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Fri Dec 17, 2010 7:04 am

What else needed to be done to run heads that were milled down .010"?

What did you do to the jugs?

Fri Dec 17, 2010 4:06 pm

Hey Summers. My machinist recommended milling the water jacket sealing surfaces and combustion chamber surfaces equal amounts in order to keep things even. The jugs/cylinders were just cleaned and honed. <EDIT delete>

*deleted my comment about milling cylinders, which I think was inaccurate

Mon Jan 10, 2011 11:14 pm

Well I talked to my machinist today about the work he did on my motor. I'd asked him to write down all the measurements when I picked everything up. He gave me measurements for the main journal sizes, rods, cylinder ID's and pistons (which I don't fully understand yet, will post them up). Basically he said that everything looked to be in very good shape.

I asked him if he miked the main journals and he said they checked them, but they didn't mike them out. He didn't think it was necessary and added that wbx's rarely need an align-bore.

He also reground the exhaust valves, which from what I hear you're not supposed to do with hard coated valves (stellite?) like these. He said that he doesn't think there would be any problems with using them.

I have to admit that I didn't really give my machinist any instructions other than to check everything and let me know what he thinks should be done. Which he did, and I went along with his recommendations. He's not a VW specialist but has been around for a few decades and seems to have a good reputation. He took the time to sit down with me and explain things and told me to call if I had any questions. So I can't complain.

I'm leaning toward getting some new TRW stainless exhaust valves. As for miking out the case I'm not sure what to do yet. The rods and any other measurements that my machinist didn't give me it looks like I'm going to have to try doing myself. I have some friends with more tools and experience than me. Maybe I'll get lucky.

Looks like I still have a lot to learn.

Wed Jan 19, 2011 12:54 am

After following and learning a lot from psych-illogical's recent rebuild thread I got to wondering about the condition of my own main bearings. So I dug them out of the old parts box and took a closer look. The shells are stamped KS VW 025.105.531 Germany (and have the elephant symbol), and I don't see any under or over sized markings on the backs of them.

This also got me wondering about if I have a blue dot or red dot crank. According to the numbers my machinist gave me it looks like I have a blue dot.

crank journals
#1 - 2.3620 / 59.9948
#2 - 2.1651 / 54.9935
#3 - 2.1650 / 54.9910
#4 - 1.5749 / 40.0025

I used an online converter to get the metric numbers and found that #'s 2, 3 & 4 are 0.0010 - 0.0035 larger than the max listen in Bentley. Is that acceptable? I'm planning on measuring the crank again myself just to be sure.

Anyway here are pics of the main bearings. I was hoping to get some feedback on their condition. 90K on the motor, btw.

main #1

main #2

main #3

main #4

And here are the saddles on one side.

main saddle #1

main saddle #2

main saddle #3

main saddle #4

Wed Feb 16, 2011 10:56 pm

If anyone can comment on the condition of the old mains I would really appreciate it. I'm wondering if they can be reused or if they look trashed. I'm not sure if the babbitt material has worn thin or if they're just average looking. Do they look like they might have spun? What could have caused the wear marks on the outside? Haven't been able to measure them yet.

I picked up a set of outside mics and checked the crank and my measurements are .0003-.0005" under what my machinist gave me. I've checked the standard and zeroed it several times.

So now I'm waiting to meet up with a friend and check my mics against his. Things are going slow though, he's been busy and all the snow kind of threw things off too.

Also picked up a dial bore gauge but haven't figured it out completely. Actually I think I got the hang of it but because I'm not sure about the accuracy of my outside mics that is holding me back right now.

Then there's the #1 thrust bearing. Don't know what I'll do if that's loose. Seriously frustrated with myself for not checking it before tearing the motor down.

But on the plus side I'm learning a lot. Saw Parliament Funkadelic last weekend. And the snow is melting fast. Woohoo.

Fri Feb 18, 2011 12:24 pm

I haven't been hanging around this forum too much lately, life gets in the way. Anyway, in looking at your photos I find the marks in the case where the bearings sit kind of interesting. My case didn't exhibit those. If I were you, I'd bolt the case together and torque the nuts and measure the bores with that fancy new bore gauge of yours. Then, I'd measure the outside of the bearings that are going in those bores (new ones please). My bearings were about .001"-.002" bigger thus providing a little crush when everything gets bolted together. If you have a little interference everything should be OK. The only one you can't really do this measurement with is the split bearing.

