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Fri Dec 20, 2013 1:07 pm

Is this possible using 83mm piston & cylinder sets in a stock 1600cc case?:

http://www.cbperformance.com/ProductDetails.asp?ProductCode=1001

http://vwparts.aircooled.net/83mm-Piston-Cylinder-Set-40hp-Slip-In-1384cc-p/vw8300t40.htm

Now you are probably wondering why the hell I want to do that? Well Im thinking of building a Porsche 1500S replica engine and class rules say that it can not be over 1500cc. I can't wait around for a used 1500 aftermarket engine to come around. There are alot more 1600cc engines out here and they are available new also so I was thinking this should be a good starting point if this is possible.

Fri Dec 20, 2013 1:13 pm

Well... you can install 85.5mm cylinders in a 1500 to increase it to a 1600, so i would assume you can put 83mm cylinders in a 1600.

The key word is assume.

Anyone done it?

Fri Dec 20, 2013 1:45 pm

yep did this on my 69' bug

since it had a dead case with pouring like leak

i got a surplus/ running 1600 off a vw brasilia...

sold the dualport heads and 1600 pistons/cylinders

cuz i had a set of NOS 1500 set and ran a pair of SP heads + the 1500 piston and cylinder kit

all good

Fri Dec 20, 2013 1:57 pm

Your links point to big bore 40hp 83mm pistons. They will not fit a 1600 engine. Wrist pin diameter is smaller and the pin height is different. You need a nos 83mm 1500 piston kit. No demand for them anymore so they are no longer made (everone uses 85.5's on both 1300, 1500 and 1600 engines). Dan

Fri Dec 20, 2013 2:02 pm

Hello.
If that is what you need, it so happens that I have a set of VW cylinders bored to 1st oversize with VW pistons too on the shelf.
I could be persuaded to sell. I have not yet found an engine i would want to use this fine set on.
They are flat top pistons, not the domed "S" version. But a flycut of the cylinderheads can make up for that :wink:

T

Fri Dec 20, 2013 2:57 pm

Dan Ruddock wrote: Your links point to big bore 40hp 83mm pistons. They will not fit a 1600 engine. Wrist pin diameter is smaller and the pin height is different. You need a nos 83mm 1500 piston kit. No demand for them anymore so they are no longer made (everone uses 85.5's on both 1300, 1500 and 1600 engines). Dan

I see. What a shame. So there are only 5 ways to go if I want a 1500cc:

1. Find VW original 83mm piston & cylinder set for 1500cc to mount in 1600cc engine. (rare & expensive compared to new sets?).

2. Fit 83mm piston & cylinder set on a 1200cc to make it a 1493cc with 1300 crank. (Change everything due to smaller case = :-({|=).

3. Have someone make custom pistons to fit in big bore 83mm cylinders for 1600cc engine. ($$$).

4. Find a 1500cc engine. ( :-({|= ).

Fri Dec 20, 2013 3:50 pm

5. Have a crank reground to 65mm and take 2mm off the cylinders or use 5.5" rods, or would the rules not allow it?

Fri Dec 20, 2013 3:59 pm

Quokka42 wrote: 5. Have a crank reground to 65mm and take 2mm off the cylinders or use 5.5" rods, or would the rules not allow it?

Have you practice this method before?

Rules say you must use vw original parts, or parts of same design, dimensions and material I think. Not sure on material. Did vw sell 5.500" rods back in the day? then it should be ok.

Fri Dec 20, 2013 4:27 pm

I have built a 1500cc 40hp engine using the 1500/1600 69mm crank, 83mm bb kit and all the other 40hp stuff. You must have a machine shop narrow the big end of the 40hp rods and put barrel spacers on it. Going the de stroke 85.5 route is better and I do see nos 1500 p/c show up in the classifieds from time to time. Are you able to use dp heads, they will fit on a 40hp. Dan

Fri Dec 20, 2013 5:01 pm

http://www.thesamba.com/vw/classifieds/detail.php?id=1217270

Fri Dec 20, 2013 7:37 pm

I don't know about 1500cc but 1300cc cylinders and pistons do still exist. http://www.justkampers.com/vw-beetle-parts/engine/...-1975.html. At least at the present time.

The heads will be next to impossible to find. 1600cc fuel injected heads should have the same valve size. You would have to have spacers made so they'll stay centered and CC them to keep the same compression ratio. Or you might be able to flycut just the diameter of the 77mm cylinders when you CC them so as to not need spacers. Or go 1300cc single port.

Fri Dec 20, 2013 7:49 pm

83mm kit may still be available, somewhere
do a google search for "mahle K70060"

Better idea is to de-stroke the crank, they will not complain that the welding wire is not made by VW :wink:

Sat Dec 21, 2013 6:42 am

The better question would be, who would know what size pistons they are? From the outside the 83 and 85.5 are identical? Unless they make you tear it down for an inspection?

Sat Dec 21, 2013 9:17 am

Using 1600cc parts will be the best way to go after some thoughts I think. De-stroking the crank as mentioned. 1600 engine has the best case and lots of new spare parts on the market...

Sat Dec 21, 2013 9:23 am

Bashr52 wrote: The better question would be, who would know what size pistons they are? From the outside the 83 and 85.5 are identical? Unless they make you tear it down for an inspection?

Exactly. If they find anything funny you can get banned from racing.

Sat Dec 21, 2013 7:07 pm

They don't have to tear it down to measure the capacity. There is a lot of shame if you are caught cheating.

Sun Dec 22, 2013 4:57 am

I don't know what the rules are for your class, but If you can, use the 1600 as a base for your engine. Find NOS or used P/Cs for 1500. I have seen many used sets of P/Cs with a gazillian miles on them still usable with honing and a new set of rings. If you can use dual port heads, do so.
I'm not saying to cheat, just use the rules to your advantage.

Fri Dec 27, 2013 2:13 am

Found a company who sells the original repair set of cylinders & pistons (311198063J) for 410$ new.

http://www.vwcustomspeed.com/product.asp?hkat=1&am...311198063J

Fri Dec 27, 2013 2:07 pm

Widowmaker wrote: Found a company who sells the original repair set of cylinders & pistons (311198063J) for 410$ new.

http://www.vwcustomspeed.com/product.asp?hkat=1&am...311198063J

Awesome!

Fri Dec 27, 2013 4:15 pm

what exactly are the class rules?