Dellorto DHLA 45M carbs

[Maggo54321]

Hi all, I just thought I'd share some knowledge I have found out today after talking to the technical team at Dellorto (Eurocarb) in the UK.

My 1989 Turbo has twin Dellorto carbs and on the top, they have embossed on them DHLA 45.  However, if you look carefully at this picture, you can see 'M' after the 45 (not embossed) - both my carbs look like this.  So initially I thought they weren't 'M's but they are.

Dellorto tell me that the 'M' should have 'Power Jets' and the next picture shows the venturi with 2 small holes for the powerjets to come through.........but although I have 'M' carbs, and although I have the holes in the venturi for the powerjets, I don't have powerjets!

Dellorto say this is a mistake, and either my carbs have been changed (unlikely as the venturis wouldn't have the holes), or the carbs on my car are a factory reject.  

Not a lot I can do, it's working fine with these (albeit I currently have another spark related issue), but thought you all might like to know (and maybe check your own carbs to see).

IMG_1403.HEIC

[jonwat]

3 hours ago, Maggo54321 said:

it's working fine with these

The power jets only function under maximum boost conditions as the main jets cannot provide enough fuel. Have you run it at maximum boost yet?

[Maggo54321]

What do you call maximum boost? Over 1bar?

[Bibs]

0.85 bar on the SE, 0.65-0.7 on the carb turbo I believe. 

[Maggo54321]

Yes I’ve had it at .7 bar and all was good

[Escape]

Thanks for sharing, one can never to much info! And knowledge about carbs is rapidly disappearing, all the more important to get stuff like this out to those interested.

[jonwat]

Yes, those carbs were unique to Lotus, some of the parts they manufactured themselves so if anything breaks you'll be looking a 3D printing to replace them.

[red vtec]

On 02/06/2023 at 08:29, jonwat said:

Yes, those carbs were unique to Lotus, some of the parts they manufactured themselves so if anything breaks you'll be looking a 3D printing to replace them.

I thought they were used on a beetle? 

[jonwat]

9 minutes ago, red vtec said:

I thought they were used on a beetle? 

I'd been speaking with Dellorto UK who said the tops of the turbo car carbs were Lotus manufactured.

[red vtec]

@jonwat thanks for information 

[snowrx]

On 02/06/2023 at 00:29, jonwat said:

Yes, those carbs were unique to Lotus, some of the parts they manufactured themselves so if anything breaks you'll be looking a 3D printing to replace them.

RE; the tops on the turbo cars

I've had some luck casting aluminum from PLA printed items. One could get a quality scan of the turbo carb tops and generate a casting model to print, then put it in plaster, bake out the plastic and replace it with aluminum. You'd need to be slightly oversize to allow for casting shrinkage and leave the holes undersize for later drilling and threading.