We are currently running on the new domain and server: www.Speed-Talk.com

IMPORTANT: Update your bookmarks to https://www.speed-talk.com/forum/
(Right-click the URL and select "Bookmark this link")

Dominator - can't even get it to idle

General engine tech -- Drag Racing to Circle Track

Moderator: Team

MELWAY
Expert
Expert
Posts: 896
Joined: Mon Dec 04, 2006 7:37 pm
Location: melbourne australia

Re: Dominator - can't even get it to idle

Post by MELWAY » Tue Jun 02, 2020 6:50 am

Freddie wrote:
Tue Jun 02, 2020 3:10 am
enigma57 wrote:
Tue Jun 02, 2020 2:07 am
Freddie, I have been following with interest. Lost track of your current jetting, though. Holley lists 92 mains for these carbs if running power valve and 96 mains if power valve is blanked off. Now that you are getting closer with air bleed sizes, you may want to try the larger main jets Holley specs and see how they work with your new air bleed sizes. I'm thinking 75 idle air bleeds and 45 high speed air bleeds as a starting point? FWIW, out of box Holley installs 0.35 primary and 0.37 secondary pump nozzle size. Out of box jetting should give you a starting point or base line to work from.

Sounds as if your initial timing is good. Double check timing to make sure total advance is limited to 36 degrees, give or take 2 degrees either way when all in, though.

Do you have a good (known) carb to try in order to tell whether everything else is OK?

Regarding your priour carb running rich as well...... Is there any indication of ring seal issues resulting from fuel wash down of cylinder walls over time?

Just a thought,

Harry
Harry, thanks for the reply. This is idle only so haven't even got into the main circuit yet. That 5 mins run time was strictly idle.

I have 84 secondary jets with a 25 PV.

Yeah the engine is a brand new rebuild for the exact reason you mentioned, fuel wash. In fact builder said he'd never seen a cleaner intake and bores as it run so rich for 5000 miles. So trying to avoid the same.

I do not have another 4500 carb (a few 4150 style but no other 4500s)

Going to try an 85 IAB tomorrow (75 right now). Clearly still need to lean it out.

Have not checked total timing yet, will do that

Also going to check coil and spark voltage and make sure that's good
Something still doesn’t seem right. I have never seen a big cube big block want an air bleed over .070 with a small idle jet like a .035
In dominators a .037-.038 jet and .066-.070 bleed work good on most engines
3370lb Sedan 9.89@136MPH 358chevN/A

Coloradoracer
Expert
Expert
Posts: 730
Joined: Sun Mar 21, 2010 9:48 pm
Location: Lehigh Acres, FL.
Contact:

Re: Dominator - can't even get it to idle

Post by Coloradoracer » Tue Jun 02, 2020 8:56 am

You need to check to make sure you don't have a leak from the metering block gaskets, and that your float levels are staying steady. Do you have restrictors in the t-slots? If not, you need them. Can start with about a .050" and tune from there. Shouldn't be pulling any fuel from them at idle though. If you have the plugs, you can block off the power valves to see if that helps. Honestly, even for the street you can keep them blocked, just have to jet accordingly. Don't even concern yourself with main jetting right now, that circuit should not be active at all.

The only way at idle it's going to be that rich is if you have a float issue or a fuel leak into the engine from somewhere. When you checked the needle and seat, HOW did you check them? As I mentioned before, I had brand new ones in my carb that would just barely stick....I cleaned them, made sure there were no burrs or anything, then reinstalled them. With fuel flowing into the carbs, they WOULD NOT shut off the fuel....Had the same issue you're describing....If you have a good 4150, just swap the needle and seats to see if it helps, they are the same. Orifice may be a different size, (.090 seat vs a .110 seat), but that's not a big deal, just trying to find out if that's a problem or not....

Do you have a power valve in the primary? If you have plugs, pull the rear pv and plug it, you do not need it!!!! If you run a pv, run it in the primary only!

