Hey guys, I'm in the process of starting a Model A Sedan build (Build thread coming in the month of February I hope.) I've collected 90% of the parts I need and have a few different options that I could stand an opinion on. I know everyone has their own opinion, so please if you comment at least back it up with a why for me. My engine is a '50 8BA that was bored .060 over and an Isky Max 1 cam installed. its running and Offy intake/finned heads with the original Distributor with a 12volt electronic ignition upgrade. My rear end is a Winters V8 unit freshly gone through and brought up to snuff by frames here on the HAMB (Thanks Dennis!) It is a 4.11 R&P with 3.48 gears currently installed. For tires I am running 15"x6" wheels with 8.00 tires in the rear and 15"x5" with 5.60 tires in the front. With all that background information, now comes my question. What transmission would be a good fit? I have the original 3 speed set up that came out of the 1950 Ford Sedan with the engine. It mates up perfect and would be an easy drop in. I also have a few buddies that have S-10 T5's for sale cheap. I know this could be debated all day long and I love tradition, but I also want to be able to drive this car at highway speeds (60-70MPH) without much worry. Would you give me your opinion and a brief explanation why? I really have no experience with either of these options as I've dreamed of a flathead forever, but never had the right opportunity until now. Thanks in advance for your help and I hope I don't get blasted too bad. Believe it or not, I've done searching and reading for awhile now.
If you want hi way speeds without much worry then a 5 speed it is. Here is my way of looking at it. If you need tranny parts it will probably be much easier to find the 5 speed parts than parts for or another 3 speed.
My $0.002: With that cam I would be shooting to have a cruising RPM between 2000 and 2400 RPMS. With a 29" Rear tire and a 3.48:1 axle ratio, you would be at 2600 RPMS with the 3 spd and between 1850 and 2000 with the T5 depending on the OD ratio at 65 mph. I would be tempted to run the 3 speed and drop the rear axle ratio to around 3.10 (the beauty of the quick-change right there) or run a bit taller tire. The other option is to bump the rear axle ratio up to 3.8 or maybe even go with 4.11, and run the T5.
You've shown you aren't scared of some new parts (electronic ignition and Winters quickchange), so I would go with the T5. You can adjust the final drive ratio to fit your driving style and highway speeds after you do some test drives.
This is good advice. My rebuttal is if the Ford transmission is good then the car is running a quick change and the transmission is paid for. LOL With tall tires a 3.48 gear won't hurt you at all on the highway. It may not have much of a hole shot. I don't recall what first gear is in those old trannies.
This is the kind of feed back I was looking for. Was just totally unsure of where to find a calculator to estimate RPM's. The helical gears aren't super expensive (like $130USD), but I also didnt like the idea of taking a stab in the dark either. Thanks for your input! alchemy---Thanks for your input! I'd like to think I'm a mixture of traditionalist and a realist. Kind of like GordonC above. I don't mind running a combination of the older and the newer, but I'd hate to be on a 1000mile road trip and be stranded on the side of the road too. I have 0 experience with those 3 speed transmissions from the early 50's. I don't drive like a maniac, most times and am just unsure if it would hold up.
The math is simple: Engine RPM = Speed (mph) x Tire Diam (in) x Rear axle Ratio x OD Ratio x 0.39 It doesn't take into account the growth in the tires or slippage in torque convertors, but it will get you close.
Alchemy always provides sage advice. I can offer more than just advice as I already answered this question for myself on my own build. I have a 49 8BA that delivers quite a punch and a Winter's QC with helical gears. In between I stuck a T-5 that I went through and freshened up, added a McLeod hydraulic T/O bearing. Flatheads don't like high RPM's for extended periods of time, my QC is 4:10 geared, the 5 speed will get it out of the hole and in the left lane on the superslab. T-5's only real draw back other than being a new (er) part is they don't take a beating real well. I shredded one in a IROC red neck machine I owned once in my youth. But the flatty shouldn't make enough HP to do damage...I hope
I'd say this engine would be lucky to hit 120HP, but it sounds mean anyway. Thanks for the "real world" advice! Around here we call those IROC's "Mullet Jewelry". No disrespect intended to those with mullets or without all their teeth. hahaha
Funny, I actually was working on a pretty mean mullet about that time. I had 3 IROC's, turned them all into parts cars. We called them donor vehicles. Do a few burnouts, jam on some Van Halen, some high speed passes and then scavenge the running gear and stick them in tri 5 Chevy's and first gen Camaros. The good ole days. How about a pic of that flatty?
