The V8 Owners Forum -

Hi Chaps -

I was wondering if anyone on here could help me out.

I'm looking to set up my weber 500 carb but wasn't sure were to start in terms of the jets rods and springs for my engine spec.

I have a newly built V8 dev 5.0 ltr, 404 cam, stage 4 heads 10:1 compression, does anyone on here have a similar spec motor that is running a weber 500?

If so could you suggest a starting point for jets/rods/springs?


thanks in advance

Jon

Starting point would be the stock settings - should at least allow it to run. Sorry if i'm stating the obvious!

Jeff

There is a chap on the Cobra forum who has a 5.0 RV8 in a Stag (Don't ask why he's on that forum)

He runs 80 primaries, 57-49 rods, this gives virtually standard cruise but about 15% leaner on the powerstep. This is quite different to alot of other RV8 lumps that I've worked on. (I don't know what secondaries he has fitted). He is "Stoutgoose" on this forum but he hardly ever logs on

My 4.6 stage III runs 86 primaries 67-52 rods (which I sort of made) you could try 67-55 rods. I run 83 secondaries, orange springs, the pilots are set to 2+1/4 turns out. This is MY setup, I don't know how well it will work on your engine!

If I was you I would not spend your money on a rolling road session, buy an Innovate LC1 and a calibration kit then do it yourself. It is quite easy to set the carb up and at the end of it you will have a nice LC1 to play with whenever you feel like it!

Pete

stricky wrote:Hi Chaps -

I was wondering if anyone on here could help me out.

I'm looking to set up my weber 500 carb but wasn't sure were to start in terms of the jets rods and springs for my engine spec.

I have a newly built V8 dev 5.0 ltr, 404 cam, stage 4 heads 10:1 compression, does anyone on here have a similar spec motor that is running a weber 500?

If so could you suggest a starting point for jets/rods/springs?


thanks in advance

Jon

The engine will run reasonably with the stock calibration which is for a 5.0 engine but will not be perfect.

As V8 Dev have built and dynoed loads of these engines can they not suggest a good set up for the carb?

Kevin

My 4.6 stage III runs 86 primaries 67-52 rods (which I sort of made) you could try 67-55 rods. I run 83 secondaries, orange springs, the pilots are set to 2+1/4 turns out.

Are you really running 83 jets on secondary side

minorv8 wrote:

My 4.6 stage III runs 86 primaries 67-52 rods (which I sort of made) you could try 67-55 rods. I run 83 secondaries, orange springs, the pilots are set to 2+1/4 turns out.

Are you really running 83 jets on secondary side

Yep! and I might even go leaner!

My LC1 is showing 12-12.5:1 at WOT and I believe that 12.5-13:1 would be a little better.

It will run with much larger secondaries, I think that it had 92's in it when it was run on a rolling road, the rolling road gas analyizer was showing around 11:1. I checked this with my LC1 before deciding that it was too rich. It made 282 BHP when running mega rich, I don't know how much more BHP is being made now but the speed of the burn must be a fair bit quicker now.

It´s surprising because 92 sec jets were on the leanish side on my similar spec engine and had to put std 95 jets in to play safe. Primary side is just about the same as yours

minorv8 wrote:It´s surprising because 92 sec jets were on the leanish side on my similar spec engine and had to put std 95 jets in to play safe. Primary side is just about the same as yours

I guess it just shows that you can not really just bung a set of jets and rods in the carb just because someone else is running the same jets!

My lump runs a piper 285 cam, an eddy performer manifold port matched to the heads and a set of 1+3/4" primaries that each lead to a side pipe with a 2" baffle in each one. It spits nice orange flames on overrun from high revs which I think look great at night time, other road users may disagree!

The heads are V8Dev stage III jobbies, they were 36cc chambers but they had a shed load skimmed off them to get the CR to 10:1

thanks for the replies chaps, interesting to find out what others are using.

I'll ring V8 dev's and see what they suggest ( good point, why didn't i think of that )

Suppose I presumed those guys wouldn't bother with carb set up's anymore

Also I'll invest in the O2 sensor and gauge would also make sense too