NO, a 4150 will not bolt to a Dominator flange without an adapter....
Mark Goulette
Owner/Driver of the Livin' The Dream rear engine dragster
Speed kills but it's better than going slow!
http://www.livinthedreamracing.com
Authorized Amsoil Retailer

Freddie
New Member
New Member
Posts: 37
Joined: Sat May 30, 2020 11:57 pm
Location: Terrill

Re: Dominator - can't even get it to idle

Post by Freddie » Tue Jun 02, 2020 9:30 am

Coloradoracer wrote:
Tue Jun 02, 2020 8:56 am
You need to check to make sure you don't have a leak from the metering block gaskets, and that your float levels are staying steady. Do you have restrictors in the t-slots? If not, you need them. Can start with about a .050" and tune from there. Shouldn't be pulling any fuel from them at idle though. If you have the plugs, you can block off the power valves to see if that helps. Honestly, even for the street you can keep them blocked, just have to jet accordingly. Don't even concern yourself with main jetting right now, that circuit should not be active at all.
No T-slot restrictors. I have never modded a carb like that before and pretty concerned I'd screw it up. if it really comes that I will send it to someone
I do have PV plugs. Have 25 front and back. I'll block both for now to be 100% sure (yep will rejet mains if that proves to be the issue
Coloradoracer wrote:
Tue Jun 02, 2020 8:56 am
The only way at idle it's going to be that rich is if you have a float issue or a fuel leak into the engine from somewhere. When you checked the needle and seat, HOW did you check them? As I mentioned before, I had brand new ones in my carb that would just barely stick....I cleaned them, made sure there were no burrs or anything, then reinstalled them. With fuel flowing into the carbs, they WOULD NOT shut off the fuel....Had the same issue you're describing....If you have a good 4150, just swap the needle and seats to see if it helps, they are the same. Orifice may be a different size, (.090 seat vs a .110 seat), but that's not a big deal, just trying to find out if that's a problem or not....
Floats are definately steady I have quadruple checked that. I will check again though to be certain, I'll also check dripping boosters.
Needle and seat were absolutely checked. I cleaned by wiping down in a alcohol bath and non lint cloth and re-installed. They move freely. I have 2 brand new ones I will install to be certain.
I don't have new gaskets but that may be the issue, they don't sit 100% flat, they are raised a tad
Coloradoracer wrote:
Tue Jun 02, 2020 8:56 am
Do you have a power valve in the primary? If you have plugs, pull the rear pv and plug it, you do not need it!!!! If you run a pv, run it in the primary only!

NO, a 4150 will not bolt to a Dominator flange without an adapter....
Yep figured that out, tried the king demon, not even close to going on. Will plug the PVs

novafornow
HotPass
HotPass
Posts: 90
Joined: Mon Feb 04, 2019 2:23 pm
Location: california

Re: Dominator - can't even get it to idle

Post by novafornow » Tue Jun 02, 2020 9:52 am

Save yourself a lot of headache and send it to Mark.

Coloradoracer
Expert
Expert
Posts: 730
Joined: Sun Mar 21, 2010 9:48 pm
Location: Lehigh Acres, FL.
Contact:

Re: Dominator - can't even get it to idle

Post by Coloradoracer » Tue Jun 02, 2020 10:15 am

novafornow wrote:
Tue Jun 02, 2020 9:52 am
Save yourself a lot of headache and send it to Mark.
^^^best option!
Mark Goulette
Owner/Driver of the Livin' The Dream rear engine dragster
Speed kills but it's better than going slow!
http://www.livinthedreamracing.com
Authorized Amsoil Retailer

Freddie
New Member
New Member
Posts: 37
Joined: Sat May 30, 2020 11:57 pm
Location: Terrill

Re: Dominator - can't even get it to idle

Post by Freddie » Tue Jun 02, 2020 10:54 am

I don't live in the US, so it's an option, just a last resort style option as shipping costs get way way up there real quick.

BobbyB
HotPass
HotPass
Posts: 276
Joined: Mon Apr 15, 2013 1:35 pm
Location:

Re: Dominator - can't even get it to idle

Post by BobbyB » Tue Jun 02, 2020 11:30 am

Freddie, Do you have a way to get a know good carb on your engine to at least break it in? Do you have an AFR gauge?

cgarb
Guru
Guru
Posts: 1800
Joined: Wed Jul 09, 2014 11:50 am
Location: Maryland

Re: Dominator - can't even get it to idle

Post by cgarb » Tue Jun 02, 2020 11:36 am

I'm not familiar with Dominator's myself. I know there is a difference 2 circuit vs 3 circuit. Is there different meetering block gaskets that if you put the wrong one on would cause an issue, similar to if you put an 850 baseplate gasket on a 750 type situation?

Freddie
New Member
New Member
Posts: 37
Joined: Sat May 30, 2020 11:57 pm
Location: Terrill

Re: Dominator - can't even get it to idle

Post by Freddie » Tue Jun 02, 2020 12:04 pm

BobbyB wrote:
Tue Jun 02, 2020 11:30 am
Freddie, Do you have a way to get a know good carb on your engine to at least break it in? Do you have an AFR gauge?
I've moved interstate recently so all my local guys are complete strangers but I do live in a street of car guys, all running small blocks but may have to hit em up for someone who has a known good 4500 laying around.

