Anyone out there running a Nailhead with a 5 speed behind it? That seems to be the transmission of choice with flatheads lately. It must make good use of all that torque since these aren't real high winding engines. Just courious. This thread sure had my imagination in high gear for building a nailhead powered roadster/PU type rod.
High torque motors dont need a bunch of gears to get the job done, or for that matter, they dnt need a lot of ratio spread between the gears either. Case in point, the '70 Buick GS 455 [with 510 ft/lbs] was actually 1/10th quicker with the standard 3 speed manual over the optional 4 speed!
I know that but it just seems like a lot of the flat heads are going to that. Harley ran 4 speeds for years and now they have 6 speeds in them. Seems like it would keep the engine in the sweet spot more.
Did you just call a flathead high torque? lmao, yeah right... The Nailhead, especially in a light car, is fine with a highway gear and a nice wide ration 4 speed. As a matter of fact most 5 speeds will not handle the torque of a Nailhead if your foot is anything like mine. If it's in a light car it will live longer due to traction not existing.
are you just looking for a manual trans? or the joy of a overdrive? I have a stock 401 with a super t-10 and no problems, gets ok MPG, and there is really no need for 1st gear. Tons of torque, fun to drive, and in a light weight hot rod makes it fun
Most Gm 5 speeds are pretty anemic compared to the early 3 & 4 speed boxes that preceded them. Most Nailheads have enough torque to uproot trees! If you're going to run a 5 speed that's less than a late Ford Top Loader or Tremec, for example, I'd be really leery of hammering gears with it. Just my 2 cents only. BTW, I've got a 401 now. When the time is right, I'll be bolting it up to a Borg Warner T-10. THAT combo will work!
the best T-5 I think had a torque rating of 320 ft. lbs. I think. That was a mustang cobra. GM pattern ones I think went up to 300ft lbs. If you want to run a nailhead.. Pull 4 of the spark plugs on it, leave them on the bench at home, and you should have around 300 ft. lbs. of torque left
lol, you're probably about right... I think stock the 425 in my 57 was rated at 465 ft. lbs., it's not stock anymore. I believe the rear in it now has a 3.31 and I've got one with a 3.08 to go in. with the 3.31 it's fine on the highway, but the 3.08 rear has posi.
Here's a thread I posted up which may help with your questions These guys on here are very helpful http://www.jalopyjournal.com/forum/showthread.php?t=331493
I'm running a Richmond 6-speed and a Winters QC with a 401 in my '32 roadster. Lotsa overkill in one package. Still building though.
Don't put much stock in T5 torque ratings - those are continuous duty, 100,000 miles torque ratings. But the T5's aluminum case makes it a relatively weak choice (when compared to the cast iron 4-spds of the muscle-car era). If you're rowing your gears, more gears keeps your engine at/near it's torque peak - many engines have a relatively flat torque curve and don't really need this "help". It's all about choices and compromises. If I were going to put a 5-spd behind a Nailhead, it'd be a Tremec TKO or something like that...
I'm running a '65 Ford 4-speed toploader behind the 322 in my Model A. Schneider cam, 3-2s and a nine inch. It seems to be handling the torque just fine, and I never seem to run out of gears. IMHO a five speed, even if it could handle the torque, would be overkill behind a Nailhead.
I always was under the impression the flatheads had pretty good low end tourque. Long stroke and all that. I've never owned one or driven one as far as I know, except for flat head Chrysler 6's in fork lifts and the old Ford N9 tractors. the point you make about the 5 speeds handling the Buick's torque is a good one. Most of todays engines are about rpms for power and lots of torque just breaks things. I know that's their strong suit. I've had plenty of experince with the Ford top loader so I think that would be my choice. Thanks for all your input. that Buick is looking might darn attractive.
For a motor that was designed 100 years ago, they make amazing torque and power... But by today's standards, no.....
flatheads may have decent torque for the size and design, but they are still a stock 225 ft. lbs. max. nailheads were advertised by the torque they put out, instead of the cu in. or HP, such as the "wildcat 465" true the torque rating are manufacturer rating to help the transmission last the life of the car it came in, but it is still a good way to compare to other tranmissions on thier relative strength. I've owned a few cars with T-5s, and knew a few people with T-5s in performance cars, they are not that strong. Unless you want to baby it around all the time, I'd choose something else. A strong maual trans is the '55-'57, six bolt cover 3 spd. It was known for being very strong, but a little bit slow shifting and noisey. I plan on using our the 3spd 6-bolts trans that came in our '57 with the upgraded 425 that we are building for it. If you want overdrive, I'm not sure what to do unless you skip right ahead to a 6-speed. Possibly some of those 4 speed overdrive chevy truck tranmissions might work, or a gear vendors OD unit on a regular 4 speed.
