Bill's T4 engine build

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wwebner
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Re: Bill's T4 engine build

Post by wwebner »

Now we are going to hang the rods for some measurements. First, wipe the bearings,rod big end and rod journal clean.
although the bearings come sealed in plastic, doesn't mean they are clean.
rods 002.jpg
2L 112.jpg
We are installing the rods "dry" for this procedure. Install the bearings in the rod end.
2L 108.jpg
Now we are going to measure the oil clearance between rod and rod journal. This is critical. tight enough to maintain oil pressure, but loose enough for the rod to move on the journal. Vw specifies .0008 to .0027 with a sloppy .006 wear limit. Plastigage, which is a precicsion wax thread. a smaal piece is laid across the rod journal.
NOTE: since the machine shop had the rods,and bearings, and also the crank shaft,flywheel and pressure plate in order to balance that rotating assembly, I had them take these measurements. But, I am going to mock this up to show the procedure.
rods 010.jpg
rods 011.jpg
Now CAREFULLY install the rod and torque to spec. This is tricky as you don't want to move the rod and smear the plastigage.
rods 013.jpg
Then, CAREFULLY, remove the rod. Also tricky so as not to smear the plastigage.
Then use the package to measure. This one (shitty picture) was between .0015 and .002, which is good. as a comparison, a sheet of printer paper is .003. Ideally, you would do this to all 4 rods.
rods 016.jpg
Now, after cleaning the wax off the rod journal and bearing, we are going to hang all the rods again to measure side clearance. This is another mock up as I can't find or did not take pics.VW specs .004 to .016 with a wear limit of .027
I had 3 that measured .006 just like the mock up.
rods 015.jpg
I had 1 that measured .017.which is within spec. But, We will deal with that next.
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wwebner
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Re: Bill's T4 engine build

Post by wwebner »

Since I have been quite anal about blueprinting this build, and although the side clearance on 3 rods was perfect, there was 1 that was at the outside of, but within allowable, spec. I decided to not accept it. I had used a set of AA H beam rods on a prior build of a Porsche 914 motor, and was impressed. SO, I bought a set for this build.
2L 003.jpg
First we will weigh them. 594 grams/ with the bearings.
2L 105.jpg
If you remember, the stock rods, after sizing and balancing, were 794 grams without the bearings.
crank 011.jpg
So, we are better than 200grams lighter :D
I had also purchased a new set of Silverline rod bearings. I made an assumption :oops: That there was no need to plastigage these NEW rods and bearings. So I proceeded to assemble.
We have a problem :cry:
2L 002.jpg
After torquing, the rod was bound on the crank journal. SHIT
Remove the rod AGAIN. No pics here, but I mic'd the inside of the stock rod and then the AA rod. Identical :?:
So, let's check the bearing. The box and bearing were marked STD.
rods 021.jpg
rods 021.jpg
Well, .059
rods 019.jpg
Let's compare it to the Kolbenschmidt that we used with the stock rods,which gave us .002
rods 020.jpg
Guess we found the problem. Like Art used to say" just because it's NEW, doesn't mean it's good.
Now let's check the side clearance.
.006 on all 4 (sorry for the bad pic)
2L 003.jpg
Next, we will hang these suckers, hopefully for the LAST time.
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wwebner
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Re: Bill's T4 engine build

Post by wwebner »

Before I move on, a little disclosure. I completed the assembly late last summer,but was too busy to to create this thread at that time. Hope this explains the sequence of some of the pics.

NOW, we can hang these rods.
First, I double check the piston pin fit. It slides in nice and tight. These photos show measurements on stock rods. AA rods were the same. Polish the pin.
2L 166.jpg
Normally you would use micrometer for these measurements but digital caliper works for visual.
Spec for the pin is 23.996 to 24.00 mm (.9445-.9448 in)
2L 061.jpg
Bushing is 24.015-24.024mm (.9454-.9457in) for a clearance of .0009in
2L 062.jpg
I think we're good.
Now to hang them. as before, wipe them down good including the bearings,rod and rod journal on the crank.
Then lube them up. I have used Spectro assembly lube for years.
2L 093.jpg
Squirt some oil into the rod journal and wipe a little white grease on the sides of the rod journal.This helps cushion the side of the rod and get a little oil to the bearing until we get oil pressure when we first crank the motor
rods 003.jpg
The AA rods use an arp bolt as opposed to the stock rod cap nut. They require a little grease on the threads.
2L 106.jpg
short break, need to take the dog out :lol:
Install the rods, making sure to orient the cap and rod, numbers on the same side. They torque to 24ft lbs moving in increments from 1 bolt to the other.
2L 111.jpg
Beautiful, they all drop from horizontal at the same rate.
2L 113.jpg
Next up we will set the crank assembly and cam in the case.
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Karl Kombi
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Re: Bill's T4 engine build

