I am building an inline four cylinder DOHC engine for use in a Track T roadster, and trying for a just-Postwar midget/dirt-track car look. I’ll probably end up going EFI and trying to make that look period, but I have to wonder about carburetion--dual carbs would look entirely appropriate. I’m thinking sideways-mounted Stromberg 97s, (throttle spindles parallel with crankshaft); Weber DCOEs would be keen but not really appropriate for the look. EFI with Hilborn stacks would work but… Pictures of old carbureted DO Offys, Cragars, Frontenacs et al generally show a log-type manifold mounted close to the head with the carb flanges offset just far outside enough to clear the cam covers, or updraft carburetion, mounted yet even closer to the engine, i.e., no resonance tuning or internal aerodynamics. Dual 97s, two venturis per carb, i.e. one venturi per cylinder—almost individual throttle bodies, but only two inlets rather than four; could these be set up as a short individual runner manifold WITHOUT a plenum? Each cylinder would be drawing from an individual runner and venturi. Ed
I ran a GMC Howard head motor for quite a while with 3 Holley 2 bbls as IR. No balance tube. Tuned as 6 single cylinder engines. Worked fine IMHO
Often forgotten are Carter sidedraft carbs as were used on 1953-1953 Corvette Blue Flame 235cu. in inline sixes. I think some others used them in singles rather than triples such as Buick ? Pontiac ? Nash ?? I have some on the shelf with thoughts of making a steel tubular manifold for one of my Chev II 4bangers. Need to get out to the garage on the first warm day !!
Carter YH was the side draft carb. It was also used in marine applications on Fords and Graymarine v8's.
Twin SU’s would be within the time and cheap if you scrounge EBay UK. Four small ones might be doable.
The Carter type YH (horizontal) carbs were used on many applications. The triple on the early Corvette sixes, and the ones used on the turbo-Corvair are probably the best known. Also used as doubles on many different makes of marine applications, Nash, and the Nash Healy. Four were used on the Latham aftermarket superchargers. There were also a number of single applications. Rochester also made some side-draft carbs (types R and RC), but you probably don't want to go there. Not mentioned in this thread, and I am surprised, are the Riley and Flynn side-draft carbs. Jon.
Yes......sitting on the shelf with the Carter sidedrafts that I mentioned earlier are some Riley sidedraft spares......I also have a pair on my Chev II midget engine......I assumed that in reading the original post, that the Riley option would not be a friendly/streetable? application for the 27T project.......but it sure would scream "I'm a serious postwar racer" Have fun.
Ah yass, Winfields and Rileys and YHs, oh my! I'd briefly thought about all of them, and Model A updrafts as well. My thinking with 97s or Model A updrafts was that both types are available new, in current production, and tuning or replacement parts only a couple days off. I doubt the updrafts would make the power the others would, which sorta rules them out, but man they'd look cool. I'd love to do SUs, but as with the DCOEs, sadly, NMH. With retirement only 3 years, 8 months, and 11 (and getting closer to 10) days off, I should have the project "done" in that time span and therefore can run the wheels off the thing. Probably. Maybe. Possibly. One more small item to think about...I'd actually like the thing to be fast. The Texas Mile ain't but an hour or so up (the former) NAFTA Interstate 69. Andy Green, watch yo' supersonic tail there, boy... Ed
No point in reinventing the wheel if there is something out there. Look through this site. https://www.piercemanifolds.com/
Don't know about the Winfields, but tuning parts are available for the Rileys a couple of days off. Tuning and replacement parts are available for the YH's a couple of days off. Jon.
I would consider running genuine SU carbs..are aviable in sizes from 1 1/8" to 2 1/2" and the Norman 3"..... 1 3/4" HS model would probally suit your application ie; 200ci A banger...they are very efficient...easy to set up....the only thing is ,make sure the throttle shaft is not worn.... or this upsets the vacuum that operate's the needle piston ... Japanese su type is a Hitachi there wouldn't be a good selection of jets and needles avaiable for them as they were mostly used on 1600cc engines
'Preciate, the answer, Rich, thanks! That's what I was looking for. I was aware of reproduction Rileys at this link, but I didn't think those particular units would work for me for several reasons, and I looked no further, assuming (yeah, that word) that Rileys and parts were made of long-gone unobtanium. I'm guessing you have sources? (Probably in your signature, right?) Ed https://zakiras.com/?page_id=113
Look into motorcycle carbs. Depending on what engine you choose to go with. I had an early rabbit with a cross flow solid lifter cam 2.0 banger with long tube headers adjustable cam gear a 9 lbs fly wheel a solid lifter 288” drag cam” and some other goodies . This thing sounded like a cross between a big twin Harley and a small blockford and went like a bat outta hell !! I used quad mikuni carbs off a Yamaha 4 cylinder cruiser bike and had the carbs jetted for the 2.0 l No issues at all and like I said ran like fuck ! Like fuck !
What are you using for an engine? Alfa Romeos look great (can grind the name off the cam cover), several years had mechanical fuel injection. Miatas engines with polished cam covers are gorgeous. Over a few years in the late 90's they had raised letters, which can be ground off. Other years had sunken lettering, which could (maybe) be filled with weld. If you hope to find a period correct DOHC, better start buying lottery tickets now. I am quite fond of Webers and SUs, both of which date back to the thirties, probably beyond, so are "period correct", but not really "geographically correct". Pre-mid-1950s Webers were sand cast (grainy surface), as used on period Jag-Fer-Ati's, sell for a few to many thousands a piece. Modernish motorcycle carbs work well, but suffer from period-incorrectness. There were some 2-barrel sidedraft Mikunis used in pairs on Yamaha (and probably others), that really do look nice, though. Regarding 94s/97s, there were bowl tops marketed that were made with twin air intakes, but I'm pretty sure these did not convert the carbs to a true "individual runner" design. All of these carb installations have the float bowl in front of the venturies, so I would guess that, due to fuel level tilting in the bowl, would result in a slightly richer mixture under acceleration (which is probably beneficial). If I were mounting the carb(s) "in-line", for track use, I'd orient the carbs with float bowls on the left (as viewed from the driver's seat), as the car has an acceleration toward the inside of the standard left turn. If you had the time, and a friend with a single carb flathead car, it might be prudent to make an adapter that would rotate the carb 90 degrees, and do a road test. Although, if a stock manifold has a common plenum, it wouldn't prove much. Alternately, if some Hamber has direct experience with this orientation, with NO equalizer and NO common plenum (e.g., log), you might get some worthwhile feedback. I'm not sure why you wouldn't make a log, since there would most likely be plenty of room between the carbs and cam covers to accommodate one. There are other carbs that would look cool, with varying degrees of findability. I think updrafts (e.g., Model A et al), would be neat, maybe rotated so air inlet is on the outboard side. Some of these are partially brass, which could look sharp. Fairly new 4 cylinder Ford industrial engines (175 cubic inch +/-) used updrafts. Also, many variations are available from tractor supply shops. There are other sidedrafts available, mostly applied to MCs/industrial/tractors. L&L (aka Linkert) made aftermarket carbs for Harleys and Indians, from the 30's through the 60's (+/-). Many have brass bodies. Zenith made a line of sidedrafts. (I think some were used on small mail trucks.) Happy Hunting!
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