Hi All , I'm fairly new to Austin 7's , but am building a short wheelbase special for trails . I have the chassis and body finished , and am about to start the engine build . I have been offered a two bearing crank with a set of late shell bearing type con rods . The asking price is pretty high , are these rods better suited to a competition engine ? Are they worth quite a lot more than standard rods ? Thanks , John

If the rods you refer to are the late shell bearing A7 rods (which will probably say "Austin" on them) you will observe thst the rod itself is offset in relation to the bit that fits on the crank. This is to allow for the presence of a centre bearing on the 3 bearing shaft it was fitted to. So on a two bearing shaft, the little end of these rods would end up offset twards one side of the piston, if you follow me. In this case the answers to your questions are no and no.

It does seem odd that you should be offered this combination. Have you been offered a Phoenix crank with modern Renault shell bearing rods or Phoenix rods? if so the answers to your questions are yes and yes!

Regards, Stuart

Stuart is Right. 2 bearing cranks only had white metalled big end bearings. so the combination is indeed wrong. If a 2 bring crank "rings" well or has been crack tested it will give stirring service and is about a tenth of the price of a pheonix!

John.

There is little to be added to the two excellent replies you already have. I would like to add the comment; the 'old fashioned' whitemetal bearings are much more forgiving than the shell bearings, shell bearings having an absolute minimum of bearing thickness. Shell bearings were designed for ease of renewal by garage 'fitters' with little engineering expertise whereas the traditional new whitemetal bearing needs to be fitted by someone with experience.

I would stick to the traditional method myself

Thanks for your informative replies , I think a standard crank and rods will do for a start then ! Unless anyone knows of a better set up ?? Thanks again , John

You said you were building a Trials car John. Where do you intend to compete with it? If VSCC or MCC you may well find that your standard crank, however crack free, will not last that long if you are to be competative. However much you intend to excerise restraint, once you set off on a hill the red mist comes down and mechanical sympathy goes out of the window!!

A minimum specification for trials use has to be a Phoenix crank with a good set of Austin rods. Even then, a competitor on the recent VSCC Scottish broke his Phoenix crank - and that was on his drive from his B&B to the start!! Thankfully, a very rare occurance. Most of the A7 entry on VSCC and MCC trials these days are running Phoenix cranks and rods although whether you go for splash or pressurised lubrication is a matter of choice and much debate. Remember, a broken crank at high revs can lead to a massive amount of damage with some that have experienced such a failure only being able to re-use one or two bits from the blown engine - in my own case some years ago, only the head and the tappet blocks!!!.

STEVE