Dual carb?

Jonah D'Avella · Post by **Jonah D'Avella** » Wed Feb 10, 2021 8:39 am

Has anyone figured out how to put dual carbs on a t? You obviously would need a special intake manifold.

Post by **TRDxB2** » Wed Feb 10, 2021 11:25 am

Yes, they have either by making their own intake manifold or adopting a dual carb intake manifold for a Model A with an adapter plate between the T engine and the A intake. Then the linkages to them and between them get to be a bit complex. What goes in needs to come out so the exhaust system needs go be modified as well.
Adapter plate https://www.modeltford.com/item/MAN-A.aspx
Model A Dual Intakes https://www.secretsofspeed.com/intake-manifolds
What's been done
http://www.mtfca.com/discus/messages/25 ... 1350882805
http://www.mtfca.com/discus/messages/17 ... 1324432042
http://www.mtfca.com/discus/messages/70 ... 1499433883

Jonah D'Avella · Post by **Jonah D'Avella** » Wed Feb 10, 2021 8:56 pm

Ok. Is splicing two ntake manifolds together very dificult?

Post by **TRDxB2** » Wed Feb 10, 2021 9:14 pm

Jonah D'Avella wrote: ↑
Wed Feb 10, 2021 8:56 pm
Ok. Is splicing two ntake manifolds together very dificult?

I'll let the others with the proper skills respond

ModelTWoods · Post by **ModelTWoods** » Thu Feb 11, 2021 2:06 am

Back in the 70's when I was still welding and brazing, I took two iron manifolds; cut the curved ends of off one just after it straightened out to go to the center; brazed in a length of black iron pipe the same size as the ends and brazed everything in place so the finished product had the same measurement between ports as original; cut the carburetor flanges off both manifolds just before they started their vertical upward curve; then brazed them onto the new manifold so the two carb flanges were level and pointed straight out toward the hood sides. Mounted two rebuilt NH swayback carbs on it and hooked the throttle linkages on both together as one (not progressive). This was before I knew that there were single aftermarket carbs out there that would run as good as the crap that I had spent so much time and effort, cobbling up. All this wasted effort for nothing. Get yourself a good Stromberg OF or use a Model A Zenith intake, carb, and exhaust and save yourself some grief.

Jonah D'Avella · Post by **Jonah D'Avella** » Thu Feb 11, 2021 6:02 am

Couple questions, first what is a swayback nh and second, did you leave this arrangement in your car for a period of time and did it work reliably without cracks or fractures along the welds?

John Codman · Post by **John Codman** » Thu Feb 11, 2021 9:35 am

Just curious - Is the engine in the OP modified? I don't see what would be gained by adding another carburetor to a stock T engine (except a complicated carburetor linkage, two mixture rods, and a PITA to keep the mixture adjusted properly). Aggravation equals the square of the number of parts in the assembly. I have never heard anyone suggest that a stock T engine is undercarbureted.

Post by **walber** » Thu Feb 11, 2021 11:15 am

Without other changes, a second carb would provide very little if any benefit. A good buddy of mine has a great running T using 2 carb but he also massaged the intake ports, uses larger intake valves, a Sherman 8 to 1 head, performance cam, stroker Scat crank, and dual exhaust. Runs real strong. Changes to carburetion, cams, and compression need to be balanced.

Post by **walber** » Thu Feb 11, 2021 12:53 pm

Jonah - A swayback NH is the typical and most common version of the NH carburetor.

Erik Barrett · Post by **Erik Barrett** » Thu Feb 11, 2021 2:45 pm

Dual NH carbs on home built manifold.

Jonah D'Avella · Post by **Jonah D'Avella** » Thu Feb 11, 2021 3:09 pm

No muffler?

Tim Williams · Post by **Tim Williams** » Thu Feb 11, 2021 3:20 pm

not usually on a speedster.

Tim

Jonah D'Avella · Post by **Jonah D'Avella** » Thu Feb 11, 2021 3:23 pm

Would that be very loud?

