are all singlerail input shafts the same?

[Clevo120Y 815]

Hey guys, is every input shaft from the very first single rail to the last one ever made the same? reason I ask is a guy I know is looking at buying a few from a bloke and he doesn't know what they are from, they are to be spares for a EL 6 speedway car, also all the boxes are from Fords. Cheers

[gerg 10,871]

As for shaft dimensions, I believe they're all the same on all Fords, and are top loader size (10-spline, 1-1/16" dia). However the primary reduction gear (the one attached to the shaft) that also doubles as 4th gear dog varies a lot between the different ratio Ford boxes, with different numbers of teeth for each. There were 3 or 4 sets of ratios available: most often referred to by the 1st gear ratio. The later 6cyl ones were 3.43, EFI 3.50, earlier 250 and 302 had 3.06, and 351s had a really tall 2.46. As long as you match the shaft to the ratios in the box you'll be right. I've come across some info elsewhere that has tooth counts and techo stuff like that. Best boxes for circle track work would be the close ratio, taller 3.06 and 2.46 boxes. Don't bother with Chylsler or any other ones, they were all different apparently.

[ando76 4,354]

gerg most of the speedway guys would be using second gear (borgy diffs) or top (9") diffs.  From memory there are two different (ford) second gear ratios 1.99 being more common and 1.96 in the V8 single rails.  But I have been wrong before today. 

 

Yeah they are all 1 1/16" 10 spline inputs - same as T5.  I have two T5 boxes here as I was looking at stripping a couple of gears out of them and running them as they have to be lighter than a single rail and will happily run ATF fluid.  Strength would be an issue in 2nd in the t5 but probably not so in the single rail.

 

single rails are becoming a bit thin on the ground so I would be grabbing them sean. 

[Clevo120Y 815]

Thanks guys, much appreciated info

[gerg 10,871]

Ando if you really want strength I'd stick with the good old single rail. If they're any heavier at all, it would only be by a couple of kilos due to the iron case. The T5 has some things about it that I reckon were a step backwards for strength, like the steep helical cut on the gears, which made it quieter but gave a lot more end thrust. This works the thrust bearings pretty hard, particularly if using any gear but 4th. Single rails have their faults too, but overall I'd like them much more than the T5 if only they had another gear. Might have a couple spare SRs once I do my T5 swap

[ando76 4,354]

Yeah gerg I was only going to go the T5 when I went 9" (to allow top gear 1:1 with 5.8 gears in the diff). 

[gerg 10,871]

Ok gotcha. You could do away with the entire layshaft and driven gears then. Fuck 5.8s.... That's rock-hopping gears!

[ando76 4,354]

Rules state 2 forward gears and reverse so gotta be a bit careful.  machine down the gears or make spacers were the plan.  Car getting written off put pay to that.  5.8's are mild mate.  you can get right up to 7's from memory. 

[gerg 10,871]

Just out of curiosity, could you use a 3-speed?

[ando76 4,354]

yes and no.  they have a smaller input shaft but still 10 spline.  The only problem is that there is not a readily available competition clutch to suit the 3 speed input shaft sizing.  Sacchs do make one but it is way dearer than a Quarter Master style 1 /16" 10 spline clutch.

 

I actually started my speedway racing with a ford 3 speed converted to floor shift with a HHHol... gmh.. shifter converted to suit. 

[gerg 10,871]

Oh yeah forgot about the shaft diameter. Lol those shifters were ancient things... Even a workmate of mine who is a Holden head and has an XU1 reckons they were rubbish