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regularman

regularman

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This is the 3.7:1 diff and its already getting up there in price with more than a day still to go. This is the one everyone is looking for, yet after driving a midget with the 3.7 I though it was still too low for highway driving. Still this makes a simple swap to get higher gearing. 3.7 on ebay
 
I think the 3.39 from the place in England would be the cat's meow, especially if it's a street car and not for racing/autocross, etc.

$300+ U.S., plus shipping. Pricey, but a lot less than OD or Rivergate.

Does anyone have experience with such gearing in a Spridget? What's it like on the highway and around town??
 
I think the 3.39 from the place in England would be the cat's meow, especially if it's a street car and not for racing/autocross, etc.

$300+ U.S., plus shipping. Pricey, but a lot less than OD or Rivergate.

Does anyone have experience with such gearing in a Spridget? What's it like on the highway and around town??
 
I bought one off Ebay in October for $240; great condition. Had to shop around for a while though...since early summer...some went for a lot more.

Mine will be be driven by a Rivergate 5 speed and Hap's 1275. Ratio should be perfect...5th gear, 3000 RPM, 68 MPH.

Ray

P1010029.jpg
 
racingenglishcars said:
I tried a 3.7 in my 59 Morris Minor 948 once. It couldn't get into 4th gear.
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My 1275 had the 3.90 in it and it was way too low for me on the highway. Seemed like the engine was screaming just to do 60. I installed the 5 speed and went with a 39/11 rear gear. I may be too high in 5th but I wont know that until I get it on the road. No problem taking off in 1st on a steep hill. I was trying to find the closest gearing to the 1200 210 that the transmission came out of. I figured if the 1200 could pull the datsun with that then the 1275 should be able to pull the midget with that. I could be wrong. I have got all the way to third gear up my fairly steep drive and it pulls good, so I think it will do ok in 4th gear at least, not so sure about 5th, but I can just drive in 4th if its too much.
 
So, I'm gonna ask a dumb question: what's the ratio on my '63 Midget?
 
Look at the stamp on the rear end, top, on the small flap peice.
 
and if you wan to know the actual ratio, just divide the number of pinion teeth into the number of ring gear teeth. That 3.70:1 is actually 3.727272.... . My 3.55 is actually 3.545454... The 3.9:1 is actually accurate at 39 teeth on the ring and 10 on the pinion.
 
I don't know about the price being that the same gear ratio is available new from Moss for 336.95 it is setup and a bolt in but then again set up is not rocket science. I,ve done it a couple times. The ad clearly states that it is not new.

Just my two cents
Anthony
 
middleagecrazy said:
I don't know about the price being that the same gear ratio is available new from Moss for 336.95 it is setup and a bolt in but then again set up is not rocket science. I,ve done it a couple times. The ad clearly states that it is not new.

Just my two cents
Anthony
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You have to have the right shims and a crush sleave and get it right though wich takes time if you don't want it to whine. You also need the BL jig blocks or the specs and make your own to get the pinion depth. Lot of time in that. if those gears are set right at the factory, they will never wear out in a million miles.
 
I have a 3.7 and I tried it with the 5 speed I have, what a dog off the line but there was an unlimited top end.
I have put a 4.22 in with the 5 speed and for me, it seems just right. I have the off the line jump that I like and 80 mph highway speeds with the 5 speed all day long are no problem.
I even tried a 3.9 with the 5 speed, I didn't like that either. But I am running a 3.9 on a stock 1275/ribcase in my 67. THAT Is OK for highway and fair enough for off the line driving.
But if a 3.7 is worth $300, watch for mine on Ebay :wink:
 
Different strokes for different folks, etc. :laugh:

I NEVER do hole shots, stop light racing or 1/4 mile drags in LBCs, so low-end power/speed isn't really important to me. Highway cruising at 50-60ish MPH (e.g., driving the lovely side roads here in VA) is what matters most. I'm more of a "spirited touring" type driver, if you know what I mean. Give me the 45-55+ MPH twisties!

The correct gearing for my driving style is the first thing I try to achieve with LBCs. For example, my stock GT6+ with 3.89 diff revved about 3,000 RPM at 50MPH and was way too revvy to cruise long distances at highway speeds comfortably. The J-type OD remedied that nicely, tho', rendering engine RPM to about 3,400 at 70 MPH. End of problem. However, the price was high: it cost me almost $2,500 to achieve this gearing. :crazy: And, wedging the J-type into a GT6 probably gave me extra grey hairs after all was said and done!