The beauty of the flatty is how FLAT the torque curve is - it ain't really much of a curve at all - more of a flat line. It may only make a couple hundred ft lbs (hopped up), but it's all in by 1500 rpm and doesn't fall off until over 4000 rpm. That's why it feels plenty strong for its size (and age). IMO, best factory 4-spd ever made. That's why NASCAR used them (even behind SBC) until Jericho came on the scene (which is just a Toploader derivative). I love this T5 myth. I've owned dozens, built several, and beat on all of them. They are a ****load stronger than most people give them credit for. It ain't no toploader, that's for sure, but for most street-driven cars, they do alright. They have several weak points in stock form - you can correct most of them except the aluminum case...a moderately prepped T5 will handle a lot of street cars that folks *think* are too hot for 'em... I ain't saying it'll live behind a nailhead being abused, just trying to point out it ain't as weak as everyone seems to think. Stock are horrible - made in mexico - RTV squeezed in to the point the shift rails bounce off it and wont' stay in gear, sloppy end play, absolutely horrible stock shifter, countershaft support is weak (can be replaced), and no internal shift stops...lots wrong, most easily fixed. I know it's possible to adapt the Saginaw 3-spd OD to the Saginaw 4-spd, so that may be an option...
Well it is not a myth to me Ernie, I've experienced it first hand. Difference is mine were all stock, one of them broke with a 235HP/300ft. lbs 1992 firebird Formula 305 HO in front of it. I worked at a first Gen camaro shop where we had several customers try the T-5 thing and broke them with mild 355s. Most of these cars also had 3.73s to 4.11s and were probably driven hard, but they were still daily driver street cars. This was 10 years ago at least so maybe there is better internals available now, but that was my impression of them first hand, not just reciting a "Myth".
I'm running a Super T-10 behind my built 401. It's a wide ratio box (3.44-2.28-1.46-1.00) mated to a 3.89 rear. It might not get the best mileage, but I know the transmission will take it. As others have suggested, most 5 speeds weren't built for nailhead torque. -Lee Atomic Radio www.atomicpinup.com
Yep, that's the difference. But to improve a T5 doesn't take much. They were very sloppily built originally - especially the early ones. I'm not talking about rebuilding with super-strength internals, I'm talking about simple, but straight-forward ***embly. I've seen so much RTV on the cover that it squeezes in and keeps the forks from fully moving the synchro into gear. Stock. OEM. However, I can almost guarantee your Camaro/Firebird lunched T5s were a result of the stock shifter. They are the biggest pieces of **** and the single best thing you can do to any T5 is replace the stock shifter with ANY other shifter that has adjustable stops. The stock shifter has no stops, so the typical hard-charging street driver slams them into gear and actually pushes the synchros past where they need to be, bend/crack the shift forks, and the next shift fails. 3rd gear is always called "weak" on the T5, but that's just the shift that is missed the most... Trust me, a stock T5 will more than handle a stock 305 - even driven hard. Change the shifter. I don't doubt you saw failures - I've seen 'em too - lots of times. The 5.0 crowd proved that T5s will handle 3500lb 11-second cars...that's more than your average street-driven car...
Ding!! we have a winner! I am glad someone else has had a lot of experience with T-5's. Everyone forgets a lighter car will be easier on the trans. I converted my 91 Trans Am with mild L98 350 to a T-5 and it made numerous track p***es in the 13.30's @ 106mph. It made 288 rwhp and 377 ft lb of torque (est 331hp/430tq at the flywheel) on a MUSTANG ch***is dyno. So in short, I doubt your Nailhead is going to make much more tq than that in the real world, you car wont be as heavy as my Trans Am was, and you wont have drag radials on the back. As long as you get a nice 87-92 V8 core to start with and do a quality rebuild on it, you'll be golden. Put some 3.08 or 3.23's in the back and cruise 80mph in the low 2000's rpm while sipping the fuel.
Guess I'll find out! I have a Tremec TKO 5-speed with heavy duty 9310 gears, steel shift forks and all that jazz . . . it will be hooked up to my blown 392. It is a light car (34 coupe), running 10" Hurst cheaters. I actually hope that it doesn't hook up too hard - that is what breaks ****. The rear is a Frankland Q.C. - it is probably a bit weak as well. If this ****** pukes, then I'll find something else . . . that is the way it works . . .
What does your torque curve look like, probably not flat like a Nailheads. L98's made 320 to 340 ft. lbs. at 3400 stock, if you did the usual SBC performance upgrades then you probably moved the torque peak up the RPM range to get your 430 at the crank. And a 401/425 makes more torque than that in stock form. Let alone built. The torque is pretty much from idle on. I haven't had a chance to dyno the 425 in my 57 Buick yet, but we've figured it's over the 500 ft.lb.. mark. The engine was 465 ft. lbs. from the factory. This is in a 4000 lb. car. I've broken the rear end mount twice with the torque. Now if you were comparing big block torque or stroker torque I could see it. Now it seems this one will go in a light car, most likely with pretty skinny tires, so if traction is not his friend then the T5 may live a bit. But if you're gonna compare, compare Apples to Apples.
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