Erik Barrett · Post by **Erik Barrett** » Thu Feb 11, 2021 3:25 pm

It’s not a noisy as it looks. Most Harleys running around make more racket. When I gave the setup to my brother he wanted it quieter so I made baffles by rolling up some expanded metal screen and stuffing them into the pipes.

Post by **DHort** » Thu Feb 11, 2021 3:38 pm

Jonah, there are also straight through NH carbs. Perhaps someone will have pictures to show you the difference.

The muffler on my T is a tractor muffler. YOu can see right thru it so I do not know if it does a lot. A friend of mine does not use
a muffler on his Speedster. All he has is a long exhaust pipe. If he got stopped he would probably tell the cop that that is the
way Ford made his particular vehicle. How much it helps to have a muffler on a T engine I would not know. Maybe someone will
post if he really helps your performance.

Post by **BE_ZERO_BE** » Thu Feb 11, 2021 3:57 pm

Here is a dual NH setup.

Jonah D'Avella · Post by **Jonah D'Avella** » Thu Feb 11, 2021 5:03 pm

How much difference would a straight through run?

ModelTWoods · Post by **ModelTWoods** » Fri Feb 12, 2021 12:49 am

Jonah D'Avella wrote: ↑
Thu Feb 11, 2021 6:02 am
Couple questions, first what is a swayback nh and second, did you leave this arrangement in your car for a period of time and did it work reliably without cracks or fractures along the welds?

A straight through Holley NH can be easily identified. With both the throttle and choke levers and plates, wide open, you can look straight through it with no obstructions. A swayback with the choke and throttles wide open will have a part of the casting around the needle valve blocking the view. Because I only had a pair of swaybacks and not a pair of straight throughs, and because the motor was completely stock (Cam, Head, Pistons, and Exhaust), the results were unsatisfactory. I'd been time and money ahead using a Model A intake, exhaust, and carb.

Post by **DHort** » Fri Feb 12, 2021 1:57 am

Terry meant straight through NH in that first sentence.

I believe the straight through is less common so it is a few dollars more, but not always. You would be better off saving your money for a Stromberg OF or similar carburetor. Stan is not selling right now, but Russ Potter may have something available.

Post by **speedytinc** » Fri Feb 12, 2021 1:40 pm

I built a dual nh side draft unit for my 27 roadster p.u. WHY? -i wanted more carburation than stock, period correct, NO FUEL PUMP, different look.i could not find pix of anything like it. so i invented one, and it had to fit under the full hood. Uses 27 vaporizer exhaust manifold capped. exh runs out thru center vaporizer plate and down. intake is made of 2 stock intake manifolds.one manifold has elbo section cut off to log. spine of removed piece was cut to fill the opening & brazed in. looks like a winfield up draft manifold without intake spigot. 2 carb flanges are mounted just inboard of intake ports. unit mounts upside down like that winfield manifold in downdraft congiguration. throttle arms linked & syncronized.
only weird thing - a little fuel slops out carb bowl breathers in a hard left turn.

Performance - had it to 70, feels like it would go faster. ran out of open freeway & i could feel my soul starting to leave my body. loves crusing 60 all day.
of course, motor has distributor, cam, hi compression head (6.5-1 lizzard), big valves, porting, rux with 308 gears, full balance engine & trans.
This carb setup lacks the kind of performance snap a previous version ran with a vw carb. less snap may add longjevity. but, no fuel pump & way cooler.

Before the nay sayers start churping: the front end & steering are restored, tight, front axle has more rake. runs straight arrow at speed.
(before addressing the front end, she had a mind of her own @ 60.)

A few of the o.c. club drove up to the national tour above frisco. this was the only one to make it up & back. not even a band adjustment.

