Wanted - Crank in mint condition pls

**spink** · 12 September 2011, 08:24

I have a 118k 7a engine here i will be dismantling in the next couple of days,crank is same as 3b

**SteveH** · 12 September 2011, 17:37

Oh dear, that doesn't sound good David! What's up?

I have a spare 7A crank too if you need one.

**s2driveruk** · 12 September 2011, 17:50

after 196k miles, i think the bottom end is starting to cry mercy, performance is being retarded a bit and there's a nasty sound under load which appears from about 2.5k revs and higher. After a chat with Darren (Djones) sounds like big end

Actually done pretty well for a 20yr old car

**DJones** · 12 September 2011, 18:35

Having listened to David's car it sounds very much like big end knock to me.

David said it feels a little more lethargic than usual even though boost has now returned following the fixing of all the air leaks.

The knock is quite sever when going under load or blipping the throttle, (silent on tick over) it would appear that the knock sensors are picking up the mechanical noise and retarding the timing.

You can never be sure until its apart but it sounds like a big end issue to me and if it is the crank will very likely need a grind (grinding not being what i would want) its probably as cheap to pick up a second hand crank.

A good 7A one would be just the job....

Darren.

**SteveH** · 12 September 2011, 19:13

Sounds about right from your description Darren. 196K isn't bad for a set of shells, most performance motors would have ended up in the scrappers many miles before. You could potentially get away with a polish of the journals if the crank is within spec, however it's probably easier to get a spare ready beforehand and have it crack tested and ready to go. There's always the option to get it lightened and knife edged too

**s2driveruk** · 12 September 2011, 19:36

thanks guys, appears i have sourced a 7a so i can get that looked at via BSB and who knows, it may well go on a small diet along the way

**djh** · 12 September 2011, 19:38

I know its more money but whilst your in there if you can afford it then try get some rods to go in mate

**S2central.net** · 12 September 2011, 19:54

SOunds like original 3B bearings have cried for mercy then - after 200k miles you cannot really expect much more... I wouldnt go crank shopping until you have seen state of yours... unless the journal damage is VERY heavy - there is no reason why not to polish/grind the crank with the correct clearance to some new/oversize bearings... have a look for the 'KS' catalog I posted here before with the RS2 spec sputter bearing you can get in all sizes - remember they MUST be fitted correct way only.

Should be a good time for some lightening & balancing along with damper and flywheel by the boys at Basset Down - she will love to rev after that !

Thank the stars it didnt start making such noises in certain tunnels to/from a certain 24hr race in France.

**s2driveruk** · 12 September 2011, 20:13

yeah very true, it got us there and back and fingers crossed It'll be making its next trip with some new internals...LM is a week later in 2012 ;-)

**S2central.net** · 12 September 2011, 20:25

Bet the car isnt running again until the week before though - LOL - I am hoping to hatch a plan for LM2012 but its early days !!!!

**s2driveruk** · 12 September 2011, 20:27

I ain't missed a deadline yet and I won't be looking to change that anytime soon...The Ring, the euro-roadtrip and Le mans, better project control on the car than anything at work for sure....similar levels of budget creep though.

Good to see you have been bitten

**europeanme** · 12 September 2011, 20:40

not sure if your in need but i have just found out i have a glyco dealer 2 minutes away...just a thought..

**Nik0las** · 14 September 2011, 19:25

I have AAN for sale if you are interested...

Wanted - Crank in mint condition pls