MK2 Golf GTI - Engine Conversion

Feb 10

MK2 Golf GTI - Engine Conversion

MK2 2 Litre 8V Conversion

After a load of PM’s asking me about my conversion, thought I would write a quick guide on the basics of the conversion and try to put together all my ramblings in one place!

Thanks goes to ‘Rahul’ (a previous forum user) for some engine code information.

For those of you with MK2 8V GTI’s after a couple of years ownership (or less), chances are you want that little bit more power. You can’t justify spending the money on a 1.8T or a VR6 conversion but you just want a little extra grunt! The 2 litre 8V conversion is for you!

A setup with a fast road cam, big valve gas flowed head, panel filter and performance exhaust you can see 145 BHP and 145 LbFt easy. The high torque value gives a lovely drive point to point.

Which block to use?

Firstly you’ll need to source a 2 litre block. There are a variety of possibilities for various different VAG family cars.

2E – Probably the most common, found in the early (pre 95) MK3 Golf GTI 8V’s. Also found in Passats from the same era.

AGG – Found in late (post 95) MK3 Golf GTI 8V’s.

The difference between these two engines is that the AGG has a crank position sensor on the front of the block (this is just left disconnected in the conversion) and a slightly different dizzy to the 2E. Both these blocks are known as ‘tall blocks’ as they are 20mm or so taller than the standard 1.8 litre block you will be replacing. The extra height gives the longer stroke hence larger capacity!

3A – Found in Audi 80’s. If you can find one, this is the ideal block to use. It’s the same height as the 1.8 litre engine. It’s known as a ‘bubble block’ because of its slightly rounded shape. I believe this engine has a larger bore coupled with a different crank to give the extra capacity.

Other engines you can use are the ABA, AWG and AWF. Full details of what cars these come from can be found here.

These engines are fairly solid so you shouldn’t have too many worries about getting one second hand. If you can find one which has documented oil changes you’ll be well away. I used an AGG block which had done 90k. Doesn’t use a drop of oil!

[Comment]The 2E is available in ceratin SEATs, the Alhambra and Toledo are least likely to have been abuse and , as some insurance companies asses the new premium based on the insurance group of the donor car, make them a dirt cheap alternative! [/Comment]

Don’t pay any more than £200 for one of these blocks unless it’s a low miler or you know about its history. There are plenty around so don’t be done.

[Comment]I would say £100 max - try and get a Passat block rather than a Mk3 Gti too, less likely to have been ragged. I’ve a Mk3 2E in the garage with a known genuine (FSH) 130k on it - should really be rebored, it’s pretty worn.

I also have a 2E from a ‘91 Passat with 190k on it - it’s a minter. Won’t even need new rings, the compression is great, and there is no lip at all on the bores.[/Comment]

Which head to use?

The beauty of this conversion is it’s simplicity. Essentially you are only changing the bottom end. Use your existing MK2 head. The MK3 head doesn’t flow as well so don’t go putting the complete engine from a MK3 in – you won’t see any power increase!

Whilst the head is off, it’s well worth getting it reconditioned, new valve stem oil seals etc etc but if money allows it is definitely worth getting it ported and polished. With the 2 litre bock, comes a requirement for more air – it needs to breathe more. Sticking a standard MK2 head on will restrict this air flow and you will probably only see a 5 BHP increase (good increase in torque however still) In order to get good BHP gains, you will need to increase the amount of air going into the engine.

Ideally this requires at least a gas flowed head but to see the sunny side of 140BHP you will need a big valve head. I had mine done and had the exhaust valves taken from 33mm to 35mm. The inlet valves remained the same at 40mm. This does however come with increased cost.

At TSR prices a standard ported and polished reconditioned head stands at £410. The big valve head though comes in at £710. If you’re really keen on sticking with 8V grunt then it’s definitely worth the money. You would be able to do a 2 litre 16V conversion for similar money though if your 8V already runs K-Jet.

Which camshaft to use?

There are various ones around that’d be suitable. It all depends on what you want from the engine. If you want something that’d be used daily with a fairly smooth idle and midrange power go for something mild like a Newman 268 or similar. If you’re up for a lumpy idle but more top end power then a Schrick 276. Good results have been achieved from the TSR203 cam I’ve been told. These camshafts retail for around £150-200ish.

Which distributor to use?

This seems to be quite a controversial point, many conflicting views so I’m just going to go on what I found.

I used the AGG block where in the MK3, the ignition timing is controlled by the ECU based on 1 pulse per revolution from the dizzy. The MK2 is more traditional in that each of the 4 sparks comes from the dizzy. The early 2E block uses this method too. This means that if using the AGG block, you will need to get a dizzy from a 2E. I’m not sure about any other block but assume the 3A from the Audi would be similar to the 2E and be fine with its original dizzy.

