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Discussion Starter · #1 ·
I have read that the N47 on ealry 80's Maxima's have different combustion chamber design (and volume) than the N47 found on the 280 and 280ZX's. I have seen the N47's on the old Maxima's in the junk yards, but I have never pulled one off to take a look.

What I want to find is a stock head to increase the compression ratio on my 260Z to somewhere between 9 and 10.5 to 1. Is there any head that can do that without shaving? and which I can get a cheap valve job done on and just slap on my L26?
 

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The Maxima used a N33 and P81 head. The only car that had the N47 and N42 was the L28 out of the 280Z. All N47's are one in the same.
 

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Discussion Starter · #3 ·
> The Maxima used a N33 and P81 head. The only
> car that had the N47 and N42 was the L28 out
> of the 280Z. All N47's are one in the same.
I have seen with my own eyeballs, at least six (6) early 80's Maximas during the past two weeks in the junkyards, and every single one had N47 cast on the head between number 1 and number 2 cylindars. So I am virtually 100% certain that you are wrong when you say that the only car that had the N47 . . .was . . the 280Z.

As to the design of the N47 in the Maxima, I have no idea whether it is the same as that in the Z. That is what I am trying to find out. Since you have never seen an N47 from a Maxima, obviously you don't have any direct first hand knowledge as to whether they are the same or not.
 

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I can verify N47 on Maxima

Not to be nasty, but I have also seen a N47 on a '83 Maxima. I know this, because I took the oil pressure sensor off of it 2 weeks ago.
What we have to remember, is that Nissan made alot of their parts interchangeable, and that can cause alot of confusion. Just like trying to find out which ratio is in which car. An '85 Maxima also had the SAME rear calipers as a '82-'83 280ZX. So, I wouldn't be surprised if a '83 Maxima had a N47 head.
 

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Discussion Starter · #5 ·
Re: I can verify N47 on Maxima

> Not to be nasty, but I have also seen a N47
> on a '83 Maxima. I know this, because I took
> the oil pressure sensor off of it 2 weeks
> ago.
> What we have to remember, is that Nissan
> made alot of their parts interchangeable,
> and that can cause alot of confusion. Just
> like trying to find out which ratio is in
> which car. An '85 Maxima also had the SAME
> rear calipers as a '82-'83 280ZX. So, I
> wouldn't be surprised if a '83 Maxima had a
> N47 head.
Dave, do you know if the combustion chamber design/size on the Maxima N47 head is the same as the Z N47? If so, give me your thoughts. I plan to pull one or two as soon as my my wife lets me out of the house long enough. When I do, I will take some pictures of the combustion chambers and put them up on the web.

P.S. -- I have read that the '83 Maxima N47 had hydraulic lifters. If I run into an '83 I'll take a look.
 

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Me too

Aside from the diesel Max I got my crankshaft from, every other Maxima I looked at had an N47, about five of them. I too would like to know if they are the same. Remember there are 2 different E-88 heads arent' there?
 

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Discussion Starter · #7 ·
Re: Me too

> Aside from the diesel Max I got my
> crankshaft from, every other Maxima I looked
> at had an N47, about five of them. I too
> would like to know if they are the same.
> Remember there are 2 different E-88 heads
> arent' there?
I believe you are right about some differences in E88's. For one thing, I think the exhaust value size changed, but I'm not sure.
 

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I have also noticed the N47 heads on the Maximas at the junkyards.

> I have seen with my own eyeballs, at least
> six (6) early 80's Maximas during the past
> two weeks in the junkyards, and every single
> one had N47 cast on the head
> between number 1 and number 2 cylindars. So
> I am virtually 100% certain that you are
> wrong when you say that the only car
> that had the N47 . . .was . . the
> 280Z.

> As to the design of the N47 in the Maxima, I
> have no idea whether it is the same as that
> in the Z. That is what I am trying to find
> out. Since you have never seen an N47 from a
> Maxima, obviously you don't have any direct
> first hand knowledge as to whether they are
> the same or not.
 

