Es2 complete engine

NoiseyNorton · Jul 20, 2015

Can anyone show me a break down or a complete picture of there es2? Engine only. I'm not entirely sure what I'm looking for, the book I bought doesn't go into detail as much as I had hoped. And would like to see a complete engine and possibly a diagram of a break down.

Nathan

NoiseyNorton · Jul 20, 2015

Totally different bikes but I'm hoping that a early post war es2 around the 50s would be similar and help get my 3t back up and going. It would appear I don't have enough room to pull the top head off. I guess I am not understanding how these engines are put together being so simple I am probably over thinking it. But it seems like there are two parts to the head?

NoiseyNorton · Jul 20, 2015

Horror · Jul 20, 2015

The rocker box comes off first which is not part of the head. With this off there is plenty of room to take off the head and barrel. Here are some pictures and engine diagram. Ignore the side valve break down diagram on the left of the top end diagram, yours is the one on the right.

NoiseyNorton · Jul 20, 2015

That is exactly what i was looking for, where did you source that diagram from? I think i may buy an ES2 head gasket and see if that would work for me, or i may just try and make one. It does not look to be too complicated and maybe i can get a piston from an ES2 to work in there also.

Nathan

Rohan · Jul 20, 2015

That diagram is in the ES2 etc Owners Manual - a little cardboard booklet that came with every new bike.
Available on fleabay as a repro for a few quid.
And probably online someplace.
Watch that different versions came out every few years - but the diagrams often didn't change !
Same with the Parts Book.

Do you know your piston and headgasket is unserviceable ?
Could be they just need some fettling ?
Have a look inside first....

NoiseyNorton · Jul 20, 2015

I believe the piston is still good, but will have to wait and see. The head gasket is reason for tear down as I'm blowing compression while running. Maybe it's warped and gasket is still good? But my money is on the gasket. I'm just trying to get all the info I can do I'm not going in blind. Rohan always keeping positive on my post.

Nathan

Horror · Jul 21, 2015

As I told you in a previous post, the head and barrel are sealed by lapping in the barrel spigot into the head with grinding paste. If you are losing compression, this is how to fix it. The gasket only seals the oil way. I read a post recently on the Norton owners website where someone had machined and fitted "O" rings around the oil way holes instead. That's probably a bit unnecessary as the oil isn't under pressure there, it's just the drain from the rocker box feed back to the crank case.

Horror · Jul 21, 2015

I've just had a closer look at your rocker box and it looks like someone has used studs and nuts instead of the original bolts to fit it. This is going to be a problem as the rocker box won't lift up over the studs to take it off. If this is the case, you can use 2 nuts tightened on the stud to undo it, a bit of heat where the stud is screwed in the head will help. If this doesn't work, you'll have to take the engine out complete and take it apart on the bench. It looks like it was built then put in the bike.