Back to the extra block studs

[Zetomagneto]

Quick summary of my thinking here:

Firstly a lot of the examples of extra block studs are from coil engines or even coil engines with the later "rear facing" starter motor. Both these engines are easier to put extra studs in. In the case of all coil engines the dynamo mounts aren't in such an awkward place (and there's the cam locking bolt). With the later motors you don't have the starter motor mounting to consider, only the the tin flywheel cover. It's much harder with a roadgoing mag engine!

Secondly the bulkhead/block clearance is tight on a road car. Design in more clearance than I did.

Thirdly any extra stud has to have some meat to tap into. The rear camshaft bearing is the one sensible point at the rear. The front cam bearing is useful in the front. Also if you put brackets on the block they must clamp to the crankcase perfectly. This means mounting them and machining them flat with the base of the block. If you use a long stud you'd need the widest foot to preload against to avoid pulling up the metal around the thread.

Finally it worth noting that some cars do run very well without extra studs - Jeremy Flann's blown Super Sports is very quick on 8 studs.

Charles

Ps. Geoff's stud thread changes were for material purposes. Finding high strength BSF/BSW fasteners is very hard and something of a lucky dip.

Charles, are you wanting to run a dynamo, obviously easier to fit an additional front stud without a dynamo, but your Bolt/stud will need to go through the timing gear cover And into the front cam bush