Anyone know who sells the 40hp 83mm big bore kit here in the UK? I know they are available in the US.

mahle used to sell them.

i bought a set a few years back, but not sure they are still available.

Try John Maher Racing...Tel:. 01870 602519
or email: [email protected]

https://www.johnmaherracing.co.uk/index.html 

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Thanks John, thinking about fitting some to a 30hp in my attempt at a vintage 'speed' engine in my bus... :unsure:

The big bore kits are for the 34hp engines. It will take machine shop work to fit larger pistons and cylinders to a 30hp engine and then you get into upgrading the crank and other ancillary bits.

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Check the vintage speed forum on the samba, lots of good ideas there ! I have been building a 'hot' 30hp motor for some time, I have opted for a 72mm stroker crank and stock size pistons. I have had some serious head work and a hot cam. Seriously addictive the vintage speed thing. Check Andi (Oval56) webpage he has built a couple of seriously nice 30hp motors, https://www.oval56.com 8)

Thanks for the replies and links... just trying to work things out, don't laugh but this will be going in a bus with reduction gears so it will be restricted by the gearing but i need to build an engine anyway so i thought i'd try and get a bit more power at the same time.

Not really sure which route to take,thought about just rebuilding/balancing the bottom and fitting the WW Okrasa kit, with maybe the 40hp 83mm kit but really not sure...Any thoughts or advise please

I wouldn't worry about the gearing, I assume if you want to build a hot 30hp motor for a bus you will want more torque rather than power? for this I would look to fit a larger crank, a 72mm crank will fit without clearancing the case my crank came from DPR machine in the USA, the WW kit looks good and wasn't available when I started my collection hence why I had the stock 30hp heads rebuilt, so by using the Okrasa heads and twin carbs will make a big difference, I would probably look to having the WW okrasa heads reworked to gain more performance. I maybe wrong but I think using larger barrels causes other issues mainly due to head studs, but is possible with quite a bit of work.

Check out the vintage speed thread on thesamba it will give you great inspiration and ideas8)

VW Heritage got the set:

https://vwheritage.com/vw_spares_Barrel-Pistons-83x64-1384cc-69-SINGLE-RELIEF-CASE-ONLY_act_shop.product_pID_183587_lang_EN_country_GB.htm 

I have bought one set, for my old 30hk/36hp. Ref. theSamba.com for fitting.

:smile:

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