AC Frua manual 4 speed conversion.

[Emmanueld]

Here is the box with the shifter ready to be installed! Unless I have made a mistake, the shifter will come out like the roadster above! It should be easy to use another shifter bent backward if needed!
   
   
   
   Emmanuel

[nanard289]

quote:Originally posted by Emmanueld
   
Here is the box with the shifter ready to be installed! Unless I have made a mistake, the shifter will come out like the roadster above! It should be easy to use another shifter bent backward if needed!
   
   
   
   Emmanuel
   

   Fantastic restoration project Emmanuel! Your new Top-loader gear box looks very nice (and very strong), it is a good choice to associate with a big block. I am impressed by the tail housing size. You will have probably to reduce your shaft line length. Shifter arm is not a big deal, you can easily adapt it or change it as you want. About the pilot bearing that is located in the crank shaft, don't hesitate to replace it to avoid my mistake []
   
   

[Emmanueld]

Hi Nanard, thanks, this is a 17" tail housing from a late 60's early 70's Torino with a 31 spline output shaft. With this setup, the transmission is exactly the same dimension as the big C6 automatic box that was on the car before, no modification to the driveshaft should be required. Don't worry, I will install a new pilot bearing, flywheel and a new clutch, probably McLeod. Nanard, the trans that is on the picture you posted, what is it? it does not look like a Toploader! []
   
   Emmanuel

[nanard289]

quote:Originally posted by Emmanueld
   
... With this setup, the transmission is exactly the same dimension as the big C6 automatic box that was on the car before, no modification to the driveshaft should be required. ...
   Emmanuel
   

   Again I suppose that you have a lot of investigations to select the right tail housing that will fit exactely to your driveshaft! For my replica I had have a good opportunity to buy a super T-10 (4 ratios) made by Tex Racing. It is also a good transmission for a small block. As you can see, the front bearing retainer is modified to install an hydraulic through out bearing to drive the clutch []

[Emmanueld]

Hi Nanard, This box is a bit special, I have requested that it be set up with wider ratios than usual. (The big block Toploader, 1 3/8 input shaft and 31 spline tail shaft was only available with a short ratio. David Kee and a few other have a 1 3/8 input shaft for the wide ratio first gear. This should give me a much more enjoyable car to drive on the road with a very high top speed!). Because I grew up in France, I like cars with long legs. For the time being, I will try the car with it's current 2.88 rear end, If it's really too long, I will go down to 3.08 which was the ratio for the manual AC Frua. Most big block US cars are running 3.54 at the minimum, some all the way to above 4.00, this is crazy, top speed is 90 miles an hour! I am dying to try it out! [:p]
   
   Emmanuel

[nanard289]

quote:Originally posted by Emmanueld
   
...Because I grew up in France, I like cars with long legs...
   

   Hi Emmanuel, 2.88 rear end ratio is not long legs, it's stilts  []
   As you know, French car taxes was calculated according to the engine displacement and .... rear end ratio! It is the reason why a lot of French car was equiped with a small engine and a long rear end ratio [] (to minimise the taxes), why the last ratio was called "overdrive" and why the top speed was not obtained on overdrive selection. It is obvious that if you like to cruise your car at low rpm (and low fuel consumption) this ratio is a good choice. However, if your Top-loader first ratio is lower than 2.8/1 it could be little hard to your clutch to drive in the city. As usually, the good choice is a compromise []

[Emmanueld]

You will find below a ratio comparison between various gearboxes:
   
   C6 Auto:         1:2.46 2:1.46 3:1.00
   Toploader close: 1:2.32 2:1.69 3:1.29 4:1.00
   Toploader Wide:  1:2.78 2:1.92 3:1.36 4:1.00
   TKO600 (Sport)   1:2.87 2:1.89 3:1.28 4:1.00 5:0.82
   
   As you can see the wide ratio Toploader is not all that wide!
   
