three cylinder aero engine

[garyParticipant @gary44937]

hi, has anyone built the three cylinder aero engine from the myers castings. gary

[garyParticipant @gary44937]

[JasonBModerator @jasonb]

I've not seen a build thread of one even on the American forums which is where it's more likely to get a mention.

[garyParticipant @gary44937]

thanks jason, that is unusual. i think it would look better with finned barrels wont know if its possible using the original castings untill i get them.

[John PurdyParticipant @johnpurdy78347]

Gary

By coincidence I just ordered the castings last week, awaiting delivery. I'll let you know the dimensions of the barrels when I get them (so you can decide if there is enough meat on them to make fins), if you haven't already ordered the castings. Actually I think finning to provide cooling on a steam engine is the opposite of what would be wanted, more like insulating to keep hot.

John

[garyParticipant @gary44937]

hi john, that would be handy, the fins are just an idea to make it look better to me not for any cooling effect but i see your point. gary

[John PurdyParticipant @johnpurdy78347]

Gary

I just received the castings this morning and the OD of the cyl. barrel is 1.975+- and the plans call for the steel liner to be 1.690 OD so that would leave a wall thickness of about .140. The plans call for the liner to be a press fit and "Loctited" in so once the liner is installed the whole could be mounted on a mandrel and the lower fins cut. The only problem would be the flat at the top of the barrel for the valve cyl. mounting. Maybe the upper ones could be cut using a small dia. slitting saw with the assembly mounted vert. on a rotary table on the mill?

John

Edited By John Purdy on 19/08/2020 01:18:18

[garyParticipant @gary44937]

thanks john, are you pleased with the quality of the castings ?

[John PurdyParticipant @johnpurdy78347]

Gary

There has been no fettling done on the castings other than cutting off the feeders, as can been seen in the pictures below, so there quite a bit of moulding flash to remover before any machining can be done. Actually I prefer it that way, other than trying to correct for the over zealous use of a grinder at the foundry. There is a little porosity evident in a couple of them.. On the ones I've checked there is plenty of machining allowance. The only potential problem evident is the core in one of the pistons was displaced to one side but there is sufficient machining allowance on the outside to compensate. Overall the castings appear to be quite good.

John

[garyParticipant @gary44937]

thanks john and good luck with the build. gary

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