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some stuff i dunno if it helps or not.....

i have a non-original head on my Z...i know this because it has hydraulic lifters and not adjustabnle......

i don't know what style head my Z has ( i don't know a thing about that....it has square exhaust ports and same side intake/exhaust, but i don't know about the head style.
 

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Discussion Starter · #10 ·
Re: some stuff i dunno if it helps or not.....

> i have a non-original head on my Z...i know
> this because it has hydraulic lifters and
> not adjustabnle......

> i don't know what style head my Z has ( i
> don't know a thing about that....it has
> square exhaust ports and same side
> intake/exhaust, but i don't know about the
> head style.
Look on the passenger side, on the side of the head, in between the 1st and 2nd cylinder. The model number of the head will be cast on the side.
 

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Re: nevermind that.

> i went and looked at my car and it has a
> P90A head...not a N47
Matt, it sounds like you have a 280zx turbo head on yours. (P90A). We just got a 240z from a Nissan tech, and it had this head on a 240z engine. The car goes great, but had a nissan comp 5 spd, and a 4:11 diff in it, so it may just be the low gears.
As far as the N47 head, yes that did come on the
L24 maximas. There is a coolant temp switch on the passenger side, and there are some other differences also. The machine shop that we deal with, gets N47's from us all of the time, and will not take the Maxima head for a z application. That doesn't mean it wont bolt up, I'm sure it will, but the differences could be combustion chamber, and or valve size. I will check with him, and post his comments. Joe
 

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Discussion Starter · #13 ·
Re: nevermind that.

> Matt, it sounds like you have a 280zx turbo
> head on yours. (P90A). We just got a 240z
> from a Nissan tech, and it had this head on
> a 240z engine. The car goes great, but had a
> nissan comp 5 spd, and a 4:11 diff in it, so
> it may just be the low gears.
> As far as the N47 head, yes that did come on
> the
> L24 maximas. There is a coolant temp switch
> on the passenger side, and there are some
> other differences also. The machine shop
> that we deal with, gets N47's from us all of
> the time, and will not take the Maxima head
> for a z application. That doesn't mean it
> wont bolt up, I'm sure it will, but the
> differences could be combustion chamber, and
> or valve size. I will check with him, and
> post his comments. Joe
Joe, I would be real interested in hearing his comments, because I am considering trying one of these on my 260Z. I am curious about waht you mean by your machine shop will not take the Maxima head for a Z application. Don't you just give it to the machine shop to rebuild per your instructions? Why do they care about the application? Is it due to warranty? Also, what do you think it should cost me to have a local machine shop here in Tampa do a basic valve job/rebuild on one of these heads (I wil bring them the head and install it)
 

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Re: nevermind that. N47 Maxima heads

> Joe, I would be real interested in hearing
> his comments, because I am considering
> trying one of these on my 260Z. I am curious
> about waht you mean by your machine shop
> will not take the Maxima head for a Z
> application. Don't you just give it to
> the machine shop to rebuild per your
> instructions? Why do they care about the
> application? Is it due to warranty? Also,
> what do you think it should cost me to have
> a local machine shop here in Tampa do a
> basic valve job/rebuild on one of these
> heads (I wil bring them the head and install
> it)
I called them today (they are independent of us), and they said that the N47 off of the maximas have a heart shaped combustion chamber compared to the round combustion chamber on the z car N47.
They also said that the intake valves were slightly smaller. They have a seat cutter (not grinder), and could cut them to the z N47 size
valve. He thought it might approach 10:1 comp ratio if you also milled the head slightly.
The reason he would not use these on a z car order would be the possiblity of it pinging +
he felt that unless you use the larger intake valves, it might be a wash in power increase.
He would gladly do this as a special order, and I may have one done. I would use the flat top pistons.
I know that we sold a Maxima head that went on a
280z, with no reported negative comments. They had requested it, and I don't know if they modified it, or not. Joe
 
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