Thread: Zenith alternatives

the weber...

prone to fuel evaporation and blocked jets

and can run too lean on a 2.25l out of the box

the stromberg carby seems popular as well

as used on holdens etc. again prone to fuel evaporation but a good simple carb when fitted with an adustable main jet... you need to make sure you get one with a decent throat size

used one and had no major issues other than the fiel evaporation issues.

i have a 55 with a 2.25 in it and it has a stromberg carby but it is a lot squater than the holden 6 variant (maybe a sunbird or something) and seems to work very well what little i have used it.

there is the solex but you will have to gin around to fit one of them.

Have you replaced that big O-ring?

I found out the hard way that using one that was almost exactly the same didn't solve the problem, but the correct one did.

Well for what its worth

I have fitted that Strombie conversion from England on two recent rebuilds one a Series 3 and the other a Brewery/Distillery Dray 2a. (Came from NZ)
https://www.breckenridgedistillery.com/hooch/about-us/

Running up to 12,000ft from about Denver at 6000' both units showed they could handle to altitude change without excessive rich running.
So I would give the Stomberg two thumbs up!
Dennis
zedcars

Originally Posted by zedcars

Well for what its worth

I have fitted that Strombie conversion from England on two recent rebuilds one a Series 3

got a limk to the kits?

Originally Posted by vnx205

Have you replaced that big O-ring?

I found out the hard way that using one that was almost exactly the same didn't solve the problem, but the correct one did.

I shouldn't have said "again". It's a new re manufactured Zenith, my old original was warping a lot. I've got a rebuild kit coming for this new one though.

I just want something to bolt on and go.

Cheers,

Peter

The Zenith 36IV was the most reliable carby I ever had on the 2.5. The previous stromburgs were troublesome. I did end up with a double barrel weber in the end, in my search for performance, which worked well. But a cam regrind* did more that the carby upgrade ever did.




*have the cam ground so that it opens all valves 5 degrees sooner and closes them 5 degrees later. It's like curing asthma - it breathes, exhales and revs freely.

Thanks for the info.
I wound the idle mixture screw in all the way tonight and it just kept running, no change, I guess that's a sign it's warped ?

Also I couldn't see any squirt of fuel when I jabbed the throtle so i think the accelerator jet is blocked or pump stuffed.

Can anyone confirm those thoughts ?

Cheers,

Peter

Originally Posted by the big fist

Thanks for the info.
I wound the idle mixture screw in all the way tonight and it just kept running, no change, I guess that's a sign it's warped ?

Could be, but not necessarily. It means that the slow speed mixture control is not working, but there are multiple possible reasons for this. As well as a warped top cover, it could be a blocked passage or even simply that the idling speed is too high - it should be around 500rpm, about half the speed commonly set on current vehicles.

Also I couldn't see any squirt of fuel when I jabbed the throtle so i think the accelerator jet is blocked or pump stuffed.

Or the linkage is incorrectly set, or excessively worn, or the valve on the pump is not working due to a bit of dirt. Or the fuel squirt is not very visible - I would not worry about it unless there is a definite flat spot on sudden acceleration.

Can anyone confirm those thoughts ?

Cheers,

Peter

The main symptom of a warped top cover is excessively rich mixture, especially when idling, with black smoke from the exhaust, coupled with high fuel consumption. There is also usually signs of leakage, both from the join at the top and from the throttle spindle.

One problem that needs to be noted, not related to the warping, is that with the widespread use of ethanol blends of petrol, the fuel tends to absorb water. If the vehicle is not used regularly, this can result in corrosion, usually in the carburetter bowl. The corrosion products have a horrible tendency to block or partly block the small passages and jets in the carburetter, and a filter does not help!

John