Post by **MrTwT1915** » Sat Feb 13, 2021 3:45 pm

Here is my setup with two straight through NH's. Inlet ports have been modified to give 4 intake ports.

matthewejacob · Post by **matthewejacob** » Sun Aug 21, 2022 12:40 am

I know this thread is old but I though I'd post my setup on here too. finding info on dual carb setups is a bit challenging and finding pictures is even harder. Mine is stock except the custom header and plate. I cut off a couple flanges off some intakes i had laying around and welded them to the plate. I have dual NH's as well. they run pretty good but not a whole lot of tuning going on there! I couldn't get enough velocity to pull fuel in without making a tube for the air to pass though. I'm curious how to be able to get it work without the tube. nothing i have tried seems to give me enough air flow. maybe it's because i have the carbs so close to the intake ports. but none the less here are some pics. I half wonder if that equalizer tube is actually causing issue. if it's pulling air from there instead of the end of the carb i'd lose some velocity. if i moved it to the front it may change it enough to let it run. any ideas would be welcome. i'd love to get rid of that tube in front.

Post by **Chad_Marcheese** » Sun Aug 21, 2022 7:17 am

Your balance tube between the intake stubs needs to be bigger. That much I can say, and you need to make it a minimum of approximately 5/8- 3/4 of your intake stub size.

So if your intake port is 1.25", your balance tube needs to be about 7/8" to 1" OD exhaust (or copper) tubing---I use that because it is thin wall. If you do that, you can probably get that setup to work well. I have seen where intakes are made with the same size tubing for the intake stubs and crossover, that's fine too. It just can't be tiny like the small copper tube you have now.

Post by **TXGOAT2** » Sun Aug 21, 2022 7:49 am

Adding a higher compression head with better combustion chamber design is probably the most cost-effective power modification you can make to a stock T engine, assuming you have an engine/transmission in good condition with aluminum pistons and in good balance. It's very important that the ignition system be functioning at 100%. Most stock T ignition systems aren't. Adding another carburetor to an otherwise stock engine could be expected to degrade performance and driveability. If you want a fast T, over 50 MPH, you need a better crankshaft to allow the engine to run safely at higher speeds and not waste HP shaking the car and rattling your dentures. Beyond that, for a road-driven car, a Model A intake/exhaust and properly selected camshaft, valves, and valve springs might be the best path forward. Attention would need to be given to maximizing oiling and cooling.

Scott_Conger · Post by **Scott_Conger** » Sun Aug 21, 2022 10:18 am

I applaud the creativity involved, but that is way too much carb and way too little pressure drop to run things with a stock engine.

If you're looking for "cool", you've got it. If you're looking for "GO" then find yourself a Zenith S4BF, Stromberg OF, or a U&J, then sit back and smile (yes there are other great carbs, but the 3 I mentioned are not too terribly hard to procure if you make an effort). The OF will mount directly on a FORD manifold, while the other two will require the correct matched manifold that came with them, making the OF probably the most economical choice overall.

Post by **TRDxB2** » Sun Aug 21, 2022 1:36 pm

Would some Model A intake fit?
Interesting setup on ebay for early Model A with dual Stromberg 97's https://www.ebay.com/itm/334324134204
https://www.ebay.com/itm/144537349698
http://www.reds-headers.com/html/model_ ... parts.html
--
--
Downdraft carbs, single or dual, may require a fuel pump since the position of the fuel bowl is likely going to be higher than the bottom of the gas tank. Linkage is another issue. The real question is why the question. Unless your planning on doing other engine modification, duals wouldn't help any.

Post by **speedytinc** » Sun Aug 21, 2022 3:22 pm

matthewejacob wrote: ↑
Sun Aug 21, 2022 12:40 am
I know this thread is old but I though I'd post my setup on here too. finding info on dual carb setups is a bit challenging and finding pictures is even harder. Mine is stock except the custom header and plate. I cut off a couple flanges off some intakes i had laying around and welded them to the plate. I have dual NH's as well. they run pretty good but not a whole lot of tuning going on there! I couldn't get enough velocity to pull fuel in without making a tube for the air to pass though. I'm curious how to be able to get it work without the tube. nothing i have tried seems to give me enough air flow. maybe it's because i have the carbs so close to the intake ports. but none the less here are some pics. I half wonder if that equalizer tube is actually causing issue. if it's pulling air from there instead of the end of the carb i'd lose some velocity. if i moved it to the front it may change it enough to let it run. any ideas would be welcome. i'd love to get rid of that tube in front.
IMG20220820174242.jpg
IMG20220820202951.jpg
IMG20220820203013.jpg

Did you say your motor is otherwise stock? If thats the case, 2 nh's are of no advantage. Too Low velocity until you get over 4000 rpm. Which you will not achieve until after the explosion. You are over carbureted.
To run those carbs you need to match the engine to them. High compression head, big valves & a performance cam, & balance work.

