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i have to replace the rings in my 78 L28 and they are dished....can flattop pistons be exchanged for the flattop ones in my car since i'm gonna be replacing the rings the block will be open and out of the car......is there any reason this conversion can't be done?

thanks.
 

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> i have to replace the rings in my 78 L28 and
> they are dished....can flattop pistons be
> exchanged for the flattop ones in my car
> since i'm gonna be replacing the rings the
> block will be open and out of the
> car......is there any reason this conversion
> can't be done?

> thanks.
Matt, Yes you can get aftermarket or nissan pistons from 82 model year. These pistons are flat top and will work with your stock valvetrain and cam. I would think you would go a little bit farther and get a cam kit while you have it apart. Motorsport sells a kit for 400.00 with a .480 lift 274 duration that will make that puppy scream. You should also grt a header for it.

Bret
 

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I have an 81zx w/ I believe what is called the P89 head (?)This will prob. confuse the issue. It was the factory's hi-perf answer that was designed for the flattops to increase the Comp. ratio/performance from the factory. I'm curious then: would not the flattop piston used w/ the standard head actually lower the compression?
 

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> I have an 81zx w/ I believe what is called
> the P89 head (?)This will prob. confuse the
> issue. It was the factory's hi-perf answer
> that was designed for the flattops to
> increase the Comp. ratio/performance from
> the factory. I'm curious then: would not the
> flattop piston used w/ the standard head
> actually lower the compression?

No, because you are removing the dished part of the piston. You will get, (I think) 10.3:1 compression using flattops in an N47 head. Which is a significant increase. If you go with a thinner head gasket you can get it up to 10.8:1. I am doing this exact mod to my 78 L28 right now. By Monday (hopefully no more suprises), I'll be able to tell you all how it's running.

Steve Graber
 

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> No, because you are removing the dished part
> of the piston. You will get, (I think)
> 10.3:1 compression using flattops in an N47
> head. Which is a significant increase. If
> you go with a thinner head gasket you can
> get it up to 10.8:1. I am doing this exact
> mod to my 78 L28 right now. By Monday
> (hopefully no more suprises), I'll be able
> to tell you all how it's running.

> Steve Graber
let me know what you guys are doing? I just bought a 78' and am contemplating drive train rebuilds at the moment and checking out what some others are doing. I'm not sure what direction I want to go, besides forward and fast.
Thanks,
Jim Skipper 78' 86'
Arlington, Tx.
 

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Best place to start for engine mods

> let me know what you guys are doing? I just
> bought a 78' and am contemplating drive
> train rebuilds at the moment and checking
> out what some others are doing. I'm not sure
> what direction I want to go, besides forward
> and fast.
> Thanks,
> Jim Skipper 78' 86'
> Arlington, Tx.

Easiest and most bang for buck is exhaust and intake mods. A good header (with a ceramic coating to keep the engine bay cool and make the header last longer) and a 2.25 or 2.5 exhaust with a decent muffler finish that off. Remove the restrictive intake filter box and replace it with a K&N filtration system.

Next step would be better sparkplug wires and a hotter coil.

I think that after those external mods you need to start looking internally for more mods. Most people begin with a hotter cam and then move on to porting the head and changing out the pistons. You don't need to do anything to the bottom end unless you want to use a maxima diesel crank and 240Z rods and pistons to turn your engine into a 3.1L stroker. At some point you run out of money to spend on a normally aspirated L28 and you need to replace the entire engine with a turbo unit where you can start all over.

All of the information you could ever want can be found in this forum, in a chiltons manual and in several of the books offered in the bookstore on this website

Steve G
 

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Re: Best place to start for engine mods

well in addition to having dished style pistons i have a P90A head, which if i'm thinking correctly should drop compression near 8:1 rather than the stock 8.8:1(am i thinking right?) on my 78 280 2+2

because of the junkyard near by with the mass numbers of 280Z and ZX's it is easy for me to get one of the heads of that type of car, which is the best type of head for this car? a n/a ZX head?
 

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Re: Look here

because of the junkyard near by with the
> mass numbers of 280Z and ZX's it is easy for
> me to get one of the heads of that type of
> car, which is the best type of head for this
> car? a n/a ZX head?

