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P65 EFI intake manifold


NZeder

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Hi, I was over at a mates tonight and he showed me an intake manifold fitted to a 280zx 2+2 (Australian Assembled 1981). It is a P65 EFI manifold and is unlike any EFI manifold we have ever since on a L28. It has a very large plenum with curved runners. The engine produces lots of torque. I will try and get a picture. The intake also has the Hitachi symbol cast onto it?

 

Anybody seen or heard of one of these before or know anything about them? It is a two piece manifold that looks like it can be unbolted and it still has the EGR on it.

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Sounds like the diesel manifold. Ask your friend if it had a throttle body on it. Diesels don't use TB's. The runner's are much bigger on that intake than the Z head, but the head could be ported to match. I think 1_fast_z has done this and welded a TB flange onto the end of the manifold IIRC.

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thanks for the pic - but not at all like that. I really need to get a pic, you know a pic says a 1000 words. Well it is sort of like that in the fact that the runner do curve up to the plenum (but the plenum runs on the side of the curves not on the top like the pic above). It bolts together from the side where as in your pic it from the bottom ie horizontal v vertical. Also this one is like the late 280zx wasted/stepped manifold ie the runners get shorter as it moves down the head. It is like nothing else we have ever seen.

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The intake he is referring to is a transplant form a Nissan Sedan, not used in the Z-Series from the factory, but will fit no problem. It was used in Cedric and Gloria Saloons and Coupes. Correct, it had a plenum with runners that came "underneath" and curved around the outside of the plenum before opening to the plenum proper. Basically the inlet to the runner is on the fender side of the plenum, and not hte motor side!

 

I transplanted one of these into a 1978 Fairlady Z, and was amazed by the down-low torque. Then again, it had the "two barrel" throttle body also, using a smaller primary body for about 3/4 of the throttle pedal throw, then a larger secondary body that opened over the last 1/4 of the pedal travel.

You cruised up to around 3500 rpm on that little hole, nad had nice high vavuum numbers for economy, and got a suprising kick when stomping it compared to the first 3/4 throttle!

 

It's a common intake overseas. I have photos on the laptop, but not on-line. There were two different "TWO BBL" Bodies, also, one for the L20A, and another for the larger L28, make sure you have the right one for the L28 if you want decent breathing!

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Tony D - that sounds like the one....to the others I did not get to the car in the weekend (at a mate house outside) and it was raining all weekend + the misses had me repairing/rebuild a fence on the farm that took most of the weekend (nothing like working outside in the cold rain, holding a chainsaw on a muddy bank trying to hold your ground and cut a post and rail fence and hoping like hell you don't slip and end up with a shorter leg)

 

I will see if I can get the pic and post by tomorrow evening (I will pop out at lunch time and get the pic)

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  • 1 month later...
  • 2 months later...

So are you :) I have been he a lot longer than on Datsun.co.nz 8) anyway I never did get back to get the photo but you have saved me the trouble - thanks again.

 

So which one had the larger TB? The P65 or the other one?

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  • 3 years later...

Hey NZeder, I have that same Intake on my '79 Fairlady Z, and it has the dual throttle butterfly - one smaller and one bigger. I'll also share some pictures for those interested. The diameter of the head-side runners are 27mm compared to 30mm on a normal manifold.

P65 Intake_1.JPG

P65 Intake_2.JPG

P65 Intake_3.JPG

P65 Intake_4.JPG

P65_Intake_4.JPG

 

Nice to see other New Zealander's on the forums

P65 Intake_1_thumb.JPG

P65 Intake_2_thumb.JPG

P65 Intake_3_thumb.JPG

P65 Intake_4_thumb.JPG

P65_Intake_1_thumb.JPG

P65_Intake_4_thumb.JPG

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There are two versions of that manifold, one for L20E and one for L28E, the head side is larger for the L28, and it takes the Throttle Body pictured on the right, I believe. One has a primary the size of an American Dime, the other about the size of an American Nickel, with corresponding secondary throttle plate differences as well.

 

The primary will run you to about 3500rpms and there is a definate 'point' in the throttle pedal play where you end up resting your foot (like GM did on the Suburbans with a big block)---keeps you on the primary even at high-speed cruise (in my 260, 3500 is citation speed in 5th gear!) with what feels like phenomenal throttle response when that secondary kicks in and travels faster in the last 1/4 pedal than the little plate did in the first 3/4 of travel! BuuuuWAAAAH!

I digress... LOL

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  • 4 months later...
There are two versions of that manifold, one for L20E and one for L28E, the head side is larger for the L28, and it takes the Throttle Body pictured on the right, I believe. One has a primary the size of an American Dime, the other about the size of an American Nickel, with corresponding secondary throttle plate differences as well.

 

The primary will run you to about 3500rpms and there is a definate 'point' in the throttle pedal play where you end up resting your foot (like GM did on the Suburbans with a big block)---keeps you on the primary even at high-speed cruise (in my 260, 3500 is citation speed in 5th gear!) with what feels like phenomenal throttle response when that secondary kicks in and travels faster in the last 1/4 pedal than the little plate did in the first 3/4 of travel! BuuuuWAAAAH!

I digress... LOL

 

I just received my P65 intake. Tony, you mention that one is for the L20 and the other is for the L28...are they both called P65? What other differences do they have? You mentioned throttle body, mine has the twin throttle plate setup and both are about the same size. The runners to the head are 28mm's. Do you think this is a 2.0 or 2.8 version? Anyone can chime in if they like. :)

 

Cheers.

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