round port headers

[4everDATSUN]

i just picked up a maxima n47 at the salvage yard. I see that it has round exhaust ports. i was told that a header for square ports will fit, but i dont know how well that works for performance. is there a round port header that will fit and not have any clearance problems in my 260z?

[fl327]

MSA makes square and round port headers. You can use a square port header for round port heads as well.

[2126]

i just picked up a maxima n47 at the salvage yard. I see that it has round exhaust ports. i was told that a header for square ports will fit, but i dont know how well that works for performance. is there a round port header that will fit and not have any clearance problems in my 260z?

 

I don't want to rain on your parade, but if you are looking for performance you may consider a differnt head. IIRC the N47 has the metal shrouds inside the exhaust ports and is, I think, the only L6 head with round ports. An N42, E88 will likey yield better performance....depending on your engine set-up. At least you will have something better to work with if future mods (porting)are planned.

[4everDATSUN]

Thanks fl327, ill ask MSA about their headers.

 

And 2126, the liners in the exhaust dont make a difference, or a significant difference, in performance. And porting a mn47 can be done. The chamber volume and shape is way better than all other heads, with out any machining.

[Mack]

yeah, the P47 is a nice head. The "evil" exhaust liners are not really all that evil. Stock for stock, a linered head will flow roughly the same as a square port head and you can mildly port the the valve bowls and get them to flow just as much as a decently ported square port head.

 

also, you really cant match the P47 head as far as combustion chamber size or shape. its 38 to 39 cc's stock. it EASILY accepts N42 and N47 larger intake valves and its pretty ping resistant. prettymuch the ultimate bolt on L6 NA head nissan made.

 

McAdam

 

oh yeah, the other nissan head that has round liners is the P79

[4everDATSUN]

Mack, which headers do you use? i know you have or still do run this head.

[Mack]

i will be putting a square port 6 into 1 header tomarro. i plan on matching it up to make sure it will not block any of the round exhaust port. ill let you know how it goes!

[4everDATSUN]

thanks mack

[Guest hegan1956]

Hi, I'm a new member to the forum. After looking at the discussion on 47 and 48 heads I was wondering what vehicles they came on? I have a 280Z with the factory heads which are round port. So does this make them 47 heads? Also has anyone heard of crossport style heads for this engine? I really dislike same side port systems.

[4everDATSUN]

hegan, first the heads arent reffered to as 47 or 48. second no Lseries z came with a crossflow head. althought they did come on the RB Lseries skylines, heavy mods nessicary for swap. and for a list of heads that came on different blocks you can visit http://www.geocities.com/zgarage2001/z.html. here you can see the terms used to denote different heads.

[4everDATSUN]

hey mack, which head gasket do you use with your engine, the maxima or z? thinkin about it the bore on the maxima was smaller, so the L28 z gasket would prob be the best.