VW Vortex - Volkswagen Forum banner

Intermediate shaft modification for stroker 1.8

7K views 42 replies 4 participants last post by  LT1M21Stingray 
#1 · (Edited)
So the butcher has a 1.8 stroker on the back burner. Eventually the engine will be going in my wife's Cabriolet along with small boost turbo set up.

I've been collecting parts for some time and I've researched this intermediate shaft issue even longer. There are a few options out there but I did not like any of them. Although shaving the gear,, so it will miss #4 rod is the go to method on the stock 1.8 block, I've just have issues with the shaved gear and longevity. I understand, no one has had an issue, and I'm concerned about nothing.

I decided to slightly press the gear off the shaft and check to see if the distributor gear is still aligned. I have found it you move the gear just over 2mm, that will allow enough clearance for the rod to pass without any damage. The distributor gear alignment seems to be ok too. What I plan on doing is drilling the end of the shaft and tapping it to accept a bolt. I will make a 2mm shim and then press the gear back on. Once it's completed, I will install the bolt and large washer to keep things from coming loose. There is plenty of room for hardware to keep the gear attached.

It's in the mock up stage and ready to go back into the corner of the shop. I hope to have the engine completely disassembled so I can get the block bored next week. The way I do things, it will probably be 15 years before I finish this project. I seriously need to get back on the POS.

This is what the shaft looks like installed

The distributor gear alignment

And the shaft out of the block for a better look.


Anyway, more useless information for those that want 2 litres but do not want to go the ABA route.
 
See less See more
3
#37 ·
it would be quite a task to do it with standard pistons. you would have to start with a very low mileage block with zero wear ridge at the top. no good shifting the pistons up if the top rings are going to be clattering at the original wear ridge. would save you money on a rebore though, and you could probably use a turbo shim head gasket. ah the list is endless:)
 
#38 ·
A slight update without any pictures. The block/shaft is at the machine shop to get bored. Mike is very familiar with the VW blocks. He machined all the ones from Bahn Brenner when they were located in Auburn.

I'm using EA113 rods. As mentioned, these rods are a little bit thinner in the right areas but the overall rod is thicker. When I installed the rod, it would hit the shaft. With the gear off, I was able to grind down the shaft so the diameter is now a little be thinner. Once there was enough clearance I pressed the gear flush [stock location]. The rod barely hits the gear. With a little trimming of the gear, I was able to get enough clearance without really effecting the thickness of the gear [which is my concern]. I suspect the gear is about 1 mm thinner than stock vs the 5mm that is usually trimmed off. I did not have time to install a stock JH rod to see if it would work. I suspect not because that rod is much more squared at the end

I'll attach photos later when I have the final product completed.
 
#42 ·
I purchased a used lathe large enough to fit my needs and small enough to fit the budget. My first task was to properly get this shaft to fit the dimensions. Like others, I removed the fuel pump lobe. Trimmed it to make it look better. Polished it to make it look shiny.

I started this thread to find another way to modify the gear to accept a 92.5mm crank without trimming the gear as much as others. I understand no one is concerned about this in the past, but it just looks like a durability issue to me.

The end result is that I did turn down the gear but the gear is 8mm thick compared to others at 5.5mm thick. I'm using the EA113 R rods and they are thinner than the stock 144mm rods. There is less material that has to be removed. I originally was going to move the gear but with the thickness of the EA113 rods, trimming the gear [I believe around 1-2mm] was the course of action.

The other issue I had was the rod would hit the space between the bearing journal and gear. That was reduced a fair amount, but I did not measure the amount removed. I will edit this later to give the final number.

Before

After

Trimmed gear
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top