about this Blog

After I (more or less) finished my 1966 Volkswagen Fastback the "Volksback", it was time for another challenge, here it is!

Samstag, 12. April 2014

oil cooler thread repair - the sequel...

I wasn't too sure about the thread repair, so I borrowed a Helicoil repair set:

 ... drilled and tapped the special thread size...
... and inserted a helicoil insert, now I feel safe:

this will last forever!

and here another pic of the oil cooler adaptor with the M6/M8 bolts already inserted and loctite'd:

During the assembly I noticed this problem: No thread for the oil pressure switch:
 but a few hours later I had this: a nice, clean M10x1 thread:

 next on the list was a new oil cooler:
... more soon

Freitag, 11. April 2014

.. what I didn't mention yesterday...

During my bolt repair action I had another incident which I forgot to mention yesterday:
... as if there wasn't enough trouble, the drill bit also broke! fortunately I could safe it with a plier!
At the end of day the I wasn't to sure about my repair and re-did it again - more of this later...

Donnerstag, 10. April 2014

cylinders, heads and oil pump - and some headaches...

After I found out about the too high compression ratio, I had to use 0,5mm shims under the cylinders to reduce the compression to a final and healthy 9,3:1
 I also managed NOT to forget the (type 3) cooling tins!

a set of new push rods 

and of course, new push rod tubes with a slight drip of sealant

just for the record: cylinder head details and valve sizes:

a re-surfaced oil pump cover (original VW part - which is still the best)

a new oil pump followed soon:

with the slimmest available paper seal, to keep the oil pressure on a good level

oil pump finished!

a mechanical fuel pump was next on the list.

Next task: the oil cooler - which gave me headaches...
The upright adaptor has M8 threads, but the holes in the case are for M6 bolts - then again, the threaded bolt in the case is 6mm and the adaptor has a hole for M8

too fat bolts...

 o.k., first step: remove the bolt from the case - easy- isn't it?

Damn - this wasn't suppose to happen!
How could this happen? I used an extractor tool?

This is the problem: The cheap tool broke and in turn the bolt snapped!

 So, after some swearing, I drilled out the remains of the old M6 bolt...

 Here is the remedy for the thread problem: Bolts with M6 AND M8 threads. A special thanks to Thomas for a nice and fast job!

Here is the new, stepped bolt already loctite'd into the case
The other 2 bolts will be used in the adaptor...
Thanks to this trick I can later use the engine in original Type 3 configuration again!

Dienstag, 1. April 2014

short block finished - next step: long block assembly!

After I lubed all bearings, coated the cam lobes and lifters with Molykote 3402-C and cleaned the sealing areas really religious, I finally assembled the halfs and torqued all bolts to the correct values. I used sealant under all washers and nuts - in hope for a clean, leak free engine.

Then I started the piston + cylinder assembly.

Every component got a bath in my ultra sonic cleaner to make sure they are really clean:

the pistons are lubed, the wrist pin clips are positioned with the sharp edge to the outside, I de-burred the edges from the stamping process prior assembly:

the cylinders required a little persuation for a good fit - of course only with a "soft" hammer!

as the seats for the cylinders were machined for a nice overall sealing surface, I have almost "0" back lash, the piston ends exactly where the cylinders ends - not good for a healthy compression ratio!

In order to calculate the compression ratio I cc'ed the heads. Starting with 60ml of motor oil in clean, new mega-syringe:
(the pic shows it filled to 61 cc - but I adjusted it to exactly 60cc before I started)
the combustion chamber, topped of with oil - spark plug hole sealed flush: 

... and the rest in the syringe: exactly 10ml

So, according to the helpful website of CSP, which provides an easy way to calculate the CR ->  look here  <- we need these values:
bore: 90.5 mm
stroke: 69 mm
head volume: 50 ccm
back lash: 0 mm
result: CR: 9,88  which is a little too high - so I will double check all values and maybe use 0,5mm shims to reduce the CR to 9,34:1 which is almost exactly my target (9.5:1)!