7Hp what should the Water cooling look like?

[ChrisE]

So the oil leaks problem is fixed, really successful, thanks to help from this forum. See the results at https://twitter.com/highbark/status/1094271649669619712

Then I thought I’d replace the hoses as they seem in a poor state and while I’m at it, bend some 28mm pipe rather than the old coper pipe which was just straight with the bend made by flexible hose.

So I drained out the water using the drain tap and took off all three top pipes.

I was really surprised that the middle pipe went to a blank plug in the inlet manifold, rather than an open brass union which would allow water to circuit around the inlet manifold and superheat the fuel-mix.

Have I misconstrued something, is the cast alloy inlet manifold not two pipes together, one with fuel mix one with hot water in or am I missing something completely? I was wondering if this engine has been rebuilt incorrectly. All a bit strange.
All back together now and running

Any advice or anyone who has done the same, would be helpful

Thanks
Chris

[k. rogers]

Hi Chris, congratulations on the breather valve - seems like it's cured the oil leak! As for the cooling system, I have only ever seen straight pipes used, so I think the rubber tubing is supposed to bend at the joints. That joint on the inlet manifold should definitely be open to aid flow and help heat the manifold. There are in effect two channels, as you correctly thought, within the manifold - one for water and one for fuel mixture. Don't know why anyone would block it off. Be careful if you try to remove it that you don't damage the aluminium. Might be better to get some better advice from someone else in the club, at the end of the day it has been running like that and the water will still circulate from either end of the manifold!
Suggest speaking to Mike Kavanagh - he will probably be manning the desk at club spares tomorrow evening!

[Keith Clements]

Perhaps they were trying to get more power as the cooler the petrol/ air mix the greater the charge in the cylinder!
However, too cold and the mixture condenses out, or worse freezes and ices up.