Smitty, I now proclaim you the "Bill Grumpy Jenkins" of marine engines !!!!

Thats some cool info.

Did you notice a difference lbs per hr fuel consumption between Tims carb and the custom 4150? Curious to see if its making less power, with less fuel, or more fuel. I would think if its making less power, with more fuel , maybe a sign the atomization is not as good?

What list number was the stock dominator ?

Scott, here are the double 5"90s and mufflers i was talking about

Both dominators were same part number, 8896.

5800-6000rpm 540

Total collector length includes pipe length bolted to it if same size

Note: I ran this for PapaSmurf's MER 540 700hp engine that was having some water reversion issues. He made his pipe 20" total length and it stopped reverting.

Note 2: Running tuned length does not always add Peak HP, but a lot of times if really fattens up the torque curve. Really depends of course how far off the original sizing was.

3rd Harmonic = 38.8 inches long ... more bottom-end Torque
4th Harmonic = 19.4 inches long ... highly recommended , best Torque Curve
5th Harmonic = 9.7 inches long ... reduced Torque , more top-end HP sometimes
6th Harmonic = 4.9 inches long ... reduced Torque , not recommended

Tuned Lengths= 19.4 best and also 9.7 or 38.8

Heres a good article that shows the importance of booster design. Even though the downleg booster carb flowed more cfm, the annular booster made more power.

Take a look at the torque numbers below 3000rpm. The annular booster is KILLING the downleg.

And you wonder how many guys slapped on an old swap meet dominator on their street car with a tight converter, and wondered why it was a slug and got chitty mileage

http://www.hotrod.com/articles/carburetor-showdown/

Spent a few hours reviewing dyno data today after shaking this out. Before fattening up norms modded 4150 we were in the .52 to .55 bsfc range from 5600/5800 up w afrs in the mid to high 13s (not sustainable afrs for 10 minutes at wot). Didnt really matter either between norms 4150, both doms or either intake, all in same range.
Fast forward to tims carb, bsfc's at hp peak and pretty much from 5800 up in the .61/.62 range, 398 lbs per hr fuel to make 650 corrected hp w afrs in 12's, thats 800 hp worth of fuel at .5 bsfc to mske a measely 650 hp, now before we blame his carb lets look back at combination, 8.5-1 548 w 252/259 @.050 cam on 114, not a rea efficient combination. And if you go back a few post you will see we poured some more jet to norms modded 4150 to drive afrs into the 12's to.make a fair comparison between tims QF and the modded 4150. Still made sbout same hp and beat the QF by 16 hp and some tq BUT bsfcs ALSO went into the .56 range then to the .59 range at hp peak, on last muffled pull used 375 lbs fuel per hr to make 675 hp, thats 750hp worth of fuel at .5 to make 675 hp, not very efficient at all, now, this IS from 5600/5800 up so not completely end of world but not patting myself on the back for making inroads here either!! Going to proceed w bolting all the efi stuff on too and see if things change much. Havent decided on next cam to test, if we can make same hp and pick up some tq w a little less cam plus increase efficiency a little i might go with it but if its going to take 800 hp worth of fuel to make 675 hp and motor makes 502 tq numbers like this I will be looking hard at going bigger and going up in compression, Smitty

One thing I noticed about tim's carbs, was the fuel curve seemed very stable thruout the rpm band. From 3000 to 6000 rpm, the air fuel ratio, didn't vary by more than 2 tenths. at 3k, it was 11.9, and by 5900, it was 11.8. I do like that . I've seen some carbs, vary big time. Some at start of the pull are pig rich, and by the time you get to peak HP, its piston burning lean. Or some start out in the 13's, and end up in the 10's at peak hp.

If i recall, with the stock out of the box jetting and what not, it was the same fuel curve shape, just was in the mid 12's for afr. We threw some jet at it, and lost like 3hp or something, and gained a couple foot lbs.

Looking forward to the efi testing!

Yes that was nice to see, also the gains and losses by changing jet was not nearly as much as people think, they say oh it's rich I'm losing 60 hp... no your not.... unless something is big time wrong, we changed at least 1 point in air fuels and only lost 2-3 hp, gained 6-10 ft lbs to