Any chance anyone has run a 261 powered car down the drag strip with 4:88 gears and knows what rpm they were turning when they crossed the 1/4 mile?

Here is a nice gear calculator that is on my site. It allows you to pick tire height, transmission and rear axle ratio. If you give me your transmission type and tire diameter or size. I can figure it up.
The program uses Excel if it is on your computer. If not there are plenty of other calculators on the web
https://www.12bolt.com/gearing-calculator.html

You are terrific. So 26 inches (215 r 70 14 rwl BFG). Trans mission is m22z
First gear is 2:98,, 2:04, 1:46, 1:1.

I have 4:11s in the car now (57 chevy). I have two potential rears I can change 4:56 and 4:88.

I really appreciate to offer to calculate.

Btw, is there a time you prefer to take calls at the shop. My son is rebuilding a 57 and we are going to put a 292 in. We just found out the crank I have for him is not good enough to salvage. That and I am going to need quite a bit in the way of other parts for his motor. If it works out, I will likely change the 261 in my 57 and do a 292 motor for that car also. Wanted to sort out a parts list and some costs if you have time to speak.

Mike

Call anytime during the day.
I ran the 4.11, 4.56 and 4.88
Guessing the shifting at 5000

Well it is hard to show the PDF's.
At 5 K RPM
4.11 MPH about 95
4.56 MPH about 85
4.88 MPH about 80

Tom, you are tremendious for doing that, many thanks. I have been pouring over the charts but I have to admit I am still not certain where I would be at rpm wise at the end of a 1/4 mile. With the 4:11 gears, shifting at about 5600-5700 rpm, I cross the finish line at about 83 miles an hour. the rpms are not up all that high when I cross and frankly the car seems to be running out of gear. At this point I can build either 4:56 or 4:88 or both. I am leaning to the conservative side and install the 4:56 gears but always wondered whether I could get down the track with the 4:88s without having to let off.

Years ago, I would read in the TPN that Inliner members Mike Smith (who would often be described as "the hippy" in the TPN) and Manny Torres ran 261 powered cars with 4:88 gears but that was a long time ago and in looking at my old issues from the 80s and 90s, no mention of the rpm situation.

I think you're going to want more gear then the 4:11 for sure I started out with the 4:56 behind my (17yr) old 250 Then I went to a 5:13 which ran at that time 96mph in 3rd gear, But I don't not remember the trap rpms. The left the line no less then 5000 and I shifted between 7&8000. I don't much about your build Other it's a 261 Or what weight or car your running.

The car is my 1957 chevy. I took my driver's test in the car when I was 16 in 77. The motor is a 59 Canadian Pontiac 261 block, 235 crank indexed, equalized, balanced, drilled for a bolt. 302 gmc rods and venolia forged pop up pistons. It is unfortunately a heavy set up. Cam is a Schneider, 282 duration, 492 lift, solid lifter. Smith Brothers 3/8 chrome moly push rods, matching precision adjuster screws, stock rockers. 1.9 intake (GM 50-52 Powerglide intake), 1.6 Manley small block chevy street flow exhaust, little pocket porting to unshroud the exhaust valve, hogged out the valve bowls a little for the larger valves. Clifford long tube headers, Clifford 2x2 intake and a pair of Holley 350 2300 2 bbls, vertex magneto, about 6 degrees initial, 24 mechanical. Car weighs about 3500 pounds, Muncie m22z four speed with the 2:94 first gear. The 4:11s have been in the car since the very early 80s. I drive the car almost exclusively on the street, but take it to the trifive nationals in Bowling Green each year where I am inevitably the only 6 cylinder car running down the track. 2800 trifives and I am the lone inliner on the dragstrip, lol.

Without an OD the 4:11 is pretty much your street limit, A buddy of mine tried the 4:56s but the motor was Not real happy for long haul or higher street mph. You may want to think about a gear vendors OD Then you can get away with a little more rear gearing. How do you like the M22z ? I have thought about it But I kind of really want a lower first gear I know I can't go any lower then a 3:11 for first gear The T10 Tranny won't live long if I went lower.

The 4:11s will go back in after the nationals. The stiffer gears are just for the nationals. I trailer the car, it is 800 miles and 12 hours so that would be, well difficult, with the 4:11s,
lol.

The stock three speed for 57 has a first gear of like 2:92. Stock rear gearing from the factory with stick in 57 is 3:55. So an effective first gear of 10.36. If you just swamped in a standard GM M22 with its 2:20 first gear you would have an effective first gear of 7.81. Not so good for an inline motor. With a 2.54 first gear you are at 9.01. Still not great. You lose that gear multiplication so necessary to get the car off and running. Fine if you have 400 hp. Not so fine when you have 175 hp.

