As in title, I'm planning to buy 1.6 16v AVY engine for my mk2F, and i would like to run it on bike carbs.

The question is how to fit mk2 polo vaccum advanced dizzy in to the AVY cam?

Don't want to built AFH/AVY hybrid, just want to run the AVY on carbs.

Already built an bike carbed AFH in last year, and was running spot on, now I'm planning to buy AVY for bit more powet than AFH.

is there even location for a dizzy on that head casting?

Yeah, pretty sure someone's spoke about modding the head to allow a dizzy.

Can't find nowt on Google though.

before i fit my AFH to my ex bready had lupo engine AFK code, and gad the same problem, heard that its possible to drill the cam, but haven't got a clue how to do it?

pic of the lupo engine:

think the AVY got veri simmilar ignition?

anyone got side pic of AVY head?

Edited 3 March, 201214 yr by Adamos_20

just found that:

so its possible , but how???

isnt mikey running one of them heads? ors he got VVT in an afh head? :S

also found that

so all i need to do is just drill hole in cam and fit dizzy? so easy?

so basically you need an adaptor plate and a hole in the cam? all i can say is use a good drill and ideally with the cam removed, if not be very very careful of swarf etc. also the position of the hole will effect where to mount the dizzy

so basically you need an adaptor plate and a hole in the cam? all i can say is use a good drill and ideally with the cam removed, if not be very very careful of swarf etc. also the position of the hole will effect where to mount the dizzy

yes, the position is very important, but if will put adaptor plate, can adjust the dizzy position, need to check the hole place in AFH cam, and drill in the same place in AVY

If you PM McLovin' I'm sure he'd be happy to help.

looool

If you PM McLovin' I'm sure he'd be happy to help.

will do, hope he give me an advice how to drill it

He was joking, I'd imagine he'll ignore or give you abuse

Yes i have a dizzy on an AVY head, and yes it's as easy as drilling the cam's drive disc and fabricating an adaptor.

Remember the adaptor needs to be sealed to the head.

I did it differently, i chopped the drive disc from the cam and machined it further in, so i didn't need an adaptor and it looks tidier.

But this brings a couple of problems..

For one, you need to remove the cam. For this, you need to remove the vvt cam pulley from the cam, and you need to mark where the cam is first, at the dizzy end. Fail to do this and your cam position is lost, as there's no key.

Also, the drive disc holds the cam in - i found out the hard way as the cam started sliding out the head whilst the engine was running!

So i needed to fit a cam retainer bridge into the cam carrier.

Oh, and the bolt that holds the vvt cam drive sprocket on is a reverse thread.

My dizzy isn't a Bosch one, it's made by some german company i can't remember the name of. The ignition curve is vastly different to that of a static cam let alone the original one, and i haven't tried to change the curve with a Bosch dizzy (although i believe it's possible).

Shocked to see pics of another one - until i realise it isn't a GTi vvt engine! They've cheekily painted the cam carrier red but there's no vvt actuator (mine was blanked off for that pic but is fitted now).

The one in the pic has the old thermostat housing, so me thinks it's a 1.3 lump with a 1.4 16v head on it.

Same dizzy as mine, btw.

So i still seem to be the only one who's done it..

What is your dizzy off then?

What is your dizzy off then?

Ebay

It's a pattern part for an MH/2G 1.3 carb Polo/Golf/Jetta engine

Any more info on this?

I've had a thought, as i haven't bought any hybrid stuff yet, i could just buy a gti lump and do this, and then i can fit a proper engine cover?

Thoughts?

Yep - don't bother.

The dizzy doesn't like advancing with the variable cam, major ignition fail when the VVT is actuated. It only worked on the inlet cam when running static.

So i put the dizzy on the outlet cam. Not easy because the AVY cams are hollow steel with seperate lobes/bearings/end floats heat shrunk onto the tubular blank camshaft (instead of one-piece machined iron for all the other engines). Drill the cam's end float guide to accept the dizzy and you take the grip out of it and have to weld the end float to hold it on. Fail to do so and the teeth on the sprockets collide..

Still, this worked to a point - the engine still ran okay when the VVT kicked in, because the ignition timing still matched the crank.

But it didn't really work as i'd hoped, because the dizzy has one curve, and the engine requires two. So either the ignition timing is set up optimum on advanced or retracted cam, but not both. With it set for off-cam it ran like an AEE which was running rich top end.

What you need is two ignition curves, one for each state. I still believe it can be done with a dizzy - well, two dizzies, one on each cam, switched by the same switch that activates the cam, with conjoined HT leads.

But why go through the hassle when the simple solution with carbs is to just go with a programmed system.. Or the stock AVY's fly-by-wire mediocrity.

So yeah i have an AVY, but only the bottom end - the head is now a 9n Sport head. Basically the same tune as the 1.6 AFH but using the later design. The AVY top is now scrap really, i can hardly sell it with the cams butchered.

So, yeah, basically a dizzy needs static cam timing - obvious really, but you know me, was worth a try!

This is the only pic i got atm, there's a couple on a memory card but i dunno where it is.

Love your frankenstein creations mikey

Can you not do away with the VVT stuff then? So it runs as an afh sorta would?

I just really cant be assed faffing about building engines, plus i want an engine cover! Lol

You could do a fixed cam type conversion Eric? But obviously budget dependant etc.

I need to understand this vvt stuff. arent the cams like afh ones then? I thougjt they just had a diffrent pulley setup lol

It basically alters the cam timing like adjusting a vernier pulley, but it's active with demand/rpm, not entirely sure how it's actuated on these!

The 75bhp/100bhp 6n2/9n engine looks identical to the AVY, just without the switch. So you can still put your fancy big plastic 1.6 16v engine cover on - you just won't be able to shut the bonnet.

The cams are timed for two positions, so it's a bit lame when running static. You'd probably get the same kind of engine from an AEE with a 1.4 cam in it. Or a 1.6 bottom end and 75bhp 1.4 16v 6n2 top.

Yeah it's the hydraulic inlet sprocket that does it - switch diverts oil pressure in the bearing into the sprocket, which pushes the paddles of an internal sprocket, and this creates the overlapped cam timing. So it works like a vernier moved hydraulically, and has two positions - overlap or not, hence the need for two ignition curves.

Hm so its do-able, but it just wouldnt run right on a standard dizzy? I see.

Well if thats out the window then i have two options. I'm buying a gti bottom end and hopefully a full afh.

So i could either use the gti bottom end,

or the gti pistons, rods and crank to make a 1.6 afh.

Now I've never built an engine before, so obviously I'm looming for the easiest option, but at the same time, that option may not be the best.

What would you suggest? Or is there another way?

Also cost wise

Ps, thanks for the info mikey!

Could u not get mappable ignition to suite the vvt eric ?