Jump to content

IGNORED

E88 not the best head?


Recommended Posts


2ManyZs enlightened me last week that the E-88 can be made better by milling it down to raise the compression some.

Most racers swear by the E-31 and that's what the major engine builders use. They are getting harder to find.

Hope that's what you wanted.

Rick

Link to post
Share on other sites

Time to stir the pot a little. What is an E88 head? I have heard conversations from respected Z folk that there are actually 4 different E88 heads on US model Z cars!

Here is the way it was explained to me (corrections are welcome). Heads with the E88 stamped on them started around 01/71 with the series II 240Z(or late '71 model.) This head is supposed to have the same combustion chamber as the E31. Then, in 09/71 with the series III 240Z('72 model year) the combustion chamber was changed to slightly lower compression design. Next, with '73 model year the E88 head was further designed for lower emissions and finally in '74 larger exhaust valves, same size as 280Z, were put into the E88 head.

I do have several of the E88 heads on spare engines but have yet to take them appart to see if I can document any noticable differences. I myself have a hard time believing there are 4 E88 heads but have found documentation of at least 2 different E88 designs.

So which Z head to use- E31, E88, N42, N47, P79, P90 or P90A. Did I miss any? First, unless you plan on changing to round port exhaust you can rule out the N47 and P79. Next it depends on which block/pistons you will be using. If using 240, 260, 280Z block with stock crank, rod piston setup then forget the P90 & P90A unless you are going to run a turbo because the compression would be too low for performance driving.

So that leaves the E31, E88 or N42. None of these are a "bad" choice, with the exception being the emissions designed E88. But trying to identify an E88 head may be a challenge.

So that narrows us down to E31 vs. N42. The E31 is supposed to benefit from a slightly higher compression combustion chamber design but because of age and limited quantity finding one in good condition can be difficult and expensive. The N42 is slightly lower compression combustion chamber design but unlike the E31 and early E88 it has larger exhaust valves and came with hardened valve seats and guides for running unleaded fuel. Plus, there are lots more available and you can shave them to get higher compression if that is desired.

Bottom line, I am guessing that the difference between the heads may be +/- 10 HP. Unless you head is damaged you would probably get more by setting your valves correctly, getting a valve job, changing the cam, recurving your distributor or porting and polishing your head and intake manifold then by searching for a new head. But it really depends on your desired results and how much $$$ you want to spend.

Sorry for the long post! I hope it makes sense and is helpful!

Link to post
Share on other sites

I have two different E88 heads, the early E88 head and a later one (atleast this is what i've been told). The casting marks are different between the two and makes idetification abit easyer. The early head has a skinny E and a uniform 88 casting mark where as the later head is uniform through out the three characters (same size and thickness). The early head has notches at the bottom of each combustion chamber, and i'm told the early head has the same compression as the E31. I'v also been told that it's an easy swap to put in the larger valves in the E88 heads, has anybody done this before?. I have the early head on my 240, which i recently put on. I changed the trans and rear end too at about the same time so i couldn't say if the early E88 head gave me anymore HP than the later one. I will say that the 5 speed 3.90 R200 and Supposed high compression E88 head have made a big difference.

Link to post
Share on other sites

Hmmm... I'll have to take a look at the casting numbers on the E88's I have.

Regarding the valves. My E88 had been fitted with 280Z valves. I believe it is relatively simple machine work because if I remember correctly the original smaller valve seats can be machined to fit the larger valves. In other words they don't have to change the head itself. But probably best to check with Rebello or another Z engine builder to be sure.

Have fun!

Link to post
Share on other sites

thanks man the long post was needed to justify the question i asked was a big help in deciding the head i should probably go for. now the only thing that lies ahead is what Z had the E#! head on it im willing to spend the money to get it but i dont know where to start looking. also how much would a head like that cost? i tried to budget out the money for the car and for each area of the car that i wanna focus on.

also does anybody know where i can get a 77 280z 5 speed tranny? because i want to get one for my z while i have my engine out of my car.

