TheSamba.com :: View topic - Rebuilding wbxer questions -attn tencent

Fri Dec 28, 2007 5:10 pm

Just finished taking out the 2.1 and will start rebuilding it next week. Previous owner ran it at least 5 years with a leaking main and oil breather tower. Every piece of dirt must of stuck to that engine. It was 3 inches thick behind the pulley. I pressure washed it with the mother of all steam cleaners for an hour. I'm surprised it didn't overheat with that dirt coat on. I have to do heads and figure w/ 240k on the odo I should go ahead and do a bottom end rebuild as well.

I would like to get extra performance if I can so I was looking at a cam from cb performance and the 2.2 piston cylinder kit from just vee dubs. I've heard some of the aftermarket piston kits lower the compression due to misshaped domes.
Anyone have experience with Just Vee Dubs. Here is a link
http://www.justveedubs.com/vwengine.php?FormName=s...=Vanagon+2 to the piston cylinder set. It seems really cheap (I think I just answered my own question).

Tencent, I think you have used the cam from cb performance. Is it ok with stock displacement? Will I lose any top end?

Does anyone have experience with the rebuilt rods from van-cafe?

I've heard it is better to use the rod bolts from a 1.9 than a 2.1. Why? The only difference I know about is the 2.1 were stretch bolts.

Hope a freshened up 2.1 will feel a lot different than a ragged out f'ed up one cause it has been a lot of work.

Thanks in advance

Fri Dec 28, 2007 5:30 pm

I would be careful with those pistons. First of all, 94mm is not a big bore size at all. That's the stock 2.1 size. There are basically two types of cheap big bore pistons out there. The ones made by AA Performance and some new ones by QSC. They both have the pins located too low, and lower the compression ratio to the lower 8s. Not good. The expensive Go Westy 96mm pistons are a good way to go when you start to take all the factors into account. They were $695 last I checked and that includes machined out cylinders and ceramic and teflon coating.

Both Tencent and I have used the rods from Van Cafe. I think they are a good value. They are nicely rebuilt and have used 1600 bug bolts installed in them. You can't duplicate this rebuild for the money. They are done by Frank Stamos at http://www.lowerendforvw.com/WaterCooledRods.html

You can buy direct from Frank, also. His core charge is cheaper than Van Cafe's and he is a great person to deal with and to talk to. He did some custom rod work for me recently and I really appreciated his service.

The reason the 1.9 bolts are better is because the 2.1s were stretch bolts. They tend to stretch at higher rpms and this allows the big ends to hammer slightly. In turn, this results in ovaled out big ends. There are other theories on what happens, but this is mine. At any rate, low oil pressure results along with the potential for a thrown rod if the engine is pushed hard under low oil pressure conditions.

The 2252 cam is a good affordable choice instead of a factory regrind. Just remember to order an early style oil pump and cam gear while you're at it.

Sounds like you've got things pretty well figured out and are on the right track to a good WBX. Just be careful with your piston selection. Compression ratio is very important for both fuel economy and power.

David

Fri Dec 28, 2007 7:02 pm

David, thanks for the info.

Does the 2252 have a different grind than stock? Could I expect any change in performance?

Re: the oil pump. I was going to use the same one tencent did on his 2.2. When you mention early style what exactly do you mean for the pump/cam gear?

Used rod bolts? I'm kind of scared. I can get dealer cost on factory 2.1 or 1.9 bolts, would it be better to use them?

I'm going to go with stock pistons/cylinders. I don't have the bling for the gowesty's. I plan to go with a conversion later so don't want to spend a ton. I will buy new stuff for the majority of the rebuild.

One last question. The heads that were given me were off a 1.9. They are almost new AMC heads. My assumption is they are the same for 1.9's and 2.1's now. Is this correct? If they are different was it valve size?

Thanks again

Fri Dec 28, 2007 7:40 pm

Bottom line on pistons, is that unless you can do some machining mods, there are only two products that you can buy new in a box and bolt on that won't cost compression and turn your motor into a dog: An OEM Mahle P&L set, stock size at 94mm with the correct compression height,

or GW's 96mm set that will make it into a 2.2 but still have the right compression ratio (actually slightly less than stock from what I hear of the latest versions, but the critical quench clearance is kept right).

