Opinion for this combo

[profe]

Thanks everybody.

It seems the winner opinion is we have to be careful with the over/undersize gears. I will try to get a +2 gear (I will email Gene Berg as I don't know any other vendor for this in Europe)

[profe]

Long time waiting for some parts!

Maybe some of you can give an opinion.

I have just received the valves from my supplier (Germany). I guess they were Mahle or TRW, made in Europe but I got this ones. Three of them are without any marks (¿?) and in the other one says is Osvat. All of them packed with Osvat packing. For me it seems strange that the four are not equal....

Please help to identify them

Thanks

[tencentlife]

Osvat are Italian. They're OK, not the best.

[profe]

Hi Tc

Your answers always make me smile.
Could you be a bit more explicity?. I knew from the package the Osvat are made in Italy (I forgot write it)

I know they are no TRW and that these are your best option. The fact is before I ordered to the supplier I asked brand and country. I explain that I was looking for quality valves as TRW or Mahle. And made in Europe or USA.
They answered me that valves they sold use to be TRW or Mahle. And made in Italy or Swiss. So I wass a bit surprissed when see the parts.

They're OK, not the best.

.
Does it means I can sleep without worry for ten years .... or only one year and a half?. I mean if would be better option fitting again mine stock OEM Mahle -with almost 200.000 but good shape-, or should I send them back to Kaefer nad order a TRW from the States (can't find them easily in Europe).

One more, those valves are two parts welded or one piece ones?. The one who says Osvat has larger stem than the other (I mean the shine part from the top to the bottom). And it seems lighter -weighted in my kitchen- than the one with no brand marks. Does it mean something?. At least both have the same stem diameter size -measured with micrometer-.

And my other doubt is if the ones that don't have any mark, are really Osvat?. Or may be they are old unused OEM Mahle?. I can't see the differences betwen mine used valves -OEM I gues Mahle- and the one that have no marks.

I remember I saw once a post about different valves option -pics inclouding- in a forum buy I can't find it again.
Thanks

[tencentlife]

Does it means I can sleep without worry for ten years .... or only one year and a half?

Boy, either option sounds pretty good to me.

All I can tell you about the Osvat exhaust valves is my one experience with them: I used a set of them in an early wbx I built. The price was good (about $12 each as I recall), but when quality and longevity depend on metallurgy it's hard to tell how good something really is except to try it and see. After one year of use, I leakdown tested that engine, and found one valve developing a pretty good leak, past being just a tiny leak but not too far gone either. Pulled off the heads and the burning was all on the valve, a new valve lapped in well without much effort so the seat had not burned yet. So I decided the quality of those valves wasn't good enough for me, and went with the industry standard I had always been able to rely on so long as I was willing to pay: TRW. That's all I have used since.

OEM valves have always had the VW/Audi logo stamped or inked just under the stem tip. I don't know which manufacturer supplied them but I have never seen a factory valve without the logo.

One more, those valves are two parts welded or one piece ones?. The one who says Osvat has larger stem than the other (I mean the shine part from the top to the bottom). And it seems lighter -weighted in my kitchen- than the one with no brand marks. Does it mean something?

I'm not sure what you're asking here, but it's easy to tell whether a valve is one-piece or welded. Use a small magnet to see which parts of the valve the magnet sticks to, head, stem, or tip. Most grades of stainless are non-magnetic, and the grades that are magnetic are mostly pretty weakly magnetic so even then you can tell the difference in how hard the magnet sticks to the metal (this is why you use a small magnet, not a big strong one). If you slide the magnet down the stem you can even tell exactly where the weld is (because you sure can't see it!). It will be right where the stem begins to become wider above the head.

Intake valves can be welded or one-piece, but exhaust valves are almost always welded, and they need to be for long life. The stem will be magnetic, the head not, and the stem tip can go either way. That is because the heads are generally an austenitic alloy, while the stems are martensitic (remember martensitic starts with "m" , like magnetic). Martensitic alloys are harder at lower temperatures, and the hard material wears well. Austenitic is softer when cold, but when it gets hot it is even harder than martensitic, but very tough, so once the valve head heats up it is extremely durable. And on the stem tip, sometimes they just trust the hardness of the martensitic steel, sometimes they go one step further and face the stem tip with stellite; stellite is extremely hard, it is one of the materials chosen for facing valve seats for that reason.

