interesting crank

[austinisuseless]

medway, that is what I thought first, but it is actually two phantom bearings in between, no extra main bearings required, as I have been told.

Still sounds, ahem!, snake oil to me.

[medwaybeat]

Ox, I know they’re phantom and it’s harmonics & all that. But it’s only a grind away from being a 5 bearing crank which has got to be less bendy like.

[austinisuseless]

Yes medway, but there is next to no room between cylinders 1 and 2, and 3 and 4 for extra main bearings for a five bearing crank,and no room to shift them without having a totaly new cylinder head. Might as well throw the whole engine away and start again.

[medwaybeat]

Ox. They get a bearing between cylinders 2 & 3 and on 1300 the pitch/spacing is fairly even. The distributor drive would have to go.

[Mike]

As we are building two Minis for Masters and wanting to ensure their competitiveness in terms of latest performance developments, I sought clarification from the MSA's technical representative for Appendix K, John Hopwood, as to the legality of these new cranks and rods.

I was advised that I could quote him unequivocally that "they are categorically not acceptable under Appendix K and as such will be illegal in any series running to those regulations".

The question remains if any series, such as Masters, will allow their inclusion and thus a variation to the printed regulations, as they already do as far as dog engagement gearboxes are concerned. I will seek clarification from Ron Maydon on his return from racing in New Zealand.

The issue now is that should they allow such components, you will need different engines for different series when they are all meant to be to the same regulations!!!

The other issue is that how do you police their illegal use when bore and stroke measurements will not identify the type of crank and rod fitted.

Of further concern/note or interest is that John Hopwood states "the use of Arrow type rods and Quaife differentials are also in contravention of the Appendix K regulations" (as are the widely used dog boxes).

Time for some honest consideration and clarification of the rules and regulations by the race organisers I think!

[Smiffy]

On those crankshafts, why on earth has he drilled holes in the counterweights?

For balance!! (there are holes thru the bottom ends also)!

It's called back drilling and it's to further lighten the crank.

[Vegard]

On those crankshafts, why on earth has he drilled holes in the counterweights?

For balance!! (there are holes thru the bottom ends also)!

It's called back drilling and it's to further lighten the crank.

Not on the counterweights they're not!

[Smiffy]

It has to be done on the counter weight, to balance the one at the small end.
But mainly the more weight removed the better.....

[251 ENG]

The holes in the web,s and flywheel flange are there because it is impossible to drill a large big end lightening hole parallel to centre line of the crank without cutting through the webs.

The cranks are made out of round steel " bars " , the BE lightening holes would be drilled before the BE bearings had been cut in to the bar .

Sometimes the holes in the webs are left open and sometimes they are plugged up with steel or heavy metal.

[251 ENG]

Using the 2 false main bearings to stiffen up a 3 bearing crank is an excellent idea , but it is not new . Been used on vintage car motors for years .

[Vegard]

It has to be done on the counter weight, to balance the one at the small end.
But mainly the more weight removed the better.....

So you are saying that a crankshaft should be as light as possible? In a 3 main crank, I strongly disagree with you. It should be bloody heavy in some areas and light in others.

[Giff]

This explains the literally screaming noise I heard a few weeks ago at the Masters.

[Smiffy]

Maybe you should ring 'em up on the 'BIG WHITE' telelphone and ask............

[251 ENG]

If you draw a line down the centre of the the crank , the counterweight on one side should weigh the same as the big end opposite it .

The longer the stroke , the bigger the counterweight needed.

The more weight you get out off the big end on the crank , the less counterweight needed.

The lighter the crank the faster it spins up and slows down.

Weddging and back drilling good for std type mini crank , blading can be bad .

3 main bearing cranks only give you 4 counterweights to play with , but 5 mains gives you 8.

Look at the size of the counterweights on the latest type of billet and forged cranks from swiftune and MED compared with the original items .

[robert]

I believe that is a Fiat 'Fire' engine?

EDIT

I am wrong, what is a 'Lady Cup Engine'

this is a fiat 'fire ' head ...

[wil_h]

Oohhh you tease!