Late model e88 heads

[kolonelklink87]

So I've been putting off doing this for a while... I've noticed that there seems to be a void in information on late-model e88 heads for l-series engines (probably due to the fact they were'nt delivered in the US). I thought I'd open some discussion on these heads before contributing to the heads sticky.

I've noticed at least two different casts for late-model e88 heads found in australia on l24e's fitted to mr30 skylines.

Both later e88's are fitted with internally oiled A cams and solid lifters. They have closed combustion chambers and fuel injector notches (machined, not cast like p90's). Both have 35mm intake ports and "square" type exaust ports. Both has 42mm intake and 35mm exaust valves.

I'll refer to two different castings as "cast-a" and "cast-b".

 

Cast-a: has vertically cast lines on all unmachined surfaces excluding the CC's much like those seen on the unidentified head on the cylinder head types sticky. Has "N42 E88" cast into the thermostat coolant outlet floor. Has a tall, well pronounced boss protruding into the CC for the spark plug... (my photos dont show this too well as I was in the process of smoothing this out and dont have a spare head of this casting). The quench pad ends in a smooth transition to the combustion chamber

 

Cast-b: does not have the cast lines nor the "n42 e88" coolant passage casting. The spark plug boss is significantly smoother than the other casting and the quench pad ends in a overhanging lip that as seen on the y70 post made by ozconnection.

 

I have not CC'd the heads and do not have the precise equipment to, i cant give it a stab using agricultural methods but given the "a-cast" has allready been machined and modified slightly i doubt this would prove a productive exercise.

 

Here are some photos of the combustion chambers... you can't pick up the differences too well but they are definately there... also i realised i should have taken both images from the same cylinder... sorry about that... i'll edit it later when i can take another photo

 

"Cast-a":

 

"Cast-b":

 

I have some opinions on the potential applications of these heads and they do see some use amongst L-series builders in Aust. but information is limited and i'd love to hear some open discussion on these heads

 

Cheers!

-pete

Edited February 28, 2010 by kolonelklink87

[Tony D]

We got two versions of the E88 that I know of offhand.

L24 on the 73 240Z

L26 on the 74 260Z

 

I don't believe we got an L28 with an E88, but I know that is what we are running on our Bonneville car (E88 on N42 Block).

 

The late Don L. Potter preferred the E88 over any of the other heads for Turbo applications. He's dead now, and I can't talk to him as to what his logic was, but he was producing winners using that formula.

[kolonelklink87]

We got two versions of the E88 that I know of offhand.

L24 on the 73 240Z

L26 on the 74 260Z

 

I don't believe we got an L28 with an E88, but I know that is what we are running on our Bonneville car (E88 on N42 Block).

 

The late Don L. Potter preferred the E88 over any of the other heads for Turbo applications. He's dead now, and I can't talk to him as to what his logic was, but he was producing winners using that formula.

 

I'm probably pushing my luck asking which version of the e88 you are using on that car and what attributes of the cast led to the choice of the cast over others? (compression, flow etc?)

 

(Still in korea? How is it? I'm envious, I've never been but was hoping to drop over when I visit japan again at the end of the year)

 

-pete

[Tony D]

I'm probably pushing my luck asking which version of the e88 you are using on that car and what attributes of the cast led to the choice of the cast over others? (compression, flow etc?)

 

(Still in korea? How is it? I'm envious, I've never been but was hoping to drop over when I visit japan again at the end of the year)

 

-pete

 

The only thing this head has in common with a stock E88 is that the casting number says 'E88'...

 

Welded combustion chambers (14.75:1 CR), Tuliped Valves (oversize), ported intake and exhaust tracts. It was formerly on a GT3 Car before we took it over and put it into Land Speed Service.

 

Korea was warmer than I'd expected. So much for my Arctic Parka I brought. Machine was inside as well, not what I was told. There goes 8kg of shipping storage in my bag... I will wear that damned thing on the plane back to LA to recover shipping storage for books this trip! But got to go back to Korea, so no shipping of a G-Nose on this trip No time for shipping it to the hotel, nor a direct flight for only one check-in.

[NZeder]

I think the reason for these head to be the choice in Oz is for the following reasons.

 

1. They are available - ie they were sold on the Oz spec R30 with the L24e engine. Unlike the US which got the N47 on the same bottom end.

