Anyone running this gear set?

[94touring]

https://minispares.com/product/Classic/Gearbox/Helical%20gears/C-STN48.aspx?1508&ReturnUrl=/shop/classic/Gearbox/Helical~gears.aspx|Back%20to%20shop

I'm curious if anyone is running these particular ratios, or a very similar ratio, and what your thoughts are.  I'm mulling going with a 5 speed and a 3.44 FD and the 5 speed boxes use this gear set.  At first I was going to go with a 3.2 FD, making 5th a 2.76, but once I saw how tall 1st-3rd are, though that probably isn't what I want. I can adjust the drop gear ratios and turn a 3.44 into a 3.30 if I decide I want taller too.  But, it would be nice to get a review before I actually pull the plug.  If I pull the plug. 

[cstudep]

Probably not much help since I have not actually used it, but I have a box with straight cut gears in it and talking back and forth with Calver about it, he said it was the same ratio as the Clubman set he helped Mini Spares develop for the 4 synchro box. He seemed to intimate it was a good ratio to build a decently powered road motor around. Looking at the numbers of the straight cut kit I was chatting with him about and the one you posted the only difference is 2nd. 1.644 vs the 1.711 of the straight cut setup.

[94touring]

What final drive did be recommend with your cam and engine specs?  3.44 or 3.6?


I have the 1275gt/cooper S ratios at the moment with a 3.1 fd.  Ratios are:

3.330 2.094 1.353 1.000

Which are a tad taller than most later A plus minis which are:

3.647 2.185 1.425 1.000

But your SC gears, aside from 2nd, and these heavy duty helicals are:

2.583 1.644 1.250 1.000 (0.865 5th gear)

So I did some playing on guess-works.com with the gear calculator and found that the much taller 1st and 2nd ratios with a 3.44 FD is basically the same as a later A plus mini running a 2.76 FD.  I've driven those and they're fine. With a high profile cam I'd think it would suck though, but I won't have that issue at least. 3rd gear in my situation going from a 3.1 to 3.44 with the ratios changed is essentially identical, maybe 100rpms shorter, and of course 4th is shorter.  5th then becomes a 2.970 overdrive.  So I think this is probably ideal.  Shouldn't be a pig to start from a stop with my cam but I can really wind 1st and 2nd out, 3rd and 4th gain some acceleration for when I'm driving sporty, and 5th becomes my highway cruise gear.  If for some reason I a want it smidge taller I can do a 0.965 drop gear ratio.

[cstudep]

If memory serves a 3.1 fd is his favorite setup for performance but he also isn't running down an interstate at 70mph on the regular, or at all most likely. As he told me, it's not a big liter V8 it's a small capacity motor so it needs to rev to get any sort of performance out of it, which makes sense.

Like you say though a 3.44 might be a decent compromise for a little less revs. It's definitely a fine line with these small engines around gearing, cam, and a tolerable RPM range at a persons most likely usage case.

looking back at our conversations this was one of the setups he mentioned and is kind of the area I was leaning toward since I have the older straight cut 3synch box that is almost identical to the  Clubman spec gear kit.
"My favourite spec is a 1330cc unit, RE13OT cam, 1.4:1 rockers, CST2001 Sport spec head, gearbox with MSC Clubman straight cut gear kit (I designed that to be what it is), 3.1FD on 10" or 12" (with low profile tyres) wheels. Slightly lumpy idle. A bit fussy until 2,300 rpm, but then BIG smiles all the way to 7,000 rpm. Over-taking is a simple prod and go affair."

[94touring]

You may have your final drive understanding flipped around. A 3.1 will rev lower at highway speeds (tall) and a 3.44 will rev higher (shorter).  I really like my 3.1 in there now because I'm cruising at 4k rpms doing 73mph compared to 4450 rpms with the 3.44 FD.  However, in a drag race to 100mph my lightened fast road 1310 with a 3.44 probably would have beat or be neck and neck with my fast road 1425cc that's heavier with a 3.1 FD.  What I'm looking to achieve is gaining acceleration to 100mph via gearing but not having to cruise the highway at 4450 rpms. Hence the 5 speed. At 73mph in 5th gear I'm showing 3800 rpms with a 3.44. 

I need to get this car on the dyno to see where my shift points should be with what my power curve is.  I can maybe increase it from 6k rpms shifts to 6500 or hell maybe 7k.  Though it's a stroker, so I'm betting 6500 is probably going to be it.  I know at the moment in 4th with a 3.1 FD I'm aerodynamically limited to 5500-5700 rpms, which is also about 100mph.  In lower gears and less wind resistant it happily will keep revving.   The 1310 with  3.44 FD would just keep on going to 6k and beyond in 4th if I didn't let up. 

[cstudep]

Yes you are correct, I am going the wrong way with my thoughts LOL. Not sure why I always do that with gearing and male/female electrical connectors. I know which is which but always mix them up when talking about them for some reason.

Thanks for the correction.

The 5 speed is definitely intriguing though, perhaps a guy can find that sweet spot where it revs happily in the lower gear range but you can cruise a little more leisurely when you want to.

[94touring]

I did a little research on that Re13OT cam.  Sounds like it's closer to a 286, which explains why Keith said it's fussy under 2300.  Now, depending on your driving style and what you're looking for, that cam for what I'm doing wouldn't be ideal.  Particularly with the taller 1st on these gearsets.  Even more so with a 3.10 FD trying to get going from a stop.  In both engines we built (Dave) for these fast road street cars, the cams are coming in lower.  Like 1200-1500rpms and pulling hard to 6000-6500.  I'm a fan of Keiths 1.4 rockers and used them on the 1310.  I may try them on this 1425. That Re13OT cam probably screams up to 6500-7k. Anyways, at minimum on these taller S straight cut gears or the clubman ratios, a 3.44 would be as low as I'd want to go.  Just because 1st gear is going to be really tall.  Add a more aggressive cam and it quickly turns into something you hate to drive light to light in town.

[cstudep]

Yeah that cam was a little aggressive for my general use case I think, he has another one that he developed that I was interested in that he does not put on his website because he doesn't want people "borrowing" the profile for it. I would have to look back at the conversation to verify but it was less aggressive than that Re13OT/286 but a little more peppy than the typical 266, I think he specifically said it is a 266 "with a little more sparkle".

[94touring]

We used the evo001 cam from minispares which is like a 266 with "sparkle" on the 1425. Used a 266 on the 1310 paired with the 1.4 rockers.  We have true S 1.3 rockers on the 1425, but like I said may try those 1.4s because with the displacement of the motor it will probably like it. You won't be disappointed with a 266 or the "sparkle" upgrade from my experience. 

On that fast road 1310 with later gear ratios and the 3.44 FD, myself and now Jim who owns it, both said the same thing.  1st gear is almost pointless. It's a very quick 1st!  You can easily start in 2nd if not on a hill. Having driven Daves 2.76 FD mini, 1st is very tame and perfectly fine.  BUT, if I used a 3.1 on these clubman gears, I just don't know I'd like that. I think adding 1.4 rockers and I have a different set of headers for the 1425 that will let it breath a bit more, I'm thinking I can go another 500 rpms in 1st and 2nd when I'm driving like a maniac to offset how tall they're going to be. I just need to drag race Jim to know for sure which car ended up faster lol.