Those bearings don't look terrible but, heck, new bearings are cheap enough. I'd just fork out the $70 or so and get a new set. Well worth the piece of mind.

Then, when your new bearings come in, put those in the case, bolt it up, torque it and use the bore gauge to measure those. Compare those measurements to your crank and calculate the clearance. Mine ended up being as much as .0035", which, if you'll recall from my recent rebuild thread is better than VWs tolerance spec of .0045". For the split bearing use plasitgage.

Fri Feb 18, 2011 6:31 pm

Hi psych. Was wondering what happened to you. I've been studying your thread very closely, tons of great info there. And thanks for your comments and suggestions. It's a steep learning curve for sure and I appreciate any feedback I can get.

The saddles had me puzzled too, as well as the wear on the backs of the bearings. I posted in the STF wasser/oxyboxer forum and got some interesting feedback about 1.9's and Type1's. The bearings can get pounded into the saddles by the crank. It makes sense and scares the sh!t outta me.

I've been playing with my fancy-shmancy new tools but my mind is in "OH SHI!!!!" mode right. Trying to be careful and not break anything. I think I've figured out the DB gauge and I guess I can check the saddles for roundness. My 2-3" mic seems to be off by about .0005". Don't think that I can check clearances accurately until I'm sure about the mics. Think I'll return the mics since they're new and get a different set.

I already have a new set of Mahle mains but was considering reusing the old ones. Not because of money but because of quality, the original stuff is supposedly better than what's on the market nowadays. Still not sure which I'm going to use yet though. That is, if the case is still OK.

Fri Feb 18, 2011 7:38 pm

klucz,

Quote: I picked up a set of outside mics and checked the crank and my measurements are .0003-.0005" under what my machinist gave me. I've checked the standard and zeroed it several times.

The 2" standard is not really a standard. It is not 2.0000". A calibration block that is 2.0000" will cost more than you micrometer set. I am no expert in tools but this is what I think you have to do. Start with the 0-1" micrometer, make sure it is zero out, then use it to measure the 1" standard. It will not be exactly 1", could be longer or shorter. Note the value and now use the 1"-2" micrometer to measure the 1" standard, adjust the micrometer so it will read what the 0-1" mic read. Now use the 1"-2" micrometer to measure the 2" standard, do the same to calibrate the 2"-3" micrometer.

Fri Feb 18, 2011 9:49 pm

Steve,

What you said about setting the mics makes sense. I think I did what you described.

Set the 0-1" mic at 0 (closed).
Measured the 1" standard and found it to be just a smidge over (less than .0001").
Set the 1-2" mic at a smidge over using the 1" std.
Measured the 2" std. with the 1-2" mic and found it to be .0004" over.
Set the 2-3" mic at .0004" over using the 2" std.

Does that sound right?

Thanks,

Paul

Fri Feb 18, 2011 10:37 pm

Yes, this is what I meant.

Fri Feb 18, 2011 10:40 pm

So the measurement you have now is close to what the machine shop told you ?

Fri Feb 18, 2011 11:16 pm

I think I trust my 2" standard more than I woud trust that method. I would expect the greatest cumulative variance along the entire extent of the leadscrew.

But more importantly, you can get hung up on absolute accuracy of these instruments, when what you will actually need them for much of the time is relative, or comparative accuracy, meaning using the individual instruments to make small relative measurements, where cumulative inaccuracies you might see over the whole extent of an instrument's range diminish to insignificance in the range for which you need to compare a dimension. When you are building the engine, the size of a thing ends up being less important than how it fits with another thing ( a lot of life is that way).

First thing's first, though; if you are working with a machinist, you need to synchronise your watches, so to speak. Take the mics you will use at home to his shop, with your standards, and measure each other's shit, and measure a few work pieces. This takes 5 minutes. If there are large inconsistencies make a determination as to whose is apt to be more accurate (it'll be his, because he's not going to change his for one customer) and make yours agree with his, i.e. adjust your mic to his standard. Then, on any pieces where you are dealing with him, use that mic so you're on the same page. I work with a crank grinder who is hours away and this coordination is essential, but it happens that all our mics agreed to a fat tenth.

