I finally got round to ripping apart a knackered B31 engine I got off fleabay a couple of years ago and found a pair of 65-2450 exhaust cams in it. I’ve been meaning to experiment with Goldie touring cams in my B31 for a while. Has anyone an opinion on using these cams as both in and ex cams? The 65-2450 is open for 18° less than the 65-2448 touring inlet cam and 8° longer than the standard 65-2420. Or has anyone an inlet cam they want to swop for a 2450??. They seem to be in reasonable nick and if anyone is interested I can post a picture later.
Cheers
Pete

email (option): petercomley@web.de

Hi Peter, The 'touring' Goldie cams were originally listed as 'racing' cams for the iron engines. They will improve the performance of the iron engines but are relatively mild. They can be used with standard valve springs etc.
Can't say I've ever tried to run the exhaust as an inlet..you will need to check the opening and closing points against other inlet cams when installed, also check out the total lift figure and compare that to other cams.
In principle there's no problem as long as a gain is derived from it.
A far better cam to pep up the B31/3 is the Goldie scrambles cam 65-2446 which is run on the inlet and exhaust. Again this can be run with standard springs but you will have to check that the valve collar clears the top of the valve guide at maximum lift.
Ideally,appropriate porting and carb alterations should also be made to benefit fully from the cams enhanced flow capabilities...a B33 inlet valve wouldn't go amiss either.
If you have access to machining facilities a modified car valve can be used...these can be sourced with the same size stem as the B31 inlet valve, avoiding the requirement to alter the valve guide to suit the larger stem of the B33 inlet valve. I use Jaguar valves which have sufficient stem length to shorten them and machine in the BSA type collet grooves.The head size is also large, allowing the valve to be machined to whatever size is deemed desirable. After shortening you will need to use a hardened valve stem cap as fitted standard to the B31..Ian

Hi ian
Thanks I'll have to play around a bit and see what the opening/closing works out at. Long term project as the M20 still needs to be done! On that subject, how is your "conrod honing man"? I still have an M20 and a B31 crank that both need big end work doing if you fancy the job
Cheers
Pete

email (option): petercomley@web.de

Hi Ian do you know where I can get some new hardened valve stem caps as I think they are the same for longstoke A7 BSAs as well. I need quite a few.
cheers Terry

Hi Terry...I think C&D Autos have them...Note though that only the B31 was fitted with them (not the B33) and inlet and exhaust valves in the B31 have different diameter stems, so different diameter caps. I believe some cars use them so that may be another possibility if you have a friendly engine shop locally...Ian

Thanks Ian