Hey I got a little project in the start up face, Abd need some advice. I got a Volvo B30E engine, 3L or about 181 ci. In stock trim it puts out about 160-170Hp. But it has an old Bosch system on it, with bad wirring and bad injectors, and the parts are getting scares/expensive. And since it's going in to a hot rod build of mine, I would like to run a carb. And not the 2 strombergs it came with in the 130Hp base model. I've been thinking about using a Stromberg 97. But would that be over carb'ing? Is it possible to jet it down to ny purpose? And what would one start out with size wise. Who knows this stuff? My friend, the HAMB. :-D
The intake configuration will make a difference in what carbs you run. They originally had two carbs, with small manifolds. Were you thinking of making a new intake? or some type of adapter(s)? The injection manifold probably is not very good for use with a carb, as far as mixture distribution. I would think that it would need two 97s, if that's what you use. Maybe you could find an original pair of carb intakes, and make a 90 degree adapter for them. my brother got the family volvo years ago, and eventually replaced the original SU carbs with a Weber (with a new manifold), and I don't like it...it worked so much better with the original carbs
The stock carb manifold, aint all that good, they are cast-iron, welded to the exhaust, and that creates some carb/heat issues. And they dont flow well, because of the odd design. If i recall correctly, it dumps the exhaust in too two pipes below the manifold and goes in to one 2" pipe after 1m. The FI Manifold got 6 long runners, almost same length. And a split exhaust, that each is 2" pipe all the way back. So I would use the FI manifold. I Think it would be much better. But i have no prufe. What car is you brothers, squirel? I run 2 Dell'orto's on my 121 (4banger), and it runs great, about 9 times better. And I'm working on getting up to 10.
The 544/B20 can be a quiet hefty combo, when running 2 webere/Dell'orto's, and asortet parts. I'll try posting pictures tomorow/tonight. So you can get an ideer of what I mean. But if one 97 can feed an V8 Flathead, you mean I need two? I know when set up Webers there is a chart to find the right size carb, jets and so forth for you engine. Is this avalible for the for stromberg 97s? How does one match cfm on a car to an engine? Is there a chart for this too?
There's a formula for cfm for size engine. Keep in mind the flathead came with one 97, but when hot rodders got hold of them and put in a bigger cam, etc they added one or two more. And it's still a flathead. As an example, a mild 350 chevy engine (5.7 l) likes about 600 cfm. That's about 4 97s worth.
I thought CFM refered to flow of air, and then jet acordingly for size of engine, and powerband. I know this sounds much simpler, then compared to making it work. When running Dell'orto's one would take a 40 mm for a 2 liter, in medium/street set up. The for my valve size and bore stroke, 34 chokes/Venturi'es. And then jet after the cam. I worked some time on a 35 fire engine with a Flathead 100hp 21 stud. And we took the carb apart a couple of times, but there is a bog differense in fixing old to work like new, compared to make a complet new set up that aint never ran together. As far as I know. And my experiance with this carb is minimal, compared to Webers, Dell'orto, Solex, zenith or Stromberg cd175.
jetting depends on the size of the carb, not the size of the engine. They all need about the same air/fuel ratio. The carb size (cfm) selection is based on engine displacement, rpm, powerband, efficiency, etc. Also the carb size depends on the manifold type, with an individual carb per cylinder you need much larger carbs.
Carb intake: FI intake: Marine intake: I'm thinking about doing a two carb set up on the FI intake, drilling for 2 97, for and aft of the throttle body. Or maby find a marine intake and go for broke with three. I did quite some jetting on my carbs, and depending where you need you powerband, you go a couple of sizes up or down from your base line, but we are talking Independent runners and basicly 1 carb pr cylinder. If I need more power in the middle range I change the E-jet, and the corresponding air or fuel corrector. I know it's not the same, when running them on same plenum and with a progressiv links, is all new to me. I find the finding the right set up for two carbs on 3cylinders each complicated, but the for 4 carb on 1 cylinder each, much more "simple". So this is gonna be an Advanced carb projekt for me. I dont wants to run 3 dellortos on this build, because since I'm using a 1928 Chevy, and going for a traditional look, they simpelt dosen't fit the time frame.
Easy way would be to measure the diameter of the throttle body inside, and adapt a carburetor of the same area. Harder would be to use 2 carburetors and modify the manifold. Don't overthink it, get the same size as stock and you will be close.
The throttle body diameter is likely quite a bit larger than any 1bbl carb. Depending on how the bottom inside the manifold looks, it might work OK with two carbs mounted on it. Mixture distribution will probably be a bit off, since the manifold was not designed to have fuel in it.
He wasn't talking about a 1 barrel. If he wanted it to work right and be engineered and tested for the motor he could buy the stock 2 carb setup. But, that is not what he wants. I am not sure why he wants to use a carb that from a design standpoint is 80 years old and has been out of production for 60 years but that is what he wants.
