I'm looking for help with my 1098 build for my mini K. I've got a 1098 complete engine as my basis.

12G295 head with 33mm inlet and 26.4mm exhaust valves
Twin HS2s
Nissan Pulsar electronic distributor
RE266ss camshaft
Compression ratio between 9.5-10:1
Fully balanced bottom end
+40 though
Maniflow freeflow exhaust manifold
RC40 exhaust system
3.1 diff.

I'm after something that is lively and fun to drive. Ideally around the 70hp and 70ftlb of torque would be nice at the flywheel.

Would this setup achieve close to those figures.

Nobody?

The 1098's supposedly made 55hp at the fly from the factory, so figure any performance mods should make 70hp fairly achievable. Remembering though these engines make useable power in the lower rev range so if your just chasing power then the engine just doesn't have the legs to make high hp without endangering the crank in Na trim.

Torque is my main aim for the engine. Nearly everyone says that the 1098 shouldn't be revved over 6000rpm. That doesn't worry me as I very rarely go that high. I'm after something that will cruise along and still let me overtake without having to rev the guts out of the engine to do so. If I can make more torque at a lower rev range I'll be happy.

I rev mine to 6000 all the time but I won't go higher

What are the specifications of your engine?

Hi Not850
The problem with the rumour about not revving 1100 past 6000 RPM was started by David Visard when he wrote in his book and put the fear of god in every body,ask him how much testing and development he has done with the 1100 and you'll find very little.
I'v been building these motors for a long time and I have NEVER broken one yet,but I have broken 998 cranks, the problem is people tell how they have broken or cracked an 1100 crank but never seem to mention when they have broken a 998 crank.
We run 1100 cranks to 8000 rpm in a lot of engines be it mini's, sprites or open wheeler race cars, like any thing put it together right and it will be reliable, if you are going to abuse your engine you will break it no mater what motor it is be it an 850 998 1100 or cooper s, just ask around about how many people have broken or cracked Cooper S and i'll bet there is more "s" cranks broken than 1100, and yet they have a shorter stroke and bigger mains giving it more over lap.
The thing with a mini is if you are going to make a performance engine be it a fast road car or a race car the lighter the flywheel the better of you are, on my fast road cars I like to use the MINI SPARES ultra light one with the light backing plate, and no I don't find it to light on the road, the thing that does a lot of damage is on and off the throttle at high RPM resulting in the crank twisting back and forth, hence this is where the light fly wheel helps.
These little 1100 are a great little motor don't be afraid to build one and give it a buzz.
Graham Russell

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"It's better to be not informed than ill-informed"

Thanks for the information Graham, I am building one similar to NOT850, matter of fact you have the head and the camshafts at present awaiting for you to work your magic on them. It was something that I have been told also that the 1100 crank would not last at higher revs, but you have put my mind at rest as I could see no good reason that they would break unless they had been made with an inherent design fault. I also do not normally rev a motor past the 6000 rpm as it is a road car and does not achieve a lot more above that rpm other than bring unwanted attention from certain members of a State Department who like to chase cars.

Having owned and worked on a couple of 1100's for many years in the past I could see no difference to any other motor of that design. Information greatly appreciated.

Graham

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1974 Leyland Clubman
Lots of good machines

Of all the things I have lost, I miss my mind the most.

I'm very new to building minis. Last one I had was about 12years ago in the UK. It was a 998 with a stage 1 kit fitted. It was so much fun to drive. I now have a mini k and want that fun back. Plus a little bit more go would be good to have aswell. I'm looking at the small bore because its the original size for the car and if something goes bang there are plenty of blocks to find unlike the 1275.

Graham Russell did I read somewhere correctly that you were developing a new camshaft that develops more torque lower in the rev range?

Have you had a look at Grahams web site , plenty of good reading there on his small bore engines .

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ex-NSW Police 1970 MK II Cooper S
VMCI #43

Hi Not850
Yes I am developing new cams all the time moving along with the times, some cams don't work like they should but I learn by my mistakes so I scrap them and start again, but I have some very good road cams now making very good torque down low and can still make good HP as well.
I have just had some very special valves made in the UK by G and S the people who make the race valves for Mini Spares, Swift Tune, MED, etc, they are made for the small bores 1.26 or 32mm for the inlets and 1.07 or 27.1mm for the exhaust, they are my design with stellite tipped ends will be here this week, no they won't be cheep they will be on par with the race valves that for sale for the 1275's now but you only get what you pay for.
With these small bore motors it is now getting easy to get Cooper "s"power and performance with head and cam design's you can use 1275 parts extractors, manifolds, carbies when they brake a crank
Come across to the small bore club and have some fun.
Graham Russell

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"It's better to be not informed than ill-informed"

I've read all three parts of project small bore and the four parts of project 68mm countless times and there is a lot of inspiration there. Looking at project small bore and what engine parts I have to use and hopefully I should get the 70ftlb that would make a fun Mini to drive. The only real question I have is I'm wondering if the torque will peak earlier with the RE266ss and standard rockers compared to the 1.5 rockers used on project 68mm?

HI not850
Your std rockers will work fine i'm pretty sure they will more than match the 1.5 rockers down the bottom end, Greig at Mini Classic runs this cam in all his STD Cooper S rebuilds because it drives so well down low it will idle at 700 RPM but makes a lot more power and torque than the STD cam.
Graham Russell

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"It's better to be not informed than ill-informed"

I just checked back on part two of project 68mm and with the single SU it is very impressive torque figures. I'm now wondering if it is worth while going straight out to the 68mm pistons or stick with a 60thou oversize?