800cc Project VW Barrels

[thepuddlejumper]

Started to collect bits for my little 800cc project, hope to start modifying the VW barrels and con-rods in the nearish future, that is until I finally get my garage built. I have a lightened flywheel, new lightened and balanced con-rods, new BIS crankshaft, Rusty's camshaft, oil cooler and some nice new silencers.  I have gone for circular led's for the rear and standard headlights for the front, the speedo is from a Fiat Autobianchina I think looks good.  Finally managed to get the scuby engine running sweet as a nut so this should also be going in one of my little fiats sooner than later, well it all depends on completing the garage.

Ralph

[Rusty's Uncle]

Hi Ralph , that speedo looks quite fruity 
I would be interested in seeing some pics of the VW barrels as I suspect that they are the ones I have on the 795 Alquati engine I have resting in my garage for more years than it should have. I think that the tuned big bore engine with a light flywheel is all a good plan but getting it all balanced is more important.

[thepuddlejumper]

Rusty, I agree it will need to be balanced. As far as the barrels and pistons are concerned I have my eye on a new set of VW 1600cc barrels and Pistons at £108 delivered. I have a laithe which needs a new electric motor, then I will be in a position to machine the barrels. Not sure if I will use a strengthening plate or adopt the Polish method of alloy welding to reinforce specific areas of the block. If anyone has carried out this type of conversion any advice would be appreciated. Rusty any photos of the Alquati barrels or dimensions e.g. Cylinder surface to block level.

Ralph

[jacw]

Apart from an enormous difference in price how different are the VW pistons and barrels compared to the 800cc forged piston & barrel kit shown on Nanni Ricambi's web site?
http://www.fiat500sport.com/engine-assembly/forged-piston-liner-kit-800-cc-o-85-mm-for-up-grading-fiat-126-engine-nanni-cylinders-0331.html
Please excuse the question from a newbie but I am thinking of this sort of upgrade for 2016. Thanks,
John

[Rusty's Uncle]

I strongly suspect that the Pistons and barrels are of VW origin but when I bought this engine some years ago I also got a couple of receipts that covered the engine conversion which was done in 1984. The first one was from a company called Lanciana who then became Italtune I believe and the Pistons etc were just referred to as a big bore kit at a cost of £172 with a further stage 1 head conversion for £84 apart from all the other parts. So the cylinder height with a ruler looks to be the same as the 126 at about 75mm and whatever they are they would have been available at that time. I have looked for part nos or markings on the barrels but no joy. The only feature that tells them apart is the threaded holes top and bottom on the outside of the fins.
.


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[thepuddlejumper]

Rusty your barrels don't look like modified vw units.  The holding down bolt positions are different, you have to cut a slot in the vw barrels to get them to fit over the 126 studs. The vw barrels need to be machined, firstly the cylinder head face there is a raised area which has to be reduced then the block face has to be machined to give the correct height i.e.piston top dead centre.  The section that protrudes into the block has to have an area removed to miss the crankshaft. Then there is the gudgeon pin or piston pin the vw is 22mm and the fiat is 20mm therefore you have to machine the fiat con rods to accept the vw pin. This is a short version, but I hope to give a more detailed explanation with photos after my build.
Ralph

[jacw]

800cc barrels on ebay for about £120.
http://www.ebay.co.uk/itm/COPPIA-CILINDRI-GHISA-LAVAZZA-85-00ALTA-QUALITA-FIAT-500-126-800CC-/331340611764?hash=item4d257080b4
Any comment?

[thepuddlejumper]

I have this company on my favourites, the pistons are £225 +£34 delivery add the cost of the barrels including postage the total = £413. This the best price I have seen the 800cc conversion, but the vw set of 4 barrels and Pistons comes in at £108 including postage. If I can get my laith running then the only external machining costs will be for the block and maybe the small ends, which would be required for both conversions. Therefore for me it makes sense to hava a go, anyway I'm looking forward to getting stuck in. If I didn't have the laith I would probably purchase the above conversion kit.

Ralph

[Rusty's Uncle]

  WOWZA those prices look like I had a good buy when I got the Alquati engine even though it was part dismantled with a few missing bits but the owner reckoned it had done less than 3,000 miles after the conversion. Then it also has the original Alquati camshaft and alloy sump which are now only available as repros. One issue you have to address is the gas escape grooves in the cylinder head which will come close to the oversize bore. On my stage 1 head the grooves were filled with weld then the head skimmed.

[jacw]

Thanks Ralph, I very much look forward to seeing your 800cc project unfold. Lots of learning for me. John

[thepuddlejumper]

Gas escape grooves, never thought about that being a problem. The standard 800cc kits from nanni etc. don't mention anything about alterations to the head. I will see how things match up when I get the VW cylinders. It looks like you got a steal with the Alquati.

Ralph

[Rusty's Uncle]

Gas escape grooves, never thought about that being a problem. The standard 800cc kits from nanni etc. don't mention anything about alterations to the head. I will see how things match up when I get the VW cylinders. It looks like you got a steal with the Alquati.

Ralph

Not sure about a steal as I took a chance on an incomplete basket case and shelled out almost £500 at the time but the engine has an interesting history and I know or have heard of 3 other 80's similar engine conversions that are still in existence in the UK. The picture of the barrels in the ebay listing that John  posted look the same as mine but those bosses had not been drilled and tapped. So the barrels must have been made for another application, question is which?