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 Post Posted: Sat Jun 02, 2012 9:09 am 
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webermaniac wrote:
Ken, what boosters do you have on the two 750s?


They are a standard Holley methanol down leg booster with .180 passages in them.

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 Post Posted: Sat Jun 02, 2012 10:38 pm 
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Ken0069 wrote:
Early on with the 1150 I was never able to get it rich enough to slow it down though. I can do that now but it took a great deal of custom work to be able to do that and EGTs still are higher than what I see with the dual 750s. Sometimes I wonder if the Dominator isn't atomizing the fuel enough and elevated EGTs are because of that, ie, raw fuel burning in the exhaust?? :-k

Thats what I constantly describe when talking about what EGT means. Its just a measure of wasted energy. You have to put EGT together with other information like CO and CO2 and HC and O2 levels exiting the exhaust. See you can have a situation where it's not completing the vaporization of the fuel in the chamber during the power stroke and its completing the burn in the pipe. The gas readings will show the O2 and HC consumption but there will be an out of balance CO and CO2 relationship. When the burn is completed in the pipe its under near normal atmospheric pressure so it wont make CO2. The WB sensor will still give a happy AFR reading.
You have the same engine underneath both types of manifold and carby setups and there different results. Now here the tricky bit. The EGT of the Dominator is higher so the residual gas left in the chamber is hotter so the incoming charge is vaporized differently. The residual hot gas is concentrated near the exhaust valve and your heads would have the plug biased towards the exhaust valve so the initial flame kernel is better from the Dominators higher EGT. The initial flame kernel determines the quality of every process that happens after that. SO the Dominator is a more consistent combustion setup. There would be less variation in combustion regularity with it. The result to date, it seems, is possibly more power from the Dominator.


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 Post Posted: Wed Jun 13, 2012 4:44 am 
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Guys I have just looked at my t-slots and they are above the blade by about .030 front and back
with blades set at idle. I thought they supposed to be exposed below blade?
Could this be part of my off idle hole?

Steve...


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 Post Posted: Wed Jun 13, 2012 6:44 am 
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ss436 wrote:
Guys I have just looked at my t-slots and they are above the blade by about .030 front and back
with blades set at idle. I thought they supposed to be exposed below blade?
Could this be part of my off idle hole?

Steve...



They should be right at the top of the blades when they are completely closed. A look at the t-slot sticky at the top of this section will explain a lot. Some castings had the slot too low, some too high, the newest ons are pretty close. I did have one with the slots .100" too high, an extreme case. Doesn't look like this carb builder is too sharp. =P~


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 Post Posted: Sat Jun 23, 2012 6:38 pm 
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Mark I opened up primary blade to expose t-slot and backed sec. off to bring idle down,
It take a stab of the throttle a lot better but idles a bit high so next I will get the blades back down and cut the t-slots down.
Also changed booster inserts to standard Holley alcohol 8 holes (from 1 large hole and two small holes pics above) and engine now pulls fuel alot earlier did a run and et .10 quicker with a smaller jet and egt's have come down as well.
It now has 198 jet .025 hsa and afr are 5.3 to 5.4, do you think a 12 or 16 hole booster might work and bring main jet down?

Steve


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 Post Posted: Sun Jun 24, 2012 7:29 am 
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Stick with the 8 hole, the 12 or 16 may not pass enough fuel with methanol. The channel in the backside of a methanol booster insert is deeper as well to provide sufficient fuel.


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 Post Posted: Tue Jul 31, 2012 4:35 am 
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Posts: 26
Just a update on my carb, I ended up cutting my transfer slots just below blades and opened idle jet
.007 thou...carb is sharp when you floor it and idles great in neutral and gear.
Ran my fastest time in qualifying then ended up winning our annual title event.
Like to thank you guys for all the help.. next time i'm going to build my own carb from scratch, I have learnt a lot from this site and tuner (before the innovate site was closed).
I read some where here that someone has all off tuner's post saved it would be awesome if they were
posted on here.
Anyway i'm going to clean my trophy...

Steve...


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