When we used to see aircooled engines "suck a valve", which was the most common mode of failure, it was because the exhaust valve metal would fatigue and fail right at the weld joint, so the head would break off and into the cylinder it would go to have a fight with the piston to see who was boss. Problem was no one ever came out of that fight a winner, the valve would usually punch the top out of the piston, then all those chunks would go below to have it out with the crankshaft and rods. What a mess. With the chronic high temps aircooled heads ran at, that failure would come like clockwork, right at about 90k miles.

You should read this article, it has a pretty good overview of this subject (and let me know if I managed to screw any of this up):

http://www.enginebuildermag.com/Article ... lloys.aspx

[profe]

Thanks tc,

I decided at last send them back to the supplier. I just don't want risk open the engine again ... until I became 70 years old!. Your information was very useful for me, as always.

It's been pretty hard for me finding the TRW here in Spain. Even in Europe. And Van's Cafe do sell them and shipp to Spain. Better don't ask price for shippment (higher than the valves ).

-Call for European folk forums-. Do anybody know a TRW supplier who has stock of a good valves set?. Thanks in advance

[profe]

Where is the mistake?

I have measured my MB & crank diameters. It seem there is something strange.

My used MB tolerances are around 0,14 mm mor or less. The engine didn't waste any drop of oil (I used to change it about 7500 km with the OEM Mahle filter). But the new KolbenSchmidts STD main bearings set have more or less same tolerances, between 0,12 mm and 0,14 mm,

I saw in this -and others- forum that a good limit value is 0,0045" (0,0045 x 25,4 = 0,114 mm). That means my engine was completly out of tolerances?. And the new KS set is not good for me?. According measures I have a blue crank.

I have checket the measures several times (see pictures bellow) and confirmed KS is STD set. My measures tools are completly new ones and I zero dial checked them before use them.

Where is the mistake?. Please help cos I don't know if I must fit the new KS MB set, the old ones, ... or neither of them.

I did it like following:

1ª First measure the out diameter of the crank with the new micrometer (after check the zero point). I took them several meassures in differents points and average them. I use this average as the right value.
2º Then I pass this value meassure to the alexometer and put thel clock zero.
3º With a support, I round the new (or the old) main bearing slowly with my hand and take the maximun and minimun differences.

Here the out diameters measures

Crankmeasures.JPG

and bellow the clearances (used MB and new KS MB).

40 mb4 measure 1.JPG

40,00 al alexómetro.JPG

Mb comparison tolerances.JPG

[tencentlife]

You want to mount up #1,2 and 3 bearings in the case. They should require a little pressure to fit in their saddles by hand, if they drop in easily then the case needs to be align-bored. Torque the main saddle nuts down to 25-30ft.lb. (no need to go all the way to 37 just to measure, do that on the final assembly), and then take your main bearing ID measurements. Leave the #4 out so you can get the bore mic in thru the pulley end to check #3 (we don't worry much about the little #4, a bench check as you have done is fine).

When you torque them up in the case, expect to find the main ID's reduced by about .0003-.0005" from the average of the free measurements you made. The ID in the case will also not be a true circle, it will be larger on the horizontal axis than the vertical. The horizontal axis measurement is what is important (it's very hard to get an accurate mic on the vertical anyway because of the wide oiling grooves in the 2.1 wbx bearings). Sometimes you do find them as much as .0048" oil clearance with stock parts, even with a blue-dot crank (a red dot crank would have ~.0005" larger clearance; unacceptable in my book).

Measuring on the bench is of little use when you want to find the exact oil clearances because the case will determine the bearings' final shape and size, it has to crush the bearings to hold them in place and only then do you see the true shape. Don't worry, "crush" doesn't exactly describe what happens, the bearings are not permanently deformed and will spring back to their original size and shape when you open the case again.

VW's spec main bearing clearances on the 2.1 wbx are really large, but with oil cooling (as I know you will have!) you should always be able to maintain good oil pressure.

