401 or 403 cam ?

[Geoff Dowdle]

Ralph ,
your 401 chassis 903 was delivered new in Sydney/Australia &restored in Sydney between 1973 - c1976 .
The engine at that time was Block 85A/1471 (ex 400/639) and head 100A/3137 (ex 403/1430, and the only 403 part in the car, as 403/1430 is a good original car that just had a replacement head at one time) , my guess is that it had a standard 401 cam.
During the restoration, parts of 401 chassis 990 were also used.
I knew the last 4 owners in Sydney , the last of which sold it back to UK in c1987.
The engine could have been rebuilt since then but I doubt it very much as it is unlikely to have covered many miles since 1976.
The complete original engine of 401/903 (85C/1815) I sold to a chap in Yorkshire in 2015 but has not fitted it to another Bristol yet.
I suggest you check the condition of the Solex carbs and record all the jet and venturi sizes, plus strip, check and lubricate the distributor before you consider a major tune up . These are difficult to tune especially by people that have no experience with them .
In my 40 plus years owning and tuning Bristol 6 cylinder engines, one of the major problems is correcting all the poor workmanship that occurred previously, carbies in particular. Float levels are often way too high.
Does the engine have a Top Dead Centre mark?

Geoff