Am i seeing what i believe i`m seeing ?? Un-matched pistons ?? Jeeeezzzz .... Time to invest in a horses head methinks ...
The first is a 104mm AA performance flat top piston with a valve pocket. The second is a 104mm domed piston from who knows where?
No, I thought at first too, but there's a shadow down inside the the second one. Maybe I should look on the laptop, better screen than the phone. Trick of the light?
Slap it together with new heads and sell? Then... Build one more like @77 Westy poss one size smaller crank. Or slap together with new heads and drive without thrashing the harris off it. Second one probably, it was great until I spent a month WOT tuning trying to get it to rev more and cruising for hours at 75mph.
Doesn't help you, Steve, but I'm bloody glad now I had to take the heads off my engine. Although...I did hand over a set of forged Mahle pistons. I wonder if they're actually in there
I do recall him saying that back in the 80`s when they churned out 10 engines a day they`d put on 3 new barrels with new pistons and a used set to cut down on expenses , free set every fourth rebuild . Old habits dying hard ...??
You guys type too fast – in my defence there is a one-hour time difference and I’m probably a bit further down the glass.
Right, I expect I warped those already 45 year old when turned from 1700 into 2400 heads through thrashing it and driving generally too fast. Do new heads then. @77 Westy yours were the 412 heads with different spark plug angles? If yes, what size chambers did you get from them and what size did they start at? From what I can find 1700 and 2000 heads are about 49.5cc but 1800 are 55cc. AA say they can get 60cc at 96mm - I had asked about 104 and have asked again. God know what shape they would end up.
Correct, I was fooled by the photo and feeling rather silly now but the heads are still beyond it I believe.
Great, new heads are better than new heads and new barrels and pistons. Sounds like @77 Westy is a good source of advice I'm off to get covered in Dynax.
There are a couple of divots, a bit odd for machining? It's 3/4 BTW, I thought I'd do the harder one first. Maybe these are better... Fresh looking scrapes at the bottom, could have been me. These look like rust pits on the left, weird. And pretty bad machining all round?
I use 1800 heads with 41mm inlet and 34mm exhaust valves. Normal 1800 combustion chamber volume is around 56cc, I took mine out to 62cc for a 9.0:1 CR with 0.062” deck and flat top pistons with no valve cut-outs.
Actual original VW heads? That's a good 6cc head start. I suspect all the castings now are the smaller 49.5 or whatever it is.
