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Bulldog
28th July 2007, 09:21 PM
Hi all,

I've searched the archives with no luck, so i need some help...

Are the cylinder heads interchangeable, left and right? Manual says to mark L and R, but this would be so each goes back where it came from. Mine are second hand and not marked. Are they physically different?

Also, another manual (V8 engine overhaul manual) says "Engines without suffix B have a steel gasket whilst engines with suffix B have a composite gasket. The two types of gasket are not interchangeable... " I want to fit composite gaskets (not a suffix B, never heard of it). Is this a problem?

And, same manual says engine numbers without suffix B have lower 4 head bolts, with suffix B have them removed. I want to leave them out or not tighten them as much as they (i'm told) put uneven pressure on the heads. Why suffix B only?

Hope someone has had some experience with this that they can share.
Thanks in advance...

jimbo110
28th July 2007, 09:31 PM
Hi all,

I've searched the archives with no luck, so i need some help...

Are the cylinder heads interchangeable, left and right? Manual says to mark L and R, but this would be so each goes back where it came from. Mine are second hand and not marked. Are they physically different?

Also, another manual (V8 engine overhaul manual) says "Engines without suffix B have a steel gasket whilst engines with suffix B have a composite gasket. The two types of gasket are not interchangeable... " I want to fit composite gaskets (not a suffix B, never heard of it). Is this a problem?

And, same manual says engine numbers without suffix B have lower 4 head bolts, with suffix B have them removed. I want to leave them out or not tighten them as much as they (i'm told) put uneven pressure on the heads. Why suffix B only?

Hope someone has had some experience with this that they can share.
Thanks in advance...
The heads are interchangeable side to side.

You can use composite gaskets, just lowers the compression slightly.

Torque the bolts up to 15-20 ft/lb only. more causes the head to bow especially with composite gaskets. P76's never had the 3rd row of bolts at all

Bulldog
28th July 2007, 09:33 PM
The heads are interchangeable side to side.

You can use composite gaskets, just lowers the compression slightly.

Torque the bolts up to 15-20 ft/lb only. more causes the head to bow especially with composite gaskets. P76's never had the 3rd row of bolts at all

1. As i thought :)
2. As i thought :)
3. As i thought :)

Thanks. :D

p38arover
28th July 2007, 09:39 PM
The 4.0/4.6 block doesn't come with holes for the lower 4 bolts - well, they shouldn't.

My block has the holes but the heads don't.

Ron

PhilipA
29th July 2007, 04:27 PM
The difference in gasket thickness is quite a lot, about 35thou more on a "Ehling" composite to be exact.
I would have the heads milled 35 thou or more to preserve the Compression ratio. If you do not you may/will find that the pushrods have no preload onto the cam followers and the valve train is very noisy unless you mill the tappet pedestals.
Regards Philip A

PhilipA
30th July 2007, 12:23 PM
Also make sure they are for a 3.5 not a 3.9 because the 3.9 gasket fire ring won`t sit on top of the liner , this is only a concern if a liner wants to shift though .



Neither does a 3.9,4.0, or 4.6. ZAT is zee problem mit der slippink liners.
But yeah, I forgot he was talking 3.5. I do not know what brands of composite are made for 3.5 and how thick they are. They will all be about 35 thou or more.
See if a specialist can let you measure a compressed one, although most just say "She'll be right mate" before they sting you again to shut up the tappets.(usually by telling you that the tappets or camshaft are stuffed and it is NOTHING to do with them)
Regards Philip A