Newbie twin carb question

My mk1 gti 8v is still running its original pooburg carb, i'd like to change it to twin carbs in the future i think i could get good results the bottom end is already 2.0l and i'm pretty sure its cammed and had headwork. I'm going make sure there is as little heatsoak possible and make a custom air scoop/inlet to supply cold air. I've been searching for info but not had much luck. If anybody can shed any light on what i need for the conversion and any hints,tips and pics of the conversion it would be greatly appreciated. I'm new to carbs so don't flame me.

Thanks
Greg

If you hav a mk1 gti 8v it shouldnt have a peiberg carb on it, it should be injection.

theres plenty of info out there for fitting twin carbs to the 8v gti engine. vwmike on here has just done it to his mk1 jetta.

my only question is.

How much do you know about cars, the I in GTI stands for injection, and therefore wouldn't have a carb in the first place. So what is/was your car and does it have a carb or not?

beat me to it, I'm slow at typing.

Stupid me you'll have to forgive me this is my first vw and i aint had it long my mate said it had a carb on it so i trusted his judgement (caddyluke), anybody got any pics of the standard bay to cross reference also any pics of 8v's on twin carbs.

Is it a mk1 gti 8v then?

matty_mk1 wrote:

Is it a mk1 gti 8v then?

yes it is a mk1 gti 8v!

I think what greg is trying to say is that he would like some useful tips/info on putting it on carbs.

Ok! no need to shout lol just trying to establish what the car is as he seems to be alil confused.

basic parts youll need to fit twin carbs is

-carbs
-throttle linkage
-manifold
-fuel pump
-fuel reg
-block injector holes

HTH

Ta Matty, would i be right in thinking the hardest bit is getting them all set up and running good?
and is it true you can block the holes up with a coin???

Yeah hardest part is having them setup and the linkage plays a big part in that as i have found out much to my cost! lol yeah ive heard you can just block the hole with a 1p coin but the best way it to tap the hole and screw a bung in.

if he buys some rendom carbs from ebay they will no doubt have to have the jets changed to match his engine and will prob need some gaskets and so on replaced.

with the fuel line you can run the standard gti pump (like i do on mine) but that pump is far to much for carbs really and plus you need to route a return for that pump also. ideally you want to swap to a facet pump with the correct output for the carbs, will still need a reg to fine tune it.

I agree with the list Matty has given you

One thing i will say is to allow for around 3 hours on the rolling road (£60+VAT an hour) as well as around £100 for jets if they are not already jetted for your size engine.

Mike £100 for jets!?!?!?

Where the flip did you buy yours from?

tyeness wrote:

Mike £100 for jets!?!?!?

Where the flip did you buy yours from?

I say £100 as you think you need to buy 4 of each...

So if you need to get idle jets, main jets and air correctors...thats 12 jets at £3-4 each which is £36-48...if you take it to a rolling road they like you to have one either side of what you are running for main's and air's...so that would be 20 jets in total with the others...£60-80

Then if you need to change pump jets/needle valves...they are more expensive each...(in a way depends if you run dellortos or weber's as most places you go to for rolling road have weber jets...but don't have dellorto jets.)

caddyluke wrote:

matty_mk1 wrote:

Is it a mk1 gti 8v then?

yes it is a mk1 gti 8v!

I think what greg is trying to say is that he would like some useful tips/info on putting it on carbs.

Thats what i am painfully trying to ask, its my first mk1 gti and i wasn't 100% sure what fuel setup it was running 1. because i'm not used to the primitive injection setup (only used to modern metal) and 2. because its been played around with prior to me owning it. Needless to say i'm terribly embarrassed at posting such a stupid comment.

I'll make sure i get carbs jetted for a 2l engine as that is what mine is. Thinking weber 40's or dellorto's? The mani and linkage are they off the shelf items? Is there a link or site where i can get more info?

Thanks
Greg

Linkage is an off the shelf item...you can buy a manifold off the shelf...but in a way it pays to get a custom built one like Bogg Brothers do.

You may still need to get jets if you get carbs suited for a 2ltr engine...every engine responds differently to carbs...so be prepared for getting extra jets just in case.

Webers are still made new...Dellortos aren't. I personally prefer Dellortos as i have had them on my air cooled cars before...but Weber's are just the same. Dellorto 40's are the equivalent of Weber 45's...ie Dellorto's are always the equivalent of the next size up Weber's.

Best place for info is to just search on the net...you will end up on VW sites, vauxhall sites etc...

Cool never knew that about the size between weber and dells, take it that makes my 45s the same as weber 48s?

in theory yes...also depends on the size of the venturi's...as you can downsize the venturi's to the equivalent of Weber 40's.

But as they come in the box they would be the same as Weber 48's/50's.

Jeebus, had no idea you needed that many jets! Suppose it's obvious if you think about it though