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Roller Rockers in Rover Mini Auto
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Author:  dawi03 [ Sat Oct 05, 2019 8:02 pm ]
Post subject:  Roller Rockers in Rover Mini Auto

Just wondering if putting rockers in a 998 auto carbed engine will improve performance much? My mechanic said it is the easiest and cheapest way to get more out of engine but not 100% sure

Thoughts on this and if anyone has done this before?

Author:  9YaTaH [ Sun Oct 06, 2019 6:59 am ]
Post subject:  Re: Roller Rockers in Rover Mini Auto

I think getting another mechanic might improve the cars performance :roll:

Author:  simon k [ Sun Oct 06, 2019 9:18 pm ]
Post subject:  Re: Roller Rockers in Rover Mini Auto

you won't get much improvement on their own - you probably wouldn't even notice. However, as part of a "package" of improvements like a bigger carb with a needle to suit, good extractors and exhaust and shave the head for more compression you'll get it going quite well

but a 998 auto is never going to be a rocket...

Author:  drmini in aust [ Mon Oct 07, 2019 5:21 am ]
Post subject:  Re: Roller Rockers in Rover Mini Auto

I played with my Matic a bit before I gave it a 1275 S transplant.
A 998 auto already has little torque off the mark, 1.5 roller rockers or a cam change will make this worse. 1.3s might give marginal improvement, but not worth it for the $$$ involved.
Shaving the head and a little porting does help, as will a freeflow exhaust manifold.
They already run an HS 4 carb.
BMC should have used the 1098 instead...;)
Edit:
If rebuilding I would throw a 1098 crank & pistons into it for more torque. Block is the same.

Author:  Ian_B [ Mon Oct 07, 2019 7:06 am ]
Post subject:  Re: Roller Rockers in Rover Mini Auto

Just witnessed a mate have to pull a big buck V8 down due to roller rocker failure .Not good
Rocker didnt break Needle roller collapsed

Author:  Ian_B [ Mon Oct 07, 2019 2:37 pm ]
Post subject:  Re: Roller Rockers in Rover Mini Auto

Was talking to a mate today and he commented on how they are used in radius arms in the same duty .

Author:  drmini in aust [ Mon Oct 07, 2019 5:52 pm ]
Post subject:  Re: Roller Rockers in Rover Mini Auto

Ian_B wrote:
Was talking to a mate today and he commented on how they are used in radius arms in the same duty .

Original MK 1 850 Minis in UK had 13/16" dia bronze bushes both ends of the arm. The inner ones used to seize up with the load.
So, around1960 they fitted a full complement (no cage) needle bearing there to cope with the load. All Oz Minis got this.

Big wheel Moke had these needle bearings fitted at both ends, for the same load reason.

Author:  9YaTaH [ Tue Oct 08, 2019 7:39 am ]
Post subject:  Re: Roller Rockers in Rover Mini Auto

drmini in aust wrote:
I played with my Matic a bit before I gave it a 1275 S transplant.
A 998 auto already has little torque off the mark...


Having once driven a nicely restored Matic...I can assure you that they launch quite well and could win just about any drag race over the first 50 yards! 8)

Author:  winston5454 [ Tue Oct 22, 2019 3:12 pm ]
Post subject:  Re: Roller Rockers in Rover Mini Auto

Hi, wondering if auto and manual crankshafts from
approximately the same year are the same ? For
example I have a 67 998 auto, would a 1100 crank
from manual car, early 70's fit ?

Author:  Scoop [ Tue Oct 22, 2019 6:54 pm ]
Post subject:  Re: Roller Rockers in Rover Mini Auto

Yes, pistons would also need to be changed due to pin heights.

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