Weber 32/36 jetting

bavarian

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Hey I’ve been looking at a couple threads on this, most of the good info I find is for a b35 and was wondering what is a good jetting recipe for a low compression 2.8l US, it’s out of an e12

Primary
60 idle
145 main
160 air corrector

secondary
50 idle
140main
170 air corrector

I believe I used this from a post on here for a 3.5 , I have a feeling I’m leaving some hp and mpg on the table
Open chokes 24:7
Any recommendations are appreciated
 

'69 2800cs

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First do the idle mixture adjustment as that will tell you if you have the right size idle jets. On my B34, I had to turn the screws out 5 turns to get the best idle, when the correct setting is 1.5 to 2 turns max. More than two turns means the jets are too small, going up two sizes in idle jet changes nothing about the idle itself but greatly enhanced low speed driveability-in town, leaving lights, etc. Single best change I made.

From there I'd recommend getting an AFR gauge. An exhaust shop can put in a bung and the kits are $200 or less...if this motor is a keeper it's worth the journey. FWIW, I found my secondary jets were way too big as I was going to 10:1 when cracking them open.

The AFR also helped me with air correctors as I had good low speed mixture on the primaries but high RPM was lean.

Anyway, not the specific jet recommendations you were looking for but check out those idles first. The engine will tell you what it wants.
 
Last edited:

bavarian

Well-Known Member
Messages
156
Reaction score
42
First do the idle mixture adjustment as that will tell you if you have the right size idle jets. On my B34, I had to turn the screws out 5 turns to get the best idle, when the correct setting is 1.5 to 2 turns max. More than two turns means the jets are too small, going up two sizes in idle jet changes nothing about the idle itself but greatly enhanced low speed driveability-in town, leaving lights, etc. Single best change I made.

From there I'd recommend getting an AFR gauge. An exhaust shop can put in a bung and the kits are $200 or less...if this motor is a keeper it's worth the journey. FWIW, I found my secondary jets were way too big as I was going to 10:1 when cracking them open.

The AFR also helped me with air correctors as I had good low speed mixture on the primaries but high RPM was lean.

Anyway, not the specific jet recommendations you were looking for but check out those idles first. The engine will tell you what it wants.
Thanks yes I set the idle I actually think the car is fine I was just used to a a much faster m30 a b35 paired to a 5 speed now I’m driving a b28 with a 4 speed and a lower gear then intended , revs freely but overheats I think the head is cracked, no bubbling in the coolant throws oil clouds but now when accelerating doesn’t build coolant pressure but doesn’t burn any coolant very strange behavior, any ideas

I did bleed it with no thermostat it hold much longer without overheating but will get there eventually with the new thermostat it gets up there fast
 
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