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Discussion Starter #1
I'm contemplating rebuilding a 2.0L engine and I want to use Weber 45 DCOEs. I've found a pair, they're type 9 with 2 progression holes. I think these were used on the Alfa 2600 originally and an Aston or two. Will 2 holes be ok on a twin cam 2.0L or will the transition be very rough?
 

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Anybody got any thoughts on these? 2 progression holes....A problem for twin cam 2.0L or not? As a guide of the state of tune, I'm aiming for about 165bhp from the motor.
 

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Don, difficult to absolutely say, as I've never used a 45DCOE9 on a twincam of any sort, (not through choice. but never had the opportunity), but I would hazard a guess that if they were used successfully on the
Alfa 2600, Aston Martin, and were recommended by Weber in aftermarket triple carb conversions for the E-Type (or any 3.4 and upwards XK engine), that they should be fine for a 2 litre T/C.

I do see your reticence, with the two-hole progression, but maybe there's no need to worry if Jag, Aston and Alfa were successfully using them ?

I've used them extensively on the BMC A & B series engines to great effect, and the progression has never been an issue once the correct idle jets were found, however, much older design of cylinder head of course.

If you've bought them, then try them, but if not, then I'd go for a pair of 152's. (The 9's will always remain a saleable item in good condition.

Steve
 

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Thanks for the info Steve. I haven't bought them yet, I still haven't actually got the engine yet as I'm still trying to weigh up the expense versus whether the 2.0 is really going to be worth it over a well set up 1600. But that's another off topic dilemma!
Do the 152s come with various progression hole set ups? Think I've seen some with 5. What would your recommendation be?
 

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Go ahead and buy them. My customers that have used the 2 progression hole 45DCOE9's have had no problems, IF the idle jet is correct. The older 9's had a pretty rich idle circuit.
Transitions were easy, even with incorrect jetting & chokes. If you jet the idle just a bit rich on the two progression hole 9's they work fine, unless you are running huge main chokes. In that case, they become more of a race Weber like the 2 hole 45DCOE14's that only need to transition off "idle" once in a race.
If you keep vacuum up, 2 hole 9's are just as nice as the three hole. All the Italian 9's are priced up there these days.
I only build mouse engines, as they were intended for high rpm power, where the 2 L was designed for low rpm torque. There are plenty of 2L engine builders out there that get LOTS of high rpm power out of a 2L, considerably more than any "mouse" engine.
Just ask Richard Jemison (Alfar7 on the BB) who builds excellent performance 2L's.
 

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Thanks for the info Steve. I haven't bought them yet, I still haven't actually got the engine yet as I'm still trying to weigh up the expense versus whether the 2.0 is really going to be worth it over a well set up 1600. But that's another off topic dilemma!
Do the 152s come with various progression hole set ups? Think I've seen some with 5. What would your recommendation be?
Don, first of all I agree with Gordon, especially if the 9's are competitively priced.
You won't lose on them, they're a sought after item.
Yes you can get 152's in three and five hole progression, the latter brought out to meet the demand when 16 valve engines came to prominence. The 5 hole are pt no 152G.
The 152G's are in big demand and hence tend to command a premium, certainly in Europe.
The std three hole 152 works well on the 2 ltr. I'm now running them with 36 chokes on my two litre, and they work just great.
To be honest you may not find a pair of 152G's for a long time, so either go for the 9's or std 152's , they'll both do a good job
Steve
 
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