Jump to content
HybridZ

L6 heads; pics and descriptions


Recommended Posts

  • Replies 93
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Popular Posts

I haven’t heard of the N-47 being manufactured with-out the liners, though that is not to say it didn’t happen. HS30-H or 1 fast Z are pretty savvy regarding what was and was-not offered from Da

  Thank you for the clarification. I really could have screwd my self over not knowing that.

So, since I didn't see this answered earlier, but are the intake ports into the head the same across all of the Z car heads? (I'm wondering because of intake manifold possibilities).

Posted Images

I had a P99 head that came off of a late production 1983 280zx turbo 5 speed.

 

It seemed identical to the P90a head but I never did study it in detail......just slapped it on a 280zx turbo I had.

 

I eventually gave the engine/tranny setup to Datsun Dynamics in 1998 but now I am curious whether it had any differences or if anybody else here had seen one.

Link to post
Share on other sites
  • 3 weeks later...
  • 3 weeks later...
So instead of badmouthing people or saying "you're totally wrong" How about telling us what you think is correct next time.

 

"Badmouthing" might not be quite the correct term. Firstly, I had my tongue planted firmly in my cheek ( although you might be forgiven for not noticing, or indeed understanding why ) and secondly I didn't write "you're totally wrong" ( whom are you quoting there? ).

 

The point is - despite what seems like hundreds of posts on this forum and others that try to clear up the misinformation and confusion - people still seem get the most basic things muddled up in their heads. I can only assume that people either don't read, or don't fully understand what they do read.

 

I am presuming that member madmatt48's post was an attempt to identify the "mystery" 'Goerz-Paeco' casting in post #1 of this thread. He seems to think that it is an S20 head ( it isn't ), and also appears to have missed Tony D's explanation of the story behind it ( or at least what is known ) and his personal involvement in taking the photos that were posted. Looks to me like a clear case of somebody not reading the whole thread and then making a post that mis-identifies something in a picture, even though the 'Goerz-Paeco' looks nothing like an S20 head. His heart may well be in the right place, but his attempts to help went off half-cocked.

 

As far as I understood it, the purpose of this thread was to identify and classify the numerous heads for the Nissan 'L-series' six cylinder engines. The S20 head does not fit on the L6 block, and therefore does not belong on this thread.

 

Member zdrift might like to read the thread through fully too, as he's asking if anyone "kno" ( tee hee ) about an E30 head and block - when 1 Tuff Z identified the type clearly in post #5........... Seeing member zdrift then ask about "one of those dohc heads for a l28 or l28et" raised a smile from me, but then he goes on to ask about an "sw20 head or complete motor", which could be pathos or bathos depending on how you look at it.

 

Slight digression: Is it just me, or does anybody else notice that very often these days the word "drift" sets off the alarm on the patent Dimwit Detector, and alerts you to the fact that you are just about to read something daft?

 

Just what is it about his statement that is incorrect. I can point out a few things but I'll let you state the TRUE facts. :ugg:

 

No, please be my guest! Feel free to correct those "few things" you see, whilst I have a day off instead of a Groundhog Day............ :-)

 

Alan T.

Link to post
Share on other sites
  • Administrators
"Badmouthing" might not be quite the correct term. Firstly, I had my tongue planted firmly in my cheek ( although you might be forgiven for not noticing, or indeed understanding why ) and secondly I didn't write "you're totally wrong" ( whom are you quoting there? ).

 

The point is - despite what seems like hundreds of posts on this forum and others that try to clear up the misinformation and confusion - people still seem get the most basic things muddled up in their heads. I can only assume that people either don't read, or don't fully understand what they do read.

 

I am presuming that member madmatt48's post was an attempt to identify the "mystery" 'Goerz-Paeco' casting in post #1 of this thread. He seems to think that it is an S20 head ( it isn't ), and also appears to have missed Tony D's explanation of the story behind it ( or at least what is known ) and his personal involvement in taking the photos that were posted. Looks to me like a clear case of somebody not reading the whole thread and then making a post that mis-identifies something in a picture, even though the 'Goerz-Paeco' looks nothing like an S20 head. His heart may well be in the right place, but his attempts to help went off half-cocked.

 

As far as I understood it, the purpose of this thread was to identify and classify the numerous heads for the Nissan 'L-series' six cylinder engines. The S20 head does not fit on the L6 block, and therefore does not belong on this thread.

 

Member zdrift might like to read the thread through fully too, as he's asking if anyone "kno" ( tee hee ) about an E30 head and block - when 1 Tuff Z identified the type clearly in post #5........... Seeing member zdrift then ask about "one of those dohc heads for a l28 or l28et" raised a smile from me, but then he goes on to ask about an "sw20 head or complete motor", which could be pathos or bathos depending on how you look at it.

 

Slight digression: Is it just me, or does anybody else notice that very often these days the word "drift" sets off the alarm on the patent Dimwit Detector, and alerts you to the fact that you are just about to read something daft?

 

 

 

No, please be my guest! Feel free to correct those "few things" you see, whilst I have a day off instead of a Groundhog Day............ :-)

 

Alan T.

 

 

Alan,

Thank you for being so tactful in your replies. Well done.

 

By the way, do you mind if I use your slight digression quote? Racers poetry ... Love IT!!!

Link to post
Share on other sites
  • 1 month later...
  • 1 month later...

 

 

any information on the 05L head? have one on my l20et hr30 skyline. when i pull the engine down i'll get pics of it but just wondering if they are complete rubbish or ok.


