What do i need to make my 1.4 (ABD) MKIII golf 'quicker' using a polo GT head and cam?

if i just fit the head and cam would it have better performance?

the only 'performance' mods i have is K&N air filter element and a de-CAT exhaust

Edited 18 June, 200818 yr by Master_G

You'll need the injection system from the polo GT, and camshaft. Mated with a 4 branch would see pretty good results

You'll need the injection system from the polo GT, and camshaft. Mated with a 4 branch would see pretty good results

I've only joined this site today so I'm still finding my way around.. is the injection system a direct replacement from the GT to my golf or would it need work? I'm tempted to just put the whole GT head on my golf and see if that works and if it does then start playing with the injection system

do you know if it would run with just the GT head on my golf?

The 1.4 and 1.3 GT head are the same so save yourself some time & money and just swap the cam. :) Fitting the injection system will probably require the engine bay wiring to be modified. It's difficult to say really. If you do change to GT injection you will also need to change the inline fuel pump.

The original injection system will work but you won't see a huge performance gain because the inlet manifold and throttle body are very small. You can upgrade the manifold to one from a gk enigne (75bhp LHD mk2 polo GT) and the throttle body from a 1.6/1.8 mk3 golf. If you decide it's too much hassle with the GT injection, this is the way to go.

i would like to change the whole head beacuse i believe the cam lobes have to bed in to the new head if i just swap the cam, any idea on what the BHP will be if just the cam is changed? i think my golf is 60bhp as standard

the cam lobes don't touch the head! you'd be advised to put the tappits from the GT head the cam came out of into your golf or fit new tappits as they wear together but swapping the head is a totally pointless exercise unless there is something wrong with the one you have.

What do i need to make my 1.4 (ABD) MKIII golf 'quicker' using a polo GT head and cam?

if i just fit the head and cam would it have better performance?

the only 'performance' mods i have is K&N air filter element and a de-CAT exhaust

ello. I av a 1.4 AEX Golf. got the basics, 90mm double cone intduction filter, engine earthing kit. platinum tip spark plugs high flow cat. straight throw exaust and i av had the head skimmed down, to up my compression ratio. opened up exaust and inlet ports to match my mainfold gaskets and opened out my cast exaust maifold. my exaust mainfold is off a MK2 polo 1.3 engine 4 into 2 into 1. doing this i found the engine suffered for detonation (bad) when under load only (laberin) but the power gains was inpresize. thr are a few ways to counter act this, 1 way is to richen you are fuel so as to help reduce combustion temps. I found that the 12v vr6 pressure regulater worked well with my standard fuel rail uppin my fuel presure from 2.2bar at idle to 2.7 bar and when throttle hits the carpet the presure increases to 3.0bar. this did the trick and detonation stoped. then i fitted a C-4 ignition coil (65kv) and racin 9mm low resistance ignition leads. just to help the spark under these new combustion condistions. i then advanced my ignition timming by abount 2 degress. my next addition is the throttle body off a 1,6 audi. I now keep up with 1.8 and 2 ltrs :-D but av the fuelin of a 1.6. thr are other problems i av had. I.e engine mounts kept snappin them for fun, and i put the vr6 radiator on (much bigger twin fan) to help reduces engine temp. I am hopin to put a blower on off a mini in the next few weeks and add 6 - 8 psi boost. :-D

You'll have fun with the wiring as the injection loom is an integral part of the main loom on the Golf.

Bedding the cam in takes half an hour - no big deal really. If you do want to use the head from a GT I suppose it's a good opportunity to get the head rebuilt and maybe add some fettling to the ports while you're there.

Ok then, i think i will only change the cam and maybe try and find a stainless manifold, I've got platinum tipped plugs too, my old man gave me about 20 brand new ones , whats the easiest and cheapest mod to make a ABD engine quicker? i have a suspicion that my head gasket is gonna blow soon, my polo went at 130,000 miles and my golf has done about 110,000.

Ok then, i think i will only change the cam and maybe try and find a stainless manifold, I've got platinum tipped plugs too, my old man gave me about 20 brand new ones , whats the easiest and cheapest mod to make a ABD engine quicker? i have a suspicion that my head gasket is gonna blow soon, my polo went at 130,000 miles and my golf has done about 110,000.

Thr r a few things to do but cheap and cheer full i can do. i think this engine is single point injection. so the fuel presure should be between 0.8 - 1.2 i think (should check with auto data) normaly for an engine with over 100,000 will be the lower. now remove induction pan and air filter. remove fuel presure regulater cap remove and strech spring a bit at a time refitting and checkin fuel presure til 1.2 bar is reached (u will only need to strech the spring about 10mm to achive this). then advance you are ignition timing by 2 - 3 degress. if u av a high flow induction filter and the engine has a direct earth with the battery. the power gains r noticable. also the Mk2 polo mainfold is a must 4 into 2 into 1. some fabrication and opening of the cast ports r needed. remmember most fuel lines r presurised so make sure engine is cold and face is well away when disconecting.

