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victordu26

Twin carb on 1.1L

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victordu26

Hello,

 

I'm French, and I'm here because I don't find enough answer in my country...

I have a 1.1L engine GG code (same as HB engine) fitted on a Golf mk1. Nobody in Golf want to tune a "small black", Polo guys know very well !

 

I want to put twin DHLA or DCOE carbs, but I have few questions...

 

- I don't find many 1.1L fitted with twin carb, but a lot of 1.3L. I want to keep my original engine, so is it possible to have good results ?

- The head is a mechnical, and I don't know if a "performance" camshaft exists for this type of head ?

- The head has holes for heating the original carb, so I have to close them ? Because the manifold for twin car I find don't close them.

- For the fuel pump, the original with a filter king is enough ? Or I need to put an electric pump ?

 

Thanks for your help, and sorry for my bad English...

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dvderlm

Schrick classic line camshaft should fit 280 or 296. Longer duration have higher lift and you would need to cut pockets in valves.

Check the 3 journal diameters as I know HB formel E was a weirdo. 

 

Yes, you have to block all the coolant pipe outlets to inlet manifold.

 

The original mechanical fuel pump might be good enough for 1.1. But Dcoe starting mechanism is rubbish. You have to operate the accelerator pedal to pump fuel

But to get fuel in the carb well to you have to turn the fuel pump so you have to spin the engine on the starter.

It can take several attempts. With poor battery this is not fun.

Electric pump solves filling the well.

DHLA has better starter system.

 

Carbs need high volume low pressure. Filter king pressure regulator is needed for an electric pump intended for injection. An inline paper filter (or 2) is sufficient for carbs

with mech pump.

 

Don't forget the ignition timing needs work.


How high do you want to rev?

That decides choke sizing and most other jets..

 

 

 

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victordu26

I check Schrick classic for Polo but it's expansive, almost 500€ ! I also found Dbilas camshafts, do you know if their cam for 0.9/1.3 are for mechnical lifters or hydraulic ?

 

I have a standard head of GG engine and Formel E head of HB, so I will compare if it's the same.

 

I thought putting a DHLA because it's cheaper, and if you tell me it's better for cold start I will defenitvely take a pair. Why the starter is different ? No need to pump on accelerator ?

 

For the fuel pump, it's cool if the original one fit without filter king !

 

What do you mean by "ignition timing need work" ? I have the standard GG ignition, and also a Formel E HB, what is the best ?

 

For the revs, today with the 31 PICT i'm at 4500 at the best, I hope going arroung 6000 rpm with the new set.

And for sure I know phillipe boursin ! I think it's compatible with DHLA...

 

Thanks for your answer :)

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residentmelon

This is a good site for calculating the Venturi Size and Jets. 

 

http://www.s262612653.websitehome.co.uk/DVAndrews/dellorto.htm

 

You say the DHLA and cheaper. are these DHLA been set up correctly to run on a 1.1 looking at the graph you will need the smallest Venturi possible. if you are buying second hand you may have to buy new Venturi, chokes and jets etc which will increase the cost. 

 

I would evaluate cost vs result 

 

As i was going to do the twin Carb (which i brought second hand and had to buy all the extra) trust me buy brand new easier and cheaper) I have also decide to keep the standard CAM run a twin progressive carb like the DMTR / DMTL and save my money to build a 1.6 16v set up instead 

 

Mainfold 

 

https://dbilas-shop.com/ansaugtrakt/ansaugbruecken/vw/2718/ansaugbruecke-vag-0-9-1-3l-8v?c=7302

 

Cam (this is not for a new Camshaft this is regrinding your existing camshaft to a new profile)

 

https://dbilas-shop.com/motor-ventiltrieb/sportnockenwellen/vw/0-9-1-3/mechanisch/seriennockenwellen-umschleifen/2482/vw-0-9-1-3/seriennockenwelle-umschleifen?c=8810

 

Depending on the CAM degree or lift you may have to get new valve springs (extra cost)

 

Carbs (just an Example might need other carbs)

 

https://www.dellorto.co.uk/shop/dellorto-car-carburettors-parts/complete-carburettors/dhla-carburettors-reconditioned/dellorto-dhla40h-reconditioned-carburettors/

 

Mainfold 200

CAM 250

CARB 700 

Rough total 1150

plus extra fuel pump king fuel reg plus throttle linkage 

1400 

 

It's it worth the few extra horse or KW or is it a pure look that your going for? This is my setup before I gave up

 

carbs.thumb.jpg.168685461910e75a36f7308889479a20.jpg

Edited by residentmelon

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dvderlm

"I check Schrick classic for Polo but it's expansive, almost 500€"

Welcome to tuning.

 

Hydraulic, usually. Dbilas might regrind a camshaft for you.

 

Or get a GK camshaft 052109101H (AJUSA and BGA still make them) 229 duration at 1mm so maybe ~270 at 0.1mm?.

https://www.amazon.fr/BGA-CS5394-Camshaft/dp/B00AN0FFVQ 

That might fit. depends on the journal bearing diameter.

 Mine revs to 7000+ on a 1.3. 