No AFR. It's old school BBC, so never put o2 sensors in it. I was looking at that yesterday though and thinking maybe I need to bite the bullet for this exercise. Even just a cheapo tailpipe sniffer might be enough to get me by

Freddie
New Member
New Member
Posts: 37
Joined: Sat May 30, 2020 11:57 pm
Location: Terrill

Re: Dominator - can't even get it to idle

Post by Freddie » Tue Jun 02, 2020 12:07 pm

cgarb wrote:
Tue Jun 02, 2020 11:36 am
I'm not familiar with Dominator's myself. I know there is a difference 2 circuit vs 3 circuit. Is there different meetering block gaskets that if you put the wrong one on would cause an issue, similar to if you put an 850 baseplate gasket on a 750 type situation?
Yeah they are different gaskets but they are the right ones. All the holes line up perfectly, one side sits flat and flush the other side, it's like the alignment pin holes are out 1-2mm and as a result the gasket lifts just a tad like it's squished. I did enlarge the hole on one to make it sit flatter, I did not do the other. Only one that appears wet is the fuel bowl side of the gasket, as you would expect it to be.

I think to be safe I will just change them out. Again I have a bunch of new ones sitting on my bench.

Coloradoracer
Expert
Expert
Posts: 730
Joined: Sun Mar 21, 2010 9:48 pm
Location: Lehigh Acres, FL.
Contact:

Re: Dominator - can't even get it to idle

Post by Coloradoracer » Tue Jun 02, 2020 12:19 pm

If you were nearby, I'd do the work on the carb for you. Simple, doesn't take much....just a little bit of drilling and tapping....and then you need the set screws you can drill to use as the feed restrictors. I have two King Demon 1295 RS that i did the two circuit conversion on for my dragster. I switched to alky and MFI, but I still have my carbs. They were much easier to tune and responded better to tuning. Installing the t-slot restrictors isn't hard at all, and moving the IFR's down isn't either. Other things is enlarging the angle channel to .160" and properly deburring the kill bleed hole. It's likely that all you'd have to do is install the t-slot restrictors and move the idle feed restrictor down since it's a two circuit already.......but I'd block the pv and see what happens....still a few things you can do that don't require any money......
Mark Goulette
Owner/Driver of the Livin' The Dream rear engine dragster
Speed kills but it's better than going slow!
http://www.livinthedreamracing.com
Authorized Amsoil Retailer

cgarb
Guru
Guru
Posts: 1800
Joined: Wed Jul 09, 2014 11:50 am
Location: Maryland

Re: Dominator - can't even get it to idle

Post by cgarb » Tue Jun 02, 2020 12:22 pm

I would be looking for a replacement, or sending that one to someone to be checked out before you ruin a motor messing around with it. Earlier someone mentioned about it possibly being a methanol carb. I know it has red metering blocks but maybe someone had it converted and just liked the red blocks because the matched their car or something. I like to try and figure out stuff myself also, but sometimes you can learn by having people who knows a product fix something for you and then having a conversation about the problem. Saves a headache for you and you learn what the issue was. Next time you can fix one yourself.

User avatar
jmarkaudio
Vendor
Posts: 4177
Joined: Wed Sep 26, 2007 11:26 am
Location: Florida
Contact:

Re: Dominator - can't even get it to idle

Post by jmarkaudio » Tue Jun 02, 2020 9:54 pm

Where are you located?
Mark Whitener
www.racingfuelsystems.com
____

Good work isn't cheap and cheap work can't be good.

Freddie
New Member
New Member
Posts: 37
Joined: Sat May 30, 2020 11:57 pm
Location: Terrill

Re: Dominator - can't even get it to idle

Post by Freddie » Tue Jun 02, 2020 10:57 pm

Australia (east Coast)

shoedoos
Expert
Expert
Posts: 623
Joined: Wed Aug 09, 2006 3:14 am
Location: New Zealand

Re: Dominator - can't even get it to idle

Post by shoedoos » Wed Jun 03, 2020 5:18 am

I may have missed it.....OP can you give us a full description of your ignition system along with how you have it set up for advance etc......if it were me, I'd be throwing 30 degrees static at it to see if it cleaned up at idle.....just don't rev it too hard if the advance mechanisms are still active...

Post Reply