1.4 and gt head is the same apart from the cam.

Which inlet manifold is used when doing the aee conversion? Would it be possible to fit a GT manifold to the head?

1.4 ABD head will accept the GT inlet, the 1.6 heads will not. A custom one made from most of a gt inlet and the end of a 1.6 spi Inlet are required. or possibly an adaptor plate but it depends on how much bulkhead clearance their is.

the biggest problem with GT injection on a 1.6 is the manifold. You need to cut and shut a 1.6 spi manifold and a GT inlet because the stud pattern for the inlet on the 1.6 head is different. I'm getting around this by using an early head, which can also be used with GT injection with the right distributor. (one from a GK engine) Might look a bit odd in a mk3 though.

how do i identify a head from a GK engine?

does the GT inlet manifold bolt straight onto this head?

which is "the right distributor?

Thanks, Paul :-D

The only dizzy I've found that fits the early heads and has the correct spacing for a GT is the GK one. You can still buy them new from bosch (£100+ exchange) You can use any early head so long as it's flat. Engines GL, (1.05) HK and GK (both 1.3) all have a flat head. Obviously the GK one will be near impossible to get but the only difference with the GK head is it has a better cam, So just go for a GL or HK head and get the gk cam from a mk1 golf 1.3 (GF) or mk1/2 derby GL/GLS (HH)

The stud pattern on all the heads prior to the introduction of the taller block 1.4/1.6 are the same. :)

You also need a cambelt of non standard length (between 112 and 114 teeth as opposed to 108. I've got a 113 tooth one from a 5 cylinder LT van but I'm not sure it will be the right one yet), and convert the block to square teeth using an early water pump and a crank pulley from a late mk2. Either that or make a vernier using the outer ring of a mk3 pulley and the centre of a mech head pulley

By the way this will only work on the ABU engine as the aea and aee have a separate tensioner which causes all sorts of problems. (the water pump won't fit)

I have been told that late spec ABD heads have larger valves and seats, therefore making triple angle valves more worthwhile.

Can anybody confirm this

I don't think they are any different, but they have smaller valve stems which should make them flow better, but the size of the valves is the same AFAIK.

My ABD is from an N reg car. Is this late spec or not?

Head needs to come off soon (again) so I can check sizes for you.

Definately a late spec one, anything after mid '92 iirc is likely to have the late spec engine bits.

Cool, cheers for that.

Will get sizes when it's off.

I got myself some cheap port polishing from a local company

right getting confussed.

anyone got a spet by step guide lol?.

so what do i need?

cheers

am i right in thinking that you just need the block where the crank mounts then you can use the rest of the bits from the GT?

Yes

Sorry to bring this up again. All in all, assuming a GT engine with Golf AFM, chip, powerflow cat-back system, induction filter, lightened flywheel and dewedged TB, will an ABD make enough of an improvement to make it worth the ballache? I'm also hoping to get a 4-branch in the near future.

This is considering i will have to hunt down an ABD bottom end, probably rebuild it, and then fit it to my car with all the associated effort and money.

I also want power to last beyond 4k - from gaz's printout it appears that things start to tail off after this point. Is this purely due to the mods he made, and can it be avoided? Or is that just the nature of the conversion?

WICKED all the info in one place spot on

but I've gota ask a question tho it olny seems fair hahahaha

would a g40 head fit on to the abd bottom end I'm asuming it would but want to make sure

gaz - I'm gna be doing this convertions but I'm not going to use the single point injection but with a 2G inlet

and with a weber carb would this be ok, i will be doing head work full re-build ported n polished high lift cam ect ect but want to know if it would be up to it, i know i will have to change the carb or jets once the bhp has gone up to cope with the extra power

I'm now on the case spot on this forum is ace compared to others I've been a member for all of a few hours and god I've got all the info in one massive chunk my mind is at rest i know have muny to spend waaaahoooo

cheers yo

The main reason I did my conversion is because the 3F I had in the car ate a big end bearing after just 93K miles due to perilous lack of servicing by the previous owner. If you have a perfectly working 3F then there is obviously less of an incentive to do away with it.

The torque starts to fall off after 4K, but it is still producing the same torque as a 3F at 6K. Headwork and a good cam will improve top end.