   The AC428 manual list the automatic cars as using 2.88 rear and the manual as using 3.08 rear. I will try the 2.88 and switch to 3.08 if too long but remember the big block is so powerful and has so much torque! [8D]
   
   Emmanuel

[Emmanueld]

I am happy to report that the transmission is in the car and that the engine is now running! The new clutch pedal is in but we have a problem with the clutch not releasing fully. We are going to install a larger bore Girling Master cylinder. Hopefully, it will solve this problem. The trans. bolted right in, as David Kee said, no modification to the driveshaft was needed and the shifter is about in the right place. I bought an original 428 Cobrajet bellhousing on E-Bay, it fits perfectly. Slight modification to the transmission mount was needed. The flywheel, clutch, fork and throwout bearing also new. Photos to follow!
   PS: the C6 is for sale on E-bay!

[Emmanueld]

I am picking up my car first thing this morning and driving to the office, it's a 30 miles drive. We will see how it feels, first drive with a clutch, it's going to be different I am sure. It looks a bit in a sad state with primer all over and no bumpers, but I will paint it only after I am sure it is running a 100%
   
   Emmanuel

[Emmanueld]

Yesterday, I picked up the car, and besides getting stuck twice with clogged fuel filters, the car performed great! I am going to pull the gas tank out and have it cleaned and sealed, I should have done it when it was out of the car 10 weeks! Oh well.
   
   Besides that, the car has taken a completely different personality, the 2.88 rear end is about right, acceleration is fantastic and the shifter looks great, It feels like a sports car! THE HEAT PROBLEM INSIDE THE CABIN IS GONE!!!, The car is cool inside and the air coming out of the vents is cool.
   
   Also, the spoiler seems to work, on the higway, engine temperature is down to about 70 degrees/C. I am happy.
   
   
   
   
   
   
   I now have to duplicate the pedal rubber, cut the center console, get Wilton carpet to match the existing one. []
   Emmanuel

[shep]

Hello Emmanuel, Do you think the loss of cabin heat is down to the manual conversion, or your chin spoiler improving air flow under the car and away from the engine bay? Regards, Andy.

[Emmanueld]

Hi Andy,
   
   The truth is that it could be a number of things or all compounded together, if you look at the thread "AC Frua repaired floors, sills and inner wings" we used massive amount of "Dynomat" insulation over the floors under the carpets. Also, ceramic aircraft insulation was sandwiched between the floors and the new aluminum panels we made. The firewall was insulated as well. All the cold air ducking inside the fenders was heavily insulated too. My car being a later model has all the cold air ducking running inside the fenders instead of under the hood, it makes it easier to insulate. A new aluminum cowling was installed under the radiator modeled after the one in Jeffrey’s car, mine was missing. Also the manual transmission runs a lot cooler than the automatic and the gap between the transmission and the tunnel is also wider. Without doing the modifications in steps one at the time and trying the car each time, it’s difficult to assess what made the most “Bang for the Buck”! The Spoiler is definitely responsible for lowering engine temperature and probably under hood temperature as well. Also the whole new 2 ½” exhaust system was ceramic coated. The car has taken a whole new personality, with my previous suspension modifications, it feels light and fast like a Cobra, yet it is quiet and cool inside and with proper weather protection. Despite the 2.88 rear end, it still feels short geared; you are going 100 MPH in no time. It’s a lot of fun.
   
   Regards,
   
   Emmanuel
   
   PS, I just bought an original 68 427 side oiler block, It will be built as a 460 cube, with a not too crazy hydraulic cam, It will completely look stock on the outside. I think I might have to install Halibrands with that type of muscle.
   
   I had a 3/4" front anti-sway bar installed, the complete hardware came from Kirkham, brackets and all, What an improvement, it now drives like a modern car! turns flat and is much more stable in a straight line as well. I have been driving around with an outboard motor gas tank, so this weekend the tank goes back in! Emmanuel

[Emmanueld]

Hi everybody, I was wondering where I could find the new rubber for my pedals, There is a place which can make it over here but it would be custom and very expensive. Looking at an MGB pedal (Almost the same but not quite) the other day made me think the rubber is probably sourced from a mass produced auto, any opinion? I can post a photo if needed!
   
   Emmanuel