engine and drivetrain How can I put a 40 DCNF onto a 2002?

[bbrilli1]

Hi all. I could use a little sage advice. (Even parsley advice would be fine) I am going to put a Weber 40 DCNF carb onto my '71 2002. I run it in FP in regional SCCA races so this must be my choice. (Oh what I would give for a pair of side drafts.) I have a Tisa sport cam and 10:1 compression and the old faithful 32/36 just isn't keeping up with the dopey miatas. Especially when when the engine is turning over 6k rpm. I doubt it is a bolt on so does any one sell a kit or will I have to fab the whole thing? Anything in particular to watch out for? Anybody have an old carb or adapter they want to get rid of? Thanks for your help.

BB

[gracer]

Robert Maples and I have both done this. Robert came up with the idea to use two 1/4" plates, one bolted to the carb, and one to the manifold.

It works Ok. I am making the same HP with the carb as I did with injection. I am still working on the correct jetting. The key is the emulsion tube. I will have mine on the dyno in a week or two. Hopefully I will have the jetting resolved durring that session. I will post results. G

[bbrilli1]

Thanks for the info G. I'd love to see what you find out on the dyno. I've never even held a dcnf in my hands so any jetting info would be great. Do you have yours mounted with the throttle control lever pointed toward the back so you can use a rod or did you switch to a cable throttle linkage?

[jgerock]

Good luck on the DCNF installation. These carbs were popular years ago for the air-cooled VW. As with any other old carb, watch out for worn out throttle shafts, stripped threads and incorrectly drilled (oversize) jets.

I'm not even sure replacement parts can be sourced for these models.

See weblink to exploded view I just found http://www.racetep.com/weber/40DCNF.pdf

Shoot - what's next? Someone trying to install a Holley "Bug Spray" on a 2002?

[kbmb02]

I am going to put a Weber 40 DCNF carb onto my '71 2002. I run it in FP in regional SCCA races so this must be my choice.

I have no answers (not yet, anyway), but do have a question: Is there documentation in the SCCA rule book / elsewhere that the 40 DCNF was raced 'back in the day' ? I've got a vintage '02 race car which I race in VARA and have considering this option, but want to make sure it's legal (with documentation) before I proceed. Anyone have more info??? Thanks!

[gracer]

I am using a throttle cable. My carb is located on the manifold with the fuel inlet on the drivers side/ with the idle screws reached from the front.

I don't think that the SCCA speced the DCNF for the 2002 untill ~ 1999. G

[bbrilli1]

Jgerock, thanks for the link. Yep, it is a weird thing putting a Ferrari carb on a BMW but that is the SCCA way. Thanks for the input.

kbmb02, gracer is correct. This is a (relatively) recent move by SCCA to equalize the cars running limited prep engines. If you can run side drafts I would do that instead of all the fabrication. If you are dead set, or required, to run one carb maybe a 38/38 DG(whatever choke)S would give you an advantage over a 32/36.

gracer, thanks again for the info. Here is my email address. bbrilli1 at live dot com. If you could either post your info here or email it I'd really appreciate it.

http://www.turbosport.co.uk/showthread.php?t=109939

Here is an interesting thread about modifying 32/36 carbs. And no I have not tried any of these tricks because that would be illegal for competition. I do think having this thread here instead of the front page will prevent some horrible damage to innocent carbs.