Hey Nathan,

Good to see you want to build a small bore. Here are my comments:

1) Don't use a 12G295 head. If you are going to port and enlarge valves anyway then start with a much cheaper 12G202 which will give you the same results as a 12G295 which is really expensive as they are rather rare.

2) Stick to a smaller bore of 1152cc as this will keep the cylinder walls thick and straight to maintain compression for longer. Try not to get too big as what josh is saying. The 50cc's is just not worth weakenning the bores for imo...

3) 6500rpm should be more than enough to get near the max output of your engine. The 1100 cranks are good but you risk doing damage beyond 7000rpm and there is no power up there for small bores. 1100 are generally torquey engines so i would build primarily for torque more than anything else. build it for a max torque output around 2500-5500 rpm. Not reving to high will save your engine for longer.

On the carb end, whatever you like. I know you like dellortos so dellorto 40 with 30mm or 32mm chokes will give you great torque. Remember that air travels faster through smaller holes, so a well tuned system with small/medium bore lcbs would be perfect.

Do you homework before spending a cent!

ps. $375 for hypertech pistons only is 2x as expensive as it should be

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Lillee - 1969 Morris Mini K

He has a 295 head already, and he wants a turbo motor.

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Starlet Conversion:
http://www.ausmini.com/forums/viewtopic.php?t=15484

Even so, if you are going to put in bigger valves and port the 295 anyway, start with a 202 and sell the 295 to pay for it. 202 = $50 or around there, 295 = $X00??

Turbo... if that's the case, talk to James (kazjim) he's the grandaddy of turbo small block

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Lillee - 1969 Morris Mini K

If you are really going to build this turbo motor, you won't be legally allowed to drive and for you to even say on here that you will just register it in your dad's name it still doesn't make it legal. More to the point you won't be insured for this car, no insuarnce company will pay out WHEN you have an accident. There not oblidged to pay when you shouldn't be driving it. Your dad should have more common sense to even allow you to go this route, as not only will the insurance be invalid but he he will be liable. Don't want to put a downer on you, but that's the law. Your on your P's, LEARN to drive first, do some advance driving courses, they will teach you HOW to drive. Getting your license isn't the end of it,beleive me. I know you race Karts ect and you are probably quite a good solid driver but racing is very different to driving on the road.

Sounds Harsh but really, the law is there to make you safe on the road with other users of the road.

My suggestion re engine is to build the motor up with the view to later add a turbo when you are leagally able to. All it will take it a different head and cam. So build an N/A and build up the turbo for later.

Once you have turbo'd the motor this will also need to be engineered to make it legal and insurable.

Maybe a 1275 will turn up at some point and you will be able to build that up to a turbo.


Cheers
Aaron
"Mr responsble"

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Good Point Aaron, i actualy drove the brick for 18 months with a "turbo" engine without the blower !

It was low-compression, and the ignition curve was no where near optimal.. in fact it was slower than most 850s !

but, it gave me the confidence in the engine, (and the time to finish the manifolds---) and the conversion was very quick....

Good alternative...
J

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Very sensible suggestions. Nathan you will find that when properly build and tunedm an 1152 or 13XX will go mroe than good enough to warrant turbo, and for much less hassle/$$$...

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Lillee - 1969 Morris Mini K

I was planning on leaving it NA for quite some time so im thinking i better bump up the compression in the rebuild and get the RE13 instead of the RE13t, whats that cam the Doc's been plugging lately?! They sound nice too. What compression should i go for with that cam? That should get me a nice street motor.

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2002 TopKart Viper with Blueprinted Yamaha KT100S @ 17hp. 160kg.

If going N/A with an RE13 cam I'd run it around 10:1, maybe a bit more.
I'm running my 1360 at 10.7:1, it was sweet with the RE13. But now I have an RE282 in it I could run even higher, according to GR.

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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.

You seem to be all over the place at the moment with this motor Nathan , exactly what do you want out of it (power , drivability , bragging potential etc ) and we might be able to tell you which way to go . As for your licence and driving , definitely avoid any turboing or supercharging for the time being , regardless of who's name it's registerred in (even if your dad would register it in his name) , a hot mini with a whine coming from under the bonnet will attract interest and interest normally includes a licence check if you look younger than 25 . It's not worth it for the couple of years it'll take to be able to drive it legally . Just have fun and learn about the car and how to drive it to get the most out of it and leave the really powerful stuff for a few years later .

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Yeh i change my mind more often than my pants. Well my mum owned a fully restored 63' with a 1098, it had a 12G295 head (she got real excited when i told her mine had one haha) twin SU's and a fairly large exhaust straight out the back it sounded fantastic! (I have to respect tradition so thats what you'll be finding on my car) I want an engine that sounds good, goes real hard, has some bragging rights (I better be able to FLOG a standard 1275!) and is reliable! I dont mind having to get some rev's up to get it moving as long as i can putter in traffic... I want to build it right the first time, so whatever direction i take in the future i know i have the bottom end to cope... (Plus i can do it all real cheap now)

Questions at the moment!
1. What rods? Correct me if im wrong, but the stockers dont seem too appealing running higher compression and probably a few revs.
2. What should I do with the gearbox and diff? Seems a bit sloppy on the shift and a little reluctant to select gears... How much should i budget here? Replacement Box?
3. Clutch?

Anymore that comes to mind i will be asking! Hopefully i'll gain enough knowledge to start answering other's questions...

Cheers

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2002 TopKart Viper with Blueprinted Yamaha KT100S @ 17hp. 160kg.

Well considering the motor runs pretty well already why not save your budget for now , just do some head work and bigger carb/s and extractors , maybe a cam if you're taking the motor out ? Have some fun with it in moderate form and sort out whatever other problems are likely to crop up and then rebuild it when it dies . Either that or be rebuilding another engine whilst driving that one and modifying it with what you're learning from the original . As well as that I've seen too many mini's taken apart to build the "ultimate road mini" only to be sold in pieces 12 months later for a couple of hundred bucks . Don't fix it if it's not broken ....
As for your questions , Rod's , not really a great lot fo choice there unless you've got a lot of cash , but get a decent set of scales and match the weights of each big end and small end . also file the small casting ridges off the sides , but use a file , not a grinder , don't want too much heat on them .
Gearbox and diff , have you driven a mini to know what the gearshift should feel like ? If it's having trouble going into gear it could be just the clutch being out of adjustment or it could be other problems , no idea on quotes .
Clutch , my rule of thumb has always been to go stronger than needed , but I tend to abuse (my work ute especially) clutches by trying to tow or snig too much , or in the mini's load them up with too many rev's .
Basically don't skimp on the costs of things , fit good quality bearings , double row timing chain and good quality bolts if you are replacing any .

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aaron, if he registers the car in his fathers name and claims it is the main family car, he can drive it regardless of whether it is turbo charged or not. Perfectly legal.