D11 with dual Sromberg 97s on Edgy intake - can’t get it running properly!

[madmutt]

Hi guys,

 

I have fitted the 218 on my D11 with dual 97s and haven’t been able to get the engine running properly since. The main problem is that the engine bogs down and sometimes dies at about 1/3 throttle. It is worse under load and if you open it up suddenly. A mate who knows his way around flatties has been helping me. When I bought the car it didn’t have the vacumn pipe from the dissy connected. Connecting the vacuum pipe to the carb port made things much worse with the engine missfiring all over the place! We thought we sorted that out by putting back the missing washers in the vacumn mechanism in the dissy (between spring and vacumn pipe). It now idles okay, and the timing is advancing when both the vacumn and mechanical advance kick in at part throttle. We just don’t if we are dealing with a carb problem or a dissy problem. We have taken the dissy apart and checked it out. We have fitted a fuel regulator and fuel pressure is 2.5 psi. We have down jetting the main jets to 43s and the power valve to 67s. The carbs were brand new.

 

We took it out for a run on Thursday after we changed the jets and set the timing up and we only made it a few hundred yards! We thought it was fouling plugs but they are new and we cleaned them to make sure! We have now run out of ideas! 

 

Any advice would be gratefully received before I shut it away at the back of the shed and star working on my '23 Model T!

 

Many thanks,

 

Simon

[Plymouthy Adams]

what manner/style of sync tool did you use to balance the carbs?

[martybose]

Good luck with this!  About 15 years ago I tried to get a dual 97 setup on a modified Offy manifold working, and never got it right.  I had adjustable main jets, and I could get it to run right at low speed but be extremely lean at full throttle, or I could get it to run right at full throttle but not idle.  I briefly considered going to Holley 94's to get a working power valve, but ultimately switched to a different manifold with a set of Langdon Carter-Webers, which worked perfectly right out of the box.

 

Marty

[knuckleharley]

You ain't going to want to hear this,but with a basically stock street engine 2 2brl carbs flow too much gas for a 218. I suspect if you got the adapters and switched to 2 1brl carbs that your problem of flooding would go away.

[greg g]

What did you change?  Was the engine running well before the change?  If so, you changed the fuel system, then blame the ignition for the problem.  It doesn't seem a mystery to me of where the trouble may lie. As noted above with out other proper changes to support extra fuel mix, the extra fuel is just that extra as in unneeded unusable.

[greg g]

I also recall that those carbs didn't like fuel pressure of more than a couple psi.  I believe the Mopar pump operates above that level.

[bones44]

Like Martybose said " Langdon Carter-Webers, which worked perfectly right out of the box" on my 230. runs great!

[knuckleharley]

17 minutes ago, bones44 said:

Like Martybose said " Langdon Carter-Webers, which worked perfectly right out of the box" on my 230. runs great!

Well,they are much more efficient carbs than the old 97 Strombergs,your engine has been rebuilt and might even have a hotter cam or bigger valves,and you have a high compression head and probably a more efficient exhaust.

2 2 barrel carbs Stromberg 97's pumping gas at the same time on a stock 218 being driven on the street is asking for problems.

 

Plus someone mentioned a higher pressure fuel pump was used on the old Mopars,and I 'd like to hear more about that. It's just one of the many things I know nothing about and would have never suspected.

[madmutt]

Hi guys,

 

Mates of mine run dual 97s on 202 ci four bangers without problems. Yes the Mopar fuel pump runs around 6psi so have fitted a fuel pressure regular to bring it down to 2.5 psi. I have checked with the Stromberg advice guy and he recommended the fuel regulator which improved things a lot. 

 

One of the misteries is why the vacumn pipe was disconnected. The car ran fine without it before fitting the dual carbs. I wish I had reconnected the vacumn on the old set up to see what happened. Any guys had any problems with their dissys?

 

many thanks,

 

Simon

 

 

[Adam H P15 D30]

I agree with the above posters that you probably have too much carb. That said, you stated they were brand new?  There was a recent thread on the H.A.M.B. about someone who bought new 97’s that were manufactured in China. He never could get them to run even marginally well. Ended up putting a used OE 97 on and his problems went away. 

 

Adam

[madmutt]

Adam,

 

My Stromberg’s were made in England.

 

Simon

[JOHN EDGE]

I add my two cents. I'd say look at the carbs and unless you've had those carbs running on something else I'd find some to try. I've been very happy with my carter Webers

[Flatie46]

Is it back firing any? If so through the carb or exaust?  Are you getting black smoke, rich smell from the exaust? Are the plugs black? Wet with fuel? White? Have you checked for an intake leak or carb base air leak? This can make adjusting the carbs impossible. 

[55 Fargo]

Dont think that little 218 can suck down its " cocktail" and is drowning.

That vacuum line is most likely not the big concern.

You are bogging as if starting out in 3rd going up the mountain.

That engine does not have the ability to process so much fuel.

What's coming out of the tail pipe?

How are the plugs looking?

Of course there will be a whole lot of advice on what you should do and run. Hope you find the solution with some help from this forum.

Also try the HAMB.

Good luck.

The 202 ci 4 cyl?

1 last suggestion, whatever solution you find please share it on this thread.

If you find a working solution with the 97s great if not tell us what that was...

Edited February 19, 2018 by 55 Fargo Spitfire

[federal39]

ok first thing you should check how much vacuum you have your power valves might be to big you have to have them under the vacuum of it you could block one off and try that to see how it works

[martybose]

1 hour ago, federal39 said:

ok first thing you should check how much vacuum you have your power valves might be to big you have to have them under the vacuum of it you could block one off and try that to see how it works

One of the joys of these carbs is that they don't have vacuum-operated power valves.

 

Marty

[greg g]

Have you done a manifold vacuum gauge reading?  With a stock cam and split intake you should pull apx.17 inches at 500 rpm.