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.
We are installing the rods "dry" for this procedure. Install the bearings in the rod end.
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.
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.
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.
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.
I had 1 that measured .017.which is within spec. But, We will deal with that next.
Bill's T4 engine build
Re: Bill's T4 engine build
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.
I had also purchased a new set of Silverline rod bearings. I made an assumption That there was no need to plastigage these NEW rods and bearings. So I proceeded to assemble.
We have a problem 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. Well, .059 Let's compare it to the Kolbenschmidt that we used with the stock rods,which gave us .002 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) Next, we will hang these suckers, hopefully for the LAST time.
First we will weigh them. 594 grams/ with the bearings.
If you remember, the stock rods, after sizing and balancing, were 794 grams without the bearings.
So, we are better than 200grams lighter I had also purchased a new set of Silverline rod bearings. I made an assumption That there was no need to plastigage these NEW rods and bearings. So I proceeded to assemble.
We have a problem 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. Well, .059 Let's compare it to the Kolbenschmidt that we used with the stock rods,which gave us .002 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) Next, we will hang these suckers, hopefully for the LAST time.
Re: Bill's T4 engine build
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. 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) Bushing is 24.015-24.024mm (.9454-.9457in) for a clearance of .0009in 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. 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 The AA rods use an arp bolt as opposed to the stock rod cap nut. They require a little grease on the threads. short break, need to take the dog out
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. Beautiful, they all drop from horizontal at the same rate. Next up we will set the crank assembly and cam in the case.
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. 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) Bushing is 24.015-24.024mm (.9454-.9457in) for a clearance of .0009in 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. 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 The AA rods use an arp bolt as opposed to the stock rod cap nut. They require a little grease on the threads. short break, need to take the dog out
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. Beautiful, they all drop from horizontal at the same rate. Next up we will set the crank assembly and cam in the case.
- Karl Kombi
- Posts: 280
- Joined: Wed Sep 27, 2017 9:56 am
Re: Bill's T4 engine build
With all this measuring, it looks like you're one of those people who wants their motor to last more than 500 miles.
Re: Bill's T4 engine build
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.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.
Re: Bill's T4 engine build
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. A little assembly lube on #4 and #1 crank journals, we did #3 when we installed the gears. This is where the marks we put on #1 and #4 bearings come in. 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
OK, I missed taking a pic of just the crank assembly seated in the case. Here, the camshaft is also installed. 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. The 6th bearing shell is a thrust bearing. fits nice and snug. Now, we are going to try it on the camshaft. Problem. 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. Or, try another thrust bearing. Another bearing, also a Kolbenschmidt, fit fine.
More on prepping next.
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. A little assembly lube on #4 and #1 crank journals, we did #3 when we installed the gears. This is where the marks we put on #1 and #4 bearings come in. 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
OK, I missed taking a pic of just the crank assembly seated in the case. Here, the camshaft is also installed. 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. The 6th bearing shell is a thrust bearing. fits nice and snug. Now, we are going to try it on the camshaft. Problem. 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. Or, try another thrust bearing. Another bearing, also a Kolbenschmidt, fit fine.
More on prepping next.
Re: Bill's T4 engine build
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.
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. At this point, I will usually loosely bolt the flywheel on in order to make it easier to rotate the assembly. 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. 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. a little white grease holds the spacer on to install. A little polishing,and some lube. Install. Now we can find TDC #1 as we proceed, next time
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. At this point, I will usually loosely bolt the flywheel on in order to make it easier to rotate the assembly. 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. 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. a little white grease holds the spacer on to install. A little polishing,and some lube. Install. Now we can find TDC #1 as we proceed, next time
Re: Bill's T4 engine build
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.
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.
Re: Bill's T4 engine build
Well shit. A couple hours into the above post, finding and loading pics, it all disappeared.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.
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. Check the treads for the sump cover. align the mounting hole in the pick up with the case threaded hole. 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. Exactly in the middle of spec
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.
Re: Bill's T4 engine build
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.
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. I am using the modified type 3 pump. sorry no pics.
Next up, we are finally ready to bolt the case halves together.
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.
There are several aftermarket pumps available such as.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. I am using the modified type 3 pump. sorry no pics.
Next up, we are finally ready to bolt the case halves together.