The stock two carb set up, is as you say designed for the engine, but i stand to loose the power increase the motor is build to make. The intake isen't the only difference, between the two engines. And the engine is designed to be in a luxuary car, driven in style and be comfy. Not made to be driven like at Hot Rod, but this can be fixet. They have a great power potential and I have three I wants to put the test. And regarting the choise of carb, this is not only the most used part, smack in the middle of my build-era, and it's also loved for it's purpose, potential and look. If it was a 1930 fix ideer with no real purpose, why do we se so many on this very site, and if is not obselite, since speedway started to reproduce them as the 9 super 7, there most be someone who thinks they work. And except them, Weber DCOE or IDF and the Dell'orto counterpart, they are the only carbs avalible in new around here. And the Webers is also more the 50 years old ind design and unchanged, because people wants them, just he way they are!! Carbs are old, and the people that wants them are getting fewer. If this sounds like a rant, my appologies. But that is the reason for my choises. I'm going for a fiftys look, and I'm starting with a 28 Chevy with no body, a Volvo engine from under my bench. And junk yard parts for the rest. Like in the older days. It will be running Chevy AD axels and brakes. The old Volvo will be dressed for the part/look. Bodywise, I might have found a nice 32 Chevy Pick up cab missing wood, all steel is there. But I got a car crush, on a boat rail speedster build on a 1929 frame on here; What exately am I buying. So i might change to that body style, but keep frame like the first plan, sort like and old racer got updated for some street use.
I don't need to buy the stock set up, I got one, but I'm gonna run the two carbs on a modified 2 liter 4 banger. So they are out of the picture. The 130hp and the 165hp engine are both 3liter straight sixes, but the 165hp is fuel injected, high compression, big valve, semi ported head, with an improved distributer (better curve) and hotter cam. And a split exhaust manifold, that's separered from the intake. And with more aftermarked exhaust choises. So engine wise this is the Best choise, for me at least. But the choise of carbs is importend, and I like the look of the 97. The fuel injection should work, but parts cost a arm and a leg. But it dosen't look good, it's a med of wires, pipes and hoses, not good looking at all.
Or should I build something like the marine intake, and run three carbs on it? But three strombergs would be overcarbing, right?
My deal with the Chevy 235, is not happening. So back to my Volvo engine. I'm thinking about milling my intake down and mount a 4bbl on center top, something like a Carter afb. Or would that be even more work then the Stromberg intake? Would it be possible to use one from, say a 200ci mustang, and just jet it down? How do I find out what cfm to shoot for, when close to no-one plays with thiese engines any more, or go injected with turbo.
You probably want around 300 to 350 CFM for a single carb. You could try modifying the manifold to make it fit, perhaps mill it flat and open up a hole big enough, then make an adapter flange to fit the carb on, and epoxy/screw the two pieces together. I've seen that done successfully, although not on an EFI manifold. I would be a little bit concerned about fuel distribution, since the manifold is designed to only flow air, not an air/fuel mix.
First off carbs on not sized by jets they are sized by air flow, CFM ratings are not how much gas you get but how much air you get. You want to run a single Stromberg on a 181 cube motor, how many 221 inch Ford flatheads (that don't breath with a ****) are running multiple Strombergs? Get it running read your plugs and go from there. Its just tuning.
Okay, so break it down for me. I'm use to fixing stock carbs, singles or dual set up. I tinkered with Webers and Dell'orto's, 4 bangers with two carbs, on IR manifolds. I'm a skilled mechanic, and understand most of the things you tell me. But if you only say no, I learn nothing. So School me! Three statements: 1. I thought you match carb size to displacement, jet for fuel amount in three systems (idle, midle range and accelerate). 2. And CFM was a simpler way of saying engine flows x-amount of air, and carb must flow in that ball park. 3. Strombergs carbs comes in about 8 millions variations. For this purpose there are thise types I would like to use. 97, 81, 48 and WW. For the looks departement, this is what I like. But could put a Holly 2bbl on and hide with the stock air cleaner. With around 300 cfm. Like the ones on Summit Racing homepage. If you are to far off with ti, it won't even start. So before I go out and by anything, I just like to know about, how you go with jetting. Because commen plenum manifold set up is new to me.
Your little mill should handle a Stromberg 97 just fine. CFM actually has to do with how much air the carb flows and not the engine. There is a lot that needs to be taken into account of course when deciding the CFM size of your carb, plenum size for one as well as how deep a breath your engine is capable of taking, and etc. You can increase port velocity by decreasing the throat opening @ the throttle blades, but if you pinch it too much you are hurting yourself and increasing the throat at the throttle blades too much can actually kill port velocity all together, its a balancing act. Never the less your little mill should handle a single 97 just fine. You'll still need to tune it but that is no hill for a stepper.
a 3 liter you should be able to run 3 two brl strombergs easily i ran a 600 double pumper on a 3.1 chevy V6 an 500cfm 2 brl on 2.5 fords, 2l toyota and 2brl holley/weber on 1.7 toyotas the biggest challange is mid range you have to play with the power valves so that it's not too rich
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