I've come across a big valve 12G940 head and now have a problem deciding what to do. I have a goal of at least 70ftlb of torque for the engine, this has come by working out what my daily drive has in torque/weight ratio and doing the same for my mini. No I know that the 1100 in the mini K has 60ftlb in standard trim and believe that the extra 10 required to reach my goal will be acheived through the addition of the 12G295 head, the twin HS2 carbs, the increase in compression ration, the RC40 exhaust and the RE266ss cam.

The real pro for running the 1098 is that if the block lunches itself there are a lot more 998/1098 blocks to be found compared to the 1275 variant. Plus the 1275 can be sold off at the end and cover most of the costs.

My biggest question before I lay down my hard to come by dollares is would it be of much benefit of going for the 68mm pistons straight away or would a +60 thou overbore be sufficient? I've read the build thread from Jester99 with the 1098 in that car with the 68mm pistons and the car sounded awesome and had a good amount of horsepower but unknown amount of torque.

Can anyone advise me? Thanks.

Hey there, just as a note of interest, I found this little article on the Calvier Special Tuning website http://www.calverst.com/cc110f.htm
Hope it gives you more food for thought.

Cheers
Maelgwn

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Maelgwn No Mini Yet

Maelgwn, I read that page. I read somewhere that the head from Minispares that Calver used is very similar in spec to the 295 head. After reading a few more threads on 1098 builds and the advice from Graham Russell I'm now highly contemplating ditching my 1275 build for my mini and building my 1098.

Not850, after following this thread, it has made me very interested in doing an 1098 build too, but first I have to find that mini in the first place. Yes there seems to be quite a bit of info out there when you search on peoples experience. The best bit is that Hot 1100's don't seem as common in OZ as Hot 1275's. Although the build pricing will probably be the same.

Anyway best of luck with your project, I'll be looking forward to your build blog

Cheers
Maelgwn

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Maelgwn No Mini Yet

We just built an 1108 (68mm GR flat top pistons but using a 998 crank). With an RE 266SS cam, Maniflow LCB and twin HS2s it is going like sh!te off a shovel.
Head is a 202 with 998 Cooper inlets and 27mm exhausts. C/R is around 10.0:1.
At least it'll stand a good rev without busting the crank! (we were gonna make it a 1220, but the 1098 crank was cracked already.)

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Any idea on the hp?

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No idea, it didn't run on GR's dyno and is still running in.
Graham would have an idea. It might get the downdraft Weber some time in the future.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I'm trying to locate a set of Imp pistons for my 1098. I found out that JP pistons make them. What are the price of the GR set if anyone knows or if Graham Russell can let me know?

I would not trust JP pistons if you are going to rev it. I think my mate paid around $375 for Graham's ones, they come with a very good ring set, Nippon.

Edit
I have broken a JP piston in the past.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

That's cheaper than the JP set. Plus with plans to get my cam ground by Russell Engineering it makes sense to get the pistons from there as well.

Hey Dr Mini,

What rods are you using in that build??

Regards

Maelgwn

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Maelgwn No Mini Yet

Stock 998 ones. Taken from a low mileage 1978 Clubby, balanced and checked for straightness. It's only a road motor so we used the original rod bolts too, after inspection.
It won't be revved past 7000 or so unless it gets a Weber in future.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Only ever owning a 998 in the past, does the 1098 sound any different to the other a series engines? For example does it have a deeper exhaust note?

Nope they all sound pretty much the same.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Please excuse my ignorance with a series engines but I read somewhere that the same camshaft will sound slightly lumpier in a small bore engine compared to a large bore. Is this correct or a load?