2. They have a P90a type heart shape but without the larger cc of the P90a

3. They have use the N42/E88 length valve not like the P90a which has a different length

 

So they are kind of the best of a N42 with the best of P90a but with small valves = no welding for a performance head job, just install larger valves and a cam etc.

 

This is just what I am lead to believe so not 100% if these are the reasons they are used in Oz but this make sense to me anyway.

[kolonelklink87]

I think the reason for these head to be the choice in Oz is for the following reasons.

 

1. They are available - ie they were sold on the Oz spec R30 with the L24e engine. Unlike the US which got the N47 on the same bottom end.

2. They have a P90a type heart shape but without the larger cc of the P90a

3. They have use the N42/E88 length valve not like the P90a which has a different length

 

So they are kind of the best of a N42 with the best of P90a but with small valves = no welding for a performance head job, just install larger valves and a cam etc.

 

This is just what I am lead to believe so not 100% if these are the reasons they are used in Oz but this make sense to me anyway.

 

As i said, the information out there doesnt seem to be very intensive, so any discussion is good

I tend to agree with you on all 3 points; i think these would make ripper heads for a high compression stroker etc due to the small chamber size...

I'm exploiting one of these for a turbo build with std. 35mm ex. and 44mm in.(OS in this head) valves.

I particularly like the look of the spark plug region in the second head... it looks to be nice and smooth ... and the longer valve length was the seller for me over the p90...

I still have considerable work to do before this is a running engine so i won't be able to contribute any numerical evidence at this point in time

 

 

Both heads seem to have mildly different exaust valve profiles to the nissan stamped ones I've pulled from a earlier open chamber e88... its possible theses were both PO fitted or nissan may have updated the exhaust valve somewhere along the line (?) the later valves have no identifiying markings.

 

-Peter

[Carl Beck]

We had at least 4 heads cast with E88 here in North America - so you have to be careful when you are buying one.

 

1. Early E88 - This head is found on late year production Series II {Late Model Year 1971 Z's} and a few very early 72 Model Year Z Cars. It has the same combustion chamber as the E31 and the same 42.4 cc volume. As I understand it, this head had improved castings and materials to address the cracking found around the exhaust ports on many of the E31's.

 

2. The standard E88 found on the 1972 Model Year 240Z's. Same combustion chamber shape as the E31 only 44.7cc combustion chamber volume. This head had improved exhaust and intake port runners. So the lower compression from the E31 was off-set by better breathing and the 70/71 & 72 L24's were all rated at 150 HP.

 

3. The E88 for the 1973 Model Year - this head had a redesigned combustion chamber to meet the stricter 73 emissions standards. 44.8 cc

 

4. The E88 for the 74 Model Year L26. This was the same combustion chamber design as 73 only with the larger 35mm exhaust valve. The L26 used a longer stroke than the L24 but the same bore - so the L26 blocks had "eyebrows" cut in the top of the cylinder bores for the larger valve to clear.

 

If you put the late 71/72 E88 side by side with the 73/74 E88's it is pretty easy to tell them apart. The earlier combustion chambers have a raised or protruding area around the spark plug - the emissions heads don't.

 

The 73/74 E88's have a raised quench area to increase combustion chamber temperatures... good for emissions but bad for HP. This is a subject of some debate. Some say that the increased volume of metal cools combustion chamber temps. Others say that when you compress a gas you increase its temp. Nissan said they increased the combustion temp. to control certain emissions...

 

If you are going to build a higher performance head - you are going to re-work a lot of factors anyway - so find a good straight head, with no micro cracking and go from there.

 

FWIW,

Carl B.

Edited March 4, 2010 by Carl Beck

[Tony D]

Holy Victor-Victoria!

"The 73/74 E88's have a raised quench area to increase combustion chamber temperatures... good for emissions but bad for HP. This is a subject of some debate. Some say that the increased volume of metal cools combustion chamber temps. Others say that when you compress a gas you increase its temp. Nissan said they increased the combustion temp. to control certain emissions..."

 

Didn't 73 and 74's have EGR to decrease combustion chamber temperatures and thereby reduce NOx?

 

Is this a typo? Did you mean to say 'decrease' combustion temperatures---then you have two emissions devices working together instead of opposite each other.

 

It is a physical law that gas temperatures increase when compressed...

