What jets do you have in your 32/36 weber

Tweety · Post by **Tweety** » Sun Jun 21, 2015 6:05 pm

Have a used 32/36 weber on the way to my place to replace my 38/38

Although the carb is jetted for a ea82 (mine is ea81) before I put it on my engine I want to check the jets. Can you tell me here what jets you have in your carbie.

Thanks

Tony

Post by **TOONGA** » Sun Jun 21, 2015 9:14 pm

I've heard 140 main and 150 -170 secondary with idle jets main and secondary that vary from 50 - 60

as well there is this

: prim main: 132, sec main: 130, prim air: 160, sec air: 165, prim idle: 50, sec idle: 55
(EA81))
: prim main: 132, sec main: 130, prim air: 175, sec air: 135, prim idle: 55, sec idle: 50
(EA81...??? mods)

from here showthread.php?t=6836

Im now running a 32/36 on my ej22 with a 145 main, a 210 secondary (probably overkill but fun) Idle jets are both 60 primary and secondary air are 170, remember that my motor is 2.2 litre.

don't for get SBs thread either

showthread.php?t=24889

TOONGA

Tweety · Post by **Tweety** » Sun Jun 21, 2015 9:47 pm

Thanks Jules,

I found the first web site after I posted this thread. The second one was good too and has a link I'm reading now.

I'm convinced the 32/36 might well perform better than the 38/38. But we'll see.

also I'm running the SPFI manifold. 6mm larger in diamter. wondering, that might have some effect on jetting.

Tony

Tweety · Post by **Tweety** » Mon Jun 22, 2015 8:13 am

The 38/38 weber carb is a good carbie. Working with both throats opening always at the same time might well give benefits. However I'm now convinced that the extra compression from 8.7:1 to 9.5:1 a little extra size of the SPFI manifold (6mm more diameter from stock ea81) was never going to be enough mods to allow the 38/38 to work to its potential.

Therefore the 32/36 as many people swear by, is the better choice.

Courtesy of the MGB and GT forum there was this comment

"No, it doesn't give "more low end power". It just opens faster and has a bigger total opening. Having a bigger total opening gives you more airflow when you need it at high RPM.

Because of the aerodynamics of the airflow through the single small barrel, you get better fuel mixing, better fuel economy, and more torque at low RPM versus the turbulent airflow of air going through two big barrels with cracked open throttle blades.

This is the reason why progressive carburetors were invented, and why even monster 1200cfm racing four barrel carburetors use the progressive design with smaller primaries.

"It is easy to make the assumption that biggest is best when selecting a main venturi size, but the purpose of the main venturi is to increase the vacuum acting on the main jet in order to draw in and effectively atomise the fuel mixture. The smaller the main venturi, the more effective this action is, but a smaller venturi will inhibit flow. A large venturi may give more power right at the top end of the power band, but will give this at the expense of lower RPM tractability. Only a circuit racer will benefit from this sort of compromise, on a road car, driveability is much more important. 95 percent of the time, a road engine is nowhere near its peak power, but is near its peak torque for 75 percent of the time. It is much more important therefore to select the main venturi for best driveability, once the venturi size has been selected, then the appropriate carburettor size can be arrived at."