I have some pix of my dual NH set up on another computer. Stay tuned, I will post tomorrow. I have been running for 15 plus years.

Previous to them I ran a 28pict VW carb. Plenty of carb on a T. The T performed much noticeably better. Accelerator pump!
I removed it to 1) get back to "period correct", 2) The VW needed an electric fuel pump that needed replacing every other year. (they only fail in the middle of a long drive) 3) The snappy acceleration concerned me regarding pinion key strain. (I know I dont have the self control.)

Previous to my build, I couldnt find any pix of dual side draft NH's, so I thought I would build one.
The intake is made of 2 stock iron manifolds.($4 worth of parts) 2 intake flanges brazed on & the open, cut off section filled with a chunk of the second manifold. Exhaust is a capped off vaporizer manifold with exhaust out the center plate via some odd adapter(may be a tractor or sleeve valve motor) The mount pattern is a match. 2" exhaust pipe. Fuel levels are matched & carbs synchronized. I have 2 long mixture adjusting rods to set the carbs for max performance on the fly thru the windshield.
The motor sports a high compression iron lizard head, big valves, 280 cam, 3.07 geared rux & a Scat crank.
The T is a 27 roadster pickup fully loaded. Chassis tuned for speed.

Performance: Less than the single VW carb. There is a gain in top speed over 1 NH. (Has the ability to breath) She will do better than 70 once I get thru the harmonic imbalance spot. The motor prefers mid to higher rpm ranges(Fuel velocity I suspect), but generally runs well in the whole speed range.

Truth be told, performance is a bit disappointing, but it is a heavy T, not a speedster.
Performance with a different carb(s) would be better, but it is period, different, "cool" & "sexy" when the hood is up.

Post by **TXGOAT2** » Sun Aug 21, 2022 3:39 pm

I believe aero drag becomes a real problem with a stock bodied Model T when you get above 35 MPH. Horsepower demand goes way up as speed increases above 30 - 35 MPH. Add a headwind and it really goes up.

Post by **Steve Jelf** » Sun Aug 21, 2022 4:23 pm

I believe aero drag becomes a real problem with a stock bodied Model T when you get above 35 MPH. Horsepower demand goes way up as speed increases above 30 - 35 MPH. Add a headwind and it really goes up.

And when a big big truck passes you in the other direction, oh boy!

Post by **speedytinc** » Tue Aug 23, 2022 8:26 am

Pictures added of a dual nh set up.

Post by **Art M** » Tue Aug 23, 2022 10:17 am

Speedy,
Your engine looks very impressive. I wonder if a 290 cam would significantly improve performance. Not trying to re engineer your details. Just wondering about 290. Maybe there is a reason that I don't know anyone who has one.

Art Mirtes

Post by **speedytinc** » Tue Aug 23, 2022 11:12 am

Art M wrote: ↑
Tue Aug 23, 2022 10:17 am
Speedy,
Your engine looks very impressive. I wonder if a 290 cam would significantly improve performance. Not trying to re engineer your details. Just wondering about 290. Maybe there is a reason that I don't know anyone who has one.

