Jump to content


Photo
- - - - -

850 Tuning


Best Answer unburntfuelinthemorning , 08 August 2019 - 09:19 PM

A 998 Cooper casting will work if you can get a good one but they normally need a lot of skimming to get a decent compression ratio as the 998 Cooper used raised pistons and yours are likely dished. 

 

Nearly as good as the Cooper head are modified small bore heads from lesser models. 

 

Use the highest octane fuel you can easily get and use the highest compression ratio you can for the fuel.

 

Separate the inlet and exhaust manifolds to get rid of the hot spot - you'll need another set of manifolds - cut the exhaust off of one and the inlet off of the other.

 

Replace any restrictive exhaust mufflers with straight though versions.  No need to increase the pipe diameter.

 

Throw in a K&N replacement element air filter and try to get the vehicle tuned on a rolling road to get the correct needle in the carb and also the distributor recurved.

 

Doing these things will get you the power you require and a little more without the vehicle looking any different.

Go to the full post


  • Please log in to reply
16 replies to this topic

#16 unburntfuelinthemorning

unburntfuelinthemorning

    Camshaft & Stage Two Head

  • TMF+ Member
  • PipPipPipPipPipPipPipPip
  • 1,914 posts
  • Location: Bedfordshire

Posted 11 August 2019 - 07:34 PM

Vizard the HS2 (see Retro Minis)and you’ll be making plenty more power on a standard 850.

That's another good addition to the list of mods which can't be seen externally.



#17 Minigman

Minigman

    One Carb Or Two?

  • TMF+ Member
  • PipPipPipPipPipPipPip
  • 779 posts
  • Location: Barnstaple

Posted 11 August 2019 - 08:05 PM


Vizard the HS2 (see Retro Minis)and you’ll be making plenty more power on a standard 850.

That's another good addition to the list of mods which can't be seen externally.
I have a 1960 DL which I desperately needed more power from for navigating the Exmoor hills where I live. I opted for a 1098 + 0.040” 1132cc engine which apart from the pulley damper looks the same as the 850. I’m still running standard HS2, combined manifold and pea shooter 1.25” single box exhaust. It has a modified 202 head, MG1100 cam and K&N filter in the standard HS2 housing. On Slarks RR it made 48bhp and 61 lb ft torque. I’m thinking of improving the manifold and vizarding the HS2. Was told by Slarks to expect a 10bhp improvement and more torque.

Edited by Minigman, 11 August 2019 - 08:06 PM.





0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users