The only way to get tighter clearances is to get .010"-under main bearings and have the crank custom-ground to undersize at your own specific journal sizes; this is what I do on every engine. At the same time the rod journals can be ground to do the same for the rods, using .010" -under rod bearings. This requires finding a good machinist who will work with you and machine to your specs. If you take that route, it is best to take the case and bearing set to the machinist along with the crank so he can mic up the bearings in the case and machine the crank journals to the tolerances you want.

With red dot cranks, and no red dot bearings available as far as I know, the ten-under bearing approach is the only way to make that crank usable.

[profe]

Thanks again for your answer, tencent.

I imagined measures would change with bearings installed in the case. You gave me an average that I will try to check soon.

I know that you really improve the MB clearances in your engines but my doubts are if VW's stock engines has more or less what I found in my measures. As this is the only one engine I have removed, I don't have more feedbacks of this issue. May be the engines you have repaired were out of tolerances or may be they measure similar values (talking about blue cranks).

KS service information says my STD MB are OK for my used crank (according my OD dot measures). And I gues VW repairs manuals confirm this. Do I take the risk?

Regards

[tencentlife]

You said above that you thought the "limit value" was .0045", but that's not the limit, that's the norm. I'd say you're good to go.

[pocketrocket]

Profe, I can get you the TRW Ex. Valves For the WBX. Email me at rocky@rockyjennings.com

[Stripped66]

You want to mount up #1,2 and 3 bearings in the case. They should require a little pressure to fit in their saddles by hand, if they drop in easily then the case needs to be align-bored.

Yes! The main bearing needs to be placed into the case and torqued up when measuring bearing clearance.

Torque the main saddle nuts down to 25-30ft.lb. (no need to go all the way to 37 just to measure, do that on the final assembly), and then take your main bearing ID measurements.

FWIW, when I measured my bearings, I had excessive ovality at 28 ft.lbs of case torque. The bearings didn't measure "round" until I torqued the case halves to 37 ft.lbs.

[tencentlife]

I would eyeball the mating surfaces if you find that to be true, you might see some light between the halves when they're mated together. if they fit true and flat, that small change in torque shouldn't make a measurable difference, too small to measure on a .0005" dial.

I just leave the torque a little light so as not to strain the studs more times than necessary, since I end up doing this bolt-up at least a couple times. One of those small points, like a lot of the things we do it's of only marginal importance. If one feels more comfortable taking it to full torque, he should do so.

[profe]

Thanks again, tc. I will do like you say.

Now I would like opinions of following pics.

Bielas Scat.JPG

Scat rods1.JPG

Pin bushed to 24 mm.JPG

I bought SCAT I beam rods rebushed to 24 mm. I tried first CB but they answer me that machined the pin to 24 it was not a good idea. Then asked to SCAT and they said: no problem!. So finally I ordered the SCAT ones.

As I don't have seen never the SCAT rebushed to 24 I am not sure if the thicknes of cuper is big enough. It looks like so slim, doesn't it?. Must I be worried about this?

I have bought a Cheater cam too. It looks great. But it seems it has less lifting than the DJ stock OEM VW. Is thiat right?. The CB 2280 kit includes bolts and shims. But the GeneBerg +2 gear includes a different set of bolts and shims. Wich ones should I fit, the CB or the GeneBerg?

By the othe hand, the MaxiPump1 pre 70 seems perfect. Even do the paper joints look OK. The plate/pump one joint is 0,07 mm and the one betwen pump and the case is 0,18 mm.

I try to attached the pics of abovw issues

Junta bomba-tapa.JPG

Junta bomba-carter.JPG

MaxiPump&cam.JPG

Thanks in advance for your opinions. I always learn something new from this forum

[Piledriver]

The pump case bore >pump body should be a .002">.005" interference fit.
Make sure the studs are clearing when you press it in, if it slides in (for any definition of slide) it is too loose.

Please advise how it fits, you may have to live with it.
I haven't seen a non-NOS pump that actually fit correctly in years.

The CB rods should be fine unless they have changed the forging, they have more meat than the stockers.
The SCAT rods even more so.

I had the CB rods rebushed locally, next time I will go with the SCAT rods.