Dominator on Indy motor fouling #7
#2806841
08/09/20 01:04 PM
08/09/20 01:04 PM
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Joined: Dec 2018
Posts: 4 VA
MHZ
OP
member
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OP
member
Joined: Dec 2018
Posts: 4
VA
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Hey guys. I run a 500" Indy motor in a A body. 440-1 heads, Indy 440-2 intake. With my 4150 series carb It's a steady 5.95-6.05 @112-ish car depending on weather & track. Typically a 1.37 or lower 60' I wanted to go to a Dominator. So I borrowed an older 7320 Holley and mounted it with a Wilson Manifolds open adapter 1.5" tall. When I fired it early this past spring it fouled #7 plug almost immediately. So I put my 4150 back on and it was good to go. Last weekend was running 6.01 on the 4150. In the meantime I ordered a new custom dominator from a well known builder. Not saying who right now because I don't need all those carb builder loyalties to come out. So this past week I put on the brand new dominator. Again with the 1.5" adapter. And guess what? #7 fouling very quickly. Plug doesn't look all that bad but I'm checking them at idle with an IR temp gun and 7 is at 200° while the others are above 500°. Here's a temp check at idle aiming the beam right at the tube about an inch or two from the port. Exhaust temp check videoI'm running Autolite AR3910's, MSD box, with 35° timing Any thoughts or guidance on correcting the issue? I'm open to suggestions. -Thanks
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Re: Dominator on Indy motor fouling #7
[Re: MHZ]
#2806850
08/09/20 01:22 PM
08/09/20 01:22 PM
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Joined: Aug 2003
Posts: 4,662 On the parachute mount
n20mstr
master
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master
Joined: Aug 2003
Posts: 4,662
On the parachute mount
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Ask the carb builder . Usually that’s why you go to these guys , service after the sale .
....BAD A$$ STREET CAR.....
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Re: Dominator on Indy motor fouling #7
[Re: MHZ]
#2806851
08/09/20 01:23 PM
08/09/20 01:23 PM
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Joined: Aug 2003
Posts: 43,007 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,007
Bend,OR USA
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Two different carbs with the same results leads me to believe the manifold with the adapter is causing your problems Is your intake a early or late 440-2? The early ones have individual raise bumps on the intake runners for injector use, the later ones have one oval boss that sits across two intake ports down low next to the heads. I don't remember now which one has the intake port wall divider sticking out into the plenum under the carb, the other one doesn't have that IHTHs
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Dominator on Indy motor fouling #7
[Re: MHZ]
#2806909
08/09/20 03:42 PM
08/09/20 03:42 PM
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Joined: Jan 2003
Posts: 14,479 So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 14,479
So. Burlington, Vt.
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I’d see if one of your friends has a different style of 4500/4150 adapter you could try.
I’d also take the carb off after letting the motor idle for a bit and see if the plenum floor is kinda wet.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: Dominator on Indy motor fouling #7
[Re: MHZ]
#2807270
08/10/20 01:17 PM
08/10/20 01:17 PM
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Joined: Jan 2003
Posts: 2,902 A shed in England
Tig
master
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master
Joined: Jan 2003
Posts: 2,902
A shed in England
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Just for info we had similar problems with an old 440 -3 manifold where # 1 and # 2 (to a lesser degree) ran lean. The info I managed to gather back then, was the then current 440 -3 did have a distribution problem. We switched to a -3X and solved the issue picking up a little H/P on the way. Pretty sure the 440 -3 manifold is now a different design but the one I had back then just looked like an opened out 4150 manifold.
'74 Challenger..9.46 @ 145.9 1/4, 6.001 @ 118 1/8 so far. 4023lb !!! # N/A, Marsh performance 655ci, Indy Maxx, T/R, Indy 600-13 X's, Street legal, pump gas, full interior, Cal-Tracs, mufflers, 3:73's and real 10.5 radials. 9.51 @ 142.4 1/4, 6.003 @ 114 1/8 with our old mule KB, 572-13, 580 wedge. RHD '68 Barracuda Fastback 323ci street/strip. Best ET 13.88 @ 99.03
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Re: Dominator on Indy motor fouling #7
[Re: mopar dave]
#2807855
08/11/20 09:06 PM
08/11/20 09:06 PM
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Joined: Jan 2003
Posts: 6,130 Melbourne , Australia
LA360
master
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master
Joined: Jan 2003
Posts: 6,130
Melbourne , Australia
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There was a post a few months back discussing the distribution issues of these manifolds, and others. I remember BradH posted some of the testing he'd done in it, along with others. I will have to see if I can find it.
Alan Jones
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