Post by Karl Kombi »

With all this measuring, it looks like you're one of those people who wants their motor to last more than 500 miles. :P
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wwebner
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Re: Bill's T4 engine build

Post by wwebner »

Karl Kombi wrote: Sat Dec 21, 2019 2:31 pm With all this measuring, it looks like you're one of those people who wants their motor to last more than 500 miles. :P
;) I hope so Joe. Measuring and trial fittings has become more important, as we will see. Especially, with parts that did not come from the same engine, and new parts that you should not trust.
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wwebner
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Re: Bill's T4 engine build

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Now, we are going to set the crank assembly in the left case half.
First, install the #2 bearing halves in both case halves. wipe the bearing saddle and the bearing clean.Again. Being sure to align the dowel hole in the bearing with the dowels in the bearing saddle.
2L 039.jpg
2L 040.jpg
2L 125.jpg
A little assembly lube on #4 and #1 crank journals, we did #3 when we installed the gears.
2L 077.jpg
This is where the marks we put on #1 and #4 bearings come in.
2L 044.jpg
install #1 and #4 bearings, again be certain that the dowel holes in the bearing are offset towards the flywheel end of the crank. Holding the crank assembly by the #1 and #2 rods, and trying to keep the crank parallel withe the case, slowly set the assembly in the case bearing saddles. This is where a second set of hands would be really helpful, as we are trying to get the 3 bearings aligned with the dowel holes and dowels, and every thing is moving. A 3rd person would help to take photos :lol:
OK, I missed taking a pic of just the crank assembly seated in the case. Here, the camshaft is also installed.
2L 114.jpg
At this point, with or without the cam installed, we want to rotate the assemby to be sure everything rotates smoothly with no hang ups. rotating the crankshaft backwards,with the camshaft installed will also check backlash of the cam gear. Watch to see if the cam lifts out of the cam bearings or moves back and forth. If not, your good. If it does,you are going to need another cam gear. we were good here.
Now, I have to backtrack a bit. Before installing the cam, we install the cam bearings.
There are 3 cam bearing journals and 6 cam bearing half shells. 5 of them have locating tangs, 3 in the right case half and 2 on the left.
assembly.jpg
assembly 006.jpg
The 6th bearing shell is a thrust bearing. fits nice and snug.
2L 046.jpg
Now, we are going to try it on the camshaft. Problem.
2L 095.jpg
This is the 3rd build I have had this issue, with 3 different camshafts. a couple of solutions. Work the bearing on some fine emery cloth.
2L 100.jpg
Or, try another thrust bearing.
2L 096.jpg
Another bearing, also a Kolbenschmidt, fit fine.
More on prepping next.
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wwebner
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Re: Bill's T4 engine build

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In the last post, we installed the crankshaft assembly and checked backlash of the cam gear. A note here. this from the Bentley manual." Camshaft gears are marked -1,0,+1or plus 2 etc.on their inner face. these numbers indicate in 1/100mm how much their pitch radius departs from the standard pitch radius denoted by 0. VW specifies 0.000-0.002 in or 0.000-0.050mm.
assembly 007.jpg
assembly 008.jpg
If you are using a reground camshaft, or re using a used camshaft,neither of which are recommended,this could be an issue. ALL replacement cam gears are bolted on as opposed to the stock riveted on gear. They are usually all marked -3 so it is rare that there is an issue with backlash.
Now we are going to align the timing marks on the cam gear and crank gear. Some assembly lube on the bearing shells and on the cam journals. Rotate the crank assembly to where the 2 timing marks on the crank gear are at about 1 or 2:00. Align the single mark on the cam gear to fall between the 2 crank gear marks and rote the cam and crank until the cam sets in the cam bearings.
Picture 033.jpg
At this point, I will usually loosely bolt the flywheel on in order to make it easier to rotate the assembly.
2L 117.jpg
We are going to rotate the crank and cam assembly a lot,in both directions. You will have to hold the #1 and 2 rods up while doing this. Watch for the cam to not lift out of the bearings, and make sure the timing marks always line up, everything rotates smoothly.
At this point, with #1 rod at it's full out and the heal of the cam facing out, you are at TDC for #1. I like to put a mark on the flywheel at the case seam. and note the location of the woodruf key on the nose of the crank, which should be at 9:00.
2L 122.jpg
2L 117.jpg
Then, install the distributor drive gear and spacer and distributor, orienting the distributor to the notch in the distributor body. Type 4 drive gear uses 1 spacer and installs at 12 degrees from the case parting line.
assembly 003.jpg
Picture 014.jpg
a little white grease holds the spacer on to install. A little polishing,and some lube.
2L 047.jpg
Install.
assembly 009.jpg
assembly 010.jpg
Now we can find TDC #1 as we proceed, next time :)
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wwebner
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Re: Bill's T4 engine build