You are going to need small venturis - 24, 25 or 26mm are the smallest I've seen for DHLA.

Be careful which DHLAs you buy. Some (40H) are cheap because they are emissions carbs for engines over 2 litres.

 

4500rpm - There's something wrong then. It should reach 6000rpm.

See

http://www.doppel-wobber.de/forum/Information_78_VW-Golf-Motor MKB GG.html

 

"What is best" neither GG or Formel E.

You need custom ignition with twin carbs. . At least 10 degrees advance at idle but not over 32-ish from about 4000rpm upwards for 9.7:1 compression.

You can't just turn the distributor for correct idle advance or you get detonation at high revs because the limit moves too.

If the Formel E has hall sender you could use an Aldon Amethyst box.

 

Edited by dvderlm

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residentmelon

Just found this 6000rpm is you peak BHP

 

http://www.carinf.com/en/f80044730.html

 

Classic Camshaft Prices 

 

https://www.maxrpm.de/Schrick-camshaft-for-VW-Golf-1-2-Polo-Derby-Audi-50-09-13L-8V-4-Zyl-296-sync-Schrick-001301960-00

 

Edited by residentmelon

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victordu26

Oh, thanks for your answers. I think you're right, the ratio money / gain is not so good with these carbs.

 

Maybe your idea to put a progressive carb is a better option, that's why I lokked for some informations.

 

For my 1.1L, it seems that a Weber DCD with small venturis is a good option, but maybe I need an other intlet manifold for this !

What is the best choice for you ?

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dvderlm

Maybe just adapter plate for the DCD.

Your manifold is restrictive compared to GK manifold  

 

Have you though about bike carbs?

Say Honda cbr400.

Not sure what head and cam combo @Mullen29 ended up with. He's limited to 1.1 litre in his competition class.

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dvderlm

How old is your fuel pump?

It might not be delivering enough to exceed 4500rpm

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dvderlm

30dmtr or DCD

I guessed at jetting a while back.

 

 

 

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victordu26

Yes I thought about bike carb but my car is a daily so I don't know if it's very "easy to use" for all day.

 

I saw DMTR but I didn't know that 30 exists, because 32/34 seems to be too big for 1.1. Weber DCD are not so easy to find

 

I have an old Weber 36 DCNF from my previous Beetle, it's too big no ? Venturis can be changed but the smallest seems to be 26mm, and it's not a progressive carb, it's a dual carb

 

What kind of inlet manifold should I fit for these carbs (DMTL or DCD or DCNF), and where to find it ?

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dvderlm

36DCNF is indeed too big unless you can get custom venturis made.

You need progressive for daily economy and big top-end.

 

Manifold needs the oval hole for DMTR or DMTL from 1.3, so an 2G or MH or  HK engine code.

and a new rubber carb flange (Febi or Birth spa). 

Where: Scrapheap, ebay, wanted-ad.

 

DCD

Needs custom adapter plate as holes are further apart.

 

For performance at high revs with big cam that HK manifold will restrict..

There's a GK manifold (75hp standard) in the classifieds with a picture of the bore size difference versus HK.

 

Are bike carbs driveable?

Should be as they are slide-carbs with needles. Don't know what French insurance or vehicle emission test is like.

 

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dvderlm

https://classiccarbs.co.uk/product/weber-3032-dmtr-carb-classic-fiat-1000-abarthlanciaautobianchiyugo-etc

 

19 and 23 venturis.

 

Will need a different accel cable lever.

eg http://www.webcon.co.uk/shopexd.asp?id=9913

Might need to be mounted backwards (float hinge away from direction of travel). I did that for ages. Not ideal in hilly country.

 

And might do better with 107 to 110 secondary main jet and F22 primary emulsion, as those match Polo engine's design, leastwise for 1.3.

Edited by dvderlm
added link to cable lever required for vw

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residentmelon
12 hours ago, victordu26 said:

Yes I thought about bike carb but my car is a daily so I don't know if it's very "easy to use" for all day.

 

 

Their is a big misconception with bike Carbs that they are fuel hungry. 

 

Just like Car Carbs they need jetting correctly and balancing and taken to good rolling road to be set up.

 

And then again if your enjoying the sound of bike carb you be driving around at high rev to hear the noise. 

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dvderlm

@VwDan found his were heavy fuel users.

 

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steveo3002

anyone good at searching would mikeymk's post claiming 80mpg

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victordu26
21 hours ago, dvderlm said:

https://classiccarbs.co.uk/product/weber-3032-dmtr-carb-classic-fiat-1000-abarthlanciaautobianchiyugo-etc

 

19 and 23 venturis.

 

Will need a different accel cable lever.

eg http://www.webcon.co.uk/shopexd.asp?id=9913

Might need to be mounted backwards (float hinge away from direction of travel). I did that for ages. Not ideal in hilly country.

 

And might do better with 107 to 110 secondary main jet and F22 primary emulsion, as those match Polo engine's design, leastwise for 1.3.