You can upgrade the manifold to one from a gk enigne (75bhp LHD mk2 polo GT) and the throttle body from a 1.6/1.8 mk3 golf.

Just to say... I've tried this, it won't work, the bolt spacing isn't quite right! Two of the bolt holes of the SPI injector mounting block line up with the GK inlet, and 2 of them don't. Wouldn't be the end of the world making some form of adaptor but it's not a direct fit.

Unless Gaz knows any secrets?

Did you not use an SPI "carb to inlet" gasket? I swear stiehlheckpolo did this to his mk3 1300 spi. I'll have to see if I've still got some carb blocks to try on an spi manifold. They can be quite awkward to fit. How far out was it?

You see on the casting of the inlet manifold the bolt holes are sort of "extruded" from the rest of the manifold on one side (maybe both, can't remember)?

Basically, I could get it to go in one way round into two holes on one side, but on the other side, the block bolts missed the bolt holes by I would say 10-15mm centre to centre. So at first, I thought it fitted, then realised 2 of the studs/bolts missed the holes. The problem is that either the inlet manifold bolt pattern is not "square" so to speak, whereas the SPI block stud pattern IS. Or the other way round...

That was with a 1.0 SPI mounting block thing. Sold my last GK inlet a few weeks ago, otherwise I'd have taken a pic.

Just had a look and I had a 1.3/1.4 SPI manifold with the block still on it, and an MH manifold to try it on. (MH is definately the same stud pattern as the GK, as I have an MH gasket on my gk setup at the moment) and 3 of the 4 studs go through the holes, the 4th misses the hole altogether! The block still fits on this manifold though, as the 4th bolt misses the manifold and goes behind it. On the GK I suspect the plenum at the back of the manifold may be bigger so it won't do this, meaning the bolt needs to be removed. It will still work like this i reckon with some blue hylomar sealant and just the three bolts used. It would still be better than the early mech head carbs only held on with 2 bolts!

I'll get a pic up later.

Ah it's just the one hole that misses.

Yeah I agree it's workable, just thought I'd point out that not all of the holes line up as they should

Yep fair enough mate, my mistake. It's good to set the record straight. Don't want to be giving people the wrong information!

Here's the pic

Yeah that looks like my mockup

What I thought of doing was running a stud down the "missed" bolt hole, securing it at the top and putting a bit of steel across to the other stud with a couple of holes in it and screwing it all together. Might work, might not.

Id totally try going for the GT injection,just take the whole lot from the GT and replace the spi set up with it. You may need to extend/shorten a few wires due to re-positioning of things like fuse box,ecu,battery,cable routing etc,but still.

Yeah that looks like my mockup

What I thought of doing was running a stud down the "missed" bolt hole, securing it at the top and putting a bit of steel across to the other stud with a couple of holes in it and screwing it all together. Might work, might not.

I was thinking a big washer might do the trick!

Sorry to hijack but I've got a question about this conversion.

I'm in the middle of fitting an ABD to my GT road rally car and when I took the cam out of the GT I found it had double valve springs fitted (I assume as standard) which is obviously good for revving the nads off it on a rally.

However when fitting them to the ABD head (with GT cam) I've got no compression 'cos the valves don't fully shut. It seems that the thinner valve stems of the ABD cause the collets to sit too deep in the GT's retainers, leaving the valves rattling round when the springs fully extended.

Has anyone else had this problem?

Is there any way to use the double springs or should I just use the single springs off the ABD's head and not rev it so high? If so what's the max revs before the valves bounce?

Cheers, Stu

The valves seem to bounce at a touch over 7k on engines WITH double valve springs like my Golf.

On my Polo I had a double valve springed 1.0 head and a single valve springed ABD head, both with a 6500 rpm rev limit and took the engine for a trip to the limiter at least once every journey and going from my rolling road graph the valves were definately not bouncing at 6500 rpm.

Is 6500 enough or not? As I said, 7200 or so is when I seem to get noticeable valve bounce in the 1272 Golf.

Have you considered using a mechanical head?

Should be fine using the double springs, ie they will fit without problems. Can you not fit the single spring retainers?

Just reading that post again...

Thinner valve stems - I think if you get the collets from a later Polo head then everything should go together nicely?

Cheers for the replies guys.

I've got the head in work today with both the GT's valve set up and the ABD's, so I'll have a look at which combo of retainers/collets works.

I'd prefer to use the double springs as this is for a competition car, so there will be times where it's going to be worth holding on to a gear between corners (to save shifting up, then down), so a higher rev limit will be beneficial.

I've got to use the bits that I've got as I'm competing next weekend, so I'll let you know what I find that works

Stu.