DGAS JETTING

[plasticpig72]

So as the title what Jets have you fitted to your DGAS Carb and for what Camshaft.
I know as someone will say do a Rolling Road Tune but those that have done a Rolling Road Tune what Jetting have you arrived at.
Thanks in advance
Alan

[anonymous-user]

It’ll be very car specific - head flow, exhaust and ignition type etc so the best way really is to splash out yourself. There’s only two jet types plus corrector it not like twin dcoes where there’s 8 variables doubled.

[plasticpig72]

True it's specific to car and engine set up.
What main jets have you guys fitted.
Have you fitted 150 main jet or bigger.
My car has main jet 142 with VA19 Camshaft.
What mains have you fitted.
Alan

[plasticpig72]

I have bought a new weber dgms carb because the flange on the original dgas is bowed.
All the jets in the new carb are the same except the main jet. I will fit the main jet from old carb 142 size. Then see how it runs and if too lean will try 150 size
Alan

[anonymous-user]

plasticpig72 said:

I have bought a new weber dgms carb because the flange on the original dgas is bowed.
All the jets in the new carb are the same except the main jet. I will fit the main jet from old carb 142 size. Then see how it runs and if too lean will try 150 size
Alan

If you fit a 40DFAV you'll get a lot more power, particularly with the better cam. Straight replacement....

[Adrian@]

The 40 DFAV does not have the dynamic range that the 38DGAS/MS and it will run lean on high speed (motorway cruising) runs, it would be simpler to bore the 38 out to near as 40 (dark arts, I hear you say), but that within the 38, is a set of 'unlisted' high speed running jets that can be 'adjusted' (drilled out) for the range of 'high speed' ...the issue is that there is zero testing by anybody with carbs today and it is a 'given' that you can buy a new carburettor with jets to suit fuel from 1978 when it has not been available since 1978! Even the sellers do not know what they are selling! Back to the plot... you need to find someone who can jet the carb to suit the engine internals (IF the tuner does NOT know about the high speed running jets, WALK AWAY) or put a lambda port into the manifold (all the best tuners will want one anyway). All my cars have them, for me to road test and read the calibration whilst I am driving/setting up rather than doing static rolling roads runs. IF you are expecting to run 142/185/42 (I would not) then IMHO use only premium fuel, as lesser fuels have ethanol/more ethanol AND even that is 'not fixed' at this point, so the fuel will change going forward. A@

Edited by Adrian@ on Friday 14th June 09:26

[plasticpig72]

thanks Adrian,
for the info and i will ask around where i live in Brittany to see if there is someone who knows what their doing.
Alan

[plasticpig72]

Well l've just fitted the new dgms with 142 main jets and manuel Choke.
I just need to get a crack in the Exhaust line welded.
Then i can try the 3000s out and check Plug colours etc.
Alan

[LLantrisant]

ask 5 owners with similar / same uprated engine and they will all give you a different jetting...but all engines are running well.

by the way: new carbs always come with a base-jetting, the rest needs to be individualized according to analyitcs during driving or, if you want to invest the money, a roaling road test


tis said, jetting tables are widely availabe through mr. google

[plasticpig72]

What i would like to know is what the 5 different owners have fitted to compare different combinations.
I think it makes a good topic
Alan

[anonymous-user]

plasticpig72 said:

What i would like to know is what the 5 different owners have fitted to compare different combinations.
I think it makes a good topic
Alan

Hi Alan

Is the DGMS a more recent carb type? I had a look in the Weber manual to see if it could help but it’s not listed. Why have you opted for DGMS and not DGAS?

[plasticpig72]

I have gone for the dgms from webcon for the price first 215 gbp good price.
I also fancied a manuel choke.
It is jetted the same as the old dgas except for the main jet size. So i have fitted the main jets from old dgas to the new dgms 142 size.
The carb is Spanish and has plastic floats.
I will test the 3000s after the w/e.
Alan

Edited by plasticpig72 on Friday 21st June 06:48

[plasticpig72]

I had a little spare time this afternoon so i started my 3000s with the new Carb and it runs very well. Tickover at 600rpm very smooth. I look forward to next week when i can take it for a drive
Alan

[plasticpig72]

Please can someone say what Idle Jets and Main Jets they have in their car. Also what Camshaft please.
I would like to know
Alan

[plasticpig72]

The old dgas had mains 142 and idles 4.5. When i accelerated it would hesitate untill 2,000 rpm.
Now with the new dgms mains 142 and idles 5.0 there is much less hesitation untill 2,000rpm.
I have ordered 55 idles to see if they will remove the hesitation and allow me to adjust the mixture screws to between 1 and 1 1/2 turns out.
Allan

[plasticpig72]

I have confirmation that at least two 3000S cars with camshaft V63 are running with Idle Jets 55. The V63 is 1500 rpm upwards.
My car is VA19 Camshaft which is also 1500 rpm upwards.
I have fitted Idle Jets 55 the same and will test in the next few days for hesitation during the transition.
Alan

[plasticpig72]

Good news i have tried my 3000S and she is running very well. So for my car with VA19 Camshaft and 55 Idle Jets it's running better than ever with with no hesitation.
I have some 57 Idles in stock but i don't think i need them.
Alan

[anonymous-user]

plasticpig72 said:

Good news i have tried my 3000S and she is running very well. So for my car with VA19 Camshaft and 55 Idle Jets it's running better than ever with with no hesitation.
I have some 57 Idles in stock but i don't think i need them.
Alan

Well done that’s a good result!