Had to go back and reread Original distributor , not a good choice,use a after market dist. and the rest is good on the engine.
@WhoDoYouFink, I think it is against HAMB policy to go an entire page without photos! Gimme something, it's Friday for Pete's sake.
For me the down side of the 5 speed is most bring the gear lever out to far back. If you can live with that them it's the way to go. I couldn't so went with an old Volvo Amazon M40 4 speed. Almost the same size as the 3 speed but with full synchro on all 4 gears. They are good for 150hp and 300ftlbs of torque, don't ask how I know! Pete
You didn't say if your three speed tranny had overdrive. In any case, those three speeds don't take much punishment. I've got a Mustang T-5 speed on my flattie with a 0.68 overdrive and a 3:50 rear end. Runs about 2000 rpm at 70 MPH.
T5. My roadster has '51 Merc , .30 over, w/Isky MAX 1, Mallory electronic distributor, Edelbrock heads & intake w/dual 97s, 9" w/3.70 gear & 235R75X15 rear tires on wire wheels & S10 T5 w/.68 OD, 1850/1900rpm at 70MPH.
If You built HOT ROD, You use 3 speed tranny. If You built Street Rod, You can use those "hip hop" trannys like T5,...... I do not understand where need over 3 gear? I do not have never need overdrive tranny. 7.00-16, 7.50-16 or 8.20-15 rear tires and 3.54 ring&pinion. You can have long drive using 60-70mph I drive very much every year and have experience. Normally need only 2 gear when driving. Only 1st gear need when start driving
I have 3.78 gears in the banjo of my 30 coupe. The 265 cid 8ba flathead also has a max 1 cam. I run 7.00-16 rear tires and have a 48 ford light duty 3 speed. I have run it 65 or so mph for a few trips over 150 miles one way and have had no issues what so ever with the rpms for extended periods....... If you want a traditional car I say stay with a traditional transmission.
kind of off topic but I just read completely through this thread and the one asking for help stabbing a dist ina 350 not once did I see dizzy mentioned for some reason that abbreviation sounds like chalk squeaking on a blackboard to me well done guys Tom
Thanks for all the comments guys. It really is helping me with my choice. I was able to trade my friend out of a S-10 T5. Ive still not decided completely, but I'm going to take some good measurements to see where the shifter would come out on both. Hurst makes a decent looking shifter unit for the old 3 speed (it is not an overdrive). The flatty I have was rebuilt by a guy 6 months ago, put into his shoebox and then taken out after 600 miles or so because it didnt have enough horsepower (swapped a SBC in.) His loss my gain. Its kind of dirty and the heads are off it with the original heads back on. He said the Offy heads didn't have enough clearance and needed thicker gaskets. I'll post a "dirty" engine pic tonight when I get out to the garage and then post an "after" pic in a few weeks when I get everything cleaned up, polished and painted. I'm building an engine run stand so I can check it out fully before setting it in the car. Someone mentioned swapping out the stock distributor for an newer MSD. You think that is necessary of a relatively mild engine like this?
I like pictures so thanks fur the effort! As for the distributor, if it runs why muck with it?. Mine has an MSD but I'm also north of 300 HP so I felt it necessary. Looking forward to seeing some photos
So I finally got a chance to post some dirty engine shots. I’ll be cleaning it up once I test fire it to make sure everything is A ok. You can see the finned heads on the cart awaiting reinstall. I also included a car pic for reference to what it’s going in. Got the dropped axle installed today. I’ll be starting a build thread when I get a little closer to where I want to be. Sent from my iPhone using The H.A.M.B. mobile app
If you have 1 change gear set, run it. Then decide what you need. all the calculators in the world won't tell you how the car will drive, too many variables. The engine will tell you what rpm it likes. The car will tell you what it's comfortable with. And, you have the computer between your ears to decide what you like best. Once you have established a baseline, come back and tell us all the parameters. This isn't rocket ship science BTW, I vote for the T5.
I like this thought process....I have an early quick change I’m going to run. Sent from my iPad using The H.A.M.B. mobile app
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