Originally Posted by mike tkach

do you have any interest in selling the [crappy qft carbs]?

Originally Posted by headshothills

Hey MT.. Thanks for the reply.... Again, solid info and thank you... Im not going to point fingers on the original motor build being complete junk, but Ill say it started out as a Teague 720, and its seen 2 different motor shops that have touched the motor, and I am the 3rd owner... From a motor standpoint being a completely F'ed build, I dont know where to start... I guess Ill start with, the mains werent studded, nor the heads...The bearings werent coated, the line hone was off, stock GM crank, even cut for a keyway, but wasnt used, Valves were so short that they had to use special keepers and the rockers were hitting on the top. Merlin heads, nor stud girdles, intake ports went in and 90'ed straight down, an engine shop put a new cam in it, but didnt even check if the valve springs had enough pressure, lets just say the springs were only 89lbs and the cam required like 220...no screens in the oil galley, Balancer had a HUGE chunk of metal for balancing on it, valve job was just a 45, cheap rings, I know Im missing stuff, but again, a complete and utter cluster F build... Even the B&M blower hone was crooked... Go figured, fell right in line with everything else....

New build got coated bearings, line honed correctly, Dragon Slayer crank, crane springs, inconel valves, new H bean rods and pistons went from an 8.53:1 to 7.5:1 setup to run higher boost, total seal rings, stud girdles for merlin heads, guess there only 1 mfg that makes them, studded mains and heads, MLS for the heads, cleaned up intake and exhaust ports, new distributor and oil pump, blah blah... LOL

Supercharger USA did the conversion, there was some major differences that we took into account, 1 was the pre-heat packing from the air packing in and escaping out, and being packed again which ultimately resulted in higher EGTs, so the 3 lobe helix would reduce this air surge and ultimately lower the EGTs cause the intake air would be cooler, I forget what the formula was for intake temp > Exhaust temp, but any help to reduce EGT was a plus, the other was efficiency, the efficiency went up 20 points, which obviously is a plus, lastly was a more sustained boost... These were our selling points on just fixing vs converting, granted it cost more for the conversion, but we also did the heat treated gears and input shaft and billet bearing retainers too.. Might as well do it right....NNot sure what you mean by the efficiency went up 20 points. Are you talking air temperature output?

On the Dyno with 8psi, we laid down after a few adjustments just under 800hp, with just under 800 ft lbs... definitely missed our mark... So we overnighted a smaller pulley the 5" cause we just didnt have the pulleys to get 10psi... Running the 16 rib 6.3" Lower and 5" upper for 10psi.. 8psi setup was 6.75" lower and 5.8" upper...

Literally saw little to nothing on the dyno... 800hp and just over 800 ftlbs with 10psi... this was at 27 degrees timing... dyno was only plotting to 6400, but if you watch the dyno it ran to 6600 and it was still building HP... Has a 7k rev chip, dont know if I would wanna see 7k too much, but its a solid build and literally sounds better spinning 6400 than it does at 3500 LOL, it just sings... Sounds to me like you were probably experiancing high EGT temps, from lack of timing. 27 Deg with 7.5:1 compression and a 4'' stroke? I'd have been starting at 30 and giving it as much timing as it likes. Probably ending up at 33-34*. You'd probably see the EGTS cool way down.

Never the less we went back to 8psi and started dialing in some timing, bumped timing to 30, and literally laid down almost the same numbers with the 10psi setup.. again shocking... At the end of the day, we left the timing at 30, went back to the 10psi setup, and found a happy medium in the various tunes we tried.... One of the biggest things aside from flow and normal tuning issue we saw with the carbs is that it kept getting fat on the top end, and not matter what we tried we couldnt get the top end lean, so it was really hurting the HP.... When carbs are too small, they go fat on the big end. Im not surprised you were seeing this

I was going to go the Holley Ultra HP route until I was persuaded by our long time family friend to go with QFT... We are currently in talks with Brasswell since they are local here in AZ, still waiting for a build and price, they said they know exactly what is happening...

Either way, When you say 1050's I see my debit card melting at the gas pumps... LOL Although, going through all this unburnt fuel with these crappy carbs prob isnt helping the cause either... Larger CFM carbs doesnt necessarily mean more fuel consumption. I can tell you my setup with twin 850's, burns as much, if not less, than when I had a smaller blower with a single dominator carb. It takes X amount of fuel to make X amount of HP. Properly tuned, you shouldnt see much if any difference between some 950 or 1050 carbs (4150 style). Thinking that smaller carbs will save you money at the pump, is just not gonna happen.

Originally Posted by MILD THUNDER

Theres probably a little more power in the setup with larger carbs and some timing.

Originally Posted by TomR

I'm new to having Blowers! I'm in the proces of rebuilding carbs. The motor's are 468ci, Dart heads, Stainless Marine GENIII's, dry pipes, with 420 Mega Blowers. Each motor has dual 850 Holley's. The plugs were black! I'm thinking that they were set up way "Fat", 88s primaries with 6.5 PV and 96s with 8.5PV secondaries. Frankly I was surprised to find the big differences in jets between the primary and secondaries given that there were powervalves in each? Looking for some knowledgable feedback.

Originally Posted by mike tkach

do you have any interest in selling the [crappy qft carbs]?

Originally Posted by Bawana

Tom I'm running 557's with Brodie heads & 420's with teflon strips & twin 850's.. Boost ref both primary & secondaries, 74 jets in front W/3.5 PV. The secondaries have 78 jets W/ 3.5 PV... My air fuel at Idle is 13:1 and runs 11:6 to 11:8 all the way to WOT.... I also had to drill a .108 hole in all the butterfly plates to clean up the idle.... So first install a good wide band O2 sensor and start jetting down. IMO boost ref all the way.. my motors run like they are fuel injected & idle like a kitty cat . Oh by the way.. cam is 248/256 633 lift 114 and I run 6 pounds of boost 30* locked ..