[Spridgets] More highway speed for a bugeye?

WeslakeMonza1330 at aol.com WeslakeMonza1330 at aol.com
Sun May 10 09:03:22 MDT 2015


Not exactly!
 
The differential doesn't change the gearing of the rear axle.  The  gearing 
of the rear axle is down to the ring and pinion or what we call over in  
the UK, the crownwheel and pinion.
 
You want the ring and pinion fitted to the differential component and all  
fitted together in the differential as a single large component - what I 
believe  you call the pumpkin.  Probably your best bet is to simply buy a good 
3.9  from Alan Fisher who is having a clear out.
 
Changing the axle ratio doesn't improve the performance of the car it  
simply changes the gearing. To reduce the engine rpm for any given speed in 4th  
gear you need to replace the 4.22 diff with the 3.9 diff or fit a 5 speed  
gearbox with either.
 
If your car is struggling to maintain 70 mph you need to understand if this 
 is because the engine is really revving out (might have a diff lower than 
a 4.2  like a 4.5 or lower from a Morris Minor or whatever) or if the engine 
is simply  not running well enough to get up the required revs.
 
Regards
 
Daniel
 
PS: there are books with this stuff in...
 
 
In a message dated 10/05/2015 15:51:41 GMT Daylight Time,  
spridgets at autox.team.net writes:

 


You only need the Differential which goes inside the pumpkin and rear  
axle.  As Derf said you want one that has 10/39 on the top of the  differential 
case but check yours first to see which you have now!  There  were at least 
3 available. Early cars were 4.22 to 1,  then there is 3.9  to 1 and the 
shorter 4.22 to 1.  The 4.22 is great for autocross -  the taller geared 3.77 
for highway use.  As was noted, the taller  gears are getting hard to find 
and usually demand a suitable hunk of  cash.


If you find a 3.9 or 3.77 that's inside a rear axle case and the seller  
won't part it out, buy the whole thing.  You'll need help picking it up!!  
DAMHIK....


Cheers!
Jim


On Sun, May 10, 2015 at 9:29 AM, derf via Spridgets  
<_spridgets at autox.team.net_ (mailto:spridgets at autox.team.net) > wrote:

I know the basics but will have to defer on the details.   This is where 
Frank would chime in and sort it all out.  There are  others who know and 
share, but none like him.  Really miss that  guy.  


 

On Sun, May 10, 2015 at 9:22 AM, ryan.kubanoff--- via  Spridgets 
<_spridgets at autox.team.net_ (mailto:spridgets at autox.team.net) > wrote:


 
So if I go to carlisle import show next weekend what should I be on  the 
lookout for or what should I avoid?  looking for rear pumpkin or  whole rear 
axle? how can I tell if possible whats good and whats  crap?
Thanks 
Ryan


 
____________________________________
From:  "derf" <_derf247 at gmail.com_ (mailto:derf247 at gmail.com) >
To: "Ryan Kubanoff"  <_ryan.kubanoff at comcast.net_ 
(mailto:ryan.kubanoff at comcast.net) >
Cc: "spridgets"  <_spridgets at autox.team.net_ 
(mailto:spridgets at autox.team.net) >
Sent: Sunday, May  10, 2015 8:39:29 AM
Subject: Re: [Spridgets] More highway speed  for a bugeye?  
 



You might also look into stronger axle shafts while you're  doing rear end 
work.  Any Spridget diff chunk should fit in your rear  housing.  Just drop 
the drive shaft, pop the axles out, and swap the  chunk.  Diff ratios are 
stamped on top of the chunk.  "10/39" is  3.9. IIRC "9/38" is what you would 
have on your 4.22.


On Sun, May 10, 2015 at 5:59 AM, ryan.kubanoff---  via Spridgets 
<_spridgets at autox.team.net_ (mailto:spridgets at autox.team.net) > wrote:


 
So i have a 74 midget with a 1275, rib case, and a stock rear that  will do 
70+ on a highway no problem.  Last year I bought a 60  bugeye that was 
modiifed by the previous owner to have a 998 cc motor,  rib case  and a stock 
bugeye rear.  It has more trouble with  highway speeds.  Could I swap out the 
stock bugeye rear for a late  model midgets?  Would that improve performance?
Thanks
Ryan



















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