25 replies to this topic

[fikus01]

i am near completion of my 1293 project but i cant help thinking ahead to further projects, i am tempted by the dark side (non a-series engines) but i feel i have to cross a new barrier for the a-series first.

it would be more of a "use up any good a-series bits i have left" project.

i have mentioned before i have a special block, its a marina block i think thats been modified to run on an a-series gearbox, vizzard rates this block as "the best a-series to modify" i dont know why but its a good one for bog bore so i was thinking 73.5mm, maybe more. but then chucking in a 1071s crank to make the powerband shift higher up the revs, maybe some rather special other lightweight bits to make it all rev nicely.

the part im stuck on is the head and cam, has anyone done a 1071 with a 7 port?? what cam wuld u use for such a thing to get the most from the engine? reading thru the vizzard book i find very little on the 1071 as far as cam choice goes unless im looking past it.

i know he says the a-series with a 5 port favours high lift short duration cams, would that stil apply at 10'000rpm and with a 7 port???

[Oldskoolbaby]

Sounds like a wiked idea mate. I reckon the 1071 and 970s motor are the dogs. Have you got the rods for the the crank. Not sure If you can fit the usuall 1275 rods with the 1071 crank. I know you can't with the 970 cause of the short stroke.

I'd go balls out if I could get hold of a 1071 or 970s motor. 73.5mm bore, forged JE or Omega pistons, Arrow rods, 310 degree cam, full race 7 Port with throttle bodies, mappable fueling/ignition and........................ well the list goes on and on.

[fikus01]

again the rods are on my to get list, i have a block and i know a mn with a crank, that is my current parts list!i've seen an 8 port one with 110bhp but im sure u can get more

[Sprocket]

There's a nice set of worked Cooper S rods on Ebay at the moment

[fikus01]

alas current project takes priority at the mo, just trying to occupy my spare time learning stuff, has anyone on here tried tuning a 1071??

[Sprocket]

Not Yet

[JetBLICK]

1071's and 970's have sooo much more power potential, but they sacrifice tourque. Frankly tho i dont care. lol I'll be going for an all-out 1071 when funds allow. I believe there was a 970 16v in a mag a long time ago that was around 200bhp I'd be going for a 1071 8-port myself.

Best thing you can do with a short stroke, as you said is take advantage of its willingness to rev. So lighten everything to buggery, balance the whole assembly, and talk to some of the race boys and workshop engineers to find out the best cam to go for. Bearing in mind that fully worked short strokes will rev happily over 10k (from what i've found out) so you gotta capitalise on that by fitting a really short final drive and a close ratio box.

You cud have a really good motor on you're hands if you do it well. Think about this, the miglia racers have around 130bhp in a 1380. They're worked so well they'll rev their nutts off, so they have a short FD and they do 0-60 in some stupid quick speed and they go on to 125 or something? And thats with a 5-port. So if you're going for this revvy style race engine, high power band type thing, a 1071 is ideal and with a 7/8-port the potential is huge! And then you also get the benifit of saying its still a traditional A-series, even the head has heratige - more than a 16v head.

by the way - if you find an 'S' block to go with your crank then it'll have tappet covers - then stick and 850 badge on the rocker cover

[Dev]

There is a guy on turbo mini's with 1071s think he is called peter.

speak to him. VERY well informed and knows a great deal.

[fikus01]

ok thanks, im set on this marina block really, i've seen 74.4mm in a normal mini block so im intereste to see how well mine will take big bore as its meant to be best for it!!

i like the 850 badge idea tho. and i do realise i'll sacrifice torque!! higher reves does mean its less likely to snap driveshafts tho

have a look on youtube and do a search on 1071, theres a video of a racer on there.

Edited by fikus01, 07 January 2007 - 07:18 PM.

[Sprocket]

74mm, piece of *yellow human water*.

Finding 74mm pistons, like hens teeth.


Oh and I was under the impression that Miglia racers were restricter to 1293cc. Reason - Miglia means 1000, originaly the 1000cc class, the Mini Sevens being 850cc. when 998 engines stopped production it was agreed that the cc would be upped to 1293. When building the ultimate 1 litre engine, cooper S engines were used, namely 970. These were some what rare and becoming rarer because of this Any want to be winner would have had a 999 (+40 970)Cooper S. Hybred engines using steel cranks and A+blocks were getting expensive and resulted in only those with big wallets and or sponsorship could seriously compete. A+1275 parts were more available, cheaper alowing for a more level playing field. The Sevens went to 998 and the step between sevens and miglia was again at a more satisfactory level.
Lesson over

[Mini-Dave]

Ah Nick your wrong! the biggest bore is 74.7mm !

you dont want to bore the hell outta it tho, not first time, your dont want to have such a rare beasty engine that when it blows up, you have to throw it in the bin!

Dave

[Mini-Dave]

Vizard used triumph pistons for the 74.7mm bores!!

[JetBLICK]

Ah Nick your wrong! the biggest bore is 74.7mm !

you dont want to bore the hell outta it tho, not first time, your dont want to have such a rare beasty engine that when it blows up, you have to throw it in the bin!

Dave

Yea - if you destroy a 1071 crank i will destroy you I want one! Only way i will forgive you is if its a crank thats already been re-ground to something stupid. S'uppose i dont mind if you do it in a marina block, but if you ruin a 's' block i'll give you the beats

Just kiddin bud, im' just envious, i want one one day go nutts - ave fun, and experiment. Be the first to do something, if it works then you'd ave created something amazing, if it don't then at least you tried to be different rather than build yet another 1380 - booooooooorrrrrrrriiiiiiinnnnnnnnngggggg

Dan

[The Matt]

......Oh and I was under the impression that Miglia racers were restricter to 1293cc. Reason - Miglia means 1000, originaly the 1000cc class...........................

I always thought 'Mille Miglia' meant 1000 miles. Mille is 1000 (like in Grazie mille) and therefore miglia must mean miles??? Although, I think 'Migliaiai' is also 1000????? Sorry, O/T.

[JetBLICK]

......Oh and I was under the impression that Miglia racers were restricter to 1293cc. Reason - Miglia means 1000, originaly the 1000cc class...........................

I always thought 'Mille Miglia' meant 1000 miles. Mille is 1000 (like in Grazie mille) and therefore miglia must mean miles??? Although, I think 'Migliaiai' is also 1000????? Sorry, O/T.

I think ur rite actually, just had a look at Bill sollis' and its a 1275 - my mistake, but that just makes it more amazing that they get that much power and all round speed