As for a carb conversion there is no problem at all in doing one. Use the head from a mk2 if you want to retain the mechanical fuel pump. Some aftermarket cams (newmann for example) still retain the drive lobe for the mechanical pump. Also use a GK inlet if you can find one as it's bigger than the 2G one.

No point in using a G40 head. It's offers no benefit.

So it produces more torque than the 3f til around 4K, after which it will tail off to around the same as it was before, basically. Any other major differences? Did you manage to test its performance against a similarly modded 3F, would it be worthwhle all in all? What I'm trying to say is, does it make a noticeable enough difference to make it worthwhile?

Are there any negatives to choosing an ABD over a 3F? You said it makes less peak power, but thats not noticeable due to the added torque and extra cc's. Is there anything else that might be a down side?

Edit: I guess what I'm after is a quick list of pro's and cons to evaulate properly!

Edited 26 March, 200818 yr by skatty_01

as i read it he says the torque fallls off arounf 4k but its making the same amount a 3f would at 6k

yeah it makes loads more torque than a 3F at it's peak in the midrange, Then then drops off at higher rpm until it meets the torque curve of a 3F at about 6K.

I ran the car at santa pod a few times, and with a taller box and a crap driver at the wheel I was getting low 17s which was similar to what yoof was getting at the time in his GT. Both cars made similar peak power. At the same RR day his got 90hp whereas mine got 93hp. The 1.4 peak power is a marginal improvement over the 3F, it's just lower down the rev range, which means if you free up the rev range with headwork, more power can be extracted than from a 3F with the same mods for the same RPM.

Negatives are subjective. The compression ratio of the ABD is lower, but the other factors involved more than make up for the difference. If you simply replaced the 3F block with an ABD one and kept everything else the same. You would have a better engine, it has more torque which means you don't need to work the engine as hard. There aren't really any downsides unless you count fuel economy. :)

Thank you for that explanation - thats what id thought, but couldn't translate into logical speech Sorry for being a 'tard! Still, you if you never ask then you never learn.

Last question to make that the definitive answer, how much worse was the fuel economy? A friends GT with the mods i mentionned will still return 35-40mpg as far as I'm aware, so will this change much?

Once again, thanks to gaz - your post effectively summarises this whole thread to the less-technically knowleadgeable amongst us!

I used to get about 35mpg with the 8p box doing the general day to day stuff (4 miles each way to work, couple mile trips to the trafford centre, that sort of thing). Obviously it would be worse with the GT box. But still ok I'd imagine. On long runs If I kept it at 60-70 it would do high 40s. I think it always ran a bit rich though, something to do with the golf AFM being bigger will make them run richer

SPOT ON GAZ!!!!!

thats peerrrrrfect thank you very much this forum beast I'm pretty new been a meber a few days or so and god I've learnt so much since I've joined, looks like I'm staying here fora while

thanks again gaz wicked

eeeeeeeeeeeeeeee yoyo

edit: p.s gaz I've heard about those GK manifolds, i spose i have to scout all forums n the bays to find one???

how much do they go for ruffly off the top of your head.

well if anyone has one I'm the man u need to conatc i want one!!

thanks guys cheers

Edited 26 March, 200818 yr by mk1nuts

SPOT ON GAZ!!!!!

thats peerrrrrfect thank you very much this forum beast I'm pretty new been a meber a few days or so and god I've learnt so much since I've joined, looks like I'm staying here fora while

thanks again gaz wicked

eeeeeeeeeeeeeeee yoyo

edit: p.s gaz I've heard about those GK manifolds, i spose i have to scout all forums n the bays to find one???

how much do they go for ruffly off the top of your head.

well if anyone has one I'm the man u need to conatc i want one!!

thanks guys cheers

Germany seems to be the best source, look on their ebay for them. Lots of bargains to be had on ebay.de!!!

yes german ebay or a chap on here called guddi_g40 may be able to get you one.

And thanks again Gaz! I think ABD will be happening over the summer, i can't afford to do it right now, though i am tempted while the engines apart... Perhaps i will get another head ported and polished, and drop that in at the same time as the ABD lump.

Should be fun