Another (modern) example: my '05 MINI S, with a 3.66 diff (and a six speed, VERY close ratio gearbox): at 70 MPH the engine turns about 3,100 RPM, very nice for a sports car and about what I'd like to achieve in an LBC in top gear. That's why I think a final drive ratio in the 3.39-3.55ish range in a Spridget would be best for my driving style.

Apparently, it takes about $350-$450 to get a different ring and pinion installed in a Spridget. This is a relatively low price, compared to installing overdrive or a five speed box. Especially if the car is driven frequently.

Not bad at all.

YMMV.
 
I can believe that. If you put new gears in a carrier you are probably going to have more than that in it when all is said and done. I have known people to put in the 3.7 with the stock transmission and it seemed to be fine on the take off, so I figured my 3.55 would be ok with the Datsun 1st gear being lower than the Mowog. I never planned on a quick start with this car, its just gonna be for driving. I set this one up for good gas mileage. Still, it seems to take off just as well as my 5 speed ranger or my kia sportage going up the drive. I am so anxious to get on the road now. I got to get those seat put in but its just so cold in the basement and it kills my motivation. Plus, I just came down with a horrible cold or flu or whatever. Its been going around here something awefull. Schools closing over it and stuff. I ache all over.
 
After I installed my five speed with a 3.9, I was relatively happy with the balance of acceleration and rpms at cruising speed. However, I wasn't happy about the long jump between 2nd and 3rd on the datsun unit. You really had to wind out the engine in second in order to continue accelerating in 3rd. It is not an issue now that the supercharger adds some uuumph.

I do not drag race the midget, but on winding roads I like to be able to come out of the corners with a little gusto. It is also helpful for getting the car back in line when you have a bit too much oversteer.

But... it all depends on what you want the car for and your driving style and habits.
 
Just looking through some of my old paperwork. I got my gears about 5 years ago from VB. My gears are 39/11. Should have 3.55:1 in 4th gear on the 5 speed and then with the OD in 5th, it should fall out somewhere around 2.91:1. If it doesn't work out, it going to be an expensive experiment. Though, I have already had some good offers on the 3.55 if it doesn't work out and I need to change it.
 
I opted (after much thought) for a 3.9 and ribcase 4-speed. Biggest issue was cost -- the 3.9 and ribcase came out of the donor midget that also gave up a 1275 and disc brakes, versus somewhere around $1500 for the 5-speed. Plus I like the idea of keeping to BMC parts. My Hap-built motor should have no problem revving, and cruising at ~ 4000 RPM should be no problem for a long day's drive.

Most of my driving will be mountain roads within 100 miles of my house, so long cruising will be a rarity for me. I'll be interested to see if the new motor can pull 4th up the long grades around here. The old 948, which was unrebuilt, couldn't do it. Of course, it had maybe 1/2 to 1/3 the power that the new motor should have.
 
drooartz said:
I opted (after much thought) for a 3.9 and ribcase 4-speed. Biggest issue was cost -- the 3.9 and ribcase came out of the donor midget that also gave up a 1275 and disc brakes, versus somewhere around $1500 for the 5-speed. Plus I like the idea of keeping to BMC parts. My Hap-built motor should have no problem revving, and cruising at ~ 4000 RPM should be no problem for a long day's drive.

Most of my driving will be mountain roads within 100 miles of my house, so long cruising will be a rarity for me. I'll be interested to see if the new motor can pull 4th up the long grades around here. The old 948, which was unrebuilt, couldn't do it. Of course, it had maybe 1/2 to 1/3 the power that the new motor should have.
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Night and day Drew, that 1275 with the 3.90 will pulls some steep hills when wound up to highway speeds. You will see what I mean. To go from a tired 950 to the 1275 will be great. Just a cheap re-ring job makes a big difference in the A series, I saw this on minis a lot. My 1275 and 3.90 combo seemed to low geared on the highway and it wanted to run hot on the highway also. I put in all new waterpump and hoses and radiator but still wanted lower rpms cause I figure that will lower friction and temp as well.
 
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