Symetrical Heads

Think I might have made a mistake,probably put my heads on back to front.
Mitigating circumstances,the heads and barrels were already apart and nothing marked up when purchased,I had all engine parts cleaned,and there are no witness marks or studs on the ports.And enthusiasm took over!
The heads are identical,the only thing I can see is a “50” marked on the top fin, which at the moment is forward facing on both heads.Tthe engine is on the bench,awaiting for a head to come off,to check which way the valves are facing! Small diameter to the front I hope,unless some one on here can clarify the “50” mark,maybe it means I have a 50-50 chance of putting the heads on the right way…
Just one other thing,being able to buy valve collett halves separately,and not in matched pairs.
Please all have a laugh on me,unless you know otherwise.
I can see why Moto Guzzi have done this,cut down production costs,valve seats make the only difference.

I will have a look at mine tomorrow, there is a 50 mark somewhere. Small valve (exhaust) to the front

??? - Not sure if you are being serious … ???

The exhaust port goes at the front and the inlet to the rear. These are very different. The spark plug will be on the ‘outside’. Also there is the extra bolt between the head and barrel that has to go to the back.

The ‘50’ shows that they are V50 heads and not V35.

It’s possible to swap left and right.

Can’t find the “50” mark. Prob on the underside of the head. Don’t quote me but I nearly did the same. Fortunately the exhaust still had the studs in. :unamused:

Can’t get my head around that at all - must be an age thing. Gonna go home and stare at mine for a few hours.

It is possible, but the results look unusual

Same here - inlet has bolt holes, exhaust has studs? And in different places. Struggling to find pix but looks like holes at inlet / exhaust are positioned differently so if carb stubs are put onto the exhaust side, carbs will be twisted at a crazy angle. (?)

Sorry Mike I don’t get any of that at all. The inlet and exhaust ports are parallel so how would the carbs be at any crazy angle? It is quite straight forward, exhaust valves are smaller and go to the front, spark plugs go on the outside of the engine, I can’t see how you could get them swapped, unless of course you wanted ram air effect like the chopper in the photo Don posted above which to my untrained eye is bonkers. I guess it would warm your seat in the winter though!

I’ve done some real stupid things in the garage just lately, but I don’t think I could manage that by mistake.

There is no picture to illustrate what I mean - needs someone to look at a V50 and tell us.

But Mike why would you want to fix the carbs to the exhaust ports? I do not understand your point at all. Exhaust valves are smaller than inlet valves and spark plugs are on the outside of the heads, anything else is nonsense.

Refer to page 27 of the V50 official manual,
Exhaust valves are 27mm in diameter ,smaller
Inlet valves are 32mm in diameter,larger
Just to clear up any confusion,all I have done (I think) is put the heads on the wrong sides,the ports are identical,inlet and exhaust gaskets will fit either side,and there are NO studs ,bolts to indicate otherwise.

Understand. :smiley:
If you have a clean head with no studs there is no external marking to tell you which is which. Have you bolted the heads down? For piece of mind you are going to have to lift a head. The gasket will be ok to reuse.

Light bulb illuminates … I’ve never had the elbows off my heads – so underneath they are the same fixings. Finally I get it. Sorry.

Surely the ex port is carrying a lot more carbon than the inlet side? And the ex side studs will be a good deal rustier.

At last! :smiley:

Yes, I can confirm I put the heads on the wrong way!
Found the inlet big valves facing forwards,quack!quack!Ooops!

Pleased that you have it sorted.