Link to post
Share on other sites

What I mean by bare is just the casting - no valves, springs, cam, rockers, etc.

You can get a complete Rebello E-31 head for between $1500 and $2000. My stock E-31 rebuild cost me about $800 - but I had the casting from an old engine.

It's very hard to say what a complete head would cost - and what condition it would be in. Just start posting and searching the internet. I'm sure someone on this site has one they wouldn't mind parting with.

Sorry I couldn't be more specific.

Link to post
Share on other sites

like anything with performance comes money.

i like the early E88 head on a F54 block. port polish the head polisht the combustion chambers, insert larger valves ss steel seats, a good cam and you have a great gas pump ready engine that will kick some arse

Link to post
Share on other sites
  • 3 years later...
hi all i was told that the E88 head was 2nd best. if im wrong correct me please but is there a better head if so where can i buy it? let me know plz and thanks

I just ran up on a F 54 block with P90 heads. I understand with flat top pistons it will have plenty of compression. I am new to this part of performance so I would like any input I cah get.

Link to post
Share on other sites

Hey guys I suck at searching for old threads but there was one here that linked to a guys web site that went through all of the combinations that you are talking about. He described all blocks, heads and the combinations. Sorry I can't be more specific but he had it all down, very informative. Maybe someone else knows how to get to that thread. I will keep looking

Link to post
Share on other sites

Quote: "I have two different E88 heads, the early E88 head and a later one (at least this is what i've been told). The casting marks are different between the two and makes identification abit easier. The early head has a skinny E and a uniform 88 casting mark where as the later head is uniform through out the three characters (same size and thickness)."

The uniform lettering of E and 88 on the later E88 heads -- was that used only on the emissions-oriented 1973 heads? I suspect it began earlier, but does anybody know? If a known 1972 head were found to have that lettering, that would tell us. (Uniform versus the skinny E.)

thanks,

Steve

Link to post
Share on other sites

PS -- On the E88 lettering question, there's a photo on this Zhome page:

http://zhome.com/ZCMnL/tech/E31andE88Heads.htm

showing the chamber side of a 1973-type head vs. the 1972-type. If anybody's got an E88 head loose, it would be interesting to see if any with the 1972-type chamber side have the later casting mark. (Royce?)

Link to post
Share on other sites

I have both a 1970 E31 head and a late 1971 (72 model year) E88 head with the small combustion chambers. The E88 is almost identical but has very slightly larger combustion chambers and flows a little better since the valves arent shrouded like the E31. The E31 bone stock produces slightly more power, but I am in the process of doing a full race build on the E88. I had it shaved .050 and shimmed the cam towers. Schneider stage 3 cam and alloy springs as well as 44mm intake and 38 mm exhaust SI racing valves. The E88 is almost done and my E31 is a fresh rebuild with less than 200 miles on it. I'm using the E31 for driving around while I am finishing the E88. After I'm done with the E31 I might be willing to sell it.

Link to post
Share on other sites
I have both a 1970 E31 head and a late 1971 (72 model year) E88 head with the small combustion chambers. The E88 is almost identical but has very slightly larger combustion chambers and flows a little better since the valves arent shrouded like the E31.

So on your E88 -- what's the 'E88' lettering like? Is the 'E' skinny or is it full width like the two 8s?

thanks,

Steve

Link to post
Share on other sites

E31 on the car right now

head_001.jpg

E88 E is as wide as 8s

head_002.jpg

Valves are pretty big on my E88 (biggest you can fit, they barely made it) and the chamber is notched under the spark plug

head_003.jpg

stock E88 valves for comparison

E88wtext.JPG

I ran the E88 for a few hundred miles with a slightly clogged oiler bar that scarred my stage two cam and instigated the rebuid with an internally oiling stage three cam (reason why it is dirty).

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...

Important Information

By using this site, you agree to our Privacy Policy and Guidelines. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.