Rejetting my 42/42 downdraft.

[Lee]

I am currently rejetting my 42/42 downdraft and looking a pair of 165, 175 and 185 jets. If you have some, please let me know.

If anybody knows URL of Overseas Distributing in British Columbia, please let me know. Thanks in advance.

[Guest Anonymous]

Hi Lee thanks for the email earlier today.

The URL is:

http://www.overseas-auto.com/

I ordered some jets from then for my 45's they had them in stock.

[jgerry2002]

42/42?? Wow I did not know that Weber made such a beast.

I have a 40/40, running 170/175 and 60 idle.

I would imagine the jets are the same as the 38/38 and 40/40. I KNOW those are interchangable.

[Lee]

The 42/42 (as well as the 45/45) use DCOE jets. The 42/42 was designed for a 2.5 liter engine and has huge ports. Which is why I have to enlarge the jets from their initial 145. The 2 liter motor doesn't enough airflow at low and mid RPM. I bought the 42/42 from Dave Pineda. It required major surgery on the intake manifold.

[Harv]

Lee,

How many intake setups have you had on that car?

Looks cool.

John

[Lee]

From the day I bought it:

Single 34mm downdraft

Twin Weber 45s

L-Jetronic with custom intake manifold

SDS EFI programmable injection/ignition

Twin Weber 45s

Downdraft 42/42

Back to EFI next year.

[Brandon]

Lee..are you going to have your car down in CT at 02fest on Sept 10th? I love seeing that car in person...it's just so nice...Always one of the highlights of 02fest east!....

[Lee]

Thanks for your guidelines Justin.

I currently have 75 idle jets and that seems to be fine as the engine idles nicely ater some fine tuning. My main jets are 145 and it is way too lean as there is no way I can open the throttle unless the engine is fully warm. And even when fully warm, I suspect the engine accelerates only thanks to the richness from the accelerator pump.

You are running 170/175 with a 40/40, so I just ordered some 175, 185, 195 and 205 jets from Overseas Distributing. I can't wait yto try that carb on a track. It should keeep me from any synching duty but will offer some torque and punch at high rev too. Shall be the best of any world as far as a carb can offer. It is only a temporary set-up as I still aim at getting back to EFI.

[scottt]

Lee,

I think I have the custom manifold EFI setup you refer to, I bought it from Dan Curtis on a 73, car should be back on the road next month after a 4 year resto. Oh, the manifold's for sale if you want to go back :-)

[jgerry2002]

No problem with the reference. I was not sure how close that 42/42 is to a 40/40 so I thought I'd throw it out there.

Your idles seem a bit high to me, noting the typical transition, I think 38/38 most are running 50 idle so if I am at 60 on a 40/40, then maybe a 70 is probably ok on a 42/42. Just a total guess on my part.

As an FYI, my 40/40 is tuned properly, running 2.0-2.5% CO like a tii and sync'd second barrell for max vacuum at idle (I know this is not what the Weber manual says) and found sweet spot ~1050-1100 rpm idle, and I also plugged the secondary enrichment holes, of which there are two instead of one like a 32/36. I just managed just over 27mpg with a stock 4-speed and 3.90 rear at 68-70mph (thats around 4000rpm) on 320 mile trip. Throttle plates were just barely cracked open, so I hardly moved my foot even on hilly sections. I can't imagine what sort of mileage I'll get a 5-speed.

I don't have any low rpm stumbling around town either. I seem to have cured that with careful tuning.