I too have an 05L head from an "M" block L20 turbo six cylinder engine. I also have a Y70 head from an E30 L20 turbo six cylinder engine.

The O5L head has 28 mm intake ports and square exhaust ports. They are smaller than the Y70 intake ports which measure 30mm's. Both heads have 38 mm intake valves and 33 mm exhaust valves. The Y70 has round exhaust ports with liners like the MN47 and P79 heads.

The bottom end of the "M" engine has the smaller rods and journal size, like the US Maxima L24E engine. The E30 version has the larger, stronger bottom end setup like the rest of the L Series six cylinder family.

Why did Nissan make these two versions of the same engine....who knows???

I can get some pictures of the Y70 on here if anyone is interested! Edited by ozconnection
Link to post
Share on other sites
  • Administrators
Can you guys help me ID what head I got? ..at the usual spot where you'd find the code, it's mysteriously blank.

supplies171.jpg

 

It's got notches for injectors, but square exhaust ports.

currywurst033.jpg

 

Inlet ports are 40mm diameter.

currywurst032.jpg

 

...I'm thinking....N42??

 

I’m not real familiar with L-series cylinder heads for other markets/countries other than domestic USA market. Though I am pretty certain that this head is NOT a domestic USA head AND it has been modified.

 

1) Injector slots and injector manifold mounting holes along with carb mounting holes indicates post 1975 production.

 

2) The EFI Intake mounting holes “appear” to be 8 x 1.25mm, (Same as the carb and exhaust mounting holes), instead of the typical USDM 10 x 1.25mm, though the pictures could be deceiving and those holes could be the 10 x 1.1.25mm holes. (See picture below showing the mounting hole size difference on an US market N-42 head.)

 

3) In looking at the manifold face, note the 2 bolt hoes above the #6 exhaust port?…. NOT on any USDM L-6 cylinder heads.

 

4) Note the vertical casting lines above and between the ports in the unmachined portions of the head near the valve cover...

 

5) The measurement of the intake port opening means absolutely nothing in identifying that head as it had been “port matched” (opening of the port had been enlarged by hand), evidenced by sanding wrap marks left in the port entrance and the injector slots indicate most of the material removed in the intake port was removed from the roof of the port.

 

6) The casting number had been removed. The picture is difficult to tell but it looks like a sanding wrap finish.

 

7) Pics of the combustion chamber and clear well lit pics of the area surrounding the intake valve guide boss would help greatly in identifying this head, so long as the intake port work did not consist of altering the guide boss.

 

 

N-42 head. EFI mounting holes 10 x 1.25mm, carb mounting holes, 8 x 1.25mm

Mis-match2Medium.jpg

Link to post
Share on other sites

Thanks Paul

 

You're right, I think the head's been ported at some point.

currywurst047.jpg

 

It's on a KGC10 Skyline (on an N42 block) so I guess you're right, the head is probably some oddball JDM edition. I think the additional holes for the injector manifold is bigger than the 2 carb intake studs tho.

Link to post
Share on other sites
  • 2 weeks later...

I gots a question for ya'll. Maybe I'm totally overlooking something, so hopefully someone can help. The P90 has a 53.6 cc chamber (blueprint OE specs), a Fel-Pro replacement 1mm (0.40) headgasket has a 3.47 bore. L28 flat top pistons pop up above the deck .020 I believe. Engine bore is 3.39, stroke is 3.11. This yields a 9.09:1 compression ratio. That's a decent amount above what Nissan claimed. What am I missing here?

Link to post
Share on other sites

For one thing, the turbo engines had dished pistons, about a 10cc dish.

 

I take this little engine calculator to have accurate specs, but I haven't confirmed this and would never presume any internal pieces I held in my hand matched an internet figure anyhow. http://www.ozdat.com/ozdatonline/enginedesign/

 

According to them, the piston has slight negative deck height as well; according to that calculator, with a 1.0 mm HG and flat tops, the compression should be about 8.66. The P90 and P79 combustion chambers are the same, so essentially a flattop/p90 combo with stock pistons and headgasket should be right in line with a stock 280ZX factory compression.

Link to post
Share on other sites
According to them, the piston has slight negative deck height as well; according to that calculator, with a 1.0 mm HG and flat tops, the compression should be about 8.66. The P90 and P79 combustion chambers are the same, so essentially a flattop/p90 combo with stock pistons and headgasket should be right in line with a stock 280ZX factory compression.

 

Now, when they say negative deck height on the calculator, do they mean that the piston is recessed into the cylinder at top dead center or above it, because, at least in 1983 for certain, on a non-turbo L28, the stock piston is most certainly above the deck at top dead center.

Link to post
Share on other sites
Now, when they say negative deck height on the calculator, do they mean that the piston is recessed into the cylinder at top dead center or above it, because, at least in 1983 for certain, on a non-turbo L28, the stock piston is most certainly above the deck at top dead center.

 

actually I believe I did mis-state that, when they indicate negative deck height it means the pistons is above the firing deck; but I checked it and it actually indicated a positive figure about equal to what you had thought the pop-out was.

 

This is all irrelevant to this thread, which was started to be an index of photos and descriptions of L cylinder heads.

Link to post
Share on other sites
  • 4 weeks later...

Hmm...I have a '72 E88 head casting, (the pitted up nasty one) that has chambers IDENTICAL to the E30 castings shown in this thread, but different from the 260Z E88 and the shaved and valved E88 also shown. the camshaft is marked E30 as well, nothing special there, but it's funny that we find so many head casting codes, and so few changes between them.

Link to post
Share on other sites

×
×
  • Create New...