Just what the title says,

Can you put a 16 valve head on an 8 valve block?

As a paper weight? Sure why not?

I'd compare head gaskets just to see if the passages match up. Then make sure the passage in the block is the same type of passage in the head....:-/

Probably no help at allllllll

You would need to change the pistons.

Wild and I picked up a 16V motor this week from a local yard. I asked him if he could use the 16V head on his 8V motor. I think he said the same as above, the pitstons are different I'm sure he will chime in below with much more detail.

 The pistons are totally different. Why not ask a local guru? The pistons have a flycut for each valve. The 16v obviously has a cut for each of the 4 valves, the 8v has a cut for each of the 2 valves. The 16v block is interchangeable either way, but the 8v is only able to accept to the 8v head. Sorry.
 Also the crank is not interchangeable. The reason for that one is the 16v has bigger counterweights than the 8v. The 16v block is clearanced for the bigger weights, and the crank is a better design and material.
Why are you wanting to know about the 8v block theory?? The one you got, got a problem??

OK, I had to chime in  
The 16V pistons do have cuts for the valves, but
the 8V pistons have dishes to lower compression, (not cuts Idaho)
I think the 16V Combustion chamber is larger due
to the shape required to fit 4 valves in there, so with
the low compression pistons, and a lower CR with the
16V head makes a better turbo engine  

You had to know it was heading that way, I mean what
else would I do

Yes the crank is counterweighted better, but I don't think
that would affect the block any/much and if it did, it's not
a difficult job to clearance a block, I mean it's aluminum
and not hard to cut.

The block on this 96' has a different shape oil pan for the
Crank Position Sensor, the only thing I can see that is different,
as soon as I get the head off I'll take a look at the CC and
pistons and I'll let you know what I think/find

Wild

 The bottom of the cylinder walls are steel, that is the main thing that is clearanced. There is a big difference in the counterweight size.
And yes, I kinda figured you, of all people, would go there!

Well if the bottom of the cylinder walls are
clearanced, then the pistons have to be the
same or they would hit (the counter weights are
up when the piston is down) so there might be
more than block clearance needed, cut/shaved
piston skirts will mean the pistons will be lighter
(I like short skirts   )  Hmm..... nothing I can't
work with

Wild

 It's not the skirts, it's the cylinder walls that are clearanced.

"so there might be more than block clearance needed"

Most engines, the piston skirt drops below the bottom
of the cylinder, unless the skirt on the piston is already
clearanced enough, it will need additional matierial removed.

Wild

This sounds interesting, and has been something I've pondered about for a while. Let us know what ya find, Wild (with pics plz )!

We've had the head off of the 16v motor, and the only thing I can really see that might pose a problem, is that the pistons on the 16v block are clearanced for the valves (4 valves per piston). I don't know if the 8 valve block is going to have enough clearance. Let me know what you find out Wild!



(You knew I'd take a picture, didn't ya.)

Heather

"so there might be more than block clearance needed"

Most engines, the piston skirt drops below the bottom
of the cylinder, unless the skirt on the piston is already
clearanced enough, it will need additional matierial removed.

Wild

The counterweights are wider and a little taller than the 8v weights. I have seen it done before, a local engine rebuilder screwed up, and he had to clearance the piss out of the bottom of the cylinder walls and the block material nearby.
And I told you there were valve reliefs on the 16v pistons!

The 16V pistons do have cuts for the valves, but
the 8V pistons have dishes to lower compression, (not cuts Idaho)

I know, I agreed with you on that, but 8V are not cut

Now I have a good look at Heathers (tks) I see that the
dishes are in the 16V pistons too    That might mess
up what I had planned, We'll see

Wild

We've had the head off of the 16v motor, and the only thing I can really see that might pose a problem, is that the pistons on the 16v block are clearanced for the valves (4 valves per piston). I don't know if the 8 valve block is going to have enough clearance. Let me know what you find out Wild!



(You knew I'd take a picture, didn't ya.)

Heather

AHhh  I see your Problem ......... That Orange FRAM
Oil Filter,    And after that whole long filter and oil thread

Wild