9 replies to this topic

[Brandon]

Specifically the exhaust manifold.

Checked the one I have installed on my NA1.8 and there's a lot of exhaust soot on the head-side of the gasket.

 

But in generally, are you permitted to cut away the gasket material that's blocking the port(s)?

[Mike Collins]

No.  But you can mount the gaskets and manifolds on an engine stand while the engine is rotated allowing you to line everything up.

[Brandon]

I guess that's why I was asking about "matching" - mine has an even ring of soot all around the port implying it's not sliding up/down at all but is actually too small.

 

Are the ports on a 1.6L smaller than the 1.8L (thinking I may have a 1.6L gasket installed)?

 

(edit)

I'll get a picture of the gasket this weekend if that helps.

Edited by Brandon, 02-07-2014 12:58 PM.

[Mike Collins]

Doubt it.  The 1.8 engine is longer than the 1.6 front to back.

[FTodaro]

Generally the ex gasket cut outs are smaller that the ports themselves, however, you can do a better job of centering it on the studs rather than just let it hang down and tightening it. I size up the fit visually and then try to hold it in the right place when i tighten the header.

[Brandon]

Appreciate the responses.  Below are pics of my gakset.  First is the whole gasket, #2 & #3 are close-ups of pairs of ports.

I've attempted to show how much intrusion into the flow path by scratching off the carbon build-up at the top & bottom edges of the ports.

Thoughts?

 

Full gasket:

 

Ports #3/#4

 

Ports #2/#1

 

[RussMcB]

While you have it apart, can you measure (and share) the width and height dimensions of the head ports, gasket and manifold ports?

 

I'm wondering if the soot is cause by something other that the gasket sticking down in the port.  For instance, maybe the sealing surfaces are not at the port edges.

 

It's hard to believe Mazda would have such a mis-matched gasket. 

[Mike Collins]

While, I'm certain you are looking for an answer....who ported your heads?  

[Brandon]

While, I'm certain you are looking for an answer....who ported your heads?  

 

Dammit Mike!  Just what I didn't need to hear!  

 

Russ, I'll post numbers this afternoon.  I should have thought of doing that before anything else.

[Brandon]

Russ wins the chicken dinner.  From the head out (to the manifold) the dimensions get gradually larger.

 

I only remember the gasket measurements: 46mm x 25mm

And the head was smaller and the manifold larger than that.

 

So it's nothing to be concerned with and I'll go back to installing my transmission!

(Wait - already done! :-) )