As for setting bearing fit and clearance, everything you do involves relative measurements, absolute numbers float abstractly in the periphery but don't determine how things get done or in most cases whether something is even acceptable. You mic your journals, you transfer that measurement to your bore gauge at zero, and you gauge the bores to see what the clearance will be. Only the inaccuracy of the bore gauge across a few thousandths matters here, The mic initially is used to decide that the journals are within spec range, after that it's just being used as a fancy locking caliper.

Where you need your mic for absolute accuracy is in determining parts selections, when you need to conform to other parties' specs. But if you had an error of 4 tenths on your mic against a crank manufacturer's numbers, would it cause you not to buy that crank? Probably not. You have to assay the potential degree of error within the context.

Sat Feb 19, 2011 12:37 am

Steve, using the method which you described gave me measurements even further off from the machinists (.0006-.0010 lower). Guess it doesn't really matter that much though.

10c, thanks so much for sharing your knowledge. I've been hung up on the red-dot/blue-dot thing. I see what you mean about how it's all relative. I'll talk to the machinist next week and hopefully sync up with him.

Still have to figure out a bunch of other stuff but it's good to get the ball rolling a little.

Sat Feb 19, 2011 5:09 am

......Keep in mind the temp of the tool, the standard, and the piece you are measuring should all be at room temp. When I did machine work our tools needed to be checked every so many days. They had to be left in a QA room that was climate controlled for so many hours before testing. The higher quality the tool, the less it will change. The tool would then get a sticker telling you when the calibration expired, you did not want to get caught using a tool that was out of date....

Sat Feb 19, 2011 7:01 am

Thanks for the tip xoo. I've been careful about keeping everything together at room temp and not warming up the tools and stds. with my hands (and making sure everything is clean). I'll keep it in mind when I take my stuff out and about.

Sat Feb 19, 2011 8:13 am

By the way the running finish in all those bearings looks fine, what you need to check is the diametrical crush (I explained in psych's tread recently how to check that), and the fit of the #1 flanges to the bearing saddles. There should be ~.002" interference on each.

Sat Feb 19, 2011 10:01 am

Sat Feb 19, 2011 11:57 am

klucz wrote: Steve, using the method which you described gave me measurements even further off from the machinists (.0006-.0010 lower). Guess it doesn't really matter that much though.

So my theory is wrong. I am buying a set of Mitutoyo gauge blocks to play with. I want to see how bad ( or good ) the HF micrometers are.

Sat Feb 19, 2011 7:10 pm

They're actually pretty good.

It's not that big a deal to make a mic, it needs a leadscrew that holds to a true 40 tpi, the rest is just parts.

I would think the racking gear, if that's what they use, in a dial indicator would be harder to manufacture accurately, but even the cheap ones are not bad at all.

Thu Feb 24, 2011 6:01 pm

Ok, Got my Mitutoyo gauge blocks. These are grade 2 blocks and the 1” block are +4/-2 micro-inch at 68 degree and the temp coefficient is 6.4 micro-in per degree F. so it made little difference for us as the HF mic only measure to 0.0001”. Using the 1” mic, I got the following reading from measuring the blocks:

0.1” blocks ( that means it could be 0.100004” or 0.099998” ) I got 0.1001”, 0.25” block I got 0.2501 inch and the 1” block I got 1.0001” so the error is only 0.0001”, not bad at all.
I then adjust the 1”-2” mic using the 1” gauge block as standard and then measure the 2” gauge block and got a reading of 2.0000”. I am pretty happy with this.

I then use the 0-1” mic and the 1”-2” mic to measure the 1” standard that came with the HF mic set and the reading I got is 1.0005 from the 0-1” mic and 1.004 from the 1”-2” mic. Using the 1”-2” mic and the 2”-3” mic to measure the 2” standard that came with the HF mic set and I got a reading of 2.0004” on both mics. So the two standards from the kit give a error of 0.0004” ( yours may not be the same ). Note that both mic are adjusted using the Mitutoyo gauge blocks for these measurements. I now believe the method I suggested before ( using the measured value of the 1” kit standard to adjust the 1”-2” mic and the measured value of the 2” mic to adjust the 2”-3” mic ) will give a reading that is more accurate. Also note that the Mitutoyo gauge block kit cost a lot more than the HF mic set so don't bother to buy one.

Now does any one know how to use the optical flat that came with the gauge blocks ?