Which Steel crank for a K Series ?

[silver-7]

 

Looking back through the archives on blatchat there seems to be some debate over the merits of a

Doud Kiddie crank or a slightly lighter Farndon version.

 

1. Which should i go for... to match to a set of Arrow con rods & a R500 flywheel ?

 

2. Is lighter necessarily better, obviously it would rev quicker ?? but would a heavier crank be better

at higher revs ?

 

3. Is there a specific crank for use in a caterham ie. with different cross drilling and oil ways ect.

 

Regards

 

Silver-7.

[Rob Walker]

Swings and roundabouts. Ones very light giving low inertia with superior oil ways. The other is more heavily counterbalanced and should produce a smoother engine that will last longer. In short both are very good and will do the job, I have the fully crossdrilled Farndon as fitted in the R500 in my latest engine.

[Peter Carmichael]

I have used DKE cranks to good effect. The one I ended up with was, I think, one rejected by Rob, but it worked well enough. I like Doug, but I wouldn't recommend waiting around while he makes you a crank. If he has got one on the shelf, buy it.

 

Edited by - Peter Carmichael on 17 Oct 2004 22:57:51

[V7 SLR]

I have recently been made aware of some counterbalancing which adds tungsten (I think) weights, thus allowing you to make the most of the lightweight crank with its superior oilways, and have it balanced as nicely as the heavier one.

 

I believe Steve Butts has recently completed a build based on this, and is very pleased with the results.

[oilyhands]

Even the heavy steel crank is under-counterbalanced. The TC material allows the counterbalance weights to be matched to the specific weights of the piston and rod assemblies. Steve Butts's crank is in fact just a regular crank rather than a steel one..

 

When selecting your crank make sure that the oilway drillings and patterns are the same as a stock crank, I.E. that crank pins 1 and 2 are fed from main bearing 2 and that crank pins 3 and 4 are fed from main bearing 4, also ensure that main bearings 2 and 4 are cross drilled. If these criteria are not checked then you will have problems with oil feed and/or trouble selecting and fitting the correct grooved main bearings in the correct places.

 

Oily

[Rob Walker]

Caterham Parts dept sell the Farndon R500 crank from stock.

[Jason Plato]

Hellier Performance on 01992 899228 also do a great price on "lightweight" PTP steel cranks

 

 

C7 TOPhere

[Peter Carmichael]

Oily,

 

The Doug Kiddie cranks are now supplied with grooved main bearing journals (1 to 4), so should work with a standard pattern of bearing shells.

[silver-7]

Guys,

 

thanks for the info.....

 

Going with the DKE crank they were more helpful on the phone ! and they have one in stock with all the correct drillings ect,

 

Rob,

Farndon crank from caterham costs £100 pound extra, direct from Farndon there would be a 4 week delay.

 

Dave J

Thanks for the tel number

 

Peter,

Do you have any plans for another mega engine ?

 

V7,

Spoke to Alan at Scholar: yes they do only charge £200 to build up a short engine including all the balancing ect

parts bearings ect on top.

 

Oily,

Just about to call you re: porting ect

 

 

Thanks Again

 

 

Alex Minchin.

 

 

 

 

 

 

 

[V7 SLR]

Alex, I was told only £100 but that didn't include balancing which I have just paid nearly £100 for so that's reasonable.

 

Bearings ought to be about £100. Gasket sets should be quite a bit less. You can guarantee they'll do a proper job too. Nice people to deal with. Stick with them, DVA and Emerald and you'll only talk with nice people.