8 replies to this topic

[Shagsta]

What is the difference between these two engines? As far as i can see looking through the Haynes manuel there is no difference in piston size or any of the other measurements. What would be the better engine to upgrade as i have both size engines and have a set of 60 thou oversize pistons and an engine rebuild kit. i would possibly look at either supercharging or turboing later on. Any help appreciated.

[Ryang556]

It's the stroke size that is different, 998 stroke is 76.2mm and 1098 stroke is 83.72mm, the 1098 doesn't like to rev as much as the 998 as past 5k it starts to have breathing problems and there is problems for the crank to go if it's constantly taken to higher rev's all the time.

I would go for the 998 any day of the week given the choice of of a 998 and 1098, I'm sure many people will agree with me as well

[lewistranter]

I agree 998, bit if you can get the 1098 head then get it! I'm sure most of them came with the 12g295 which is probably the best head made for a series! (correct me if I'm wrong)

[project mini chris]

... But if you get a good 1098, my god are they torquey compared to a 998 and even some 1275's! Yes, they suffer from crank wear, valve bounce when you push them hard and are not particularly revvy... but build/ find a good engine and you have lots of low down torque and grunt from that little engine!
Very under-estimated are 1100's! I'm building my Pre- A+ 1098, with a pocketed block, 12g940 head, MG Metro Cam and MiniSpeed 3:44 Gearbox!

[MiniElliott]

The 1098 has the 12G202 head. It's still a good head over standard but nowhere near as good as the 12G295. Also 1098 pistons are shorter so they don't protrude the block at TDC due to the longer stroke.

[project mini chris]

I agree 998, bit if you can get the 1098 head then get it! I'm sure most of them came with the 12g295 which is probably the best head made for a series! (correct me if I'm wrong)

MG1100's had the 12g202 Head's, and these were also fitted to many Pre A+ Engines, aswell as some 295's (But there's were primarily 998 Cooper Heads). Later A+ Engines had the 998's CAM 4180 Heads

[dave-88_123]

if you are planning on spending some cash a tuned 1098 is amazing in comparison to the 998 but if your on a budget use a 998 as 1098 can be tempremental as standard

[Mal_whitby]

Providing you don't spend a lot of time at high RPM (and let's be honest very few road cars do), then a 1098 is a good engine. They have better low and mid range torque than the 998. There's nothing wrong with the 998, they're good too, for everyday driving a 1098 is also a good engine.

BMC used the 1098 in the heavier Austin / Morris 1100 and derivatives (model no. ado16), they never put a 998 engine in those heavier cars for good reason, because they'd be under powered (or more specifically under torqued). The 1098 is not tempremental if it's not revved too hard, as a road going engine they're very good. The Austin / Morris 1100 was Britain's best selling car for 10 years, millions of em have been used because they're a good all round road going engine.

Edited by Mal_whitby, 05 July 2012 - 11:46 AM.

[jakejakejake1]

Another thing to consider is if you turbo the car, it won't need to rev that high to make power, so the disadvantages of the low revving 1098 are negated somewhat.

But parts are easier to find for the 998 as they were/ are more popular.