There are four different cylinder head castings [that I know of] for the E-engines. The casting # is on the exhaust side of the head, just to the left of cyl. #1 exhaust port, [at the base of that one "long" head bolt]. The earliest one is the 31M casting. For high performance applications, this is the least desirable casting, as the intake ports are heavily shrouded in the bowl area, to promote a "swirled" intake charge. These were on all E15S and E16S engines up to about '84. This is when the 33M heads came out. They are reputed to be worth 5 more horsepower than the 31M heads. The reason is that the 33M head has straight, clear intake ports, without the "swirl" shrouding in them. This head was used on E16S's and E16i's until the end of US market E16 production in '88. The third head was the 15M head, which is the beloved E15ET Pulsar Turbo head [or Cherry Turbo-depending on what country your in]. This head, has the smaller 17.9cc combustion chambers, larger valves, and is reputed to be a thicker casting, to deal with the extreme heat associated with turbo engines. An additional benefit of this is that this allows them to be ported a bit more than the others. The last head that I know of is known in the Nissan Motorsport catalog as the "Fuel Injection" [or FI] head. These did not come on any US market Nissans. It also wears the 15M casting number, but that number is not visible on the outside of the head like the others. It can only be seen under the valve cover. This head is essentially the same as the Turbo head in every way, except that it is a "thinwall" casting, for normally aspirated use. My understanding is, that this is a European O.E. head, where emmisions are not as stringent as the US versions. These heads were sold through Nissan Motorsport [I bought three of them], but are now NLA [no longer available]. About five years ago,I actually bought the last "FI" head, and was told by Nissan Motorsport, that they now are selling actual Turbo heads. And I'll tell you, that the price went way up too! I'm not sure why the latest Motorsport catalog still calls them the "FI" head. If anyone knows of any other E-series cylinder heads I haven't mentioned, please tell us. Especially from other markets around the world. I'd love to know about it!
There was also a 17M head that was used on the J-spec E15ET motors in the Sunny VZ-R. The used the valve cover stud pattern from the latter 33M heads and was supposed to have slightly better ports. I've also seen a very early head in the junk yard with a "A33" as the casting number.
Wow, great info Ryco. Thanks alot! Do you know anything more about the J-spec E15ET engine? Like, did they have water cooled turbos, more boost, and were they rated at more than 100 hp? I know, that that Japan doesn't use horsepower as a measurement, but perhaps there is a conversion? I seem to remember Nissan having a retrofit kit available, here in the US, for adding water cooling to the N12 pulsar's turbo. Or was it the 200SX turbo? Do you remember Ryco? Is yours water cooled?
Mine is water-cooled. I'm not sure if it was from the factory. My car was born in 9/83. The retro kit consists of a different thermostat housing, lower heater return line, water lines to/from turbo, and banjo fittings. When I removed my turbo, I ended up screwing my water lines completely up. Instead of buying a new kit from Nissan for about $600, I ordered some braided, stainless-steel house from Summit Racing. Cost me $140 but is removable with ease and looks about 20 times cooler.
The J-Spec E15 had a different intake manifold. It used a side mounted TB like a modern GA or SR motor. The exhaust manifold kinda looks like a later model ('87) manifold with a turbo flange on it. The Aussies call it the mid-mount manifold. The US (Aussie unleaded) manifold came as that close coupled, high-mount piece of crap (You know what I'm talking about). In Australia, they also had a leaded E15ET that used a low-mount manifold that more closely resembled our high-mount manifold. I beleive the J-Spec E15 made about 110HP but I'm not completely sure. As far as water cooling or boost, I have absolutely now idea.
Originally posted by ryco n12 Here's a question - Which retainers do I use with the Nismo double-valve springs for the E15/E16? E15/E16 valve locks?
***** Hello Ryco, again thanks for the E15ET info! I wish I knew where I could see some of these Aussie E15ET engines. Do you know of any websites? To answer your retainer question: When I got my .490" lift cam, I was in the same predicament you are. Again, Dave Rebello [Rebello race engines in CA] bailed me out. He said that you could use the intake retainers off of any '90-'92 KA24E [not the KA24DE] engine, part# 13209-40F00. They come eight to a bag, perfect. They fit perfectly, and they use the original E16 valve locks too. I always wondered why the Nissan Motorsport catalog sells the steel bottom spring seats for dual springs, but never mentioned anything about a retainer? You can't use one without the other! By the way, I'm assuming that you have [or are going to] machine off the step from the bottom of the spring seat area, to clear the inner spring? I couldn't find a spring seat cutter for our Nissan engine. I did this by making my own tool cutter. I copied one that I had for a Pontiac V-8, made by Isky.
I got my cam from Rebello Racing, in CA. At .490" lift, it is the smallest of three cam grinds he sells, and it really works great from 5,500 to 7,000 rpm. The other two cams are for really killer applications, where 8,800 rpm and 225 hp. are generated. That stuff is too expensive for me!
Yeah, that 11M head is mine. It came on that engine I got in the '83 B11. I highly suspect the block was a JDM E15. The head says 11M on the front in the standard place, and in the middle of the inside of the head, just under the camshaft, it also says 11M. This block had notched pistons to clear the valves, I kinda expected it to say 15M when I cleared the grease off the front casting number. heh.. Was 11M a special japanese casting? If it was, is there anything special about it that I might want? IE, is it better than a 33M? I have my freshly rebuilt 33M head on that engine for the time being.
Gotta love a good mystery.
Originally posted by malaysia_boy how to read the head model? where can i look for the identification?
is there any number on E13 head?
***** The casting number should be on the head somewhere. The location can vary. I have seen the 33M casting number in the right front of the engine bay, on the exhaust side of the head, just to the left of cyl. #1 exhaust port, [at the base of that one "long" head bolt]. I have also seen the casting number above the intake manifold ports on the 31M head. Martin can tell you where the 15M casting number was on the head I recently sold him.
List of E-series cylinder heads
By the way, I'm assuming that you have [or are going to] machine off the step from the bottom of the spring seat area, to clear the inner spring? I couldn't find a spring seat cutter for our Nissan engine. I did this by making my own tool cutter. I copied one that I had for a Pontiac V-8, made by Isky. 
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