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Discussion Starter #1
Hi, I'm planing to put a new head(somthing realy hot) on my 260 engine.Right now it has E-88 late model head.So the question is which head is perform better?Is E-31 realy the best one?
And I found a guy who has a E-31 head for sale.He wants to sale it with the 240 engine block
for 300$.I don't need the engine(it's sounds like engine is realy bad) , so ,basicly that is hte price just for the head. And I don't know if it's a good price for E-31.
Anybody knows the real price of that mysterious head?
And have anybody heard about BOSCH multiple discharge ignition?I heard that they are producing it like a aftermarket product for Porche.
Thank you for stopping buy.
Danila.
 

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Hi , I think that $300 is way too much for a E-31 head , especially one from a bad motor , chances are the head needs work . Valve seats at least.
I have a E-31 head that I will put on my 81zx motor in my 71z some day but I will need to put close to $700 in head work before it will be worth it
 

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Discussion Starter #3
I would only get the head if your going to have the larger valves installed. Your head is a late model E88, chances are you have larger valves and without changing anything but the heads I doubt you will get any benefit, maybe even loose HP, the larger valves give 15-20hp gain. I'd just have a good valve job, take some emmery paper to the valve seat edges and take out any sharp edge's and you will be better off all the way around. If there is a real good head worker around you might also have them unshroud the valves, this will increase the flow a lot.
Or plan on spending a lot of money to make changing the head worth it.
I wish there were places that made aftermarket heads for the Z's like they do for the chev's and Fords, that is what is really needed for our cars.
> Hi, I'm planing to put a new head(somthing
> realy hot) on my 260 engine.Right now it has
> E-88 late model head.So the question is
> which head is perform better?Is E-31 realy
> the best one?
> And I found a guy who has a E-31 head for
> sale.He wants to sale it with the 240 engine
> block
> for 300$.I don't need the engine(it's sounds
> like engine is realy bad) , so ,basicly that
> is hte price just for the head. And I don't
> know if it's a good price for E-31.
> Anybody knows the real price of that
> mysterious head?
> And have anybody heard about BOSCH multiple
> discharge ignition?I heard that they are
> producing it like a aftermarket product for
> Porche.
> Thank you for stopping buy.
> Danila.
 

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The E-31 is a very good head if you want high compression. However, to get power from the E-31, you need to install the larger valves from the 280Z heads. Machining the E31 for the larger valves is no big deal, but it does cost money. Now, it depends on how far you want to go, but you might want to port/polish the head as well. To take advantage of the higher compression, you will also want a good cam. This will also necessitate better valve springs and a different valvetrain. Also, w/a new cam, you must use new rocker arms. As you can see, the costs add up quickly. However, the E31 has the best potential for power without shaving.

If you are concerned about price, you may want to think about using a different head. The most cost effective head, IMO, is the N42. This has the larger valves, good combustion chambers, and rectangular exhaust ports. You don't need to shave it to get a reasonable compression ratio and porting isn't really necessary for a street engine. The N42 with a flat-top piston L28 block makes a great street motor. You can use the stock cam and valvetrain, and it will perform quite well, and remains streetable and reliable. A friend of mine had an engine such as this built by Robello. They used flattop pistons, the N42, stock cam, and cheated the valvetrain toward the piviot of the rockers for a little more lift. He used the stock carbs with jets from Robello, and a header and 2.5 exhaust. With a 4.625:1 differential, his 240Z did a [email protected] It was smooth running and quite reliable...

The decision is up to you. Good Luck!!!

Ian
 

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Aftermarket Z-Car heads?

Do you all realize that BRE was getting 250hp out of the L24 in the early '70's? There is no reason I can think of for an aftermarket head for the Nissan L6. Electromotive got over 500hp out of the L28ET in their Turbo IMSA car in the early '80's. With all of the developments in cylinder head modification, you can easily make the L6 a 1.5hp/cid motor.

Consider this:

A Chevy 350 w/aluminum aftermarket heads will make a reasonable 350hp. That's only 1hp/cid. Who has heard of a Chevy 350 w/525hp (1.5hp/cid) that was a reasonable cost? For a reasonable price, you can get a stock L6 head to flow enough for 250hp, which is roughly 1.5hp/cid. What you all need is a person who really knows how to work the Nissan L6 heads. Try B.C. Geralomy in Sacramento, Ca. Comments anyone?

> I would only get the head if your going to
> have the larger valves installed. Your head
> is a late model E88, chances are you have
> larger valves and without changing anything
> but the heads I doubt you will get any
> benefit, maybe even loose HP, the larger
> valves give 15-20hp gain. I'd just have a
> good valve job, take some emmery paper to
> the valve seat edges and take out any sharp
> edge's and you will be better off all the
> way around. If there is a real
> good head worker around you might also
> have them unshroud the valves, this will
> increase the flow a lot.
> Or plan on spending a lot of money to make
> changing the head worth it.
> I wish there were places that made
> aftermarket heads for the Z's like they do
> for the chev's and Fords, that is what is
> really needed for our cars.
 

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Discussion Starter #6
> I would only get the head if your going to
> have the larger valves installed. Your head
> is a late model E88, chances are you have
> larger valves and without changing anything
> but the heads I doubt you will get any
> benefit, maybe even loose HP, the larger
> valves give 15-20hp gain. I'd just have a
> good valve job, take some emmery paper to
> the valve seat edges and take out any sharp
> edge's and you will be better off all the
> way around. If there is a real
> good head worker around you might also
> have them unshroud the valves, this will
> increase the flow a lot.
> Or plan on spending a lot of money to make
> changing the head worth it.
> I wish there were places that made
> aftermarket heads for the Z's like they do
> for the chev's and Fords, that is what is
> really needed for our cars.
Thank you guys for your responses.This information really rescue my Z from a wrong setup.
Danila.
 

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Discussion Starter #7
Re: Aftermarket Z-Car heads?

> Do you all realize that BRE was getting
> 250hp out of the L24 in the early '70's?
> There is no reason I can think of for an
> aftermarket head for the Nissan L6.
> Electromotive got over 500hp out of the
> L28ET in their Turbo IMSA car in the early
> '80's. With all of the developments in
> cylinder head modification, you can easily
> make the L6 a 1.5hp/cid motor.

> Consider this:

> A Chevy 350 w/aluminum aftermarket heads
> will make a reasonable 350hp. That's only
> 1hp/cid. Who has heard of a Chevy 350
> w/525hp (1.5hp/cid) that was a reasonable
> cost? For a reasonable price, you can get a
> stock L6 head to flow enough for 250hp,
> which is roughly 1.5hp/cid. What you all
> need is a person who really knows how to
> work the Nissan L6 heads. Try B.C. Geralomy
> in Sacramento, Ca. Comments anyone?

What's wrong with cubic inches? As I understand it, cubic inches = torque, torque = acceleration, hp = how long your engine maintains torque before you can get more power from shifting up a gear(i.e. powerband).

The weight:power ratio is all that should matter here, and 350hp with an extra 100lbs and a whole bunch of torque is much better than 250hp with less torque and slightly less weight. Of course, there's a little thing called cost, but, as you've said, speed = bucks.

Am I making sense here?

Project#2501
 
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