There is also some other method that I know of whereby you can buy an adapter gear from TSR to adapt your existing MK2 dizzy to work with the 2L blocks. Not sure on this though.

[Comment]The 2E dizzy is the one to use, no matter what block you decide on. It plugs straight in to the existing wiring, and changing the gears on the existing dizzy etc. can be a right bollox.[/Comment]

[Comment]For the K-Jet, you have no choice but to use the original distributor with the TSR adaptor ring and the cog off the distributor that (hopefully) came with the 2.0L block. The K-Jet dizzy uses mechanical advance in the distributor body, whereas the advance in digifant and later injection is controlled by the ECU.[/Comment]

Other ancillaries

As you will be taking the engine out and stripping the ancillaries, it’s worth replacing the consumable parts. New cambelt, tensioner, etc and anything else that may need replacing. It’s loads easier to work on an engine when it’s out of the car!

Regarding the head gasket, use the one to match the block you used. Well worth getting one of the new style metal ones that are now available. Get a head gasket kit to match the MK2 head but dont use the head gasket itself. This’ll include new inlet/exhaust/rocker cover gaskets. Remember also to get new head bolts – they are stretch bolts so can’t be used twice!

If you’re looking for 150+ BHP then you will need to invest in a 4 branch manifold. Plenty of opinions on the forum of which ones are the best. TSR now do one specifically for this conversion if using the taller block. Not cheap though at around £300 IIRC.

[Comment]With the K-Jet you have to find somewhere to put the control pressure/warm up regulator. On the original block, this is bolted onto the aluminium plate next to the oil filter pedestal where the mechanical fuel pump is mounted on the carb models. Since you have to buy the distributor adaptor from TSR for a 2.0L into K-Jet, I would suggest buying the breather adaptors / cover plates from them as well and removing the black plastic breather box on the front of the 2.0L block. Remove the CPR mounting plate from the original block (2 Allen bolts) and get someone with a TIG or equivalent to weld it onto the front of the TSR breather cover (also ally) before fitting that to the new 2.0l block. Make sure that it all fits with respect to the CPR pedestal and hoses (especially if you are using an Audi 100 CPR with vac enrichment) before welding it up! This puts the CPR back where it was on the 1.8 block.[/Comment]

Onto the conversion…

Whip your old 1.8 litre engine out of the MK2. If you don’t have an engine crane, remember that the front of the MK2 comes off so the engine can be slid out through the front and the car rolled into the desired position.

Once out, strip off all the ancillaries over to the new block not before giving it a good clean up! Once its out it might be worth having the gearbox reconditioned, it’s a right pain the in **** getting the gearbox out again once the engine is in! Similarly, with the engine out there maybe other things you want to recondition/replace. Steering rack, subframe bushes etc.

The head you will find will go straight onto the new 2 litre block. Some people have said that there is a stud on the top of the bottom end they are using…just cut it off!

Replace the inlet and exhaust manifolds and build up the new block, part by part. Once all done, you’ll all ready to whack it back into your newly cleaned engine bay!

If you are using the tall block from the MK3, AGG or 2E, you will find that your exhaust manifold won’t fit too nicely to the downpipe. I had a 15mm spacer plate made up so to lower the downpipe and avoid it fouling the bulkhead.

[Comment]I’ve used tall blocks in Mk2’s with no problems (standard downpipe etc) but the Mk1 will knock. I either cut a plate and gasket to block the front breather, or plug it into the existing system (easier!).[/Comment]

[Comment]I have just installed a 2.0 GTI engine(ADY) in my Mark 1 Cabriolet and I used the standard Mark 1 manifold and downpipe(C-clip type) and it fitted with no clearance problems at all.[:P][/Comment]

I think this applies to most 2L engines but they have a crank case breather. This needs to be plumbed into the rocker cover breather pipe otherwise your car will not idle.

How hard is the conversion?

If you are handy with a spanner and well motivated then you will have no problems doing the conversion. The beauty of the MK2 is it’s simplicity – everything (well most things) are logical so with a bit of common sense, you will have no trouble. I managed it mostly all myself with the exception of a couple of things which needed two people.

Is it worth it?

If you want serious power then this isn’t the one, look to 2litre 16v or VR6 or 20vt. If you have a keen interest in cars and their mechanics, handy with a spanner and but not the money for a 200+ BHP beast then this is definitely for you! If you have not done something like this before then ultimately you will learn a huge amount which will put you in good stead for when you decide to do a 2 litre 16v or VR6 conversion in 12 months time when you will no longer have enough power!

My car now is a dream to drive. With its 268 degree camshaft the peak power is at just 3500 rpm which makes for a very drivable car. Similar power to a 1.8 16v but much more torque low down.