Penguinracer

Hi All, following from my question regarding rods & pistons I've now decided to stroke my 2.5 out to 2.8 litres. It's my understanding that to avoid the need for machining the block for clearance & to maintain reasonable rod angles I should use standard length aftermarket rods & aftermarket pistons with the gudgeon pin higher up the piston so as to maintain an 8:1 compression ratio. Andial used Carillo rods (standard length) & Mahle pistons. I'd read somewhere (ok, Clarke's Garage) that no block clearancing is required with the Carillos as the wrist pins are lower but using some other aftermarket standard length rods does require machining the block for wrist pin clearance.

The Carillo/Mahle combo sounds like a good option - is there another rod/piston combo you can recommend? i.e Pauter (std length)/Wossner;

How should the crank be prepared & how much weight should be taken off it?

Piston size - if my bores are good should I go for 100.5mm pistons? (I'm staying with the Alusil bores)

Thanks Tim

Chris White

Any of the aftermarket rods will work. For the pistons the limiting factor is the Alusil coating, there are lots of companies that will make a piston for the 2.8 application but only a few that can supply them coated specifically for Alusil. Mahle and Wossner are the two that I am familiar with.

If you have a shop the can do the over boring then it would make sense to go oversized if your current bores aren’t ‘perfect’.

For street cars I prefer a stock weight crank and a light flywheel. If you lighten the crank and the flywheel along with a ‘grabby’ clutch you may end up with a car that is a little fussy to get moving, it will like to stall if you aren’t careful with the clutch.

Ski

I have a complete kit, crank, pistons - new Mahle with Ferrostan coating 100.5mm, and a set of new Wossner rods and ARP bolts. Crank is perfect - $3000 + shipping on the crank.

Penguinracer

Thanks Chris & Ski. Any particular rod preferences? I've located a crank locally but I'm just getting it checked out. I'd get the crank balanced but does it need to be nitrided or cross-drilled? I'll be running a dry sump so knife-edging shouldn't be necessary.

Tim