Don Terrill’s Speed-Talk

I have an 8896 Dominator that is driving me nuts! I have a rich condition at idle and part throttle. I have tried installing Quick Fuel billet blocks and tinkered with the idle and intermediate air bleeds and I am not getting anywhere. I have tried setting the idle mixture with a vacuum gauge, but the aggressive roller cam causes erratic readings. I have even tried to set it with a O2 sensor, but no luck. I read up how the 3 circuit dominators have issue with rich idle and intermediate mixtures. I thought about converting the dominator to a 2 circuit, but there is not a lot of data on a full race motor conversions. Can anyone give me a few pointers on how to get this dominator on the right path?

Everything you need to know here.
http://motorsportsvillage.com/forum/vie ... f=6&t=3742

Yep , i did what mark mentioned and it fricken kicks a$$.

I've run a 1050, 1150 and 1250 2 circuit carbs on both my 23 degree 427 and my SB2.2 head 461, the 461 made 843 HP and ran 7.62 in my dragster. I reworked a QF 1250, made it a 2 circuit, runs on a 1000+ HP Steve Schmidt 584, 7.20's at over 180. Another 1050 I sent out recently was tested with Q16, they had no issue getting it too rich to to kill power. And the one in the picture below is a 2 circuit.




Just finished this one. 2 circuit.

jason snyder wrote:Yep , i did what mark mentioned and it fricken kicks a$$.

X2

Ok, I must have missed something. I have read and re0read the posts and it seems like I should have a good starting point. The details are as followed:

No Name metering blocks from ebay with all adjustable bleeds
Angle Channel drilled to .160
Emulsion set to .028 on 1&3. 2&4 are blocked with blank jets.
Kill Bleeds were already .028
Idle Jet set to .040
Idle Air set to .065
TSlot set to .062
Main Air set to .026

It is a drag car with a 427 Big Block with a .720" solid roller cam. The issue I am running into is the carb is leaning the motor out badly. It will not idle with out repeative throttle pumps, and even when trying pushing the carb out of the idle circuit ie 3K RPM the motor seems to run on what the squirters deliver than then leans out to a stalled engine.

I have seen carb in the fourm that have the old idle bleeders still int he carb, so I left mine in. Does the removal of the old idle bleeders a must?

Any Help would be great!!

Yes, the idle restriction needs to be the bottom only, take the top out.

Yes the idle bleeder in the in the top of the mettering block is out. I was talking about the old idle air bleeds on the top of the carb. Since converting to a 2 circuit, doesnt that remove the old idle circuit from operation?

The outermost bleeds that were the idle air bleeds no longer have a function, open or plugged does not matter. If the metering blocks are the Pro Comp cast zinc blocks they are at the bottom of the list to use. Every hole and thread needs to be worked over, and the mainwells are on the small side of what I would like to see. Make sure the bowl screws are snug, sealing the blocks to the body well. Look for any evidence of a vacuum leak.

They are the cast zinc blocks, I was unaware of issues with these metering blocks. At this point I feel a whole new quick fuel carb is in need. I have dumped so much money in this current dominator with little to no improvement. Would you know where I could possibly purchased completed 2 circut moded mettering blocks, or better yet send the whole carb to have it looked at and get a good base tune?

Mike, the amount I know about carbs cannot be measured. But what I do know is the guy who posted above you (Mark) might be a good guy to send your carb to. There are some other on this site who are good too. It would be money well spent.

Paul Miller

I would like to see you tackle this yourself if we can figure it out. The main wells may run it on the lean side up top but you still should be able to jet it enough to get it close unless oxygenated fuel is used. Idle and transition are different, you should be able to make it idle well. One thing to look at is the transition slot. Pull the carb, back off the idle SPEED screws all the way. Turn the carb over, the bottom of the transition slots should be right at the edge of the closed blades. The castings from Holley varied quite a bit, the non HP were the best, the HP's we're typically down too far past the blades on the earlier versions, not down enough on some of the next versions. The newest castings are better. There can be some extreme examples, I had one that was .100 too high. You can make a tool to file them to the closed blade, but it makes the t-slot area larger and significantly alters the operation of the circuit. The calibration for the idle jet, idle bleed, and t-slot jet on the one I had ended up significantly different than what most will like. This is the first thing we need to look at on yours. Here is a link to t-slot tuning, if it has to be lengthened try to take it just to the top of the closed blades. Make ABSOLUTELY sure the blades are seated all the way around first, occasionally they are not lined up well and the screws have to be loosened slightly to allow them to square up.

http://motorsportsvillage.com/forum/vie ... f=6&t=3811