Heard from ex-nissan works mechanic Gordon dobey, Steve newing and many others that a classic rally race a10 can make 130hp from the same capacity and 10,000rpm.
Does anyone know whats involved from first hand experience?
The crank is forged and similar to the minis 150hp aftermarket 3 bearing one and there is also aftermarket pistons to take the a10 to about 1090cc (however not allowed in racing! - bastard on jp car lovers!!)
With the 59mm motorbike stroke the a10 has and later oval port heads im sure its possible.

Must have some serious bottom end strength, with only three mains bearings.......

At 10,000 rpm, surely you would be taking your life in your hands being in the same car as that engine.
Thats more than 2 hp per cubic inch.

It's probably possible, but that 3 bearing crank has got to be a wory.

Mini 3 bearing 1470cc can do 160hp with lesser quality metallurgy.
An a13 also can reach 160hp with less capacity.
My little old A10 did almost 9000 rpm with quad mikunis and extractors on the old round port head shaved to its limits.
It didnt make any power over 7K though.

Been there,done that and I doubt the hp figure very much,mine was only 1010cc but had plenty of goodies - balanced crank,massive cam,head work,webbers,extractors etc and only produced 48kw at the wheels.I believe that converts to about 80 bhp,it did spin to somewhere around 10,000 rpm though,sadly it would barely last 2 rallies before stretching rod bolts and chewing out crank bearings.They were never gonna be a 1 litre grunter with 3 main bottom ends,do the big hp motorbike engines have the same?? anyone???
Al.

A quick note in support of Chris Dodgeman

The inertia loads (i.e. the ones that want to tear the engine apart) increase in direct proportion to the fourth power of the RPM.

Therefore the loads at 10,000 RPM are 16 times greater than the loads at 5,000.

Secondly, if you aren't getting any power over 8,000, why go to 10,000 and risk the whole deal turning into a hand grenade?
Surely, the next gear up is a saner proposition

I went to 9k cause I wanted it to blow up so I could get the a15 in at the time which sat around ready for action.
The best rod bolts should do the trick instead of the nissan ones. As for 10,000rpm and 130hp is incredible so I posted it up in hope someone knew of this little beast.

While I haven't seen the engine firsthand, I did speak to a gent who owned an a10 that could do this, maybe not 130hp but over 100hp and at the same revs. He was saying he used a round port head! Wasn't the sort of type to tell porkie-pies.
Anyway I thought I would dig this thread up because it's pretty interesting stuff, the type of power motorbikes are into. Does anyone know how many main bearings your 1000cc motorbikes have?

Peter Houghtons fuel injected 988cc Cherry made 109bhp at 10,000rpm.

I don't doubt the 10,000 RPM part, as for the power figures I've always heard 140 BHP for an A12 & 175 BHP for an A14. I alway mention in these posts that these power figures result in 6 hrs of run time between rebuilds. Also most of the motors are running 14-1 compression.

As for bike cranks I seem to recall ( I haven't had a big four stroke in apart quite awhile) they are 4 main bearing units. Keep in mind some of them are roller bearing units.

Tom