No, not yet,the engine is still in bits

Oh joy of joy's,the parts have arrived:D:D:D





So now I will start to rebuild the engine.
First job,lap the new valves in.The seats look good,and both exhaust valves and seats have lapped in ok,but the intake valves dont look to good.The seats look ok,but I am not happy with the valves.Maybe the seats need re cutting?





You can just see it in these pics.The inlet valve seat is very narrow compared to the exhaust,and it is only sealing on a narrow band of the valve.

see 2cvgb

They are supposed to be like that inlet doesn't need a wide seat like the exhaust , which has to loose much more heat.

Let the rebuild commence:).
Re-build the heads first.After lapping in the new valves and fitting the valve springs,



Its time to lap in the cylinder heads.If you dont know what that means,I'll explain.Because 2cv engines dont have cylinder head gaskets,its important that the sealing area between the cylinder top and the head is as flat and clean as possible.To do this,we need to lap it in with some fine grinding paste.To do this,you really need one of these,



Its an old barrel with the cooling fins taken off and just cleaned up on a grindstone.
So,what you do is put some grinding paste on the top area that contacts the cylinder head,place the barrel into the head,and just gently turn it back and forth with a smooth twisting action.



After a while,just wipe out the paste and see if the seating area is flat and all traces of black have gone.There should be a nice matt grey ring around the inside of the head,




Before and after.
Make sure that all the grinding paste is cleaned away,dont want any of that ruining the engine.A tin of carb cleaner is great for the job.



And there you are,two heads ready to roll.

I always put a smear of copper grease on the barrel top too gives a good gas tight sea,l never had a leaker yet even on some marginal ones

Good idea,I'll do that too

I also recommend you put some large penny washers on the push rod tubes by the lip that holds the spring that holds the tube seal in place - does that make sense?

This makes the spring put more pressure on the rubber tube seals (make sure you use M4 ones not M28 ones) so the seal is better.

That way when you turn up to an event you wont have lost a litre of oil on the journey there and you won't have to walk to the co-op to buy bottles of pastis and wine for Ken and Sean to thank them for fixing your engine in a field...

Sam,no disrespect to Ken or Sean,but I think I could fix it myself

I've learnt a lot since then

How to date your M4 Engine:

Cam followers/push rod

'66 M4 push rod and cam follower on the left
'63 M4 push rod and cam follower on the right

Cam follower detail

'66 right
'63 left

To date your heads

Early heads: (pre '63ish) have straighter inlet cavities and have flat exhaust valves.

Later heads: have modified airflow in the heads, the 'tunnels' are less straight. Later types came with and without valve stem seals. Also, later heads have dished and slightly larger exhaust valves.

Experimentation has shown that valves themselves however are interchangeable between newer and older heads.

Sam,
Grasshopper think right chopstick downside up.