Both are very high-quality products as good or better than original.

There are other, cheaper aftermarket P&L sets that can be used to get a 2.2, but to get the right CR and quench you have to do mods to the rods or pistons, custom work that aint cheap unless you have the machinery to do it yourself, and regardless you need to know how to measure and calculate the changes to be made so everything works out right. Not for the inexperienced rebuilder.

The wbx isn't hard on pistons, rings and cylinders like the aircooleds are, so you actually can treat them like most engines: mike the ring lands and diameters, check the cylinder bores, and if they're not too far gone the cyls can be honed and you can clean up and rering the old pistons.

The 2252 has about ten degrees less duration than stock, and is symmetrical (stock had less lift on exhaust ). It is for all practical purposes a replacement for the stock 2.1 cam; if you changed nothing else but the cam, I doubt you'd notice a change in how it drives, if anything the torque peak would be at a slightly lower rpm.

All aftermarket cams are ground on the pre-'71 style long blanks. That means that they use the old-style "shallow" cam gear, and the pump has to be the pre-'71 style to match the camshaft. From '71 on, Type 1 cams were groud on a shorter blank, using the "dished" cam gear, and a pump with a longer reach on the driven gear shaft to engage the shorter camshaft. Wbx's originally used the late style cam, with gear and pump to match, but if you buy any aftermarket cam it's going to be the early style so your original wbx pump won't match. Not a problem anyway because you'd have to be insane not to put in a fresh pump on a fresh rebuild, so you'll be buying a new one anyway.

The early rod bolts used in the 1.9 and Type 1's are plenty stout and don't generally suffer from age, so they are used over and over, whereas the stretch bolts used in the 2.1 are a type that, at best, should not be reused. I don't know why they used that type as a rod bolt, they are not suitable to that application in my opinion. If you really want to spring for new bolts, then you might as well pay extra and get ARP high-tensile fasteners and have total insurance. If you're determined to have new bolts, ARP's or equivalent may be your only option anyway; the stock bolts are probably not available new. If you can actually get them, then by all means use the 1.9 type, not the 2.1's. You know, though, that the rod big ends must be resizd after rod bolts are changed. Overall the rebuilt rods from VC or Stamos are a good value.

The original 1.9 heads from VW had smaller intake ports, so you would not want to use them on a larger engine, but AMC made only one casting for wbx heads, so they are interchangeable between the motor sizes.

Sun Dec 30, 2007 5:33 pm

D Clymer

Can't remember which thread I saw it in, but you mentioned a special wbx build you did that will rear its head in January. Anything that might be of use before i put my together. Inquiring minds want to know...

Sun Dec 30, 2007 6:39 pm

I can think of a couple things. With that many miles on the bottom end, you might want to send the crank to DPR Machine Shop and have them measure it and at the very least polish the journal surfaces. If you have a big enough micrometer and you're experienced with this, you can scratch that suggestion, but DPR is very reasonable for crank work and they do a good job. They charged my only $180 to counterweight and regrind a 2.1 crank. WBX cranks tend to not wear very much and it will probably still be okay to run standard bearings, but it would be nice to know. Also, look at the old bearings when you remove them for markings of "std." There's always the chance that engine has already been rebuilt and has .010 under main bearings. You'd want to know that before you order new ones. Van Cafe seems to have the best price on Kolbenschmidt bearings. In fact, they are a good place to shop for all the internal engine parts as I think you've found. Also, keep in mind that the main bearing sets do not come with the thrust bearing. You need to buy that seperately.

The camshaft bearings that Van-Cafe sells are Glyco (I believe) and they have double thrust surfaces. I found that the CB cam I had was a tight fit, and the thrust surfaces needed to be reduced slightly. You can use 600-800 grit wet/dry sandpaper with oil and a very flat surface to do this if needed. You want just a slight amount of end play - just enough to detect.

