mustangmark

To the best of my knowledge b&m never made a top plate for their 250 blower for a Holley 4500 dominator. I am currently using an adaptor on my set up but really need the 3/4" that the adaptor is taking away for flame arrestor clearance.

Can anyone tell me if The Blower Shop's dominator/4500 top plate that they offer with their billet 250 blower will interchange or bolt onto the b&m housing?

Rookie

iTrader: (4)

I have a dominator on mine. Actually I believe it will accommodate a 4150 or 4500.

I also have Dual 4150 plates.

supermx96

Your single carb plate must be modified with some machine work ???

I never see a non modified single top plate for 4500 carb when i have try to find one.

I run mine with 4500 to 4150 adaptor last summer, I will try to run with twin carb setup for the next season.

mustangmark

I used an adaptor plate on mine but in order to keep the fuel from deadheading against the edges of the adaptor and top plate I had to remove and blend a lot of material from both. It came out ok but in the process reduced the width of the gasket for the top plate to about 1/2 it's original size along either side of the plenum. It works fine but I'm still having a height issue. Did anyone else remove material and blend the sides of their adaptor and top plate like I did?

MILD THUNDER

iTrader: (3)

Mine had the B&M adapter, modified for the 4500 carb. Didnt use a actual 4500 to 4150 adapter, just the B&M plate was machined.

I have two fiberglass hatch inserts that I took out of my setup. They give about 2.5-3" additional clearance for a single round flame arrestor. For sale if you need them.

Rookie

iTrader: (4)

How concerned is everyone about running a single carb on a 250? The bottom of this thread the poster has some #'s I am/would be concerned about.

http://www.hotrodders.com/forum/b-m-blower-189957.html

MILD THUNDER

iTrader: (3)

My results concurred with that thread you posted rookie. Rear cylinders run fat, fronts lean. Dual carbs much better.

mustangmark

I appreciate the offer M/T. I've already got a arrow scoop glassed onto my hatch. I did a little digging and found a guy that is willing to make a billit top plate for me. I'm not sure I'm going to go that direction or not yet. I need to find out what its going to set me back. I read the link in the other post and have heard that there can be fuel distribution issues using a single carb on the 250 blower. I currently run the top plate that mounts the carb in the center instead of forward and a Nickerson stage 5 dominator. So far...no issues and Ive consistently spun the motor to 6200rpm. I just picked up a 26p bravo1 to drop the rpm a little. The current prop is a 24p bravo1.

eddie

iTrader: (7)

Here are the instructions for the 250 if that helps at all: https://dl.dropbox.com/u/42339868/25...directions.pdf

supermx96

I can say that the front offset carb plate doesn't help at all on my setup, the rear cylinder # 5-7 & 6-8 run a way leaner than the front cylinder # 1-3 & 2-4. It is the reason i want to run on two carb setup next summer.

I think with center carb plate the # 1-2 & 7-8 will run leaner than the center cylinder, but probably the center plate is a bether setup than the offset in my opinion.