Art Mirtes

Thanks Art
This motor has been an experimental exercise. As far as a 290 cam goes, if there was some different overlap/duration difference other than just .010 more lift, there might be some improvement. I dont know. It has a 280 with 1.75" intake valves. I figure flow volume wise I have a higher equivalent lift. maybe .310-.320. Was advanced 1/2 tooth until the cam gear broke. The next change, I may try advancing 1 full tooth, If those smarter than I think that it would run better. Cams are a magical mystery to me.

matthewejacob · Post by **matthewejacob** » Thu Aug 25, 2022 12:15 pm

Wow, didn't think i'd revive this old thread that much! Thanks for all the photos and comments. speedy, you are on the mark about the velocity. It dawned on me that I may have been losing vacume from that crossover pulling from the other intake and I went out there, removed it and it, plugged the ports and it fired right up. You are also right about the velocity at low rpms, I can't get it to "lope" real low like it did with that 1" copper but it idles low enough that it's acceptable for me. I'm not looking to build an actual racer, just though it would look neat with that set up. Money is always an issue and I'm trying to get it to a point where I can drive it, then start tinkering with the engine some more. I did put high compression pistons in my 25 depot hack and I've been really pleased with the results so I may either do that or get a high compression head for the speedster. (the head doesn't require me to crawl under it)

I'm glad to see a few more pictures on here of the setups. I think just letting it breath with the header and dual set up alone helped wake it up a little. It's way more responsive than a stock set up and i'm fairly content with it so far. But that may change once i drive it. I really wanted to get rid of that copper pipe, but... i may find that it just runs better on it who knows. I think the hardest thing about those NH's is that there just really isn't much fine tuning you can do with them. They love fuel and even the slightest adjustment on those mixture screws (especially with two of them) makes big changes.

I want to do a lot with it but baby steps. I have a body to build so right now my money is kind of being set aside to get that done but I needed to get it running first.

Post by **speedytinc** » Thu Aug 25, 2022 12:49 pm

I think a crossover is needed, but as another poster said, it must be larger. It will at least make carb setting less critical. My setup has it.

Re read what I said about carb tuning. Fuel levels exact match,(plastic hoses from the drain valves for a visual level match) syncyonizer used to set both idle screw stops, & 2 long mixture adjusting rods to set on the fly for best performance. Set & forget.

I had a crazy thought regarding you doing this on a "stock" motor.
Back in the day holly & edlebrock made a tripple carb set up manifold for ford 6 log manifolds. I had one on the wife's 63 falcon 6. You could make all 3 run or not cut the front & rear holes into the manifold & just run the center carb only. Looks real cool.

Why not set up a tripple NH?? run the center carb only. The outers would be for show only. wouldnt that be uber extremely cool on a speedster??

matthewejacob · Post by **matthewejacob** » Thu Aug 25, 2022 2:27 pm

ha. yes that would look really cool. I'll try and make some of those changes to see if i can fine tune it a bit more. It actually runs surprisingly well without the crossover. I'm like you, I thought it should be there as well. So i'll try to enlarge it and see if it makes a difference. problem is, once i do it, i can't go back! that was quite a bit of welding to get all that on there to start with. I wonder if I made sort of an H pipe to put in between the carb and the flange if that would do it or if it would look funny. not sure i have enough meat on those two flanges to cut out and inch hole in them. they are model a flanges at the header plate and model t flanges where the NHs are mounted and are welded together. I suppose i could just remake that whole thing as an H pipe and be done with it. it's just i'd have to cut those two flanges off and start over. or at least cut the model T flanges off and re-work that thing.

And Chad, thanks for pointing that out. I had no idea that it was to small. I'm gonna work on this weekend and see how I fair. I'll update once i get it going.

Post by **TXGOAT2** » Thu Aug 25, 2022 2:45 pm

I'd think a high compression head would be a better choice than high compression pistons, since the head would give both increased coompression and a better chamber design. Three carburetors?
3 NH, run on the middle one, one and have a vacuum servo to tip in the 2 outside ones at high speeds? Outside carbs could have throttle plates that shut tight to simplify idle mixture. Set outside carburetors mixture on the rich side and block the idle circuits.

