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Humm, I have collected three sets of machine in 88's. I'm not sure if A or B pistons but old school Cima stuff. 78x88 would be great.

I have had great luck with 94's in the 69 stroke motors I have built. I always though they would be a problem but so far they have out performed my expectations by far. All of the piston/cylinder failures I have investigated were caused by failures in another systems such as ignition timing, fuel delivery or cooling. It seems people often focus on the broken part, the piston, and try to make it stronger without following up on why it failed. The 94's hold up amazingly well in my opinion if the motor is running well but can fail real quick if things go bad in the motor. I run oil temp, oil pressure and dual head temp gauges in two of my three VW's just so I can catch this kind of problem. So far I have fished one shop towel out of the fan. I also tune with a wide band...makes a lot of difference in my opinion.

The last blown piston I fixed ( I blew it up) was in my brothers rail (FI/Turbo). It lunched the piston while I was running sand mountain. I diagnosed the failure was due to a piece of foam weather strip from the gas tank worked its way into the fan and blocked almost all the air flow.

I would love to try the thick wall 92's. 78x92. I don't have a lot of experience running stroked motors on the street. My newest build is in my Baja (86x94) and it seems to be running high oil temps on the highway. I think it would be tough to keep cool in the bus but it sure would make it fly.

Marc wrote:A stroker would be the best choice. My son had a 1995 (88x82, with stock rods) in his `73 bus and it had no problem flat-towing his race bug - even ended up putting taller tires on it 'cause it had so much grunt there was no need to rev it. Problem there is that there are no longer any off-the-shelf "B" pistons in 88mm bore, and going beyond 74mm with "A" pistons brings on some problems. IMO 94s are too thin for a bus (they're only .006" thicker than slip-in 87s). AA also makes some thickwall 92s which fit the same case & head registers as 94s, or you can turn down the skirts so they'll fit a case cut for "classic" 92s/late 90.5s. With a 78mm stroke you'd have 2074cc (2085 if it's actually 78.4mm) ...that should do the job.

Can my bus really tow 1322lbs without brakes and 2645 with brakes? Wow. If I flat tow the Baja I will be over the 1322 by a bit and no towing brakes..

Theo wrote:Can my bus really tow 1322lbs without brakes and 2645 with brakes? Wow. If I flat tow the Baja I will be over the 1322 by a bit and no towing brakes..

Here's a `71 bus owner's manual that specifies 1100 pounds:
http://www.thesamba.com/vw/archives/man ... page59.jpg

In my state they don't mandate brakes until the towed vehicle exceeds 50% of the weight of the towing rig, so although it may be legal to tow a lightened Bug with a Bus (and we've done it) it's really not very smart or safe.


I doubt that you have any 88Bs, the only ones I've ever had were custom-made from unfinished blanks for Gene Berg. With the 94s, it's not the piston that's the issue but the cylinder thickness. Even 90.5s are marginal IMO on a Bus - but those thickwall 92s are ideal.

Measure from the centerline of the wristpin to the top of the piston. If it's ~39.6mm (~1.56") they're "A"s. "B"s are ~34mm (~1.34")

1100 lbs sounds more reasonable.

I checked the 88's. Two sets of thick wall A's. One set is notched.

I have to say, these look like bus pistons.

If you've got a worn counterweighted 69mm crank around, you could have it offset-ground to Buick/Chev 2" journal diameter and approximately 73mm stroke (DPR in Santa Ana CA can do that for you if there's noone local).
Add a set of rods like these and you're good to go:
http://aapistons.com/index.php?main_pag ... fd9792f7c9

Same displacement as 90.5 x 69 (still OK with stock heater boxes up to ~4500RPM) but a little torqueier. You'll need ~.080" cylinder base spacers but that shouldn't make it too wide - you may even be able to use stock-length pushrods. With stock chamber volumes your static C.R. should end up in the 8-8¼:1 range which should be no problem at your altitude.

Still no 2-liter, but a significant step up from a 1679. Same stroke with 90.5s ≈ 1878cc, with 92s ≈ 1941cc (I'd use 1½" heater boxes for either of those).

A healthy Type I 2-liter dual-carb'd in my `73, made my friend's fresh `78 2-liter FI look like he was running on three...It feels against nature, but the next engine will be smaller (and rev higher), we've chosen to try 92x72.5 (modified stock crank). Without re-gearing the early 002 trans, having gobs of torque and a limited powerband isn't all that fantastic for spirited driving - first gear is almost pointless except for hills, and second a little too tall...

Cruising at 73MPH @ 4000 RPM in fourth all day is great with ear plugs
but then I put in a spare 1775 (peak power @ 6300RPM) to freshen up the 2-liter
Doing 75MPH @ 7300RPM in third along on-ramps from time to time is fantastic...had to start using the odd-numbered gears though.

Dan another local who used to chime-in on stroker Bus topics, put together a mild mannered stump-pulling 2110 with ICT's into his Bus years ago - his other ride is a nine-second turbo 'glass buggy - don't know if he ever tow'd it though. I remember he said it felt like he had a Cummins - he was also a diesel guy I think.

After searching my stash of cases and motors I only have one universal case and that one is a built 69x88 turbo motor. Currently in my Ghia. I'm rethinking the Ghia motor (84x92TW) and pondering putting the turbo motor in the bus. This is a FI/Mexi/megasquirt system. Does anyone know if the CB hideaway turbo header will fit a 71 bus?

We started cleaning up the bus. Found the motor used an adapter and is not a universal case. Someone cut low scoops in the back and someone patched them up badly. Battery rot. Body is otherwise solid.

you have no idea how much I hate you and your rust situatoin

fusername wrote:you have no idea how much I hate you and your rust situatoin

That's two of us , I'm jealous.

OK, now we have three...