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Upgrading carbs on a 2.0l air-cooled engine

Posted: 23 Sep 2015, 11:31
by markbradley
Hi,

I've seen a few threads on this topic, but I've got a few other questions I want to ask before I upgrade from those nasty solex carbs.

What I'm looking for is more power, something that will start in cold weather and that's not a complete ball ache to fit.

From what I've been reading, my best option is Delloroto 36 DRLAs or Weber 40 IDFs. Is there much difference between the two? What are they like starting in the cold? Also, what else would I need to upgrade if I'm getting bigger carbs (electric fuel pump, exhaust etc.).

Cheers!

Re: Upgrading carbs on a 2.0l air-cooled engine

Posted: 23 Sep 2015, 12:23
by dazwatson
Hi Mark,

I upgradad to DRLA 40's & wow completely different drive in the van now, pulls up hills well & after you get over the throaty roar when booting it when driven sensibly & on motorways even though I've never worked it out I believe the MPG is uneffected.

Few things I changed was to an electric fuel pump, Empi oil breather which you put in place of your old breather & this goes back & tapped into your pushrod covers (you need this due to higher oil compression) & an anti pulse valve (something to do with the timing :shock: )

You will also need to drill & tap the one manifold for your brake servo.

I run standard heat exchangers (on my bucketlist to change to J tubes)

All sounds pretty complex, but trust me I'm no engineering genius & I manged it with help from friends!

Cold start with no chokes is ok, I leave the pump to tickover for about 10 secs & then a few pumps on the pedal & she's away, just let it tick over for a minute or two & then I'm good to go!

Do it, you won't be disappointed.

Happy to get some piccies together if you want.

Daz

Re: Upgrading carbs on a 2.0l air-cooled engine

Posted: 23 Sep 2015, 17:00
by markbradley
Brilliant, glad to hear it's not a massive job! If you could take a couple snaps that would be really helpful too!

Also, any idea on where I could purchase some at a decent price?

Cheers!

Re: Upgrading carbs on a 2.0l air-cooled engine

Posted: 23 Sep 2015, 17:14
by kevtherev
markbradley wrote:Brilliant, glad to hear it's not a massive job! If you could take a couple snaps that would be really helpful too!

Also, any idea on where I could purchase some at a decent price?

Cheers!
Dellorto stopped making these carbs a few years ago, so you'll be looking for used ones, in the usual places

Re: Upgrading carbs on a 2.0l air-cooled engine

Posted: 23 Sep 2015, 17:28
by markbradley
Ahh, that'll be why I can't find any new ones then!

What are peoples thoughts on Weber IDF 36s and 40s? From what I've heard they're pretty similar to the Dells, do they have an automatic choke? And will I have to upgrade my exhaust as well?

Re: Upgrading carbs on a 2.0l air-cooled engine

Posted: 24 Sep 2015, 22:12
by mr_nunn
I'm sure those Dells etc are great, but also worth considering getting the twin solex's rebuilt/refurb'd. I had mine done at gasure.co.uk (renowned for working on these carbs) and it's driven great since. And a much cheaper option.

Re: Upgrading carbs on a 2.0l air-cooled engine

Posted: 25 Sep 2015, 10:46
by CovKid
Plus much depends on how old that engine is.

Re: Upgrading carbs on a 2.0l air-cooled engine

Posted: 26 Sep 2015, 10:28
by sarran1955
Hello,

A demo of the difference before and after tuning twin solexes on a 2l CU.. :wink:

https://www.youtube.com/watch?v=4qayyc9Z4E0" onclick="window.open(this.href);return false;

https://www.youtube.com/watch?v=najLc9GlLJ0" onclick="window.open(this.href);return false;

At no real cost...

Cordialement,

:ok

Re: Upgrading carbs on a 2.0l air-cooled engine

Posted: 29 Sep 2015, 20:51
by markbradley
If I buy this Weber twin 40s kit, will I need a conversion kit as well? Or will they fir straight on?

https://www.vwheritage.com/shop/AC129K1 ... -kit-t1-2/" onclick="window.open(this.href);return false;

Re: Upgrading carbs on a 2.0l air-cooled engine

Posted: 29 Sep 2015, 21:49
by CovKid
Good luck going that route if thats what you want to do but it can be akin to fitting a bionic arm on a pensioner as well as being forced into upgrading other things you hadn't planned for, just to make it all work.

If you really want more power it has to breathe properly, both on induction and through the exhaust. Fuel consumption is likely to be even worse. Be cheaper to sort out any issues and get it running at its optimum. A well serviced and properly tuned Aircooled can be quite a perky engine. Sounds like the chokes aren't set up correctly and carbs need checking for leaks.

Other than that, for moderately more (depending on what you can find), a different engine may be your salvation but as with most Aircooled bodies, the lack of a radiator poses an extra challenge. Those original carbs (if the throttle flaps have not been rebuilt) will be troublesome to get a smooth idle and just annoy the hell out of you. Rebuilt they can run really sweet. If you haven't already contacted him, you could talk to Roger Ball. He does mail order carb rebushing. His number is in the WIKI (in the peirberg carb section).

Re: Upgrading carbs on a 2.0l air-cooled engine

Posted: 30 Sep 2015, 23:08
by Moonrakers
"akin to fitting a bionic arm on a pensioner"

I like that :rollin

Re: Upgrading carbs on a 2.0l air-cooled engine

Posted: 03 Oct 2015, 11:22
by billy739
800£?

wow , fuel injection would probably cost £200 max (I fitted it to a 1600 for £30)

Re: Upgrading carbs on a 2.0l air-cooled engine

Posted: 05 Oct 2015, 08:04
by sarran1955
Hello,

billy739 wrote:800£?

wow , fuel injection would probably cost £200 max (I fitted it to a 1600 for £30)

Fuel injection.. now there's the way to go.. 8)

I've been looking at possibilities for my next CT engine..

I'm thinking of using (from stock) the single point injection system from a Skoda 136 engine.

This would have some advantages, as the plenum inlet of this engine was designed for a carburettor, and the Bosch

system was grafted on to meet EU emission requirements.

So with some 'cut and shut' and a spare CT inlet manifold.... :wink:

The possibilities are endless....... :rofl :rofl :rofl

Cordialement,

:ok

Oh.. and it would be ready 'chipped ' to run on lower grade fuel..(88 ron)