Idling query

[sidecar]

So glad we have MFI and Methanol on the dragster. Carbs were a nightmare LOL

Nightmare, nightmare? it's all good fun!

John, email with attachment sent.

I've just been out for a spin after drilling a 12mm hole in each counter weight. The results seem very good, the motor has more poke off the line and through the rev range. The holes are just slightly too large because if I stamp the throttle down VERY quickly when in top gear at about 2000 RPM the motor dies for a fraction of second, the mixture goes to 16:1 but then it picks up again. (Mind you the acclerator pump is on a very lean setting as the pump arm has been extended).

I'm going to fill the holes with solder then drill them out to 10mm.

I don't think that this mod would work too well on a smaller RV8. (Or you would have to go carefully making the holes slighlty bigger each time with testing in between).

I can explain where I drilled them if anybody is interested.

I weighted the assembly before I did any drilling "just in case" (I now have a small bag of bolts that is the same weight as the standard flapper valve!)



Pete

[v8alex]

Pete - thanks for the spreadsheet - works a treat!

Anyway, went for a longer run today and the car is still a little lean running with the 83 65-52 set-up, so I'll take it another step richer to 86 67-55 (Pete - your original - point 6 on the 1404 cal chart) and then see how it runs and maybe then lean it out a bit with the mixture screws. However, it is much better than before and also running cooler - I noticed the oil pressure a couple of PSI higher than before, so the oil is cooler and hence thicker. Also returned a respectable 26mpg.

With the funny idle - I noticed when dropping the car in neutral, the revs dropped each time I dabbed the brakes, with a bigger drop the harder I applied the brakes. Reading the Edlebrock manual leads me to think the floats are not set correctly which is something I've not looked into yet, so that's tomorrows job. It could also be too high fuel pressure (I run a Carter electronic fuel pump), but I don't think this is the cause of the problem.

The hot idle is also too high sometimes as before, so again, this might be sorted by adjusting the floats.

Watch this space.....

Alex

[Cobratone]

So glad we have MFI and Methanol on the dragster. Carbs were a nightmare LOL

Nightmare, nightmare? it all good fun!

John, email with attachment sent.

I've just been out for a spin after drilling a 12mm hole in each counter weight. The results seem very good, the motor has more poke off the line and through the rev range. The holes are just slightly too large because if I stamp the throttle down VERY quickly when in top gear at about 2000 RPM the motor dies for a fraction of second, the mixture goes to 16:1 but then it picks up again. (Mind you the acclerator pump is on a very lean setting as the pump arm has been extended).

I'm going to fill the holes with solder then drill them out to 10mm.

I don't think that this mod would work too well on a smaller RV8. (Or you would have to go carefully making the holes slighlty bigger each time with testing in between).

I can explain where I drilled them if anybody is interested.

I weighted the assembly before I did any drilling "just in case" (I now have a small bag of bolts that is the same weight as the standard flapper valve!)



Pete

Yes, carbs are MUCH simpler than EFI aren't they Pete