Use of a Big 97 Stromberg Carb.
 

59a Flathead street use in a 46 Mercury. New build.
bored 3 5/16 with a 53 Mercury camshaft grind.
presently running single stromberg 97 carb.
For this set up is a" Big Stromberg 97" ok for this set up or too big.
Or to just stick with standard stromberg 97. with 46 jets.?
Thinking about a new carb to go with new engine rebuild.
Thanks Phil NZ

Re: Use of a Big 97 Stromberg Carb.
 

Re: Use of a Big 97 Stromberg Carb.
 

So to stick with the standard Stromberg 97 then?
Phil NZ

Re: Use of a Big 97 Stromberg Carb.
 

Try running a Stromberg 48, a little bigger.

Re: Use of a Big 97 Stromberg Carb.
 

Max what’s your thoughts on these big 97’s I’ve heard good and bad about them. I planned to use one in a 4” mercury crank motor but haven’t yet.

Re: Use of a Big 97 Stromberg Carb.
 

Or use a Holley 94 like originally came in the car.

Sal

Re: Use of a Big 97 Stromberg Carb.
 

I would think that any engine of Mercury size (255 ci) and up would benefit from a larger carburetor. Mercury had the larger four bolt Holley's from the factory. If your going for a totally stock restoration, it's one thing, but for a driver, I would think it would be a benefit. I have a Rochester 2G on a bored out Merc manifold on the warmed over '51 Merc in my car and am very satisfied with it. The Mercury engine, a set of Edmunds heads, a Mallory dual point and the Rochester carb gave a noticeable increase in performance in my case.

Re: Use of a Big 97 Stromberg Carb.
 

You have to bore out the manifold to match the big97, and on the spare 33 eng (276) I had to use an 8ba manifold, then the fuel pump mount needs mods ,then the gen wont fit, need mods to the vac brake line, etc.
I have only run it on the engine stand and don't think I will run it in the 33.
Lawrie

Re: Use of a Big 97 Stromberg Carb.
 

I think the Mercury is a '46, so it would still have the 239 engine. But a slightly larger carb ain't gonna hurt.

Sal

Re: Use of a Big 97 Stromberg Carb.
 

He said a 3 5/16" bore, which yields 258ci, and is actually bigger than a later stock Mercury. I have bored several Mercury manifolds to the proper size (both aluminum and cast iron) and never had a problem; I don't know about the earlier manifolds.

From my experience, I believe that a 2G is superior to the older Holleys.

Re: Use of a Big 97 Stromberg Carb.
 

I'm not wanting to modify too much. So to go maybe with a new standard sized Stromberg 97 and go with 46 jets. I've spent the money on the engine build and just want a new carb to finish it off. The Strombergs are available in NZ without the 2 to 3 months covid 19 delays. Appreciate all input and advice.
Phil NZ

Re: Use of a Big 97 Stromberg Carb.
 

Phil, Why are you saying .046 jets?
97's were used 36-38 on 221's.
I have a couple of original issue 97's; these have '67' cast into them which tells they are original issue on 36 commercial vehicles. These original carbs are also stamped with the main jet size. One has .045, the other .046. So, these are how they came from the factory, jetted to suit 221's. You may want to jet up a bit I think?

Re: Use of a Big 97 Stromberg Carb.
 

Yes Brian. My 39 coupe is running a Stromberg 97 jetted at 46.
Its a 221 plus 80 thou. This was checked on a dyno and needed to go from 45 to 46 as little lean at top end.

So with the single 97 at the 258 cu maybe around a 48 but to stick with 65 pv.
Just getting this engine fine tunned. Running NGK 6L and these are looking good at present set up. ie 97 carb jetted 46.

Phil NZ

Re: Use of a Big 97 Stromberg Carb.
 

I ran a 2GC on an early 33/34 intake on our stockcar. Had to sleeve the bore and fill the PB vacuum with JB weld for the center intake bolt. Ran great. I would alsosuggest a modified GM distributor as well. A well tuned engine woll last longer and provide economical service.
Gramps

Re: Use of a Big 97 Stromberg Carb.
 

what should a Stromberg 48 carburettor be jetted too for a 221C.I Fords V8 engine.

Re: Use of a Big 97 Stromberg Carb.
 

So will stick with the standard Stromberg 97 and jet up to suit as required as per spark plug indications. NGk B L 6.
always appreciate all comments and advice received..
Phil NZ

Re: Use of a Big 97 Stromberg Carb.
 

I still think a bigger carburetor would be appropriate for a 258" engine with an upgraded camshaft.

Re: Use of a Big 97 Stromberg Carb.
 

Ian; 0.048in main jets and a Number 63 power valve

Re: Use of a Big 97 Stromberg Carb.
 

Use an AF meter to get the best AF. Plug reading doesn't work anymore.

Re: Use of a Big 97 Stromberg Carb.
 

Phil,
Rule of thumb from a long time ago is go up no more than two size or ' risk '
upsetting a/f numbers. I slipped a 48 bowl between 97 air horn and base and used #50
jets and a #60 pv to run my '32 p/up...286 cu in....it runs wicked good. I've got some
48 bowls..get back to me at [email protected] if you wish.
Charlie ny

Re: Use of a Big 97 Stromberg Carb.
 

Charlie:

Interesting. I bought a manifold that had two Strombergs with this exact mod. 97 tops and bases and 48 center sections.

Re: Use of a Big 97 Stromberg Carb.
 

Another carb you might consider is: the 1 1/16 EAC style 94 which was used on the "Y" block engines and has the right vacuum output for the stock dist.

Re: Use of a Big 97 Stromberg Carb.
 

Thanks so much for all this info. Now have ruled out the Stromberg big 97 idea.
Its a street vehicle and top speed open road at 60 to 65 mph normally.
So the modified Stromberg with the 48 bowl and 50 jets with the 60pv could be the ticket.
As Charlie suggests, my distributor is the standard crab and is a recent purchase from 3rd Generation. Will put up the specs of the cam I am running for those that understand these things.
Phil NZ

Re: Use of a Big 97 Stromberg Carb.
 

My cam specs are:
Grind: B4i-10 Lobe separation: 109.8. Timing: 2 retard. Overlap(@.050") -12.0

iINTAKE
centreline:110.0 tappet lift: .314.
int open @ .050" -5.8 btdc Int adv open:15.8 btdc. duration .050" 207.8 adv duration: 257.7 duration @.200" 131.3 lobe area: 23.87. lash;.012. cam lift at tdc; .0311.
Int close@ 0.50": 33.6 abdc. int adv: close: 61.9 abdc.

EXHAUST.
centreline;109.6. tappet lift:.316.
exh [email protected]" -6.2 atdc. exh adv close; 21.3 atdc. duration.050": 208.1
adv duration: 261.6. duration @.200" 131.6. lobe area: 23.92. lash; .012. cam lift at tdc: .0319.
exh open @ .050" 34.2 bbdc. exh adv open: 60.4 bbdc.

hope i got it copied right.
Phil NZ