Bill's T4 engine build

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wwebner
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Bill's T4 engine build

Post by wwebner »

Well, I meant to start this thread last winter when I started this project. As many local member know, I drive a 1976 Westy. I have owned it since June of 1988. I turned over 250,000 miles this past year. In may of 1989 I built a fresh motor for it at 103,000 miles. Now at 250,276 miles. After 147,000 miles, it's time . Most of these miles were towing 1000lbs of trailer and loaded with my family all over the Midwest,Northeast and East coast. It still runs great, but is seeping and leaking oil from too many places. I could have torn it down and inspected and re assembled/re sealed, BUT,
I have been stashing components for it' eventual replacement since late 90's. So, let's build a new motor. The current one is a fully balance stock displacement motor and worked so well that I figured I would do the same with a few more details. So, here goes. I will try to keep this updated every few days.
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wwebner
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Re: Bill's T4 engine build

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The case.

I chose a case that I had that looked to be a good candidate. After some measurments that confirmed that it had not been align bored or did not need one, off to the machine shop. I had them double check the crank bore. Perfect spec
at 70.00mm for 1,2and 3 and 50mm for # 4

First, I pulled the oil galley plugs(pressed in) and tapped them for threaded plugs. This does 2 things. That they are not going to blow out and puke oil and allows for thourough cleaning of the Main oil galleys. There are 5 of them.

this pic shows them installed. Actually I don't install the plug until I am done with all the case work
Picture 031.jpg


This one after being installed, needs to be ground down a bit( you may find a shallow plug for this)
case 021.jpg
This is why. These dowels on the flywheel will hit the protruding plug and when you try to turn over the engine, you will only get so far before it stops.
2L 085.jpg

I had the machine shop "deck" the case. After the cylinder studs and case dowels are removed, the case is clamped on a flat table and measured from the case parting line to the cylinder seat. When the shortest distance cylinder is found,it is then machined perfectly parallel to the parting seem. The 3 remaining cylinder mating surfaces are then machined to exactly the same distance as the first. this does 2 things, obviously, a perfectly machined surface parallel to the case mating line for the cylinder, and puts the crankshaft perfectly in the center of the case. It proved to be a benefit later as we will see when setting the deck ht.
case 001.jpg

to be continued when I find the rest of the pics.
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wwebner
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Re: Bill's T4 engine build

Post by wwebner »

OK. Now we need to check ALL the threads in the case. Important to do this now as it can be a big problem later,ESPECIALLY if it is from a motor that is not just torn down for rebuild. In this case, none of the components are coming from the same motor.
2L 037.jpg
2L 041.jpg
This one is VERY important. It holds the oil pick up in place. It is 71mm long. Too long or to short and you will have problems. Check it carefully. It is sometimes bent, do to someone over tightening the strainer sump cover,which only torques to 9ft lbs. If is bent, get another one and check the threads in the case as they may be damaged.
2L 130.jpg
2L 129.jpg
on assembly it goes thru the left case half here. Which is easy to miss on teardown,as it is usually buried in crud.
2L 134.jpg
Now here's where I ran into a big problem. When I tried to check the cylinder studs, I found that several had f'd up threads in the alum case. Bummer. I sent the case to Jorge at European motorworks and he installed threaded inserts in all the cyl. stud holes. Nicely done. recessed.
2L 011.jpg
I got this tool from Gene Berg many years ago. It allows you to cut/clean up the seat for the oil pressure relief piston.
case 003.jpg
case 004.jpg
I also polished the bore with a dremmel and small buffing wheel and some semichrome polish and with a magnet made sure the piston moved smoothly in the bore.
While we are polishing. Did the same with the lifer bores.May seem anal, but fiction causes heat and robs power.
2L 042.jpg
Also polished the lifters. They should slide thru the bore without hang up,( bore diam was checked prior)
2L 043.jpg
to be continued
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Karl Kombi
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Re: Bill's T4 engine build

Post by Karl Kombi »

Thanks Bill for the great storyline of your build. It's a welcome break from the recent silence on the forum! :D
I'm assuming that the "cracks" in the casting between the lifter openings are superficial and not really anything...
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wwebner
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Re: Bill's T4 engine build

Post by wwebner »

Joe, yes superficial casting marks. Identical to other cases I have.

Now, a little more case work for today. since it involves the crank shaft I will jump ahead a bit.
Current motor has a counter weighted crank, as will this one. It's the ONLY crank that I would use on any air cooled VW.