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Now that we can find TDC for #1, close enough for now,( we will dial it in when we measure deck ht), this will come in handy once we get the case haves assembled.
A couple more things before we are ready to assemble the case.
We need to install and locate the oil pick up. Type 4 has an O ring,supplied with the gasket set.
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wwebner
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Re: Bill's T4 engine build

Post by wwebner »

wwebner wrote: Sat Dec 28, 2019 11:51 am Now that we can find TDC for #1, close enough for now,( we will dial it in when we measure deck ht), this will come in handy once we get the case haves assembled.
A couple more things before we are ready to assemble the case.
We need to install and locate the oil pick up. Type 4 has an O ring,supplied with the gasket set.
Well shit. A couple hours into the above post, finding and loading pics, it all disappeared.
We'll try again.
Now we will install the oil pick up. there is an O ring supplied in the gasket set that goes on the end of the tube.
The one on the right is a 914 used with a windage tray,which I did not use.
t4 case 017.jpg
Check the treads for the sump cover.
2L 050.jpg
align the mounting hole in the pick up with the case threaded hole.
2L 089.jpg
Do this now or have problems when you bolt the case halves together.
Now is a good time to check the crankshaft end play. Spec. is .003 t0 .005. I like to choose 2 shims (3 are needed). Mic them, write down the thickness, install them and torque the flywheel. Now measure the end play,which will be larger than spec. Do some math and determine the thickness of the 3rd shim needed to get to the desired end play.
This can take some time going through shims and measuring them. You may get lucky and have the correct thickness to get you to spec. If not, since you did the math, you know the thickness of the 3 shim pack that you need and you can select the proper shims to get there. Shims for type 4 come in 5 thicknesses, 0.24mm,0.30mm,0.32mm,0.36mm and 0.38mm. They are not as readily available as type 1. Go Westy, European Motorworks and Buss Depot. This process will slow you up if you don't have a good variety and have to order them.
I was lucky and had what I needed.
2L 140.jpg
Exactly in the middle of spec :D
A little side note here. If you can't get it tight enough with the shims available (the thickest available 0.038mm (.015in)
like the problem I had with a 914, I had a machine shop make some .020in. If you are too tight with the thinest shims (.009in), you can have a machine shop mill a few thou from the nose of the flywheel.
Submitting so we don't "time out" again. will edit shortly.
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wwebner
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Re: Bill's T4 engine build

Post by wwebner »

One more thing to check. The oil pump. Type 4 oil pumps are no longer available. They have 24mm gears. I won't waste any time explaining disassembly and inspection. Don't use it. It is between 37 and 47 years old and probably 100,000 plus miles on it. And there will be a clearance issue with the bolts on cam gear.
Picture 034.jpg
There are remedies for this, shallow hesd bolts, recessing the bolt holes in the gear, but why bother. Ignore this, and this is what happens.
IM003611.JPG
IM003610.JPG
There are several aftermarket pumps available such as.http://www.europeanmotorworks.com/vw/ty ... olers.html
Jorge at European Motorworks also offers a modified type 3 pump with 26mm gears. Not shown on his web site.
Back when I built the current motor, the Melling pump with 30mm gears was the thing to use. However, it was found that after years of use, do to it being cast iron, leaks developed around the pump body and the aluminum case.
This is a Melling pump. The modified type 3 pump is similar, but it is aluminum.
assembly 011.jpg
I am using the modified type 3 pump. sorry no pics.
Next up, we are finally ready to bolt the case halves together.
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