b230 problems.

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bmw2101
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Blev medlem: tis feb 16, 2021 9:33 pm

Re: b230 problems.

Inlägg av bmw2101 »

Je probably a bit out of my price range unfortunatly.

PSA ill probably make one myself then out of mind steal, i had one made years ago for my lada for a single 45 out of steal, that worked really well. We have a cnc laser at work, and i am a fabricater for job... Just it takes time. I was looking today, 40mm exhaust tube, and 51mm tube will do the job really well.

will keep you all posted! thankyou!
Baxman
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Blev medlem: ons dec 17, 2008 10:49 am
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Re: b230 problems.

Inlägg av Baxman »

Mikuni HSR carbs on a Volvo Penta manifold will be good.
http://www.v-performance.com/products/air_fuel.html
bmw2101
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Blev medlem: tis feb 16, 2021 9:33 pm

Re: b230 problems.

Inlägg av bmw2101 »

thanks! they look nice!


I have bought the strombergs now, and also today i priced up with a firm local to get a cnc cut inlet manifold made for them, and its not worth my time to make my own, its extremely cheap ! I think he will do the linkages aswell if i ask him! I hope this unlocks some power from the engine.
Baxman
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Re: b230 problems.

Inlägg av Baxman »

You are welcome and yes they do, don't they?

Good. The Strombergs are VERY underrated carburetors IMO. People have flowed them to about 240 CFM, but they can be "ported" and improved to flow about 300 cfm. The most important part is getting the needle profile right to get the AFR in the ballpark. Racing engines uses weak springs, no damper oil and very thin needles for maximum respons.
psa
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Blev medlem: lör apr 21, 2012 9:21 pm

Re: b230 problems.

Inlägg av psa »

I would have to agree, that old design was a homerun in many ways.
I have never flow tested them, but have modified a lot of them over the years.
I would actually take it a little easy with the spring and see how it is, even if you get the fuel curve to work both during acceleration and at steady speed, the slight softness in throttle response actually behaves as a mild traction control.
But the needles are probably going to need some work either way.
bmw2101
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Blev medlem: tis feb 16, 2021 9:33 pm

Re: b230 problems.

Inlägg av bmw2101 »

is there a factory inlet that suits them? Im just wondering.. ?


These 2 i have will fuel properly im very sure.... I cant wait to get them on the motor.


was looking at a mates triumph stag v8 today, and it only had cd150s on it !!
psa
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Blev medlem: lör apr 21, 2012 9:21 pm

Re: b230 problems.

Inlägg av psa »

It depends on what you mean, there's the twin solex manifold for Volvo Penta but they are not the same, and for modifying a stock the regular A manifold is probably the best. Some take off the entire face of the A manifold and weld a plate in its place, I welded short tubes and individual plates to them. I'm not sure which is best.
bmw2101
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Blev medlem: tis feb 16, 2021 9:33 pm

Re: b230 problems.

Inlägg av bmw2101 »

does the penta one not fit the head? i just found one on ebay locally its not dear as i thought it would be. I could modify the flange easily enough.

Bild
psa
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Blev medlem: lör apr 21, 2012 9:21 pm

Re: b230 problems.

Inlägg av psa »

It should fit, they used the same base engines. It's only the medium sized diesel engines that they make entirely on their own.
If it's easier or not to work with that manifold I can't tell, I've never seen one up close.
Thunderbo1t
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Re: b230 problems.

Inlägg av Thunderbo1t »

Baxman skrev: lör apr 17, 2021 1:55 pm You are welcome and yes they do, don't they?

Good. The Strombergs are VERY underrated carburetors IMO. People have flowed them to about 240 CFM, but they can be "ported" and improved to flow about 300 cfm. The most important part is getting the needle profile right to get the AFR in the ballpark. Racing engines uses weak springs, no damper oil and very thin needles for maximum respons.
If you use no damper oil, would it not act as it has no accelerator enrichement, and just bog down? Or could the thinner needles compensate so much? Midrange throttle would then be pig rich? Just curios :wink:
quattro
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Blev medlem: sön mar 01, 2009 2:47 pm
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Re: b230 problems.

Inlägg av quattro »

If you use no damper oil, would it not act as it has no accelerator enrichement, and just bog down? Or could the thinner needles compensate so much? Midrange throttle would then be pig rich?

If I remember correctly that's exactly the case. But this relates to SUs a long time ago, so it might not be fully applicable to modern Strombergs...
Anyway, When you step on the accelerator with no damping oil, the "cylinders" will fly up immediately and air will come rushing in. Since air is much lighter and more easy to move the air will outrace the gasoline wich results in a weak mixture.
With damping oil the cylinders will rise much more slowly. The velocity of the air passing through the opening will increase significantly during a few seconds. Thereby creating a much higher suction force which will increase the amount of gasoline in the air and thereby create a richer mixture.

Getting this kind of carburators to work well is a question of balancing how easily and quickly the cylinders will rise with the design of the needles. That getting rid of the oil would be part of the solution sounds strange to my experience (based on SUs). But stronger springs might well be.
That response time will suffer is inherent in the design, but also a question of getting the right balance.

On the other hand, since the need for accelereation enrichment is related to engine speed, I don't think that an engine that spends most of it's time at high revs would be that much affected by quickly rising cylinders.
bmw2101
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Blev medlem: tis feb 16, 2021 9:33 pm

Re: b230 problems.

Inlägg av bmw2101 »

well ive got my manifold now, im well happy with it, just need to mod the flange to get the carbs to fit and also to make a linkage for it.

MANIFOLD
Baxman
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Re: b230 problems.

Inlägg av Baxman »

Thunderbo1t skrev: sön apr 18, 2021 12:54 pm If you use no damper oil, would it not act as it has no accelerator enrichement, and just bog down? Or could the thinner needles compensate so much? Midrange throttle would then be pig rich? Just curios :wink:
In a stock carburetor, yes it would. The stock needle profile is correct for a mild stock engine running high AFR and one needs damper oil then going from low load, high vacuum to high load, low vacuum to avoid a lean bog. For an engine modified for track use, this changes and some racers in England are running without damper spring and without damper oil but they have to use a needle developed for this.
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