The crank on the right is a stock crank. Notis the 2 center rod journals are on the same side. This creates an imbalance.
The counter weights are welded on a stock crank to offset this imbalance.The crank is then balanced. The result is a crank that rotates perfectly with no "whip" do to imbalance. Which results in an extremely smooth running engine capable of much higher RPM without beating the center main bearings and journals.
IM003721.JPG
Do to this added material, it is sometimes needed to :clearance some areas of the case.
I use a couple of used bearing for this since it may require taking the crank out and back in a few times.
2L 064.jpg
It's also a good idea to install the flywheel with a couple of the flywheel shims for this process.

Here you can see where some material needs to be removed from the case.
case 017.jpg
after a little grinding. You do need todo this check with the crank in both case halves.
case 018.jpg
most of the work was done on this journal.
case 024.jpg
out of time for today.
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wwebner
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Re: Bill's T4 engine build

Post by wwebner »

We are going to set the case aside and move to the crank shaft.
Check it AGAIN. 1,2 and 3 spec is 5.97-5.99 they were all spot on. No pic for #4, but it was also spot on.
crank 007.jpg
Now clean the oil passages. A gun cleaning bore snake works well for this.
crank 004.jpg
crank 005.jpg
crank 006.jpg
Now to install the crank gears and # 3 bearing. Bruce documented this well and the procedure for type 1 and type 4 are the same. BUT, I had a little problem.
After wiping the journal and bearing with brake cleaner and wiping the journal with assembly lube,
I pump a little oil into the journal. This pic shows another journal (no pic of #3)
crank 024.jpg
2L 092.jpg
I heat the gears on a piece of fire brick with a torch.
crank 013.jpg
Be sure you orient the gear so the timing marks face the nose of the crank.
crank 012.jpg
Install the spacer and heat and install the dist drive gear.
crank 023.jpg
Then, install the snap ring in the groove in the crank. This is where i had a small problem. The snap ring would not seat in the groove.
crank 016.jpg
Shit. Maybe I did not have the gears seated. Pull them off and try again.
crank 018.jpg
Re installed and had the same issue. Pull them off again.
I had used a NEW brass dist drive gear. Let's check it out.
POS
crank 019.jpg
crank 020.jpg
Grab a used dist drive gear and guess what.
crank 025.jpg
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wwebner
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Re: Bill's T4 engine build

Post by wwebner »

Before we move on. I am going to back up a bit. Before installing # 3 main bearing, you need to orient the bearing, so the dowel holes are aligned.
Note, the dowel holes are offset.
crank gears.jpg
They are all offset towards the flywheel end.
2L 040.jpg
Also, set the bearings in the case, making sure they seat nicely and mark the parting line. Also a good idea to put a magic marker mark on the.flywheel side of the bearing. #1 shown, but the same was done to #'s 3and 4
2L 044.jpg
Now we can move back to the crank.
The pilot bearing in the type 4 is in the end of the crank. It is in the gland nut on Type one, and in the flywheel on 914.
ALWAYS REPLACE . When this bearing fails, it grabs the trans mainshaft like a Chinese finger and you are stuck in whatever gear you are in. Then, it's pull the motor, which is not easy,as the crank and mainshaft are locked together.
Picture 020.jpg
Pull the old one out
Picture 021.jpg
Pack the new one with grease, I use Spectro synthetic
Picture 023.jpg
Install the new bearing.
Picture 024.jpg
Next up, we will install the rods
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Marla
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Re: Bill's T4 engine build

Post by Marla »

I'll just sit and watch... where's my popcorn?
It's Marla with an " L"
(My list of assets is just too long...)
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Karl Kombi
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Re: Bill's T4 engine build

Post by Karl Kombi »

I have a huge bowl right in front of me. Do you want some?
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wwebner
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Re: Bill's T4 engine build

Post by wwebner »

Now that every one has their popcorn :lol: We will move on to the connecting rods.
sometime,way back around 2000, I took a set of stock 2 liter rods to the machine shop to have them re-bushed sized and balanced, total weight and end to end.
To re-bush them, install new bushings in the small end. For this process, they press out the old bushings and press in new bushings which have a smaller inside diameter, then hone them out to spec, using one of your wrist pins for measurements.
rods 008.jpg
To "size" the big end, they remove a few thousandths from the mating surface, in this case the rod ,as opposed to the cap.
rods 007.jpg
The big end is now oval. Then they hone the big end perfectly round and size to spec.
2L 088.jpg
I also had them machine this groove,per a VW tech bulletin that I had. According to VW, this increases "oil splash" to the bottom of the piston.
Now let's check the weight.
They got them pretty nuts on within 1 gram 794 -grams. VW specs a 6ram difference between rods new .
crank 011.jpg
Short break . I am being beckoned for supper ;)
This pic shows where they machine off material on the small end to balance end to end with the other rods.
(the difference in weight is this one has the rod bearing install, which is 37grams.)
rods 006.jpg
Next up ( tomorrow) we will hang the rods and take some measurements.
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