Cylinder Head Help - Engine Gurus!

[thelowlife]

When I purchased the bike the P.O. mentioned that he had an oil leak which he believed came from on of the tappet covers. I haven't started any engine work until recently, I noticed that he didn't seal any of the tappets and there was a small leak, but upon further inspection...

I found a nice hole in my exhaust valve collar, looks like I found that oil leak. I do have a spare motor and I'd like to swap the cylinder heads over from the second motor. I don't want to use the spare motor in the frame because of serial numbers and the spare motor has a siezed piston but the heads look brand new. After discussing this with my brother he mentioned that I should keep as much of the cases I can together rather then swapping.

So heres the details:

Original motor is a 72' with the broken exhaust valve collar

Spare motor is a 80'

So my question(s) are as follows:

Can the heads from a 80' be swapped over to my 72', are the rocker arms the same? If they are not the same can I swap the rocker arms without issue?

I believe that the cam in the 72' is slightly diffrent from the 80'. So with the head from the 80, top set up from the 80' (and potentially the rockers from the 72 if they are different and swappable) can I run the cam from the 72' in all the 80's head parts without issue?

Thanks in advance for any an all advice.

 

[Highside]

Sounds like you need to adjust the muffler bearings.

 

[jayel]

have it filled, heli-arced... yes the cam or at least the cam sprockets are different between 256 and 447 engines but can be changed, also gasket sealing surfaces on the 70-71 heads and cylinders are different from those on 72-83 motors so inspect carefully if you switch heads

 

[grizld1]

The 72 cam will install in the 80 head without a problem, but as jayel wrote, the 80 cam sprocket isn't compatible with the 72 crank. Rockers, etc. are the same, except for the left cylinder exhaust rocker, which works with the compression release on the XS2. You can install it in the 80 head cover. Head covers are line-bored to the heads, so keep them paired.

 

[Jack]

When I purchased the bike the P.O. mentioned that he had an oil leak which he believed came from on of the tappet covers. I haven't started any engine work until recently, I noticed that he didn't seal any of the tappets and there was a small leak, but upon further inspection...

I found a nice hole in my exhaust valve collar, looks like I found that oil leak. I do have a spare motor and I'd like to swap the cylinder heads over from the second motor. I don't want to use the spare motor in the frame because of serial numbers and the spare motor has a siezed piston but the heads look brand new. After discussing this with my brother he mentioned that I should keep as much of the cases I can together rather then swapping.

So heres the details:

Original motor is a 72' with the broken exhaust valve collar

Spare motor is a 80'

So my question(s) are as follows:

Can the heads from a 80' be swapped over to my 72', are the rocker arms the same? If they are not the same can I swap the rocker arms without issue?

I believe that the cam in the 72' is slightly diffrent from the 80'. So with the head from the 80, top set up from the 80' (and potentially the rockers from the 72 if they are different and swappable) can I run the cam from the 72' in all the 80's head parts without issue?

Thanks in advance for any an all advice.

We have a language barrier here"what is a exhaust collar" are you referring to the valve stem?

 

[ippytattoo]

Looks as though you are referring to the valve guide. You should be able to get new valve guides from MikesXS and there is also a thread somewhere around here ,forgive me i can't remember exactly where, that gives you info about changing them. I would say replace the valve guides and seals, lap the valves and use the original head if that is the only thing wrong.

 

[thelowlife]

I don't believe it is the valve guide

 

[Jack]

I don't believe it is the valve guide

Then what is it? You're the OP

 

[thelowlife]

Its where the valve comes out? I don't know what it is called specifically but its not a valve guide its its molded piece in the cylinder head that holds the valve guide and valve.

If you look at the picture you can see the valve guide behind the broken part.

 

[scabber]

It's the valve guide boss area the correct term. that snot hanging in the picture could be part of the exhaust gasket or carbon bad picture

 

[Jack]

Its where the valve comes out? I don't know what it is called specifically but its not a valve guide its its molded piece in the cylinder head that holds the valve guide and valve.

If you look at the picture you can see the valve guide behind the broken part.

Can you take a few more different angle shots,that particular shot is just to confusing for me. It sounds like your talking about the guide boss but there's more than enough meat there to support the guide without fear of completely breaking off,even when poorly cast from the factory

 

[Highside]

Yes, that picture is terrible. I'm still not sure what I'm looking at here.

 

[thelowlife]

The picture is the exhaust valve its for some reason rotated 90 degrees. I don't understand why it is so hard to see?

 

[Highside]

The picture is the exhaust valve its for some reason rotated 90 degrees. I don't understand why it is so hard to see?

Your question doesn't match what's pictured. About the only way an exhaust valve can cause an oil leak is if the stem is worn or gouged. It usually blows blue smoke too.

 

[DirtyErnie]

The exhaust guide boss area is torched down to the valve guide, you're seeing a whole lot of missing aluminum that's also known as a fugg'd-up head. Someone would have to weld that area up and then have the valve guides re-machined if you want to use the '72 head.

Use the '72 cam with the '72 crank. Use the '80 rocker cover with the '80 head.
take a good hard look at the fit between the '72 barrels and the '80 head.

That's what I'm seeing here anyways...

 

[thelowlife]

The exhaust guide boss area is torched down to the valve guide, you're seeing a whole lot of missing aluminum that's also known as a fugg'd-up head. Someone would have to weld that area up and then have the valve guides re-machined if you want to use the '72 head.

Use the '72 cam with the '72 crank. Use the '80 rocker cover with the '80 head.
take a good hard look at the fit between the '72 barrels and the '80 head.

That's what I'm seeing here anyways...

Thank you sir!

 

[Highside]

The exhaust guide boss area is torched down to the valve guide, you're seeing a whole lot of missing aluminum that's also known as a fugg'd-up head. Someone would have to weld that area up and then have the valve guides re-machined if you want to use the '72 head.

Use the '72 cam with the '72 crank. Use the '80 rocker cover with the '80 head.
take a good hard look at the fit between the '72 barrels and the '80 head.

That's what I'm seeing here anyways...

Thank you sir!

Oooooooooohhh!!!

I see it now, it's funny how it looks on the screen of my lap top, I thought I was looking at an extreme close-up of the valve tip. When I looked at the pic at a different angle, I could see that i was looking at a shot down the exhaust port.

Yes, it's going to take a bit of welding, the trick is, is being able to get the welding torch down into that part of the port, and at the correct angle. It can be done, but you might have to use a low-profile torch that is air cooled. That can be trickier to weld than it looks.

You might be better off just usung a different head.

 

[XSLeo]

I don't think it needs welding. I think that piece sticking down toward the valve is a torn exhaust gasket.
Leo

 

[tysonhumphrey]

what if you swap the 447head and the 447crank everything should work fine