matthewejacob · Post by **matthewejacob** » Thu Aug 25, 2022 2:59 pm

my other issue is i have that tubed header on there which is kind of a pain to work around. speedy, yours is probably ideal becasue you can use the existing clamps to hold the exhaust on. when i was thinking about this i originally thought about just using a model a exhaust manifold. then i thought, well a tubed header would look really cool on this. it just got out of hand really fast, and so here I am trying to make this all work.

txgoat, you guys are a bad influence! The next picture you may see is a third NH on there.... I really need to take baby steps. I should probably try to fix what i have first. I've been around Ts my whole life but this is first speedster i've tried to build. I really want to take it to the old car festival in MI next year so i'm trying to get it finished over the winter. I do have another NH laying out there. maybe once i get it going i'll start working on fabricating a triple set up. this it getting out of hand!

Post by **speedytinc** » Thu Aug 25, 2022 4:18 pm

matthewejacob wrote: ↑
Thu Aug 25, 2022 2:59 pm
my other issue is i have that tubed header on there which is kind of a pain to work around. speedy, yours is probably ideal becasue you can use the existing clamps to hold the exhaust on. when i was thinking about this i originally thought about just using a model a exhaust manifold. then i thought, well a tubed header would look really cool on this. it just got out of hand really fast, and so here I am trying to make this all work.

txgoat, you guys are a bad influence! The next picture you may see is a third NH on there.... I really need to take baby steps. I should probably try to fix what i have first. I've been around Ts my whole life but this is first speedster i've tried to build. I really want to take it to the old car festival in MI next year so i'm trying to get it finished over the winter. I do have another NH laying out there. maybe once i get it going i'll start working on fabricating a triple set up. this it getting out of hand!

I did choose stock manifolds because I could get it all under the hood.
I dont think an A manifold would allow the hood closing, but on an open speedster, I would have opted for the A exhaust manifold. A modified A intake that also picks up the hot spot would be good. Yea, 3 NH's in line, progressive linkage. Sexy!
You got me going now. I am going to pick up a few of them stock $2 T intake manifolds for the flanges & experiment a little.

Good luck. Fun aint it?

Scott_Conger · Post by **Scott_Conger** » Thu Aug 25, 2022 4:46 pm

Matthew, far be it from me to tell anyone what the definition of "fun" is, but there are some easily researched basics regarding carburetion which you are not taking advantage of.

The NH does not have an idle circuit beyond that of a primitive bubbler with no air control. The NH has a fixed venturi which cannot be tuned to the displacement of the engine, and believe me, there are some pretty hard rules governed by physics which are not working in your best interest.

Back when these cars were made, Zenith (for example) made a number of carbs which were generally dimensioned at the throat in around 4 different sizes depending on the vehicle's displacement. From there, each of those 4 different (throat sized) carbs were further broken down by a somewhat inflexible progressive venturi calculation (called the "choke" in the 1920's) based on the stroke and diameter of the pistons (and the "breathing" of the engine through the valves was calculated/designed by the auto manufacturer). The choice(s) of slow speed jets was by factory "suggestion" and had to be fine tuned to the car/cam. You have no such venturi or idle adjustments with an NH.

The venturi of the NH is proportioned to the swept volume of the "T". Adding another NH without reducing the size of BOTH venturis will create a car which will run better (if you're lucky) at very high speeds but tend to be a pisser at low RPMs (so, let's add yet a third NH?). Believe me or not when I say that CFM through the carb is NOT the determining factor for performance, but it is definitely true.

like I said, if piddling with these things is your thing, go for it, but I can't think of a much worse carb to start with, given it's design limitations. There were some really cool, beautiful, and importantly, POTENT accessory carbs made for "T"s which will make the thing really rock, with a good head and cam.

Post by **speedytinc** » Thu Aug 25, 2022 5:42 pm

Scott, you may have missed the point here. Mathew's motor is "stock". adding the second carb is more likely to make for poorer performance. 1 stock NH would be adequate for his motor as is. A better single carb would increase his performance, agreed.
My idea of adding the second & 3rd carb is only for cosmetics. (cool factor) & to lose the function of his second carb. These 2 extra carbs would not be hooked up. Speedster eye candy. They would cause more trouble & grief if made to function.

