I've had this on the shelf for a while now and I am thinking of having it rebuilt for use on our 27 speedster. If someone else here has or is running one of these Id love to hear your comments, Thanks.
You will go ZOOM like you can't believe. They were pretty expensive when new and hard to find now. In the 70's Townsend Automotive made a T manifold that mounted a SO4 -- which is a similar carb that was stock on some Chevys in the 20's -- they run OK but not like a S4BF does. The biggest problem with them is that, like all Zeniths of that vintage, they have a pot metal Venturi that has probably deteriorated by now. I have to machine new Venturi for any of the Zeniths. Not a big job but the old one has to be pressed out and the new one pressed in.
This is one I did last winter, I just did a matching set for a guy in North Carolina, must not have taken any photos of them before I shipped them. Can't find them anyway.
I often find old dirty carbs in boxes at swap meets. Is the intake flange the only dead giveaway to know that its for a T?
F in the model number is good:
Stan, Thanks for your insight!
Here's a pamphlet from the period.
Thanks for the Pamphlet, Jay. Another carb that really runs on a T is a Zenith HP4A or 4S. A lot of speedster guys like the HP5A but it is a little big for a T. The 5A is rare the 4A is even rarer and the 4S is made from unobtainium! I've only seen three or four of the 4A and 4S. They will fit in where the standard T carbs go and will really light up the Zoom! Have to make a manifold adapter but that is no big deal.
I just did an HP5A for a guy back east but must not have taken any pics of it.
Thank you Jay for the interesting accessory. I always enjoy them and keep wondering when you are going to write a book about all the accessories.
Question: Jay, take a look at Marv's "1926 coupe" in the thread titled "1926 Coupe?" (imagine that!). What can you tell us about his carburetor manifold setup? How about the linkage on the driver's side of the engine, etc. His car appears to have a lot of interesting accessories that you have probably seen before. If you would, please post your answer on the 1926 Coupe thread. Thank you. Jim Patrick
Good think'n Jim! If anybody would recognize some of that oddball stuff, Jay would!
I have a an S4BF on my speedster and it is mind-blowing. I have a gorgeous rebuilt NH that I was running previously. The difference just has to be seen to be believed - easier to start, slower idle, ridiculously faster acceleration, and more top end.
The only negative I can think of is that the linkage arm on the carb is very long and the carb itself is pretty sensitive to input from the controls, so when you are operating the throttle lever it is MUCH more sensitive. With my NH I could pull both levers down to level and be going just over 40 mph. With the Zenith I can't get the throttle lever but about halfway to level before I'm up to speed. I'm going to make a shorter linkage arm for the throttle rod, it should give me a little range and fine adjustment back.
Hey Stan, any time you mention a rare carb or something that you say is really cool I try to research and see if I can find one, and even better find one for a good price. For instance, a previous post you mentioned is what lead to me finding and buying my S4BF that is complete and only needed some gaskets for $215. It runs great.
So! I found an HP4A from a guy who has a gozillion carbs but he says demand is through the roof, he has guys building retro-racers calling him all the time looking for that exact carb, and usually they want two! Only wants a paltry $1,500. Lol
Aparently I need another job to fund my need for speed.
Jim, Glad you are enjoying my accessory posts. I don't know about a book but I have been giving thought to organizing all the accessory posts (over 500 to date) and hanging a website that I can update with new info. as I come by it for each accessory. I think it would make a good winter project.
Seth, Thanks for the feedback on how the SB4F runs. I just sent the one in the photos to Stan Howe for him to work his magic on. I can't wait to see how it runs on our 1927 speedster that I currently run a straight through NH on. I have a second SB4F that I would like Stan to restore as well but need to sell off a few duplicate accessories to pay for it to keep domestic tranquility at home.
Jay, do YOU have another Zenith intake? I'd be glad to help you keep domestic tranquility. =) I've been hunting high and low for one but so far I'm striking out. I found through google image search where Ernie Splitter posted a pic this year on January 30th showing that he has 2 and didn't know what they were for. I PM'ed him today but haven't heard back yet. He hasn't been on the board since May though. I need to work something out, as I posted in another thread, my magneto coil got wrecked so I'm taking it out and going to try a Bosch triple gear drive and DU-4 magneto. My currect updraft intake is centered and looks like it came from a U&J carb.
I bet you'll love it. I've heard that the straight through NH is pretty great. I just can't imagine it's as jaw-dropping as this Zenith is.
I know it wouldn't really be period per se (at least from any pics that I've seen), but I thought about flipping the choke body upside down and then fabricating a funnel-shaped intake that would go through the hole in my belly pan and face forward - effectively giving me some "forced" intake of cool air that hasn't passed through the radiator when I'm at speed. Not sure how well it would work or if there would be any sort of noticeable effect, but these are the things I dream up when I'm bored at work.
Update: Ernest Spittler (I spelled his name incorrectly in the previous post) is going to sell me one of his intakes. He still has the other Zenith intake and it is for sale for $100 plus shipping. He said he'd be glad to sell it if I knew anyone else that needs one.
See the link to see a picture of it. I'm getting the one without the vacuum line hole in it. Mr. Stan, or anyone else looking for a Zenith intake, Mr. Spittler is the man to talk to!
Have you seen anything for recommended jet sizes for the Zenith carbs? I've got a HP5A on my Fronty speedster that seems pretty happy now that I stole some jets out of a salvage HP4A. Runs great in the RPM range I like of about 1000 to 2500 but never has idled particularly well. Of course, the jets seem to be unobtainable too but if I had a better guide for what would be recommended, it would be at least give me something to look for.
I hope the ruckstell and warford from the auction turned out to be good ones. I didn't need either of them bad enough to bid very seriously.
He's right. HP4A's are rare. I don't have one. HP5A's are not quite as rare. I don't have one of those, either. HP4S's are pretty rare, I do have one of those. The only difference in the 4A and the 4S is the orientation of the throttle shaft. 4S is vertical, 4A is horizontal. Zoom Zoom!!!!
Jim Patrick, The manifold on Marv's 26 coupe closely resembles a Simmons Vaporizer setup, or at least a part of one, from what I can see.
Hi Walt. All you can do is start drilling the jets until you get what you want. The idle tube length is pretty critical, too. But mostly the idle jet. I just don't have a real good answer but if you'll bring your speedster over and let me keep it for the summer and fall I'll fool with it. =)
As has been noted on another thread, the manifold setup on Marv's car may be a Kingston Gasifier. I think it and the Simmons looked similar.
Watch your mailbox, Jay!! Zoom Zoom!!!
Hey, since you brought this thread back up, thought I'd take a moment to mention: I have had my correct Zenith intake to match my carb and run it a decent amount. There's definitely a difference in the way the engine runs with the correct intake versus the U&J intake I had with an adapter plate. I don't think it's changed the top end or anything that dramatic, it just seems smoother. I'm very pleased. Plus, now that I'm running a front plate magneto, I need the Zenith intake so that the carb sits back far enough.