The M-22Z is aftermarket. You can purchase the M22Z gearset from AutoGear and rebuild your existing Muncie M-20, 21 0r 22, the gears can be retrofitted. The M22Z has a first gear ratio of like 2:94 so with the stock 3:55 you are right at 10.43. I ran a sag 3:11 first gear for a number of years just that reason, with stock 3:55 you are at 11.04. But while those transmissions are at least as strong as the small peanut chevy three speed, they generally can not take a huge amount of abuse. Notwithstanding, the sag is a really good choice if you are trying to be careful with the bread and you dont heap any abuse on the transmission. Frankly, I see completly rebuilt sags in the 700-800 range. A used sag is like 300-400, rebuild kit at 100, new forks about 175. So about 575-675 if you are rebuilding your self. Not terrible for a rebuilt 4 speed with a decent first gear ratio.

I needed/wanted something that could take a little abuse so I ran the sag while I saved and then put the M22Z in. With the 4:11s I am at 12.08 for the first gear and its not a granny gear by any means. The car gets moving right away. Just as an aside, the Italian M22Z gear sets are machined to a way closer tolerance than the original GM M-22 gear sets and are thus quieter than the original sets. So you get a bit of a whine, but much more tolerable.

I really like the transmission. I used a used case, rebushed, used main shaft, all new gears, bearings, mid plate, retainer, forks, small parts. I would post photos but I have no photo host and I can not post directly from my photo library. If you like an old school feel for your car, its a pretty good transmission. That being said, I think you can buy one brand new, everyting including the case, for like 2600 or so. Much better then the $5000 transmissions that seem to be the rage these days.

Yeah my Muncie has the 2.54 first I wanted the T10 with the 2.88 first gear Because I know the 3.11 first will not live behind my l6 the input shaft is to small in DIA. But It would leave good 1 time maybe LOL.

Hold out for the M22Z gear set then. Or sell the current muncie and get a brand new M22Z. You will like it.

Sounds like a plan I like my sticks lol
I am running an Old 60s style hurst inline shifter on my Muncie and I have another one here some place lol

If you are referring to the Hurst Vertigate, they are the bomb! Fast shifting.

Yes , I had 3 of them at one time and I gave one to buddy.

So I opted to use the 4:56 gears for this years nationals. They were used gears in very good condition out of a restored vette. Using used gears in these 55-64 chevy rears is always a crap shoot as to whether they make noise or not. Usually with me its always a sh#t show so I fully expected them to make some noise. Had a reasonably decent pattern, not perfect but decent enough. Lo and behold, no noises. Just the new clutches in the posi chattering a bit.

So I will report back when I get home from the nationals and post the trap speeds. I generally like to shift about 5500-5800 rpm. These 235/261 cranks cant really take a lot of rpm, notwithstanding that the head runs out air pretty quickly. We shall see what the rpms are.

We'll be waiting to hear how it all works out. Good luck & have fun.

Back from the Tri-five Nationals in Bowling Green KY. Weather was great and out of 2500 cars at that show, probably less then a dozen inline powered cars. Mine was the only inline car to head down the drag strip. Tiny tires, 4:56 gears and a slippery starting line. Want to know whats nice about tiny tires and a slippery starting line? I did not break anything. Made well over 20 or so fun runs over the three days. It was an enourmous amount of fun.

So because the tires slipped pertty good launching with a little bit of rpm, I mostly had to launch from idle (about 900-1000 with the schneider cam). Shifted the 261 at about 5800 rpm and crossed the 1/4 mile at about 5600-5700 rpm. Not terrible. So I think I was right not to install the 4:88 gears.

That being said, my son is building a 57 four door sedan and wants to install a 292 with higher compression pistons and good rumbly cam, lump port head, and a Holly Sniper set up so we will start back to working on that. Have to figure out some front motor mounts and hope I can fit it all in. Will be a lot faster then my old 261. Who knows, I may just up my motor to a 292 also.

Happy to hear all went well. Did you get any Photo's ?

I have some, waiting to receive more from a friend that was with us. My issue, I dont have a photo hosting site and dont actually know how to post photos here.

235/261 cranks cant really take a lot of rpm

Why is that?

Those cranks are steel and relatively strong, but they are old. Once you get into the upper rpms, over 5000, the harmonics are bad. But the other issue with higher rpms, the head simply will not breathe that high, at least not without doing some crazy stuff to the head, and even then, probably not all that much of an improvement.