Can, or how, do I fit two carburetors to one model T engine?

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Model T Ford Forum: Forum 2012: Can, or how, do I fit two carburetors to one model T engine?
Top of pagePrevious messageNext messageBottom of page Link to this message  By Matthew Atchinson on Friday, October 19, 2012 - 06:15 pm:

Hey guys,

So while i've been at college and my poor little T sitting unfinished in the garage at home, I have been thinking of ways to increase the output of the car on a budget. I happen to have two Holley NH carbs at home: one is useable and could go on the car right now. The Other I would need to send off to refurbish or do it myself. My question is this: I have heard of putting two carbs on the car: sending an intake pipe to two pistons per carb. Is this even possible? If so, how would I go about this? Would it really increase the output of the car that much? I'd like to eventually get my speedster going in the 50-55 range so that traffic wouldn't kill me. I would love to rebuild the engine professionally with new parts replacing the old, high compression head, etc when I get the money, but for now i'm fine with a budget solution to power. Two carbs would severely lower gas mileage too yes?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jim Thode Chehalis Washington on Friday, October 19, 2012 - 06:28 pm:

Matthew,
I'm sure you could mount two carbs on a Model T but you would likely see no increase in power. As long as T's have been around and as many made you can bet that is adding a carburetor increased the power, then it would be a common modification.

Increasing the compression, displacement and making it breath better will increase the power. If you tune an original T very well you should get over 50 at little cost.

Jim


Top of pagePrevious messageNext messageBottom of page Link to this message  By Terry Woods, Katy, Texas on Friday, October 19, 2012 - 07:17 pm:

Matthew, A much better and easier alternative to fabricating a special manifold to mount two NH's, would be to simply use a Winfield or Zenith manifold and use a Model A type updraft carb or another updraft such as a Stromberg OE-1. I have taken two Model T manifolds and cut and brazed them together along with a short piece of iron pipe, the same size as the manifold passages but didn't ever use it when I learned of the alternatives. To get the speed you want, you're going to, more than likely, raise the compression of the engine by milling the head; using an aftermarket head, or using high compression pistons. Don't forget about improving your brakes, also, or you're inviting an accident.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mike Garrison on Friday, October 19, 2012 - 07:32 pm:

Talk to Clayton "Mr Model T" oh crap I can't think of his last name. Somebody help out here please!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mike Garrison on Friday, October 19, 2012 - 07:34 pm:

Paddison? I know the spelling isn't right!


Top of pagePrevious messageNext messageBottom of page Link to this message  By mike_black on Friday, October 19, 2012 - 07:46 pm:

Mathew,
Get your speedster running/drivable and go from there. I've got two speedsters, and IMHO the biggest "go-fast-cheap" thing is weight and wind resistance. On one I built a boat tail body (I even made doors for it)with 1/2 of windshield(offering some passenger wind protection), then a full hood and front fenders, then splash aprons and running boards, and finally some home made rear fenders. At 50-55, those front fenders are like holding up a sheet of plywood. To see the difference the excess weight makes, go for a ride in a touring car alone, then add 3 more adults and travel the same route. I'll still run 60+ with 2 adults, but, that's because of the things that cost money! The "real" speedster without the excess weight and wind resistance, got me stopped by an AR Trooper years ago doing 82. I was loosening her up for a 200+ mile run on the interstate. You can see the difference in the two. Power settup is similar--downdraft carb, elec fuelpump, ported for altered "B-model" manifolds, alum oversized pistons,high compression head, distributor, oil slingers where the magnets were, eng and trans balanced, muncie trans, Ruckstel with high speed gears, 21 in model A wire wheels, and lowered front and rear. One has 18 in knobbys on the rear and an oil pump, and one has hyd brakes.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Walt Berdan, Bellevue, WA on Friday, October 19, 2012 - 10:34 pm:

Two friends of mine have gone the two carb route. They made short (about 3") stub manifolds and both chose to use the new Kohler carbs that are sold as replacement carbs for a T. Both cars also have had the engines balanced and use Z heads, they run very nicely with good power and more speed than I trust with 2 wheel brakes (60 easy).

Walt


Top of pagePrevious messageNext messageBottom of page Link to this message  By Terry Woods, Katy, Texas on Friday, October 19, 2012 - 11:19 pm:

To elaborate on the manifold that I mentioned that I made earlier, I cut the center section (the part that points downward) from a stock manifold and brazed the two ends left over to a short length of black iron pipe with the same size diameter as the manifold ends. Then I used the carb mounting flanges and about 1 inch of the manifold between the flange and where the manifold starts to turn upward (cut from two separate manifolds). I drilled two holes in the 1 inch black iron pipe and after radiusing the carb mounting flange stubs, brazed them to the black iron pipe. I was proud of the work that I had done, but I still had linkage to make and progressive linkage was going to be a nightmare. I know that you are trying to do this on a budget, but there has to be a cheaper, easier way to accomplish your goal. For me, it was using a Model A or B intake (I was lucky enough to find a reproduction one cast from aluminum) and are using a Stromberg OE-1 carb rebuilt by Stan Howe which is so pretty, it ought to be hanging on a wall or in a glass shadow box, and a Model B exhaust manifold. Of course, you need to use the special spacer that is sold by vendors to align the manifolds with the ports on the T block and they don't give them away, but if you spring for one of them, Model A intake and exhaust manifolds are a dime a dozen in most parts and I have a Model A Tillotson carb, I'll offer you for free.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bob Cascisa - Poulsbo, Washington on Saturday, October 20, 2012 - 12:17 am:

Here is a dual NH set up I saw at Richmond.