Post by **TXGOAT2** » Thu Aug 25, 2022 5:55 pm

Could smaller, Briggs Stratton bowl-type carburetors be an option? Or maybe variable venturi carburetors off an MG or Triumph?

Post by **TXGOAT2** » Thu Aug 25, 2022 5:58 pm

If you had a crank and rods that would allow 3400 RPM, you could use 2 or 3 carburetors to good effect. 60-70 HP?

Post by **speedytinc** » Thu Aug 25, 2022 6:29 pm

TXGOAT2 wrote: ↑
Thu Aug 25, 2022 5:55 pm
Could smaller, Briggs Stratton bowl-type carburetors be an option? Or maybe variable venturi carburetors off an MG or Triumph?

Sure, why not. It depends on what the goal is. Period correct, functional, full out race?
Adding a second carb adds a lot of hassle over one. Linkage, synchronization, jetting, etc.

I like the potential functionally of a modern pre fuel injection harley carb. Variable venture. From T sized to huge, but its far from period.
That would be on a full race overhead.

matthewejacob · Post by **matthewejacob** » Thu Aug 25, 2022 8:45 pm

Scott, I understand what you are saying. I was just trying to keep it period correct looking, I may forgo that with the NH's for reasons you were stating. they are just very crude carburetors. I'll say more about this further in. Yes, it screams at higher RPMs, sounds great. But lower rpms its pretty doggish.

So a few more thoughts, tonight I made the crossover pipe almost an inch in diameter. had no effect. still won't pull in fuel. it may just be the limitations of the NH. can't get enough air across to pull fuel in. so... my thought is this. I want it to run well, not JUST be pretty. I want that too, but you can't always have your cake and eat it too.

I have two brand new walbro carbs. they are just kohler twin cylinder carbs. they are similar to the carbs mac's sold a while back that are no longer available. just looks like they've had minor updates. those things have a low and a high adjustment, much more fine tunable. and they are made to bolt directly to the head so velocity, theoretically, should not be an issue. I found one guy that has done this. still looks cool, but you can tell they are modern carbs. I may go this route, in fact, i'm gonna try it just to see how it behaves.

The thing will run fine without the crossover, it's just much harder to adjust them and get them in sync, if that's really possible with and NH. i either have the front two cylinders richer than the back two or visa versa. it's just kind of a cat and mouse game. I love the way it looks, but I just don't think the trade off is worth it.

It's eventually going to get a new high compression head but there is so much other stuff i need to do first. I'm curious about pistons vs head. my 25 has HC pistons. it runs well, but honestly i often wonder if i made the right call. my grandpa's has a scat crank. and that made a world of difference. it's smooth, it pulls up hills nicely. just really transformed the car. I'm eventually putting one of those in the speedster. the hack doesn't really NEED it. I can only afford to make that purchase once. but all that is down the road. I understand on a stock motor dual carbs are more eye candy than anything else. But it will look good!

you guys have all been a great help. I don't know what we would do with these forums. I've solved many a problems on here. just the first time i've actually posted. I'll keep coming back here to post the progress just so it's noted somewhere for others to stumble on.

Post by **TXGOAT2** » Thu Aug 25, 2022 9:02 pm

The Model A had a sort of rams's horn intake with a single carburetor. They worked well for low speed torque. Would a split rams' horn arrangment work better for a performance engine? Instead of a single, shared riser, have separate "horns" for each port, and 2 carburetors close together on separate risers, with the diameter and length of each horn and riser tuned to suit the engine?

matthewejacob · Post by **matthewejacob** » Fri Aug 26, 2022 9:41 pm

had a chance to put the new carbs on. world of difference and it runs with the crossover tube on it now. much more tunable. I have to get my radiator fixed so i can run it long enough to tune it. that's another issue. its a honeycomb rad from the 1910's and no one around here seems to know how to fix it. has one small leak on the side. anyway, different issue. here is a pic of the set up now minus the tube. i have to make a proper one. this, i think is doable.