[Carl Beck]

Didn't 73 and 74's have EGR to decrease combustion chamber temperatures and thereby reduce NOx?

 

Is this a typo? Did you mean to say 'decrease' combustion temperatures---then you have two emissions devices working together instead of opposite each other.

 

Hi Tony:

Good points.. I qualify the following by saying "As I Understood It At The Time".

 

The time - was a discussion years {decades} ago on this subject on the old Z Car List. From a vague memory, I believe it was Mike Kojima {but don't want to certify that unless I can dig though the archives and find the thread again} - - that made the remark when the subject of the operational problems with the 73's were being discussed and the changes to the combustion chamber design were brought up. {looking for a change plus a distinction or cause/effect relationships}

 

Yes - the EGR was intended to reduce combustion chamber temperatures - When they were reaching their Peak. NOx concentrations are greatest as the combustion temperatures approach 2500 degrees. That is at periods of sustained highway cruise or mid range acceleration and that is when the EGR system is kicked in...

 

Increasing the "normal" lower level combustion temperatures at other times reduces CO and HC... So the L24's in the US were setup to run slightly hotter in 73. They weren't to the point of needing sodium filled valves or anything, but they did run hotter than the earlier cars. In-turn the exhaust manifolds ran hotter as well.

 

So - yes to two solutions did work together, but each had its desired effect at different engine loads/rpm and manifold pressures... etc.

 

 

FWIW,

Carl B.

[Noddle]

1. They are available - ie they were sold on the Oz spec R30 with the L24e engine. Unlike the US which got the N47 on the same bottom end.

 

My '85 MR30 had the N47 small chamber head

 

Nigel

[kolonelklink87]

My '85 MR30 had the N47 small chamber head

 

Nigel

 

... what size is that intake valve?

thats interesting... sure it wasnt a swap/replacement? every mr30 i've encountered, which isnt heaps, has had the e88 casting.

[Daeron]

We had at least 4 heads cast with E88 here in North America - so you have to be careful when you are buying one.

 

1. Early E88 - This head is found on late year production Series II {Late Model Year 1971 Z's} and a few very early 72 Model Year Z Cars. It has the same combustion chamber as the E31 and the same 42.4 cc volume. As I understand it, this head had improved castings and materials to address the cracking found around the exhaust ports on many of the E31's.

 

2. The standard E88 found on the 1972 Model Year 240Z's. Same combustion chamber shape as the E31 only 44.7cc combustion chamber volume. This head had improved exhaust and intake port runners. So the lower compression from the E31 was off-set by better breathing and the 70/71 & 72 L24's were all rated at 150 HP.

 

3. The E88 for the 1973 Model Year - this head had a redesigned combustion chamber to meet the stricter 73 emissions standards. 44.8 cc

 

4. The E88 for the 74 Model Year L26. This was the same combustion chamber design as 73 only with the larger 35mm exhaust valve. The L26 used a longer stroke than the L24 but the same bore - so the L26 blocks had "eyebrows" cut in the top of the cylinder bores for the larger valve to clear.

 

If you put the late 71/72 E88 side by side with the 73/74 E88's it is pretty easy to tell them apart. The earlier combustion chambers have a raised or protruding area around the spark plug - the emissions heads don't.

 

The 73/74 E88's have a raised quench area to increase combustion chamber temperatures... good for emissions but bad for HP. This is a subject of some debate. Some say that the increased volume of metal cools combustion chamber temps. Others say that when you compress a gas you increase its temp. Nissan said they increased the combustion temp. to control certain emissions...

 

If you are going to build a higher performance head - you are going to re-work a lot of factors anyway - so find a good straight head, with no micro cracking and go from there.

 

FWIW,

Carl B.

The E31 head has the peanut-shaped combustion chamber.

 

I gather from your statements that at least the #1 E88 head also has the peanut-shaped combustion chamber, but I cannot tell from your descriptions; which E88 heads were full open-chambered and which had the peanut-shape?

 

The fact that this thread has not already answered this question for me is vexing and bothersome; add that to the fact that this is a question that has been nagging me for some time anyhow, and I have to ask. I am curious because I've got some inherited head castings (along with a plethora of other junque) that need to be sorted and "prioritized." If anyone can get *some* pics up, I may be able to get other pics, so we can finally get good, high-res documentation on (at least the USDM variants) of this casting. (It is a missing point from the L6 head sticky here, too)

[ozconnection]

... what size is that intake valve?

thats interesting... sure it wasnt a swap/replacement? every mr30 i've encountered, which isnt heaps, has had the e88 casting.

