Ah, yes, now I remember.....
Discussion
After fitting an 'A+' 1275 engine onto a gearbox this afternoon, when I turned the engine over by hand, something was jamming.
Then I remembered, with early 3-syncro Cooper gearbox casings, it is sometimes necessary to remove some metal from the gear casing to permit the later rods to rotate. It's no.3 big-end nut which is hitting the casing and all I have to do is machine away a bit of the casing until it clears.
I think the last time I had to do this was in 1968 when i fitted a 1275 'S' engine onto an early 998 Cooper box.
Another reason to always do a 'trial dry build' when mating assemblies which have not been mated together before. The original engine off that box was an early MG1300 lump with the 'lumps'on the big end caps and they cleared OK.
I hope I don't forget this over the next 40 years!
Then I remembered, with early 3-syncro Cooper gearbox casings, it is sometimes necessary to remove some metal from the gear casing to permit the later rods to rotate. It's no.3 big-end nut which is hitting the casing and all I have to do is machine away a bit of the casing until it clears.
I think the last time I had to do this was in 1968 when i fitted a 1275 'S' engine onto an early 998 Cooper box.
Another reason to always do a 'trial dry build' when mating assemblies which have not been mated together before. The original engine off that box was an early MG1300 lump with the 'lumps'on the big end caps and they cleared OK.
I hope I don't forget this over the next 40 years!
pete
years ago i had a perfect 3 syc case and was modding it to fit a 1071 sa crank onto it, somehow in a beer fuddled state the dummy 1071 block i was using got a 1275 crank put into it.
every time it hit, we ground a bit more out, knowing that a 1071 would fit into it with only small grinding out needed, when, opps, day light!!! curses!!!
remotes are a great gearbox, that nice alloy remote stops the engine thrasing around, sure the selector forks take a bit more time to fit than in a rod change, but i like them
years ago i had a perfect 3 syc case and was modding it to fit a 1071 sa crank onto it, somehow in a beer fuddled state the dummy 1071 block i was using got a 1275 crank put into it.
every time it hit, we ground a bit more out, knowing that a 1071 would fit into it with only small grinding out needed, when, opps, day light!!! curses!!!
remotes are a great gearbox, that nice alloy remote stops the engine thrasing around, sure the selector forks take a bit more time to fit than in a rod change, but i like them
It's a customer's car. He gave me a beautiful S/C C/R 3-sync box, in lovely condition and wants an A+ 1275 added. The box is clearly an early Cooper or 'S' and it has the remote change. I just forgot about the clearance issue. I compared the clearance at the interface plane with a 1275 GT block ass'y I have and the big end caps come about 1.5 mm closer to the gearbox casing, hence the foul a bit further inside the box. There appears to be plenty of 'meat', sufficient to remove about 2 mm locally. I'll just keep doing it a bit at a time. It's actually the web inside the box which the rod nut is hitting. It just reminded me that it's something I should have remembered.
You do't just live and learn, you live and learn, forget, then live and re-learn! Perhaps it's my age.
You do't just live and learn, you live and learn, forget, then live and re-learn! Perhaps it's my age.
So if you have anything with "S" size big end journals you don't need mods on the 3-sync casing - irrespective of displacement (970, 1071, 1275 & small bore 998 / 1098?)From the recesses of my (now failing due to age) memory, I seem to remember that the early casings, typically the 850 with the wand-type lever and the early 997/998 3-syncro boxes would not accept the long throw 'S' cranks and rods. A genuine 'S' box will accept everything A-series, but now, I realise, not 'A+'.
The best thing to do is to do a trial-build when mating any block with any box if you have any doubt at all. I know it takes a bit longer, but it's worth it.
The best thing to do is to do a trial-build when mating any block with any box if you have any doubt at all. I know it takes a bit longer, but it's worth it.
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