[Dave R (Roppa440)]

Just the extra bit on the linkage for the kickdown lever.

[Christer N (Christer)]

Thanks!

I hope I didn´t upset you too much with Smokey´s damn comments, but I think it is important that as many different views as possible get room on a message board like this. Then the people can draw their own conclusions and we all get a little bit wiser, hopefully. Often, the truth is somewhere in the middle.

[Dave R (Roppa440)]

Stop worrying about upsetting me!

All I can say is that my car drives better after fine tuning. Yours will too.

[Dave-R (Roppa440)]

I just read the above for the first time in ages. I would add this.

When playing with my carbs I found that power did indeed increase as I made it richer. The power you make is determined by the amount of fuel you burn so 'the more the merrier'. However I felt that after reaching an air/fuel ratio of 13:1 (as indicated on my meter) it did not seem to be making any more power when made richer. I have settled at 12.5:1 for now until I can prove it either way on the drag strip. I am also changing to a better rich/lean monitor to see if it reads the same.

[Tim]

I know it's back to basics, but please could someone confirm my Holley 800 double pumper carb is part of Holley's 4150 range?

Thank You!

[dave-r]

I had to check in my book at home first because this is the sort of thing I always get mixed up!

The 4150 series have a metering block with changable jets on each side of the carb. They don't normally have idle mixture screws on the secondary side block though.

The 4160 series only have one metering block (with idle mixture screws) on the primary side. On the secondary side they employ a non-adjustable metering plate that lives hidden inside the fuel bowl.

The book I have is the SA Design book on Holley carbs by Dave Emanuel.

Hope that helps.

[Tim]

Thank you for this information Dave. I'll have a furtle under the air filter at the weekend, and work out which one I've got.

I want to get a couple of fairly basic books on tuning Holley's, mostly so I can work out what the different parts are, and what you can do with them. Once I've got myself to that level of understanding, I can have a crack at setting mine up as described in your Carb Tuning post.

I can smell the singed eyebrows already

[dave-r]

I will try to give you a run through the basics without confusing you (I confuse myself usually) when i see you in a few weeks Tim. I will bring that rich/lean indicator with me too.

[Tim]

That would be greatly appreciated Dave, many thanks.

[dave-r]

I just read the above for the first time in ages. I would add this.

When playing with my carbs I found that power did indeed increase as I made it richer. The power you make is determined by the amount of fuel you burn so 'the more the merrier'. However I felt that after reaching an air/fuel ratio of 13:1 (as indicated on my meter) it did not seem to be making any more power when made richer. I have settled at 12.5:1 for now until I can prove it either way on the drag strip. I am also changing to a better rich/lean monitor to see if it reads the same.

I said that a year ago. Mopar Action just did some experiments at Ray Barton's on their magazine project 440 to see the effect of mixture/jetting on horsepower.

They started with a mixture in the range 13.6 - 13.1 to 1

Going up two jet sizes gave them a mixture around 13.2 - 12.8 and this small change increased power by 7HP.

Going up again two jet sizes made the mixture around 12.6-12.9 and the power dropped back down 7HP!

So it looks like my gut feeling was right and best mixture is around 13 to 1 and not 12.5 as most sources and 'experts' will tell you.

It is not often I am right so forgive me for being smug about this.

Of course now I have to go out and re-jet the bloody six pack again.