Ok so I need :

 

-1.3 intake manifold

- 30/32 DMTR with the good accel cable lever

- Adaptator plate for the DMTR, does this one fit ? (Same as 32/34 or not ?) https://www.dellorto.co.uk/shop/weber-carburettors-parts/carburettor-parts-weber-carburettors-parts/other-parts/99900-896-weber-32-34-dmtl-pierburg-adaptor-plate/

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dvderlm

Yes that adapter plate looks like it fits.

Some bolts and studs

https://www.dellorto.co.uk/shop/weber-carburettors-parts/carburettor-parts-weber-carburettors-parts/other-parts/99900-896ap-weber-32-34-dmtl-pierburg-adaptor-plate-kit/

 

A Colortune sparkplug to set idle right(or garage with gas analyser).

A cable nipple (cylindrical) to hold the accel cable in the lever.

A manual choke cable. There's a cutout in dash below air vent near steering wheel.

 

Might need a bit of metal sheet bent and cut to hold accel cable outer.

The choke cable clamp is attached to carb.

And new rubber carb flange between adapter and inlet manifold. Or cork gasket or thick gasket paper.

 

Some patience to get primary and second stage right.

50 idle jet might be too big and 40 to 45 might better match 1093 cc with Polo crossflow head.

Eventually different emulsion tube(s).

F22 and F33 are both thin tubes that can draw more fuel from the carb well. 

I don't know how F43 or F38 behave.

Bigger secondary main or smaller secondary air corrector or both and maybe even change of float height.

 

 

And, most importantly work out why you only get 4500rpm now.

Fuel pump, throttle not opening fully, collapsed exhaust, poorly ignition, low compression, worn valve guides?? 

Edited by dvderlm

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residentmelon
11 hours ago, dvderlm said:

And, most importantly work out why you only get 4500rpm now.

Fuel pump, throttle not opening fully, collapsed exhaust, poorly ignition, low compression, worn valve guides?? 

 

This is very good advice, and I would do this before spending the money on a new CARB. You could find that your in the same position with a new CARB

 

Edited by residentmelon

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victordu26

Today I have an HB motor in my Golf, with a long gearbox of Formel E. The GG engine was put outside because it eat 1L oil for 1000km...

I say 4500 rpm because I won't go more, it's very noisy, and I think with the gearbox it's difficult to go at more RPM

The goal is to refurb the GG engine, after it will be better I think, and I don't know if I keep the Formel E box or not

 

I'll have also to find a "dual carb" airbox to adapt, I prefer avoid K&N air filter

 

For the idle setting, I'v already a Lambda sensor put in the exhaust, with a gauge to set it well. 

 

For the choke mine is already manual

 

Thanks for your advice

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dvderlm

New piston rings (valve seals, clean oil breather) for the GG then.

 

Formel E is very long in top gear, so it would be hard to reach top revs in that gear.

 

airbox...

I found a K&N (56-9159) plus a hot/cold air feed was fine. Thermo valve taken from air filter housing.

is that because of appearance?

Or for a garage tester's approval?

 

What about these trumpets (plus a foam sock such as Ramair)?

https://www.ebay.co.uk/itm/Weber-32-DMTR-alloy-trumpet-NEW-Fiat-128-Rally-Coupe-3P-A112-ABARTH-1050-Zastava/191908329506

 

You might need a vacuum gauge as well as Lambda sensor to set idle mixture. AFR readings can pulse up and down below 1000rpm.

 

 

Edited by dvderlm

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dvderlm

Jetting. The lambda gauge will help enormously. Empty roads and a hill.

 

F43 is quite a fat emulsion tube(6.2mm), so not very responsive.

F38 is a thin tube with not many high holes and will probably be fine.

Get the mix right with these by changing main or air corrector or float height or all three.

Then consider change of emulsion tube.

 

Does the gauge have a logging facility that can show AFR versus engine RPM?

If so you can look for the rich and lean points while accelerating hard up a hill and pick an emulsion tube that matches.

Search for  Dave Vizard weber on youtube.

 

1.3 Polo usually have F22 primary and F30 secondary, I ended up with dual F33 by "seat of the pants" feel.  

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victordu26

Hello, sorry for my absence, I was on holidays 😎

 

For the airbox I don't like the appearance of K&N filters, but I think it will be mandatory in my case.

 

My AFR is this one : https://www.plxdevices.com/SM-AFR-Gen4-Wideband-AFR-with-MultiGauge-Link-p/897346002870.htm

It's very responsive and avoid to put an horrible gauge ! 

Thanks for Dave Vizard, it's very instructive.

 

Now the engine is disassembled, and the piston rings were totally out of dimension... 1.8 mm of end gaps, for 1mm max and 0.4 for new ones ! 

The block is in good condition, in VW tolerances, I'll just make a honing

 

For the head, I'll totally refurb it, polish, change valve guides, grinding...

 

e4mner10.jpg
luhe8p10.jpg
nrzpfg10.jpg

 

My question is about the heating of the intake manifold.

With my 1.1, heating is done by exhaust holes in the head?

With 1.3 manifold, I have to block the hole on the head (how ?) and to add water in it. What is the easier solution for the water with my actual hoses ?

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