Be_Zero_Be


Top of pagePrevious messageNext messageBottom of page Link to this message  By Erich Bruckner, Vancouver, WA on Saturday, October 20, 2012 - 12:25 am:


Top of pagePrevious messageNext messageBottom of page Link to this message  By kep NZ on Saturday, October 20, 2012 - 03:42 am:

Hey that yellow '26 with the '28 chev' 'head looking thing on it, Do you need to modify the firewall when fitting one of those 'heads?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Richard Wolf on Saturday, October 20, 2012 - 06:21 am:

A friend of mine had a twin carb setup, he made, on one of his cars years ago. Never heard if it worked.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dan Treace, North FL on Saturday, October 20, 2012 - 10:04 am:

May be easier to use one bigger carb, and spend some time on headers for exhaust and intake. Getting 2 carbs to link up is some work.

Having the 20hp T 4 cyl to breath better will give you more power and speed.

After these mods, be sure to address the brakes :-)






Top of pagePrevious messageNext messageBottom of page Link to this message  By Erich Bruckner, Vancouver, WA on Saturday, October 20, 2012 - 10:27 am:

Here is another option for a single carb.

http://www.flickr.com/photos/bruckzone/7986383522/in/set-72157631538061038/


Top of pagePrevious messageNext messageBottom of page Link to this message  By Charlie B actually in Toms River N.J. on Saturday, October 20, 2012 - 10:35 am:

Just remember if you put more in you really have to get more out. Exhaust wise that is. So to really experience the added power exhaust system mods would be needed too. Dan's "header" set-up is a good example. The results could be disappointing if you just add a carb and there's nothing simple about it. The most telling thing has been mentioned above: there's no 2 carb manifolds available.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Erich Bruckner, Vancouver, WA on Saturday, October 20, 2012 - 10:39 am:

There is always a limiting factor. Bigger valves will be needed at some point to get more gas into/out of the engine.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mike Robison on Saturday, October 20, 2012 - 01:34 pm:

Thanks Erich for posting the Twin NH set up. I was going to go to My Uncles to snap a photo. That manifold and linkage he made. The Linkage is progressive linkage. He said it really made his Model T fly but pulled it off because one carb wasn't level and always leaked.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Frank Harris from Long Beach & Big Bear on Saturday, October 20, 2012 - 06:01 pm:

I have dual throat down draft Stromberg 97 that works very well. We rotated it 90 degrees so that each throat provides a mixture for each bank of two cylinders.So it works as if we have two carburetors. We put out 48.6 horsepower with a T crank and a flat head with a Bosch 09 distributor with hand cranked advance.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Matthew Atchinson on Saturday, October 20, 2012 - 11:08 pm:

Thanks for all of the responses guys. It sounds like due to the difficulties of getting two carbs to work, I may just look for a period correct carb that woud give good results: maybe a 4 ball or kingston or something? I know the early model NH's apparently had better flow due to open mouth without the bridge piece in the middle. Are there any other ways to increase output cheaply? Thanls for the input on the weight. I do plan on making it very light and reducing wind resistance in a period correct style,


Top of pagePrevious messageNext messageBottom of page Link to this message  By Wayne Sheldon, Grass Valley, CA on Sunday, October 21, 2012 - 05:55 pm:

My gray race car I used to have had valves as big as can be put into a T block, so it breathed really well. I put a brass bowl Carter carburetor from a mid'20s Ch##y on it. Best performance I ever saw from a proper vintage T Ford stock head.
They are common, and fairly cheap (and vintage).
Drive carefully, and enjoy, W2


Top of pagePrevious messageNext messageBottom of page Link to this message  By Erich Bruckner, Vancouver, WA on Sunday, October 21, 2012 - 07:53 pm:

Mike, I thought that was a very clever intake idea.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bob Robb on Sunday, October 21, 2012 - 08:23 pm:

Dual carbsThese are a pair of one-barrel Zenith downdraft carbs off a 1930's IHC Marine Engine, mounted on a homemade intake manifold made from a section of fence post purchased from Lowes Home Improvement Center 5-years ago.
The T has a Wakesha Richardo head, distributor, stainless valves, hard seats and aluminum pistons, and runs better than any T I've ever driven.
No trouble after I silver-soldered the jets closed and re-drilled them (twice) to get the right fuel mixture.
You could mount the two NH Holleys on the side of the fence post, would look great too.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Roger Karlsson, southern Sweden on Sunday, October 21, 2012 - 08:57 pm:

Here is a thread with homemade headers for speedsters: http://www.mtfca.com/discus/messages/29/46038.html?1205330875
In the thread Kent Sumner showed his homemade intake for double Holley NH's:
double nh:s

You can buy headers for the T from Red's Headers in California ($175): http://reds-headers.net/index.php?main_page=product_info&cPath=1&products_id=798


Top of pagePrevious messageNext messageBottom of page Link to this message  By Erik Barrett on Sunday, October 21, 2012 - 10:29 pm:

Matthew,
Don't be afraid to try a dual carb setup. I have built two speedsters with dual NH Holley carbs. High compression flatheads with T cranks and stock cams. They run great, are period correct and look cool.. If I were to build another I would include a balance tube between the intake runners. I can post photos if there is interest. My exhaust system is four "zoomie stacks" about 16" long. It is not as noisy as you would think. There is a limit to how much you can improve performance without serious modifications to the cam and valves, as well as compression ratio.. It is all possible, just takes money.
Fordially, Erik


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tony Bowker on Monday, October 22, 2012 - 01:13 am:

Slightly off topic but today we had our annual speedster run, 25th version and we had several car with more than one carb. The most impressive was that of Dave Parker from AZ who had two 2 1/4 inch devices attached to his block. It must work, he won...
Twin Dual Engine, twin Carbs, coils, seats


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