Zenith jetting advice for 2.2l e

[tornik550]

I am new to zenith carbs. I purchased a 1970 2.2e engine that had zenith carbs on it. I plan on getting it running first then eventually getting a different fuel delivery system however I have thre zenith's for now. The engine is visibly in good condition, had good conpression and a good leak down. The only problem I can find is that the spark plugs are all carbon fouled and the oil smells like oil from a car with a way too rich mixture. I am going to completely rebuild the carbs.

Does anybody have any recommendations for a starting point for jetting? I have searched and couldn't find any info since zeniths didn't come stock on an e engine.

[al lkosmal]

Here's the PMO settings for Webers for a 2.2E

Main Vent = 30
Main jet = 125
Air correction = 180
idle jet = 55
Emulsion tube = F26

regards,
al

[porschetub]

Yep but the Zenith is a differant beast

[jluetjen]

When you say a 2.2E, please confirm that P&C's are 2.2E, as well as the heads. Have the heads been ported? Are you using E cams? The reason that I'm asking is sometimes people will say that an engine is a "2.2E, but I've got 2.7 P&C's on it with 10.3:1 CR and the heads have been ported..." So I figured I'd double-check.

What are you running for venturi? Everything starts from there (aside from the engine configuration). If my memory is correct you can make some slight modifications to allow the use of Weber or PMO venture. Once you have those defined, you can start to have a discussion about some starting points for the rest of the settings.

[tornik550]

When you say a 2.2E, please confirm that P&C's are 2.2E, as well as the heads. Have the heads been ported? Are you using E cams? The reason that I'm asking is sometimes people will say that an engine is a "2.2E, but I've got 2.7 P&C's on it with 10.3:1 CR and the heads have been ported..." So I figured I'd double-check.



What are you running for venturi? Everything starts from there (aside from the engine configuration). If my memory is correct you can make some slight modifications to allow the use of Weber or PMO venture. Once you have those defined, you can start to have a discussion about some starting points for the rest of the settings.

You have very good questions which I wish I could answer however I simply do not know if my p&c are stock and if my cam is stock. i would love to find out but I would prefer not to remove a head. Is there any fairly easy way to figure out what size Pistons I have? Is there an easy way to see what cams I have?

[tornik550]

Ok, so after a bit of research and help from some of the forum users- I believe that I have figured out what is in my engine. It appears that I have 2.7l pistons and cylinders and stock 2.2l E camshafts. I do not know the conpression ratio. My zeniths have stock vents.

I am currently rebuilding the carbs. Any idea of where I should start with jetting?

[al lkosmal]

So, it sounds like you basically have a 2.7 w/E-cams.....a nice engine.

I would start here:

Main Vent = 34
Main jet = 145
Air correction = 180
idle jet = 60
Emulsion tube = F3

This is the PMO/weber setup for 2.7 w/E-cams

I'd contact Paul Abbott at Performance Oriented regarding where to get the 34 vents/jets, etc. (there used to be a guy on Pelican who would mod weber vents to be used in Zeniths....also you could but a set of jet reamers and mod your own jets)
Note: while Zeniths are different than Webers (in some ways a better design) I think the recommended jet sizes will be the same..........perhaps Paul Abbott or Richard Parr (PMO) will chime in.

[Neffets]

my old 2.7 with zenith's and the small port heads I used
32mm vent
135 main
160 air
55 idle
stock emulsion tubes

[al lkosmal]

Originally Posted by Neffets

my old 2.7 with zenith's and the small port heads I used
32mm vent
135 main
160 air
55 idle
stock emulsion tubes

Good point...the 2.2E has ports 32/32 the same size as the 2.7 small port heads, so this may be a good starting point for this engine.

[tornik550]

Where can I find larger than stock zenith venturis? I have seen that you can use weber vents but I would prefer to use zenith specific vents if possible. If I am stuck using weber vents- where can I get shims to make the weber vents the correct height?

[chris_seven]

Weber venturis don't fit they are the wrong shape and the venturi position is very different.

The 'venturi' position on the Weber is around 8mm from the end and 13mm on the Zenith.

This affects the pressure drop relative to the main jet and hence the fuelling.

Weber jet sizes for a given venturi don't correlate well in a Zenith due to this factor.


The Weber venturi has an OD of 46mm and is 45mm long.

The Zenith Venturi is the same length at 45mm but has the lower end at 46mm diameter and the top end at 50mm diameter.

I don't know of anyone making 32mm dia but we make 34 and 36mm.

[tornik550]

Originally Posted by chris_seven

Weber venturis don't fit they are the wrong shape and the venturi position is very different.

The 'venturi' position on the Weber is around 8mm from the end and 13mm on the Zenith.

This affects the pressure drop relative to the main jet and hence the fuelling.

Weber jet sizes for a given venturi don't correlate well in a Zenith due to this factor.


The Weber venturi has an OD of 46mm and is 45mm long.

The Zenith Venturi is the same length at 45mm but has the lower end at 46mm diameter and the top end at 50mm diameter.

I don't know of anyone making 32mm dia but we make 34 and 36mm.

Perfect!!!! How can I purchase a set of 34's from you?

[chris_seven]

PM sent.

You may also need to increase the size of the Pump Jet to increase the fuel delivery of accelerator pump.

We usually upgrade this jet from 0.3 to 0.5 and this has been beneficial on 3.0 litre engines and they have worked quite well.