3B block wanted, wear not a problem

[steve briance]

Hello all,

I am looking to buy a used 3b block, it doesn't matter to me if it is really corroded, worn, ovalised, scored (within reason) as i am planning to get some machining done to it. I think cracks would be the only thing that would put me off.

Anyone who has one for sale please get in touch, i have cash waiting or if it is of interest, i have a pair of 7A cams i could do a swap with for the block?

cheers all

Steve

[s2driveruk]

i definitely have a block....just havent seen it in such a long time cant remember if 3b or aby. Will check and get back to you

[steve briance]

nice one! this could be a good opportunity for me to come and remove a large item from your shed to make way for other spares that we all like to put away just in case

cheers

[quattrodave]

7A available on standard bore, any use ? to all intents its same as a 3B just 1.5mm extra on the bore.

[steve briance]

Ah, nice idea but it is a 7a I am building and my current bore is standard but on the limit of going up to the first oversize. I don't think oversize pistons are avaialble which is a bit of a snag so I was thinking 3b and bore to 82.5 and re use my old pistons with fresh rings and that will be as good as I think you can get.

If you have had your 7a bores measured and found them to be well within specs, it might work but otherwise it'll be the same position as mine and, I don't think it will help. But... if you can tell me where on earth to get any oversize pistons for the 7a then i will be a very happy tinkerer!

Cheers

[quattrodave]

Hmm, I rebuilt my 7A engine with a lower mileage block and new rings as I had the same problem, the block I have available has a bore step wear at the top hence I sourced a better block.

I believe that (I know the top ring is a different size) the VW 16v pistons should fit the 7A and are easier to source in oversize but you have to buy 2 sets to get 5 pistons. But without seeing some to compare I can;t confirm.

7A standard size ring sets are available at a price, I had to buy 2 different sets to get a full set of rings as some 7A pistons have a 1.2 mill top ring and others have a 1.5 mill top ring (the 16v VW ones are 1.2), mine were 1.5.

Oversize 7A piston sets are available from Wiseco at €999 a set.

link to a source -https://www.bar-tek-tuning.de/en/audi-2-3l-20v-7a-high-performance-pistons-kit-wiseco

[steve briance]

Ive checked out the Mahle catalogue and vw 9a pistons re the correct bore but compression height is on 30.9mm not the Audi 7a 33.4. I checked out vw Abf pistons and they are closer at 31.4 but have 21mm small end pins. Damn it.

I've sent an email to a place in the uk who sell Wiseco pitons as the 83mm bore 7 a are 'unavailable' which to me reads we won't be making any more of those, who on earth has a 7a engined car nowadays?