I'm just starting to look into building a quick 1100. Parts are cheap, and I want to do the assembly myself. The expensive part is most likely the machining.

I'm wondering what would be considered necessary on a rebuild. For example, it would be stupid not to rebore and hone the bores and regrind the crank, that's money well spent. I think buying new decent pistons is probably worth it too. But what about wedging the crank? Porting the cylinder head? Where do I stop?

There's a saying that the first 70% of upgrades will be 30% of your costs, and the next 30% of upgrades are going to be 70% of your costs. So people who have had the work done, what do think is really worth the money? (Prices are guesstimates - are these numbers realistic?)

Necessaries:
- Rebore + hone: $150
- Crank regrind: $200
- Cam regrind: $150

Other potential options:
- Machine flywheel: $150?
- New pistons: $200-$400 (depending on quality)
- Wedge, balance Crank: $400?
- Cross-drill crank: $100?
- Port cylinder head: $200?
- Bigger valves $350?

The bottom line is, I could rebuild with a rebore, new pistons and cam and a head clean-up for ~$1000. Is it really worth doubling the price for the other options? How much difference will there be, and is there anything else you would recommend?

If you rebore it you will need a new set of oversize pistons & rings to suit.
Grind the crank if there's more than 1/2 a thou wear (either ovality or taper). CRACK TEST IT FIRST.
Wedging the crank is not needed on a street 1098. Balancing yes, should be ~$50.
Cross drilling- not needed on a street 1098, but align the block's oilways with the main bearing shells, they are always out. Use a die grinder.
Fit new cam bearings.
Grind the cam- the stock one precludes good power production. A cam with 260-270deg duration works well. Fit new lifters but get them radius ground first (as their faces are rubbish shape when supplied).
Rockers- the stock 1098 ones are fine for lift, just fit new bushes and shaft.
Head porting is worth it, just follow Vizard's book. But if you have to pay a specialist for this it will cost you.
Fit new valves, guides & double springs. Use the 998 Cooper inlet valves if porting it.
Flywheel lightening will improve acceleration, is worth doing. Should be $150 including balancing (essential if lightened).
Carbies- bin the single HS2 and fit an HS4 on a late 998 manifold. Or fit twin HS2s.
Zorst- either a 3 into 1 freeflow, or an LCB works well on a 1098.

I had my bottom end all checked, measured, honed, ground crank and crack tested, decked block, all new bearings and rings and that cost about $600-$700.
The head was surface ground, new exhaust valves, a few seats put in, lifters refaced and that cost about $400.
Then timing chain, water pump, cam grind, gasket sets. It all adds up.
Should really reco the gearbox while your at it. Carby and dizzy should also get some attention.
If you wanted to come by some time and have a look at my receipts and the bits let me know.
Good luck doing a quick 1100 for 1k.

I'm very interested in this thread as i'm thinking of the same for the clubby van that i have .

I have a few options available , one being a 1275 that i have , or , reusing the original matching numbered block that is in the car , and fitting an 1100 crank & rods to it with a nice cam & head + twin 1-1/4" carbies .

Keep the ideas coming .