Major Seal 30cc Build

[Weldsol]

Lets try this. I sealed the head studs with wellseal which was fine when the engine was cold but as the water temperature increased water started coming up the studs. I don't want to epoxy them in so I am trying high temp silicone and spaced the head up with wood shims and slightly preloaded the studs to take up any play. I also have a plan to join the 2 castings of the head with epoxy and make as one.
Thank you for the kind words. It's been a fun project and I'm sure it wont be the last.

Hi Basil these things re sent to try us, I may have the same issue with my engine but mine uses cap heads not studs so maybe not as easy to fix as yours.
Hope you get it fixed ok
Paul

 

[JtH]

Basil, beautiful work. I have a full set of castings, plans and materials sitting ready to go in my Australian workshop, but am presently marooned in New Zealand ( not actually an bad place to be stuck) Did you build the engine without reference to other resources or did you discover additional online resources - apart from this wonderful web site? Once again warmest congratulations. You have set the bar high!

 

[Basil]

Thank you, So very kind. This is my first model engine build, I took a lot of care with everything, learned a massive amount from this group. Wasn't sure how it would run though. I've wanted to build something like this for many many years. Today I discovered I'd made an error and got the twin coil firing order wrong. I'm used to 1-3-4-2 so I mistakenly placed the wasted spark on cylinder 3 instead of 4, I was getting a number 1 fire but wasted on number 3 at bottom dead center. It runs better now! lol. You've always got to laugh at yourself.

 

[ruben]

hola me gustaria conseguir los planos del motor para hacerlo yo mismo
donde los podría conseguir

gracias

un saludo

 

[AlanS]

Moving onto the cam! The firing order on the plans is 1243. This is an unusual firing order for a 4 cylinder engine, most everything I've seen is 1342. As I've mentioned before this is going to be installed in a boat and I have decide to have the flywheel at the front which will have a gear and one way bearing for an electric start. All of this messes with the cam lobe positioning not to mention the 1 exhaust, 2 intakes, 1 exhaust and a repeat of the same for port configuration.
To clear this up in my head I decided to CAD it up. I have been 3D printing for about a year now with an Epax X1. CAD is a fantastic tool but I find there is no substitute for holding something in your hand and giving it a good lookover. I machined a flywheel up for another boat a while ago, drew something up in CAD and thought "that should do it". Decided first to 3D print before cutting metal. When in hand it was obvious it was too small for the engine.
Very happy to have something to refer to when getting ready to grind the next set of lobes. I absolutely detest throwing parts in the bin
Some pictures of my 3D resin printing.
Onwards and upwards!

Regarding your comment on the firing order. There is a correction on the plans from 1243 to 1342. There was also a similar correction in the magazine article covering this engine’s predecessor, the 15cc Seal. I have built a Seal Major, using the David Braid drawings and some castings.