28 replies to this topic

[maystro]

I bought this engine about 16 years ago which I can't believe it has been that long.  

 

It's  a 998 A+ long motor bored 40 though with run in miles.

High compression, Hepolite flat top pistons

Stage 2 unleaded 12g202 unleaded head

Stage 2 cam with mini/late MGB cam followers

Stupid me swapped the cam for this one which is way to lumpy for a daily driver - Kent 276 or quite possibly 286 I can't remember but I can only drive around town in third gear for speeds under 60 kpm, and so spark plugs have a very limited life.  

Oversize valves , stelite valve seats

polished ports

A+ series double row timing chain

High volume pin drive oil pump 

Fully balanced.  

 

I'm sending the head off to a machine shop because it looked totally coked up and a little oily.  

 

Ok my question is a 1100 going  to give me much of a performance boost over my 998 bored 40 though, or should I scrap the lot and get a 1275 block?

[cal844]

The 998 with the right mods will give the same power as a stock 1275.

[ads7]

Stay with what you have, bar replacing the cam for a cooper 997 or mg metro type profile.

Small bore run so much smoother in my experience

[Spider]

Going from a stock 998 to a stock 1100 IMO, is well worth it.

 

If the funds will stretch, a  1275 is a better choice, but the 1100 isn't too bad at all.

[whistler]

Just finishing a 1098 overbored engine and expecting around 75lbft torque. You can upgrade the 998 engine to 1098 by changing the crank and either fitting 1098 pistons or having the 998 pistons crown reduced in height (depending on crown thickness). Everything else is the same.

[Spider]

I did mean to include in my post ^ that I always felt a 998 was just that bit too small in a Moke, and you were always 'pushing' them and certainly on the open road, you could seldom 'cruise' easy, where as the 1100 engine lands on the other side of that 'hump' and feels a much happier engine to drive with.

 

Just finishing a 1098 overbored engine and expecting around 75lbft torque. You can upgrade the 998 engine to 1098 by changing the crank and either fitting 1098 pistons or having the 998 pistons crown reduced in height (depending on crown thickness). Everything else is the same.

 

As they came from the factory, yes, It was the Crank and Pistons that were different, and they also had a better head too

 

If converting from a 998 making that in to an 1100 engine, it's fairly important to also fit an 1100 distributor and needle in the carb too.

[robert.hedges]

I would also note the need for a harmonic dampener. The older 998's didn't have the rubber dampener part in the pulley.

[timmy850]

I know it’s not a great comparison but I went from a standard 998 with a stage one kit to a modified 1098 and the difference is huge. Sure it probably won’t rev the same as a 998, but it doesn’t need to as it makes more power at a lower RPM.

Mine is
+080 flat top pistons
266 cam
12G202 head that’s been ported and chamber was modified - 31.8mm inlet and 27.2mm exhaust valves
Programmable ignition

Mine is very smooth and lots of low down grunt, which is perfect for a road car.

[Mini Manannán]

Fairly irrelevant comparison, but I remember, 35+ years ago, going from an 850 to 1100 and thinking what a beautifully smooth and powerful engine I'd upgraded to.

[PoolGuy]

The modified 1100’s are of interest to me. Whistler and Timmy, do you have threads with info about your builds?

[whistler]

The modified 1100’s are of interest to me. Whistler and Timmy, do you have threads with info about your builds?

Timmy has a thread but I don't. Mine is a 1098 +0.100" with flat top pistons, KC modied head for 9.75CR, piper bp255 cam, fully balanced crank assembly, lightened flywheel, S/C C/R gearbox with cross pin diff and 3.4:1 FD. At the moment it has a HIF38 and a standard 45D distributor but that's just for initial startup. Later I'll probably go up to a HIF44 and a modified distributor (Keith has given me the direction to go for his recommended advance curves)

The design is based on Keith Calver's modified 1098 of a few years ago with a few adjustments recommended by Keith. Hoping for around 75lbft torque for what is basically a road car. If I wanted more from the engine then I would probably follow Graham Russell's further modifications he's used in his articles.

If there's any specific questions I can answer then please message me.

[timmy850]

My thread is here (some of the photos have disappeared), this is when I collected the block from the shop. I got most of the assembly done in 2019
http://www.theminifo...22#entry3454566

My block and head were done by Graham Russell:
About 10:1 compression
Crack checked & reground crank
RE266SS cam
4 synchro and magic wand - standard ratio & 3.44 diff
Lightened & balanced factory flywheel & blue dot clutch
Mine had a Dellorto 40 DHLA but recently swapped to twin HS2

If you have any other questions just ask!

[maystro]

@whistler & @timmy thanks mate for the info. You two are running some big bores though which must nearly equate to nearly the same displacement as a 1275 with the stroker 1100 crank.
Have you had any issues with blown head gaskets running such big bores in a 998 block.

[whistler]

@whistler & @timmy thanks mate for the info. You two are running some big bores though which must nearly equate to nearly the same displacement as a 1275 with the stroker 1100 crank.
Have you had any issues with blown head gaskets running such big bores in a 998 block.

Mine's not running yet. Have a ead of this. http://russellengine...re-engine-pt-1/

[timmy850]

Mine adds up to 1166cc, I haven't had any head gasket issues yet. 

 

The minispares site says the C-AEA647 gasket is good up to +100 overbores. If you are going for a 68mm bore I think you need to go a 1275 head gasket

http://www.minispare...s/C-AEA647.aspx