10 replies to this topic

[salient]

I want to fit my 1275S engine to a 22G846 gearbox. Does anybody know if the crank when rotating will contact the gearbox walls? I am hoping that I won’t have to remove material from the gearbox.

The 846 gearbox was fitted to the elf/hornet so was only fitted to 998 engines which have smaller strokes to the 1275 S.

 thanks 

[nicklouse]

Is that a typo or a miss read?

22G346?

[Shooter63]

I'm sure that was a 4 synchro box, so anything should fit on the top

Shooter

[Spider]

In all ways that matter, it's the same as a 22G1128 All Synchro Box.

All engines will fit this no problem.
 

[salient]

Thanks all for your comments. I managed to find a 22G1128. casing so have started to build the gearbox with a set of S close ratio gears. I have quite a few gearbox bit to choose from so for each part I was able to select those in the best condition. When I assembled all parts I found that I could not select 2nd gear and as I tried to force it the reverse gear started to move. Clearly there was something wrong. It took me quite a while to realise that I had fitted a 3 synchro selector fork by mistake. I had to cut it down top and tail so that it would clear the casing and the reverse selector and then all gears selected fine. Just goes to show how difficult it can be when selecting from a pile of bits rather than from a stripped gearbox set.

[salient]

Has anybody tried to fit a 21 tooth diff pinion to the end of the mainshaft? I did and found that I had to bore out the bearing retainer to clear the outside diameter of the pinion teeth. I guess those MPI’s fitted with this pinion must have a different bearing retainer fitted. Wonder what problems I will encounter next. 

[imack]

Years ago I installed a 2.9:1 final drive to a 22g1128 box and spent ages with a 1/2 round file creating clearance in the bearing retainer. No idea how many teeth a 2.9 pinion had though.

[salient]

Thanks imack. This final drive is 2.76 so pinion is even bigger. Fortunately It only took me a few minutes on my lathe to machine out the necessary material.

[Spider]

I mean no disrespect here.

 

,,,,,,, so have started to build the gearbox with a set of S close ratio gears.,,,,,,,,,,

 

 

,,,,,,, This final drive is 2.76 ,,,,,,,,,,,,

 

Respectfully, have you thought this combination through ?  Especially if the engine is running even a mild cam, I'd suggest for the road, that wouldn't be a very nice combination. 1st Gear (and all others too) will be very tall, you'll find you need to use a fair bit of clutch slip to get moving and be forever rowing back and forth through the gears.
 

[salient]

Yes I am a little concerned about this issue but I just wanted to see how drive able this set up would be.

[stoneface]

I'm with Spider on this, but you may like it.

 

I was running SCCR gears with 3.2 diff on a road car and it was not great even with a higher torque engine I'm running.

 

I know the ratios of the S close ratio set is slightly different, but with a 2.76 diff they won't be far off what I was running.

 

I've since taken the close ratios out and fitted standard instead.

 

I'm deffinately no expert but many say the S close ratio and 3.44 diff is a great combination.

 

But, alot depends on the spec of your engine and cam. And what your expections and usage are.