 

That's no typo Pete, R30's here in Oz did also have N47 heads, I had one, then tried to take out the liners and was left with a junk head. I threw it out shortly thereafter. That was years ago though when I didn't know what I had.

 

The intake valves are 42mm and the exhaust are 35mm.

 

Cheers

[kolonelklink87]

That's no typo Pete, R30's here in Oz did also have N47 heads, I had one, then tried to take out the liners and was left with a junk head. I threw it out shortly thereafter. That was years ago though when I didn't know what I had.

 

The intake valves are 42mm and the exhaust are 35mm.

 

Cheers

 

I recently had a discussion with a fellow on a local forum who was looking into running an n47 with a tongue down the exhaust after hogging it out. I wonder how it'll work out....?

 

(mark: itb's are ready for welding... if i cant find some bloody time during a weekday to drop them off)

 

so anyhow... any insight into the logic of running the two different heads on the same car?

[ozconnection]

I recently had a discussion with a fellow on a local forum who was looking into running an n47 with a tongue down the exhaust after hogging it out. I wonder how it'll work out....?

 

(mark: itb's are ready for welding... if i cant find some bloody time during a weekday to drop them off)

 

so anyhow... any insight into the logic of running the two different heads on the same car?

 

Why? These guys who remove the liners, did they do so because they flow benched them first? Dumb idea to wreck what 'may' actually be a reasonably good flowing port as it is.

 

Has ANYONE flowed the P79/N47 exhaust ports??

 

ITB's will be very cool Pete, email me some pics as soon as you can please, love to see it 'finished'

 

 

As far as why Nissan ran E88/N47 heads concurrently on the R30's is up for debate. Since these were the last of the R30/L24E's for exporting ot Oz, maybe it was to empty the shelves. Dunno.

 

Cheers

[Tony D]

"Buildout Cars" are always a taboo area of discussion. They do things the 'absolutists' simply can't understand...like put round top carbs on a car with 1973-Specification bumpers (talking USA here...)

 

In Response to Carl...my understanding was the 73 cars had the leaner mixtures which also clean up the CO/HC by 'running hotter' but can be compensated for in the upper rpm ranges by more EGR and Needle Taper.

 

Flowbench testing of the P79/N47 head can be found in one of Bryan Blake's Posts, he flowbenched them. (1 Fast Z)

 

Running two heads 'concurrently' may be as simple as a running production change---cars up to midyear ran one, cars after midyear ran another. As they all occur in the same production year cycle for most of the world, you end up with a 1983 with one head in 5/83, and another in 7/83. Such was the situation on S30 doors for the US market in 1976!

 

I would guess heads are no different. Parts is parts.

 

On a side note, things at Eraring Power Generation Station in Dora Creek are degenerating quickly, and ALAS, I may have to make another visit down under..."oh bother," said pooh bear, "those ozzies are biting my arsecrack again!"

[ozconnection]

"Buildout Cars" are always a taboo area of discussion. They do things the 'absolutists' simply can't understand...like put round top carbs on a car with 1973-Specification bumpers (talking USA here...)

 

In Response to Carl...my understanding was the 73 cars had the leaner mixtures which also clean up the CO/HC by 'running hotter' but can be compensated for in the upper rpm ranges by more EGR and Needle Taper.

 

Flowbench testing of the P79/N47 head can be found in one of Bryan Blake's Posts, he flowbenched them. (1 Fast Z)

 

Running two heads 'concurrently' may be as simple as a running production change---cars up to midyear ran one, cars after midyear ran another. As they all occur in the same production year cycle for most of the world, you end up with a 1983 with one head in 5/83, and another in 7/83. Such was the situation on S30 doors for the US market in 1976!

 

I would guess heads are no different. Parts is parts.

 

On a side note, things at Eraring Power Generation Station in Dora Creek are degenerating quickly, and ALAS, I may have to make another visit down under..."oh bother," said pooh bear, "those ozzies are biting my arsecrack again!"

 

Ah yes, I forgot about what Bryan had done there, thanks for reminding me.

 

Like I said, just let us know when you're coming Tony!

 

Cheers.