Lastly, take a good look at the water jacket gasket surfaces. If there is any corrosion that has eaten away the case, you'll want to repair it. Boston Bob mentions that he uses JB Weld to fix any of these spots. I had Rocky Jennnings (of OxyBoxer fame) do some case modifications for me recently and he found a problem area on the water jacket on my case. He actually ground out the corroded area, TIG welded it, and then machined it.

Also, if you find your heads have pitting or vein like contact corrosion, you should address that too. I know you're trying to keep this engine on a budget, so sending them out to have them rebuilt is probably outside the budget, but I have heard of people cleaning the surfaces, filling the pits with JB Weld, and then sanding the deck smooth. This would not be my preference, but it does sound like it works.

Tencent mentioned a very good point in his post. Piston wear on a WBX is surprisingly minimal and you may be able to get away without replacing them. That would help a lot on keeping this rebuild on budget. But look the pistons over and make sure they are OEM 2.1 pistons. They will say something like Mahle 93.98mm on the crown. If they say Brazil or China on them I would dump them. If you do end up buying pistons, you should go with the GoWesty 96mm ones. OEM 2.1 pistons and cyl. from Van Cafe are over $500. This is a good value for a high quality piston and brand new cylinders. However for $695 the GoWestys give you an extra 100cc, are forged and lighter, and come with ceramic and anti friction coatings. These pistons would make this engine desirable to someone else when you decide to do your conversion.

I think you're on the right track with the rod choice. I understand your reluctance about the used bolts bit, but unless they are stretch bolts, there is no reason they can't be used again. $70 is a lot less than anyone else wants for rebuilt rods, and Frank keeps the price low by using the bolts from his supply or air cooled cores.

Main thing is, keep us all posted on here on how the progress is going. This forum is a great resource of helpful people, and it's good for others to see that a rebuilt WBX is a good and attainable option.

And, yes, come the start of January I will have a very exciting engine build to share on here. A few more hints: This wbx will have as much displacement as the biggest wbx's built so far, but with a different bore and stroke. It will have a different solution for valve lifters in order to lengthen the list of usable performance cams, and it will run with a different fuel injection system. :D

David

Sun Dec 30, 2007 6:52 pm

Quote: And, yes, come the start of January I will have a very exciting engine build to share on here. A few more hints: This wbx will have as much displacement as the biggest wbx's built so far, but with a different bore and stroke. It will have a different solution for valve lifters in order to lengthen the list of usable performance cams, and it will run with a different fuel injection system.

I speak for many when I say that we wait with bated breath....

Sun Dec 30, 2007 8:16 pm

tencentlife wrote:

I speak for many when I say that we wait with bated breath....

I know I am! Sounds neat!

Mon Dec 31, 2007 12:08 pm

F*&%K!!!

The motor is out of the van and you tell me this!!! Maybe I don't want to do a conversion after all. The fuel injection system on the wbx is one of the things I thought held back any potential.

Different fuel injection? Motoronic? Megasquirt? Knock-sensor?????????

Is this something you're going to be selling?

Ah hell, just tell me what day you plan on sharing and I'll save my questions for then.

It sounds very interesting.

Mon Dec 31, 2007 12:27 pm

Heh, heh. No this fuel injection change isn't going to be anything major like that. The actual engine buildup will be much more exciting.

I do have future plans to retrofit Bosch Motronic 2.9 to the wbx, though. It has a hot film AFM, a throttle body potentiometer instead of switches, and a sophisticated knock sensor ignition. It does use about three additional sensors that the Digifant system doesn't though, so that's where the difficulty would be. I have figured out where to place the knock sensor on an unsupported sleeve type engine like the wbx, so that's progress.

I think something along these lines would be an important upgrade for dedicated wbx owners. It would have much better driveability than Digifant, and would allow high compression ratios of 10.5 and slightly higher to be used.

David

Mon Dec 31, 2007 4:24 pm

I worked a little bit more on the van today and have another question.

When I drained the coolant from the van I did with a wet/dry vac. I didn't see the coolant. After removing the head I noticed the water jacket was full of rusty coating. I went back to the van and drained some more coolant from another hose and it is rust colored and completely brown. Does that mean I was getting oil in the coolant? I also looked at the two large plastic coolant lines running to the front of the van and they have a nice brown coating inside.

