Hey guys

posted this on behalf of a friend who's planning a weapon of a project polo!!!

Hi All

Just a quick question about parts/bolt patterns – Is the bell housing bolt pattern on the Mk3 polo series of engines the same as the rest of the VW range, ie: mk2 golf gti lumps, AGU 20vT lumps?

Cheers

nope

you can only fit 084/085 gearboxs onto the mk3 polo engines, none of the "golf" 020/02A etc... boxes will fit.

can you not use the bell housing from a mk4 sdi engine? as they use an 085 box on a tall block engine?

edit, i see that prob wouldnt help with strength issuses tho lol

Edited 1 September, 200917 yr by Rod Stylz

Yeah, you can swap the bell housing over from the 085 diesel gearboxes for a petrol one. Starter motor mounting is on the front for the diesels and on the back for petrols.

So does that mean you can put a diesel box onto a petrol polo by removing the diesel innards and placing them in a petrol housing?

That could be handy

they aren't any stronger, see the amount of threads on here about blown gearboxes on diesels.

if your mate is putting something like a 20vt engine into a mk3 polo then I'd seriously recommend not putting an 085 gearbox onto it, use a golf box. 085s are just too weak, ask pretty much anyone who has ran a g40 with over 150bhp for any length of time!

I'm actually a bit confused as to what the question is now though, are you trying to put an 085 onto a golf tall block engine or put the gearbox from a tall block onto a polo small block engine?

What do you g40 boys run then to get the gear box reliability. I'm currently doing a 1.6 bike carb conversion in my MK2 and have heard the can produce a fair amount of torque. mikeymk minced two boxes with a similar setup

we just replace gearboxes and rebuild them regularly and put up with it. Nowt you can do without spending silly money on things like Super1600 rally gearboxes for like £12k. Although there is a company in germany who sell an adaptor plate to fit an 02 box to a small block but the plate alone is something like €1500 and on top of that you need custom driveshafts, custom mounts, make a gear linkage that I can think of off the top of my head.

Sorg do an 02x casing with the small block pattern welded on. It's around €1k. There's a possiblilty that the late mk3 Golf with the small block AEX engine has a suitable 02x gearbox too, but my local scrapyard that had 2 has squashed them both so I didn't get chance to have a play.

Some of the late AEE engines in mk3 Golfs have a coupling for 02x gearboxes. You would still need to fabricate driveshafts and mounts to fit this in a mk1/2/3 polo though.

I take it a diesel 6n gearbox wont go in?

Whooops. Just realised I have asked a question that has already been answered. But surely the 085 boxes on the diesel 6n's must be stronger? Its a 1.9 diesel. Bugger!

Edited 2 September, 200917 yr by Tommo32

Only way to tell is to try one on a torque monster and see how long it lasts after a full recon. Ratios are certainly friendlier for performance petrol cars.

But surely the 085 boxes on the diesel 6n's must be stronger? Its a 1.9 diesel. Bugger!

nope, 085 boxes are shit no matter what car or engine they are bolted to. Just search this section for "diesel gearbox" and read the amount of threads from people with blown up ones!

Yeah I can imagine. It just seems illogical, especially seeing that mammoth driveshaft!

Most small-block 1.4/1.6 Golfs have the different bolt pattern and take the 020 series box (not ABD),but apart from the other clearance issues the 020 series box is huge.

hi all!

I'm Dave, the thread was originally my idea and I nagged Mike to post for me lol but I've finally joined. I come from the Ford world of big power zetec turbo's in fiesta's and KA's. I've grown bored of the whole Ford thing and would like a big power Polo, and noticed not many 20vT in polo's.

All Ford bell housing bolt patterns are the same, and a common trick I've used is to put a 2.0ltr block onto the original gearbox of a fiesta with a strenghened quaife gearset and final drive. This means all you have to sort out is a drivers side engine mount and makes life a lot easier (no driveshafts/gearbox mounts to sort). So my theory goes if a 20vT will mate to something like a G40 'box, its an easy route to big power in a small VW package lol.

But having had a read, I realise now that the polo's are all ''small block'', and the golf stuff is all ''big block''. So I'm still gonna have a go at building a high powered polo, but don't think this particular combination is gonna be the way forward

Dave

Edited 4 September, 200917 yr by dave-imi

It is a bit of a weak point,Dave. 1.8t has been put in the bay of a pre-'94 Polo,but there's big work involved.

It'd probably be easier to put it in the back. That's been done too.

Post-'94 and its a completely different car. VR6, 1.8T, still requires far more work than you're used to.

Converting an XR2 to 2.0 16v is easier than putting a 1.6 16v in an '80s Polo,but i couldn't find an XR2 that still had a floor. The last one i had certainly didnt. But neither did the last Polo.

The Nova is another one - Saab 2.3 turbo, Saab/Vauxhall 3.2 V6, both possible with the Vauxhall box.

The trick part will be finding a Nova..

If you like silly,a front drive Audi box bolts to an Audi V8,and this was fitted mid-engined in an '80s Polo. Looked fantastic in situ,but i believe the project was never completed.

Was done in a Lotus Esprit though,so the unit works.

Definitely food for thought, am having another week of research and will begin a project thread to show you what I'm up to and how I'm getting on :)