I picked up these pistons off ebay a while back and they finally turned up in the mail. The ad was a bit vague but the price was right so I grabbed them. They were advertised as being forged to fit "big bore VW" but the crown looks wrong to me. There are no part numbers or brand markings on them either. They are 94mm bore and vw wristpin, just a weird dome on them. Anyone ever seen anything like them?
I might see about getting them milled flat so I can use them.
waltermitty ·
must be for something else there are only three of them.
Mitchell
bajachris88 ·
does the crown sit nicely in a 94mm type 1 head?
Camo ·
The problem I see is tha the crown is on the side and not at the top or bottom as required in our VW motors. I think you can have a slightly raised on the upper side (towards top of case) to raise compression, but unless these are for a big deck height and to compensate lower compression I think you need to look into it further.
Also, as I said I believe the raised section is in the wrong position for VW.
Kev
MrSpeedy ·
I haven't got a head spare at the moment to see how they fit unfortunatly. They might end up as shiny ash trays if they arent suitable for the 1916 I want to build 🙁
Performance Upholstery ·
Ask Dave butler... He'd be able to give you an explanation.
matberry ·
Not VW in my opinion
fish26 ·
Could be VW but not air-cooled
hulbyw ·
There was an article in Hot VW's a while back where they used modified Toyota pistons in a VW engine. If I can find the mag I will post more details
Cheers......Wayne
helbus ·
Check the deck height and the compression ratio that will be achieved based on the head cc. Were rings included?
modnrod ·
Mill the piston top flat, then it looks just right.
hulbyw ·
Found the HotVW's mag. The Toyota pistons actually have a negative dome piston, so completely different to the ones you have bought. They are cast not forged. Article mentions about wrist pin offset which is something you may need to consider
Cheers.Wayne
dangerous ·
Yes those are made for AC VW and others too.
Making a big cam fit is bogus, and the lump is right in the way.
Make sure the gudgeon pin is in the right way, it should be solid on one end.