Engine advice

[jonjosar]

I,m new on here but not so new to Minis. In the past, i,ve limited any modifications that ive done to cylinder head, carbs, exhaust etc but i,m in the mind to do some more serious engine modifications to my 1995 SPI.
At the moment, the car is 100% standard. The original engine has approximately 85k on it. i say approx as the odometer reads 1.6 miles for every one the car does and i,ve no idea how long it has been doing it. The engine runs spot on and seems strong but its a bit lacking in "grunt". I,ve toyed with an engine conversion but have decided i,m going to stay with the A series.
So, bearing in mind all of the above, what would your views be on the spec and build of an engine that i will use everyday, (allbeit only about 3k per year) and give me about 100bhp. I may use the car for an odd track day as well.
I,d like to keep the fuel injection but i,m not setting this in stone. I,ve heard of some using weber fuel systems injection unit or possibly a larger throttle body of some ilk from the Rover range? Maybe motorbike throttle bodies?
Over boring? What size? 1293? 1380? etc
Cylinder head? Crossflow v modified A series?
Gearbox? Cross pin dif. Would i need a straight cut or would this be overkill and also the extra noise factor. Clutch etc?
I know that i will need to upgrade the brakes and all the bushings, mountings and steadies. I will be replacing the rear subframe anyway and the car already uses hilos on the front along with adjustable tie rods and some polybushings.
Finally, budget. I can carry out a fair bit of the work myself but i wouldnt be 100% sure on some of the more technical specs but i,ve been watching and reading other posts by some of the guys on here and there seems to be a fair knowledge around.
I,m hoping to see this done for approx £1500. Am i being realistic or am i living in "airy fairy land"?
Any advice will be gratefully taken onboard. Cheers.

[purplehaze]

there are alot of people on here that can help with any query or question you have
id start off with making sure the engine is 100%
as there is no point tuning a car until you know its going to last
and not fall apart with the extra grunt, i think its fairly hard to get gains out of the A series but it can be done
do your research on parts and prices before you do anyhting and there is a sea of parts you can get
but the usual parts are exhaust fueling air filters stuff like that, then a good tune, then clutch flywheel diffs, but your talking big money for those bits, but good luck with it anyway mate
hope all goes well and hope you get the answers you look for

[jonjosar]

Thanks for that, as you say, some of the bits are mad money and this is where i,m trying to see what is worth spending it on and what bits are "luxuries" if you know what i mean. I just want to build myself a strong, reliable but ultimately quick engine.
I,d be renewing the bearings and pistons anyway as tbh, i,m reckoning that i need to go to 1380 to get what i,m looking for.
I,ve been doing a bit of reading and i keep coming across terms such as " off centre boring" etc and i,m not sure what relevance this has to a build and it sounds a bit bewlidering.

[macker]

if you want to talk to somebody about building engines or any engineering I can highly reccomend HRE, Hickey Race Engineering, Paul goes by the name merlin on the forum,
He built up a nice 1380 motor for me & along the engineering process he listened to what i wanted & made suggestions of how to best acheive things,
Best talk budget with him too as i think that 1500 would be a little on the low side, Fair enough it could be done for that money but wouldn't last piddlin time, imo

[purplehaze]

yes you can build it for 1500 but its all going to be cheap second hand parts, and thats all good for driving every now and then but for track and everyday use, you probably talking more towards the 2500 - 3000 for a propper build of a reliable fast motor, iv got a 1275 motor fully rebuilt running twin carbs with custom straight pipe and few little other bits and its fairly pokie, prob bout 70 to 80 bhp prob more,

[jonjosar]

Hmm, thats interesting. I might give him a call and have a chat with him. As you say, £1500 might be a bit on the low side. I,m trying to steer away from a second hand unit unless i can reliably know whats in it. Too many horror stories out there.
Cheers again.

[Billy]

NCT?

[The Marcos Graveyard]

No problem with NCT if it's set up right. With a bit of adjustment I put a 112bhp 1380 A series through the NCT a number of times.

[DAVEY_C]

just remember if you go 1380 its the maxamum ofset bore available for a 1275 engine so if anything should happen the block is basicaly scrap, true they can now sleeve the bores if needed but thats not always the answer, i'm not saying their unreliable or anything but there's no comeback from them... at least with the likes of a 1330 or so there is more meat between the bores and your leaving youself headroom too.
all i'm saying is explore all possible scenario's and decide which you would prefer because a 1330 is not to far behind a 1380 for power potential. even a 1310 can leave you more options for internals you can use at a reasonable price as oposed to a larger bore.

i'd advise joining http://www.theminiforum.co.uk/forums/ to get more of an idea of all options available to you

[jonjosar]

Again thats interesting about the size of overbore. I hadnt thought about how much meat to take off the block to give me 1380.
And i,ve heard before that the difference between the power output of a 1330 and a 1380 is so minimal that its not worth going into offset boring and the huge extra cost that it involves. It may be a case that i should just stick to inline boring +20 and go 1293 for the reliability. I dont envisage revving the nuts off it for long periods so would i be right in thinking that the standard crank, balanced would be man enough for the job?

[woody]

TMG your 1380 isn't a '96 which has a cat and fuel injection and a much lower emmision limit. The NCT is a major factor in what you can do with the engine and also I belive the SPi will limit the max power below 100bhp. You may want to look at a multi injection system with something like Megasquirt .an LCB ,small overbore and the best head you can afford.

[scottser32]

i done alot of reasearch into tunning my 1.3 spi but sadly found out that spi's arent the best to tune beacause the ecu can only handle about 80hp so an expensive rebuild isn gonna do much, if ya want some serious power from an spi ya need to supercharge it but then that makes the car unreliable and not really an everday car not to menton the cost of it. you could always change it to carbs but as far as i can tell its kinda hit and miss, sum people says it works, some people say it doesnt, recently theres been upgraded ecu's developed which are able to handle much more horsepower but there quite expensive i think around 900 pounds i have some mini magazines with stuff about tunning spi's ill have a look at them and get back to ya as its been a while since i read the articles and iv sold me mini since . frankly tho its a rit pain in the arse to tune an spi in my opinion if it was me id save up a bit then take the gamble and switch it to carbs and then do the usual stuff eg new sport cam, bigger bore size, stage 3 head, new exhaust and a good set of carbs. im no expert but from the stuff iv read thats what iv taken from it so just thought id pass it on.