The Jalopy Journal
Discussion in 'Traditional Hot Rods' started by Six Ball, Jul 23, 2016.
@Six Ball...I'm lurking, looking and enjoying your vision and passion......quality takes time.
Thanks Stogy, I need to make more progress than just moving your pictures to different posts.
Balance is good......pat yourself on the back...your making progress and its not a job its a passion with no set deadlines. Good on you.
Well, there is a deadline. I'm closing in on 73 and I can see the tunnel at the end of the light.
I am catching up and hope to be healthy and active as you are when I get there...Many more healthy years to you and may your 26 rumble under your buttocks in the near future...
Better it than the rumbles there now!
I would go with the 24mm venturis first too. Some years ago, I was really surprised when we dynoed a car with Weber carbs, how little top end we lost going down by 3mm from the "recommended " venturis for that motor and state of tune. The real difference was in the midrange power and in the pickup/acceleration on the rolling road.
Six Ball - while the adjustable main metering jets shown in your picture are highly desirable for SINGLE carb applications; they add several degrees of difficulty to dialing in a dual application.
Stueeee, Thanks. I really don't think I'll have to go that small but there isn't a choice between 29mm and the 24mm so the 24s and a pocket knife might be the deal. I have a pair of Webers in the drawer too.
Jon, But they are just so cool. Nothing is easy for me with carbs. The more the messier. Actually I've used this type before on Chevy and GMC sixes. I've never tried to run a pair on an engine this small. If I can't get them to work there are other options. Thanks for the heads up.
I was able to weigh the flywheels this morning.
12 3/4" 153 tooth that came with the 153 weighs 20 lbs. #366861N
14" 168 tooth that will work with the adapter set up weighs 28 lbs. #3729004
Both use the same 10 1/2" clutch.
Any chance to run one carb as a dummy? I have 2 working on my 216 six and it will run well, better actually, with one blocked off and the idle screw opened up on the functioning carb.
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Six Ball - if you place sensors to a gas analyzer in each exhaust port, you can make it work, but just adds several degrees of difficulty. Fixed jets are SO MUCH easier with a multiple set-up.
Crusty - if the duals run better on one, something is very wrong! You will have a major cylinder imbalance. If you would like to discuss - 573-392-7378 (9-4 Mon-Tues central time).
crusty chevy, I agree with Jon. If it doesn't run better with two something isn't working right. Even bone stock 216s run better with two one barrels and dual exhaust if it's done right. one little thing can screw it up. I'm trying hard in this build to not have stuff that looks line other stuff. Thanks for offering you thought though this isn't all worked out yet and I know I'm not seeing it all.
Austin, I don't know what your post is but thanks for checking in.
Jon, The exhaust sensors makes sense and I could do that. I also have a set of very similar Zenith carbs with fixed main jets. The look the same otherwise. I'll have to check their model #. I know a lot of guys ran these 28/228s in "the day" and they were sought after but a lot has been learned since then. Thanks
@Six Ball Austin just wanted to make sure I saw your post because he knows I like the 153 stuff
That's great we need people looking out for us. There has to be something wrong with us spending all this time solving problems that could be fixed by simply bolting a 283-327 in the same hole.
No shit. Lol
That’s being said if your adapter uses the stock block mounted boss to mount the starter is there any reason you can’t use the 153 tooth fly wheel? Seems the switch to the other fly wheel is because the starter gets mounted to the adapter and moves it out further away necessitating the broader fly wheel to reach the starter?
I could use the smaller flywheel but I'd have to butcher the power glide and aluminum adapters. I don't think the big flywheel will be a problem. A stock model a flywheel weighs 65 lbs and it takes a lot to get it to 53 lbs though they can go less. I'm sure 8 lbs more than than the stock 153 unit is not going hurt that much. Better off the line at stop lights maybe retain a little power on hills. It'll be OK. If not it won't be hard to change. It'll also give it a bit more of the older look with real Chevy parts I want.
I only ask because I’ve mine bolted to a early ford trans using a speed gems sbc adapter and some of the adapters to do such a swap say they need the bigger flywheel. Just thought I’d pick Your brain a little
Jon, The other pair of carbs I have are Zenith 11480A. That is another 28/288 with fixed main jets. They use the same rebuild kit. I'm sure you know all this.
I read a post of yours on the Stovebolt site that said:
"The main venturi (this is the item that primarily controls air flow) of the 11275 is 30mm. The carburetor is rated 196 CFM.
The main venturi of the 9439 is 28mm. The carburetor is rated 172 CFM."
So it seems the 24mm venturies might be a place to start with this engine.
Six Ball - when dealing with a four-cylinder, the CFM required REALLY depends on the design of the intake manifold, much more so than with a V-8. An IR design could require as much as 4 times the CFM required for a single carb using a plenum design
Intake manifold design is NOT my field, however there is a gentleman that posts on some of the other forums (Stovebolt for sure), and I think here as well that goes by the username of "panic". His posts and articles on intake manifold design is WAY above my pay grade. I would certainly suggest asking his opinion.
But looking at some "factory" data; O.M.C. used that 153 CID with dual Carter RBS carbs. The RBS carbs were horrible, but WERE low-profile, so desirable in a boat with a closed bilge. Anyway, the dual Carter RBS's used by O.M.C. had 32mm venturii.
I am a firm believer that following the direction of the factory engineers is certainly a good starting point.
Yes, I am aware of panic. In fact he has responded to my questions on this on the Inlines International site. And no, I don't really understand his answers. He is far beyond my understanding. At this point I need to know what works I don't have to know why.
Thanks for reminding me of the O.M.C. That is a good correlation the Zenith flows 195 CFM and the RBS 225. The single bbl 153 boat motor was rated at 120 hp and the dual carb was 130 hp. I thought I might need to go smaller I may have to go bigger. At least it will run with two of these and I can dial them in later. Thanks for your help.
Since I'm not familiar at all with 4 cylinders, how do you plan to install your banger in the chassis? What does a typical engine frame/mount look like anyway? Any photos to show?
Mine will have two front mounts and one from the rear of the transmission. The bell housing is the same as a small block and the front isn't too different. They were used in Chevy IIs along with 230 sixes and 283s. There are at least three threads here about these engines. Sadly a lot of the pictures are gone and some of the info is wrong. I wrote some of that. Here are some pictures I lifted from those treads.
Appreciate these photos Six Ball - also wondering if your chassis and the Model A's are similar in width in the engine bays. Are the height of the rails similar as well?
I'll take some measurements and post them. I have an A frame I can measure too. The guy I bought the body from said that some of the mounting holes matched a '26-'27 T.
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