Ohhh but if you went manual r380 box ashcroft sell a rather nice straight cut gear set from quaife!
Be interesting to see how ashcrofts uprated torque converter and clutch packs cope with it.
Too nice too offroad, just use it to annoy fast road cars!
Mr Dirty
I looked at all options - this engine would munch an R380 - the Ashcroft uprated LT85 is agricultural but much stronger and with an AP Racing clutch would have been ok - this is what my mate has bought to mate up to my old TVR engine which he now has in his 90 - it is much fun!!!!!1
However the whole point for me was to build a civilised hot rod/ cruiser
that would look cool, sound fantastic and be very fast.
I had a long chat with Dave Ashcroft about my options and we came up with the solution I now have.
It is a ZF HP22 with uprated heavy duty Internals, uprated sprag clutches and govenor/pump (Stage 1) and the front end from a HP24 which is much stronger than the 22 front end - this is a stage 2.
We then went for the biggest torque convertor available - Ashcrofrt supply an adaptor for the big rover (5.0 plus engines), but not for the Chevy.
I had the old Overfinch adaptor from the original auto setup which was basically just a slightly thicker flexplate with a boss assembly - this was the standard overfinch application and can only be used with the medium torque convertor - most of the torque was wasted and lock-up was painfully slow in coming.
The guy who built my engine is a Santa Pod Mechanical legend and he came up with a design that is very similar to the system he builds for Chevy dragsters (but not as hardcore) in that is it uses a lightweight ring bolted to the torque convertor, and then a semi-flexible plate bolts to this and then this in turn bolts to the boss which is in turn bolted to the flywheel.
The principle is that no one area is taking all the torque at once and everything gives a little, so spreading the load across the friction system.
He has had no failures with this system.
In practice it works very well - there is a little reluctance to change up from very cold but after the first up-change it is superb - the changes are virtually imperceptible and lock-up is virtually instantaneous.
Dave Ashcroft told me the damage to gearboxes really occcurs on full-throttle kickdown but I have so much torque I have set the kickdown to the minimum sensitivity - I don't really need it and changing down to third manually to overtake is no chore in any case.
As I said earlier in the thread the whole thing runs like a dream and this engine/gearbox did 2000 miles in the disco before the defender rebuild started.
The only subsequent addition is a new late-type(post 97) 1.2 transfer box from Ashcroft as they have taper bearings and the input bearing is cross-drilled to prevent wear - they supply the correct gearbox output shaft with the transfer box.
This later item doesn't whine after 10000 miles like the earlier ones.
Thanks for your interest.
