Go Back   The Ford Barn > General Discussion > Early V8 (1932-53)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 03-04-2018, 03:07 PM   #1
wjfraser
Junior Member
 
Join Date: Sep 2010
Posts: 17
Default Need info on Holley 94 carb setting on Merc engine

Hello Barners. I need some assistance.

I would like to replace the stock 855 carb and manifold on my 1950 Merc flathead (4 inch crank) engine, completely stock, with a completely rebuilt1950 Ford Holley 94 8BA carb and manifold.

Merc is 255 cubic inches and 1950 Ford was 239 cubic inches.

Any changes that I should be aware of for the change?
What jet numbers and power valve numbers should I use on the 94, in order to compensate for the increase in cubic inches?

Any other things to take into consideration?

Thanks for assistance. Bill
wjfraser is offline   Reply With Quote
Old 03-04-2018, 03:21 PM   #2
tubman
Senior Member
 
tubman's Avatar
 
Join Date: Dec 2013
Location: Minnesota, Florida Keys
Posts: 10,259
Default Re: Need info on Holley 94 carb setting on Merc engine

I'll bet it'll work fine. If it's in good shape, put it on and run it. It's pretty close to start with and if you notice any minor problems, you can correct them down the line, like any carb tuning regimen. You may want to consider putting a small base Rochester 2G on the Merc manifold. The throttle bores are a little larger, but if you put it on backwards, everything lines up, fuel line, throttle linkage, and even the automatic choke. It's basically a better carb to start with and parts and availability are much better.

Last edited by tubman; 03-04-2018 at 04:16 PM. Reason: More detail.
tubman is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 03-04-2018, 04:12 PM   #3
flatjack9
Senior Member
 
flatjack9's Avatar
 
Join Date: May 2010
Location: Oshkosh, Wi
Posts: 4,516
Default Re: Need info on Holley 94 carb setting on Merc engine

People have to realize that a carburetor meters fuel dependent on the air flow through the venturi. They are pretty much self regulating unless the carb is totally mismatched to the application. If you have to make major jet changes, the carb is misapplied. In your case I would not expect any problems.
flatjack9 is offline   Reply With Quote
Old 03-04-2018, 09:19 PM   #4
19Fordy
Senior Member
 
19Fordy's Avatar
 
Join Date: May 2010
Location: Coral Springs FL
Posts: 10,872
Default Re: Need info on Holley 94 carb setting on Merc engine

I used an 8BA/ 8RT intake with a Holley 94 on a '50 Merc engine for years and found it to be a direct bolt on. Ran great. Notice location of vacuum fitting for Load-A-Matic distributor. Distributor shown is mechanical advance but I did use the OEM distributor for years. Engine was in 40 Ford. Used stock Holley # 51 with Gross Jet later on as they last "forever".
Attached Images
File Type: jpg IMG_3199b.jpg (60.5 KB, 39 views)
File Type: jpg IMG_3200b.jpg (32.7 KB, 34 views)
File Type: jpg IMG_3197b.jpg (59.3 KB, 32 views)
File Type: jpg IMG_3201b.jpg (30.8 KB, 35 views)
File Type: jpg IMG_3204b.jpg (62.2 KB, 39 views)

Last edited by 19Fordy; 03-05-2018 at 11:01 AM.
19Fordy is offline   Reply With Quote
Old 03-05-2018, 10:24 PM   #5
Strick
Senior Member
 
Strick's Avatar
 
Join Date: May 2010
Location: Marietta, GA
Posts: 1,097
Default Re: Need info on Holley 94 carb setting on Merc engine

if you don't want to swap the manifold, Charlie NY set me up years ago with a late 1940s Lincoln Zephyr 4-bolt carb base to fit the Merc manifold and that bolted up to a 8BA carb. Trick set-up from back in the day. Worked great!
__________________
1940 Mercury

Looking for DENVER heads - 81AS - 99AS - 19AS
Strick is offline   Reply With Quote
Old 03-06-2018, 11:07 AM   #6
scicala
Senior Member
 
scicala's Avatar
 
Join Date: Jun 2010
Location: Detroit suburb, MI
Posts: 3,697
Default Re: Need info on Holley 94 carb setting on Merc engine

Sponsored Links (Register now to hide all advertisements)
If changing to a 3 bolt carb type intake on the Merc 255, why not opt for a '55 or '56 Ford 272 Y-Block 2110 (94) carb ? They have the 1 1/16" venturi for more air flow, and the 1956 model had larger throttle bores too (may require boring the two throttle bore holes in the intake though). The 1956 model also had an auto choke like the Merc originally had too.


Sal
scicala is offline   Reply With Quote
Old 03-06-2018, 01:06 PM   #7
tubman
Senior Member
 
tubman's Avatar
 
Join Date: Dec 2013
Location: Minnesota, Florida Keys
Posts: 10,259
Default Re: Need info on Holley 94 carb setting on Merc engine

On the subject of automatic chokes, I have done two when putting Rochester 2G's on Mercury manifolds, so I have found out a couple of things. The first one I did had the choke stove (the round "thingy" with "rich-lean" on it) mounted on the carb. There was about a 5/16 hole in the Merc manifold about halfway up the side of the manifold. On the Mercury, there are some fittings and a tube that goes to the choke stove. Putting a Ford manifold on a Mercury and utilizing an automatic choke of this type would be quite simple; just drill the proper sized hole in the appropriate place in the Ford manifold. The second one I did was on a '51 Mercury manifold. These have a "divorced" choke where the choke stove is mounted on the manifold and a rod from it connects to the carb. Trying to modify the Ford manifold to use a choke like this would be near impossible.

Surprisingly, I have found that making the choke function properly is probably the most difficult part of changing from the original carburetor.
tubman is offline   Reply With Quote
Old 03-06-2018, 02:24 PM   #8
mfirth
Senior Member
 
Join Date: Aug 2017
Location: ohio
Posts: 986
Default Re: Need info on Holley 94 carb setting on Merc engine

Not sure a 94 would perform as well as the 855. I had a 239 8ba with an 855 on it & an Isky Max 1 cam. The 855 woke that engine up noticeably. The 855 developed a vac leak so i went back to the 94. You could tell that the car ran better with the 855. Based on that, i think the 255 Merc would be somewhat starved for fuel. ? Just my 2 cents worth. mike
mfirth is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 04:39 AM.