Posted By |
Discussion Topic:
Dual carbs
|
|
nelsonford |
07-22-2014 @ 3:27 PM
|
|
|
Member
Posts: 52
Joined: Nov 2009
|
Does anyone know a good book or web sit where you can get information on setting up dual carbs? Like correct jet sizes for Stromberg 97'S. Do you need an electric fuel pump (6V) with a pressure regulator using the standard pump as well and filters? I have been running 94's with just the standard ford pump for years but with problems and now they are leaking pretty badly. I found 2 97'S which look in pretty nice shape one is a factory rebuild still in th box so I want to try them. Thanks, Nelsonford
|
ken ct. |
07-22-2014 @ 3:55 PM
|
|
|
Senior
Posts: 1513
Joined: Jan 2010
|
I would change MJ's to .043 or .044's and possibly the PV's to #67 or # 68. OMO. Other than that same hook ups as the 94's. ken ct.
|
40 Coupe |
07-23-2014 @ 4:30 AM
|
|
|
Senior
Posts: 1676
Joined: Oct 2009
|
There does not appear to be one source of information. You may want to SEARCH on fordbarn.com for info regarding syncing the two carbs. You don't indicate what engine but I have a mild 21 stud and use .043M & 69PV. the 97 Std sizes for one Carb on a manifold are .045M & 65PV
|
Whifty |
07-23-2014 @ 2:46 PM
|
|
|
Member
Posts: 45
Joined: May 2014
|
This might help. http://www.flatheadv8.org/rumblest/fuel.pdf
|
JM |
07-24-2014 @ 10:14 AM
|
|
|
Senior
Posts: 822
Joined: Oct 2009
|
I have no idea which engine you are planning to put dual carbs on, but I am getting ready to do this on a '36 LB, 21 stud engine that is basically stock except for a + 0.030 over bore. What I am using is an Eddie Meyer's 2x2 intake with two Stromberg 81's that are rebuilt with stock jets and power valves. Choke mechanism locked open on one carb. John
This message was edited by JM on 7-24-14 @ 10:18 AM
|
supereal |
07-24-2014 @ 2:44 PM
|
|
|
Senior
Posts: 6819
Joined: Oct 2009
|
The problem with the Stromberg carbs is that they are difficult to work on. Many multi carb setups used them because they needed less space between them. Be sure that the linkage is set so the throttle plates are in exact sync. The stock fuel pump should be sufficient. Most carb leaks are due to a warped body or stripped screw holes. We check them by placing emery paper on a piece of glass, then rubbing the gasket face on the paper. You will be able to see if the part is warped, and where. A vacuum gauge is a good way to adjust the carbs. doing so is tricky, as the increase in the venturi capacity skews the vacuum, making idling, in particular, uneven.
|
nelsonford |
07-25-2014 @ 6:45 AM
|
|
|
Member
Posts: 52
Joined: Nov 2009
|
The car is a '48 Merc coupe. The engine is stock with old Edelbrock heads & Fenton intake and Fenton headers with 2" pipes and smittys. I found a snag, one of the pair of carbs is a 48 with the larger venturi. Anyone want to trade a 97 for a 48? I may have to work on the 94's a bit more. I have more parts. The engine did run good for a while but now breaks up at higher rpms. The carbs seem to leak badly at the accelerator pumps and stop after it runs for a while. I have power valve plugs and #51 jets in both. Thanks, you guys are great. Nelsonford
|