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OD in Spridget.

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vagt6

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Awhile back someone posted a link here to a website of a chap who installed a D-type OD in a Spridget. It was not a pretty install, but it was documented with photos if I recall correctly.

Does anyone have that link?

I want to study this, OD would be fabulous in one of these cars, IMHO.

Thanks!
 
Excellent! Thanks, Morris. If you tackle this project, please share photos with us.

I don't exactly remember, but isn't a D-type a bit smaller and thus a bit easier to fit, possibly?

D-type vs. J-type for this project: if the Dtype is easier to fit, it would be my choice. Less expensive to purchase, too.

Anyone else??
 
I have been curious about whether a D-type will fit, too. It's a completely different box, though. And not so easy to find it seems to me. Also, I think the D-type box does not have a synchro first.
 
The website guy's install was in a 1500. Will this mod work with earlier Spridgets???

So . . . would the Jtype bolt right up to a MK III or earlier Spridget just like the 1500???

Gosh, I hate that non-synchro first gear biz. /bcforum/images/%%GRAEMLIN_URL%%/wall.gif
 
Nope, for the 1275 A-series engines, you are pretty much forced to go with a 5-speed.
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]forced[/QUOTE]

Yeah... you poor guys. It would be terrible to have a 5 speed option that does not require cutting up your frame. /bcforum/images/%%GRAEMLIN_URL%%/frown.gif
 
Yeah, but the Spit OD is easier to find and more affordable.
 
A 1275 question for youse guys regarding gearing:

With a 3.91 rear end (or others FWIW), roughy how many RPMs are you turning at 60MPH with the A-series 1275 in a Spridget?

I'm trying to get a feel of what it's like to drive the side roads in a Spridget (not Interstate /bcforum/images/%%GRAEMLIN_URL%%/nonod.gif).
 
vagt6 said:
A 1275 question for youse guys regarding gearing:

With a 3.91 rear end (or others FWIW), roughy how many RPMs are you turning at 60MPH with the A-series 1275 in a Spridget?

I'm trying to get a feel of what it's like to drive the side roads in a Spridget (not Interstate /bcforum/images/%%GRAEMLIN_URL%%/nonod.gif).
Click to expand...

I posted this a while back, here it is a gain; it's a link to a spreadsheet on my website that provides an insight into the relationship of engine RPM to speed with different transmissions (4 speed stock and 5 speed conversion) and rear end combinations. Keep in mind that tire size is an important variable. The chart makes no assumptions about engine capability, resistance, or whether it's raining or the wind is blowing /bcforum/images/%%GRAEMLIN_URL%%/smile.gif :

https://www.raysmg.com/rays_mg_midget_whatzit3.htm

Ray
 
Guys,

Keep in mind that one of the simplest things to do is to swap final drive ratios.
These engines are torquey and can tend to easily deal with a taller starting-off ratio,
Most "A" powered cars had a 4:22 ratio (except later cars). Most 1500s had a 3.9 ratio, but certain later 1500 cars had a 3.7.

And a 3.55 is said to be available from certain vendors (probably easier to find in the UK)

Also, overall tire diameter make a difference. When my green car (below) was on the street I used low-profile Sumitomos (50 aspect ratio), but when I went on longer drives, I'd fit some 80 series tires to the back...makes a useful difference.
 
What's a quick & dirty way to find out what gear ratio I have?
 
Look at the pad on the diff housing, on the right side of the snout. There will be 2 numbers stamped, such as 9/38. Divide the larger by the smaller number.

A 9/38 will be a 4.22 gear ratio.

Standard gear ratios are: 41/11 = 3.73 ; 39/10 = 3.90 ; 38/9 = 4.22; 41/9 = 4.555.
 
Is that a universal thing, or just with Spridgets?
 
aeronca65t said:
Guys,

Keep in mind that one of the simplest things to do is to swap final drive ratios.
These engines are torquey and can tend to easily deal with a taller starting-off ratio,
Most "A" powered cars had a 4:22 ratio (except later cars). Most 1500s had a 3.9 ratio, but certain later 1500 cars had a 3.7.

And a 3.55 is said to be available from certain vendors (probably easier to find in the UK)

Also, overall tire diameter make a difference. When my green car (below) was on the street I used low-profile Sumitomos (50 aspect ratio), but when I went on longer drives, I'd fit some 80 series tires to the back...makes a useful difference.
Click to expand...
I have a 3:55 ring and pinion. I got it from Vicky Brit several years ago. Setting the pinion depth is tedious and time consuming work. From what I am told this was the original gear setup for the Lotus Seven kit car. Also for the five speed question. If you have the 3:90 gear and put in the 5 speed, 4th gear will be a straight through 1:1 transmission ratio just like 4th in the original Mowog transmission, so it should drive the same.
 
Kim, that's good stuff to know about the 3.55. Actually better than OD, actually, cheaper too.

If anyone knows a source for the Spridget 3.55 ring/pinion, please post it.

Good thread, this. /bcforum/images/%%GRAEMLIN_URL%%/thumbsup.gif
 
vagt6 said:
Kim, that's good stuff to know about the 3.55. Actually better than OD, actually, cheaper too.

If anyone knows a source for the Spridget 3.55 ring/pinion, please post it.

Good thread, this. /bcforum/images/%%GRAEMLIN_URL%%/thumbsup.gif
Click to expand...
I have both a datsun 5 speed and the 3.55:1 rear diff. I don't know if it takes any less time to get the gears set right in the case than it does to do a whole conversion. It took a lot of time. Also finding someone who can set one up for you is a rare pearl ( I did my own). You have to be able to understand the markings and have the right Jigs to measure from or make them. Its not like setting up the gears in a Ford or Chevy and if they are not right, they will whine like hades.
 
Steffen, thank you for posting that link and welcome to the Forum! Nice source of parts in England.

3.39 ring & pinion is 162.50 pounds = $318.68 US. Shipping would be the clincher, but ring and pinion gears are not terribly heavy.

Nothing is cheap, ay? /bcforum/images/%%GRAEMLIN_URL%%/cry.gif
 
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