Can someone please explain to me the difference between an E30 and an E88 head? I have a '76 260z with the L26 motor, and scored a couple of free heads, one being an E30 and the other an E88.

E30 is early 240Z.
E88 is 2.4E Skyline (if it has fuel injector notches in the intake ports).

Do a search for more information.

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Classic Auto Fabrications:
http://www.ozdat.com/forum/viewtopic.php?f=38&t=31659

http://www.lescollinsracing.com/

The E88 also came on the L26 in the 260z, with larger combustion chambers, 44cc vs 39cc IIRC.

it thought the E30 was a single carby L6 head - 240K and 240C only...?

the E30 has the "smaller" intake valves and small ports - great for economy but not so good for power. small peanut combustion chamber too - around 9.4:1 CR versus the E88s 8.5ish:1.

didn't the E88 head show up on ALL twin carb L24 engines...?

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frankenstein projects R us.

The Republic of Western Australia -
Propping up the Nation's Economy since 1901.

So if I'm building the motor for performance, which would be better? The E88 with the larger valves or the E30 with the higher compression?

I have no idea what's been done to the motor that's in the car except for some minor things (better coil, elec. fuel pump) and it was running ok. Any suggestions?

I am looking at spending a bit getting the motor done, so I just need to know which would be the better head to start with. Last time I got larger valves fitted to a head I didn't think it was all that expensive, so that doesn't worry me.

Geordie,

It all depends how far you want to go I suppose. If you are going to change the pistons then you can fit some flat-tops to get around 9.2:1. FYI that N42/N47 heads have larger valves than the E88 and E31 and seem to be the performance head of choice (unless you are going turbo in which case some people use the P79/P90 to reduce compression).

I would suggest you get some L24 flat top pistons and an N42 head which will give you around 9.2:1 by my calcuations.

Some links:

http://www.ozdat.com/ozdatonline/enginedesign/
http://www.geocities.com/zgarage2001/heads.html

Dave

_________________
USA Daily: 2014 Nissan GT-R, very minor modifications for the track
USA Project: 1978 280Z, minor suspension upgrades, VK56DE conversion in progress. SOLD
AUS Race Car: 1973 240Z, L28ET, Autronic, GT35R. SOLD
AUS Project: 1972 1600, 3200km old S15 SR20DET, ground up rebuild. SOLD

Seems the 1983 P90a L6 head had hydrolic lifters. Almost silent running. Parts NLA

My bad.
Yes E31 is 240Z.
And E88 is off L26 260Z - Ive never bothered to look...
And as stated, E88 is also the 2.4E skyline head (with VERY good ports & chambers).
E30 is 240K, but I have also seen different markings on these heads.

Remember, for a NA road engine that won't see huge revs,
gas speed is the number one prioraty.
So you may not see a huge gain in hp/torque by fitting larger valves to the E30 head - UNLESS you de-shroud the combustion chamber around the valves (which will also mean you'll drop CR), & open up the throats behind the valves.

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Classic Auto Fabrications:
http://www.ozdat.com/forum/viewtopic.php?f=38&t=31659

http://www.lescollinsracing.com/

Ok, so how do I tell the difference between an E88 head from a 260z and one from a Skyline?

As for the engine, it'll be mostly a race car, with the occasional street race (legal of course!!). Need to build something decent to beat the father-in-law's Torana!! So I'm looking high compression, high revs, avgas etc.

Sat next to each other you can see the size difference in the combustion chambers, but the E88 from the skyline was injected as dave mentioned and had notches for the injectors.

I think your glasses need cleaning bob...

If your wanting to build somthing THAT seroius, I suggest you track down a P90 head...

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Classic Auto Fabrications:
http://www.ozdat.com/forum/viewtopic.php?f=38&t=31659

http://www.lescollinsracing.com/

Sorry, as Lurch said.

Why a P90 head lurch? They are open chamber and as such difficult to get high compression out of. A N42 is equivalent valve sizes but smaller combustion chamber (and more readily available I think?)

Dave

_________________
USA Daily: 2014 Nissan GT-R, very minor modifications for the track
USA Project: 1978 280Z, minor suspension upgrades, VK56DE conversion in progress. SOLD
AUS Race Car: 1973 240Z, L28ET, Autronic, GT35R. SOLD
AUS Project: 1972 1600, 3200km old S15 SR20DET, ground up rebuild. SOLD

I'll pick it up on saturday when I drop off the exhaust. Not rubbish to me I assure you.

Dave

_________________
USA Daily: 2014 Nissan GT-R, very minor modifications for the track
USA Project: 1978 280Z, minor suspension upgrades, VK56DE conversion in progress. SOLD
AUS Race Car: 1973 240Z, L28ET, Autronic, GT35R. SOLD
AUS Project: 1972 1600, 3200km old S15 SR20DET, ground up rebuild. SOLD