the rings and the sealing area between the cylinder and the head.
Mark Stephens determined that somewhere between .020 and .025 deck ht became 0 on fully warmed aircooled VW motor. Making .030 to .040 ideal. This means that on a fully warmed engine, the comp ratio is going to be higher than your cold calculations. Also, eventual carbon build up decreases the chamber volume which also increase you comp ratio. This is why I tend to be conservative on comp ratio and like to be a bit under 8:1.
We will get back to this when we get back to the heads. Next up will be piston prep.

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wwebner
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Re: Bill's T4 engine build

Post by wwebner » Fri Jan 31, 2020 1:02 pm

Now on to piston prep.
First thing, we are going to weigh them. Past experience with the NPR pistons, sadly no longer available, is that they are within 1 gram of each other. This held true for this set all 4 at 726 grams.
2L 149.jpg
Next I like to put a little valve grinding compound around the rim of the cylinder. Then place the cylinder in the head
and rotate the cylinder back and forth, lapping the surfaces.
2L 158.jpg
2L 157.jpg
Wipe it well and wash both surfaces thoughoughly with brake clean.
2L 159.jpg
Also, wipe down the inside cylinder walls. I like to scrub them in a bucket with blue Dawn. then clean again with brake clean. This step is important as there is a thin film from the factory to prevent rust.
Next, we will remove the rings from the piston. I do the same cleaning with them as with the cylinders. It is best to do one piston at a time so you don't mix the top and middle ring. Then, wipe the rings with brake clean.
2L 167.jpg
Since this set came with rings, there should be no need to to check some measurements. But, we are going to do it anyway. This MUST be done if you are re ringing a set of pistons.
Install the ring ( top or bottom) in the cylinder and square it with the piston.
2L 164.jpg
2L 163.jpg
Using a feeler gauge, measure the gap. Spec for the top ring is .014 -.022. We are .017
2L 165.jpg
Do the same for the middle ring. spec is .012 - .022. I did not do this as I am using Total Seal gapless middle rings.
The Total Seal gapless middle ring Is a 2 piece ring with a machined ring and a rail ring.
2L 160.jpg
When assembled, with the gaps at 180 degrees, they form a gapless ring.
2L 162.jpg
A leakdown test will show the cylinder holding 99% using these rings.
Here is a pdf showing proper ring orientation.
ring orientation.pdf
(2.64 MiB) Downloaded 5 times
Next up, we will install the pistons in the cylinders and get them ready to install.

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wwebner
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Re: Bill's T4 engine build

Post by wwebner » Fri Feb 14, 2020 2:57 pm

OK, I found some time to continue. I did not get pics of the piston and cylinder assembly, so, refer to the manual.
a couple of hints: like all the other parts, wash the piston pins with brake clean to remove any film. I like to polish them.
2L 166.jpg

It's a good idea to number the pistons and cylinders 1-4. Before you assemble then you need to note their installation sequence for the type 4. arrow on the piston pointing toward the flywheel.

I usually do the #1&2 side first. install the circlip in the side of the piston on the flywheel side. The pin needs to install from the #2 side,as the flange on the flywheel side will not allow for the pin to install from that side.
For #2, install the clip on the #1 side and install the pin from the opposite side.
Stuff a rag in the cylinder hole so when you drop the second clip it won't fall into the case.

Here's the assembly ready to install on the rod. Some permatex at the cylinder base, then the shim, and another thin coat of permatex. Lube the pin with some assembly lube.
2L 173.jpg
On the #3 &4 side, you need to install #4 first. circlip in the piston on the side towards the rear. The flange for the oil cooler will not allow installation of the pin from that side.
assembly 015.jpg
For #3, depending on your engine holder, you may need to move it to the #1 & 2 side. Check with the rod at it's full out position to see if you can get the pin in from that side.
assembly 014.jpg
Make sure the circlips are seated in their groove in the piston. I use a spare piston pin to make sure the clip is seated.
once your sure they are seated, slide the cylinder down to the case.
You can install the head on ea side as you get the piston cylinder assembly seated on the case. Follow the torque sequence in the manual. A little permatex on the head studs and washers.
2L 171.jpg
I run a small bead of Locktite 518 around the cyliner to head mating surface.
2L 170.jpg
Re torque each head to spec.
Despite a good pic. ( I completed this build months ago and am trying to recreate for this thread) we now have a long block, less rocker and push rod assembly.
DSCF9657.JPG
Just a note on the heads and spark plugs.
This is a standard spark plug. Notice the gap. It is directing the spark towards the side of the chamber.
2L 168.jpg
An old racers trick was to shim the plug so that the gap was pointed towards the center of the chamber.
We don't need to do that.Bosch made a 3 electrode plug W8DTC, Which they stopped making. But Mick at Micks' 440 465 1985 can still get them. also available i step hotter W7dtc.
assembly 018.jpg
As you can see, this plug directs the spark towards the center of the chamber, which is what we want.
2L 169.jpg
It may be awhile before I get back to this. Then the rockers etc.

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