I'm guessing the radiator is pretty plugged up as well. Is there a way to clean it out short of removing each piece and flushing them out.

Should I be concerned about this when putting the new motor back in?

Mon Dec 31, 2007 6:57 pm

Who put the coolant in your van the last time? Do you know if it had the right mixture of coolant and water? If it was mostly water, it would definitely generate rust off the cylinder sleeves and head studs. If that's the case, take a good look at the head studs and look for pitting. Pitted and eroded studs should be replaced. Luckily 2.1 head studs come out without too much trouble. If they are fine, I would just flush everything well. You could disconnect the radiator hoses at the front to make sure you can get plenty of water through.

If you think there was oil in the coolant, you probably should have the heads magnafluxed to check for cracking. If they are sound, I think you're good to go as far as engine assembly. Oily hoses are potentially a big problem because they get weakened by oil. If they are oily and haven't yet gotten all bloated, you can probably clean them with soap and water, but they'd have to be removed to do this well. Anyway, hopefully this isn't the problem.

What kind of shape were the cylinder head gasket surfaces in? Much pitting?

David

Mon Dec 31, 2007 10:40 pm

D Clymer wrote: Luckily 2.1 head studs come out without too much trouble. If they are fine, I would just flush everything well.

Can you elaborate on the difference between the 1.9 and 2.1 rod bolts?

-Damon

Tue Jan 01, 2008 6:21 pm

remraf, make sure you also pressure test your oil/water heat exchanger if you suspect it was oil in the cooling system. That is a place where oil at pressure is close to the cooling system, which is at lower pressure so the oil can be forced past a leak to contaminate the coolant.

It does sound like it might be rust, though. Oil in coolant will make butterscotch pudding, whereas rust would just coat everything with a thin film of red. Also, did the engine need the oil topped up often but not the coolant? That could be another sign of oil leakage internally.

Tue Jan 01, 2008 9:33 pm

Tencent

Can you elaborate on the oil/water heat exchanger? Which part is this exactly?

Edit-- Are you talking about the oil cooler?

Wed Jan 02, 2008 9:07 am

Yeah, the "oil cooler". Oil and water come very close there, as you'd expect, and will mix if there's a leak. Much of the time, oil is at higher pressure than water so the leakage will be that way; at other times, such as at idle when hot and after a hot shutdown, water is at higher pressure so it will contaminate the oil. So if that leaked you would have probably also seen water in the oil when you drained it. Unless that went into the shopvac too.

Damon, I've described the rod bolts diff several times elsewhere. Do a search on "2.1 rod bolt" and my name and you'll find my posts. David has also talked about them. If you meant "head studs", he'll have to elaborate.

Wed Jan 02, 2008 9:18 am

remraf wrote: Tencent

Can you elaborate on the oil/water heat exchanger? Which part is this exactly?

Edit-- Are you talking about the oil cooler?

From one of MMach's posts:

Wed Jan 02, 2008 1:41 pm

tencentlife wrote:
Damon, I've described the rod bolts diff several times elsewhere. Do a search on "2.1 rod bolt" and my name and you'll find my posts. David has also talked about them. If you meant "head studs", he'll have to elaborate.

Sorry 10c, i'm a typing dummy. I definitely know the difference between ROD bolts (which i asked about :roll: ). What i meant to ask D Clymer was about the inferred difference between HEAD studs - i didn't think there was a difference between 1.9 and 2.1, but it kinds of sounds like he is saying there is...

Thanks for the clarification, anway :-)

Wed Jan 02, 2008 5:30 pm

The head studs are the same between the 1.9 and the 2.1, but VW apparently modified the threaded holes in the 2.1 crankcase to make the studs easier to thread in and out. I got this from Rocky Jennings who did some case machining for me recently. I've only removed studs on 2.1 cases (and had no problems), but Rocky tells me it is a real chore to remove them on a 1.9 case.

David

Wed Jan 02, 2008 5:59 pm

Yeah, I thought it might be a typo, Damon.

Now, this difference in the thread-cutting is news to me.