45 DCOE 9 VS 13

[twincamman]

I have a set with the same casting differences ---but both are stamped DCOE18----the castings are completely Identical to yours as both the tops are different ---they worked on the elan but were never spot on --so I replaced them with an eye to wasting one on the 948 sprite motor and matching the other for the cortina motor [althoI don't have a Cortina - if you have 2 shoe sizes left 8 1/2 and right 11 and limp we may be able to work a deal postage to the U K may be a bear though ---ED

[SJ Lambert]

I've just got a second pair of 45 DCOE 9s to run on a T/C race motor in an open wheeler - will probably be around 1600cc capacity with a McCoy ported head. Long rods and short pistons.

Will undoubtedly dyno engine when it goes together, which may be some point in time in the reasonabley distant future - but while I gather it all together I ought look to collect a varying range of chokes, air correctors, mains and emulsion tubes etc for track day experimentation as well?

The original period motor has 40mm chokes - So, say new engine dynos well with 40s, is it worth trying 39s on the track as well to see whether such variations improve driveability? - though I don't have the original DCOEs to hand at the moment to check the rest of their calibration, I imagine that mains and air correctors for the new motor may end up being set around the 160 mark for each. Seems like aux venturis are often 4.5s - I presume that's what most 45s have - so wonder whether atmospheric variations ever call for changes to set up or once you obtain a good calibration should you "stick with it"?

Cheers
James

[rgh0]

Depends on what cams you end up running but i doubt you will see any benefit in using any thing larger than 38mm chokes for the engine you are planning on building.

Cheers
Rohan

[SJ Lambert]

Thanks Rohan, I'll start getting together the jets that I'll need.

[SJ Lambert]

Still haven't discovered what the difference between the 9 and 13 is.

Were either fitted to any particular vehicles as original equipment?

Edit - looks like the Aston Martin DB 4/5/6 ?? may have had the "9"s and an Alfa in triples as well - so looks like they at least were aimed at a choke per inlet tract.........

[twincamman]

4......???????

[bill308]

James,

Didn't George state that the progression holes were different in his post of May 02?

Bill

[gino1]

Hi all,
Both the carbs in the pics look original to me. The Spanish repros have a triangular shaped strip on the top right hand side. It doesn't do anything and I think it was introduced just to distinguish theirs from the originals, everything esle appears to be identical.
Gino
Milano
italy

[florawills]

Hi all,
Both the carbs in the pics look original to me. The Spanish repros have a triangular shaped strip on the top right hand side. It doesn't do anything and I think it was introduced just to distinguish theirs from the originals, everything esle appears to be identical.
Gino
Milano
italy

Hi gino1,

Yes 45 DCOE 9 Weber shares the same performance characteristics as the 45 DCOE 152 carbs and it deals for historic applications and those who prefer a cleaner & original look.

The only difference that matters between carbs of different spec numbers is the location of the progression holes. If you're trying to use two carbs with different progression holes on the same engine, you won't be able to get it to run decently at idle and low rpm. The progression holes are visible by removing the small brass plug just next to the mixture screw adjacent to each bore. It is not easy to modify - there are other threads about that.

[SJ Lambert]

I?m just putting the original 9s back on my car and have noticed a tiny difference in the body castings between the other pair (the others are said to have been a triple set that had the middle one cracked from an Aston Martin)

Both pairs are Italian.

[SJ Lambert]

I noticed today that the auxiliary venturis in my original 45s are "one armed" too!

[jasper2347]

Don't know what size motor you are building or what it is going to be used for? I have a Porsche 924 (as well as the Elan) we hillclimb and sprint with modified 2.0 lump. We had a second hand pair of 45's on and had no end of bother setting up, even on rolling road. Fine at full throttle, but lousy everywhere else. We were told to get shot and buy a set of new 40's. We got nearly as much selling the 45's on evilbay as the new ones were. Immediate response to tuning and more bhp than the 45's. Also much less lumpy low down and better throttle response. Problem with the second hand carbs. is you never know how much work they have done and where the air leaks are, or any blocked passages inside. Best of luck in getting the car sorted. Have fun. Rob