weber jets

[daz 104]

any one no what jets to run in weber 500 on a 4.6

[sidecar]

Its impossible to give you the exact setup for your engine as it depends on many things such as the heads, the cam, the exhaust, the inlet manifold.

My stage III 4.6 lump runs with the following setup:-

Primaries =83
Rods = 65-47
Secondaries = 80
Springs = silver

One thing you do want to make sure about is that you are not over fueling your engine especially on the cruise circuit, the RV8 seems to tolerate a rich mixture without giving you much indication but the bores and rings will be getting damaged. The above setup is 16% leaner on cruise compared to the base setup.

[daz 104]

thanks . im running 67.55 with 86 jet ans 83 seconds

its a 4.6 with stage 2 heads sleath cam and comp of 9.75.1

[sidecar]

Your setup is 8% leaner than base on cruise and 7% leaner than base on the acceleration circuit. I use a spreadsheet to work this out, the Eddy charts are crap, they are full of errors and don't include all the jet and rod combos!

I found that my engine did not want leaning off at all on the acceleration circuit.

I aimed for an AFR which was as lean as possible before the response went bad on cruise which ended up being 14.5-15:1

The acceleration was around 12-12.5:1 and the WOT was 12.5:1-13:1 from memory

(Measured using an LC1)

[daz 104]

Thanks for help i keep trying different jets i dont have any way of checking AFR

[daz 104]

Thanks for help i keep trying different jets i dont have any way of checking AFR

[DaviesDJ]

While jetting my 600 on a 5.0 I found that leaning the accelerator circuit dropped power significantly - and above 14.5 I found the engine a lot less happy on cruise, but perhaps I was pushing it a bit as when I stripped my engine there was a bit of wear on the thrust face from obvious over fuelling - for 150 pounds get yourself and AFR gauge - you will be suprised at the results - better than a dyno session IMHO - all the best - Dave

[daz 104]

thanks might invest in one of those .