Check out Bryan Little's site. He has taken a fair amount of time, and outlined some excellent combinations. Read his engine and head section. I will also soon have my head section back up, with some new, possibly controversial,(ie not be thought of before, like my advocation of the P series heads). Anyways, look at Bryan's site, the Datsun Garage. It is great.
-Bob Hanvey
 

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Re: Look here

well, are you saying i should keep this P90A head around just in case?
i can think of one good reason fo this head and the self-adjusting hydraulic lefters are one. could they possibly have better flow characteristics?

keep me informed...caus ei wanna know about this P-head application.
 

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Re: Best place to start for engine mods

> Easiest and most bang for buck is exhaust
> and intake mods. A good header (with a
> ceramic coating to keep the engine bay cool
> and make the header last longer) and a 2.25
> or 2.5 exhaust with a decent muffler
> finish that off. Remove the restrictive
> intake filter box and replace it with a K&N
> filtration system.

Speaking of exhaust Steve do you have anyone in phoenix you'd recommend? I had one made about 2 years ago, but I'm getting tired of it scraping on speedbumps because the guy was too lazy to make a couple extra bends in the dang thing (guess ya get what ya pay for eh?) Plus I'm contemplating new springs that will probably lower the car an inch or so and this obviously could pose a problem for that too.
 

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Re: Best place to start for engine mods

> Speaking of exhaust Steve do you have anyone
> in phoenix you'd recommend? I had one made
> about 2 years ago, but I'm getting tired of
> it scraping on speedbumps because the guy
> was too lazy to make a couple extra bends in
> the dang thing (guess ya get what ya pay for
> eh?) Plus I'm contemplating new springs that
> will probably lower the car an inch or so
> and this obviously could pose a problem for
> that too.

I keep reading from the experts on this site that the NISMO header is the best. Where does one get it? I don't know. Does it stick way down? I don't know. I have a friend that bought a pacesetter (the factory is in southwest Phoenix) and is satisfied with the outlet location. Jet hot has a location in Chandler, AZ

Personally, I am using a 6-2-1 header that I bought used from somebody. The flange is nice and thick and the tube seems to be fairly thick too. I port matched the outlets to the head with a grinder. Be aware that not all headers have the tubes perfectly aligned to the exhaust ports in the head, mine were way off. I had the flange surfaced at a machine shop and then jet-hotted inside and out.

I'll let you all know how it works this next week after I get my engine back together and into the car.

Steve G
 

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Re: Look here

> well, are you saying i should keep this P90A
> head around just in case?
> i can think of one good reason fo this head
> and the self-adjusting hydraulic lefters are
> one. could they possibly have better flow
> characteristics?

It really depends on your application. The hydraulic lifters are great, but not if they are worn out. There is always a trade-off. For now, I am sticking by using the P-90 heads for forced induction,(ie turbo), or large motors, ie strokers. They do flow well, but you need other info to compare it to. For a NA 280 motor, I would say don't go with it. The compression is just too low without serious shaving of the head.
-Bob Hanvey
 

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Re: Best place to start for engine mods

> I keep reading from the experts on this site
> that the NISMO header is the best. Where
> does one get it? I don't know. Does it stick
> way down? I don't know. I have a friend that
> bought a pacesetter (the factory is in
> southwest Phoenix) and is satisfied with the
> outlet location. Jet hot has a location in
> Chandler, AZ

> Personally, I am using a 6-2-1 header that I
> bought used from somebody. The flange is
> nice and thick and the tube seems to be
> fairly thick too. I port matched the outlets
> to the head with a grinder. Be aware that
> not all headers have the tubes perfectly
> aligned to the exhaust ports in the head,
> mine were way off. I had the flange surfaced
> at a machine shop and then jet-hotted inside
> and out.

> I'll let you all know how it works this next
> week after I get my engine back together and
> into the car.

> Steve G

Sorry, bit of a misunderstanding, I was asking about just the exhaust piping itself. (Still running a stock iron manifold myself) I'd just order the NISMO one from Brown and Brown Nissan parts counter because they're about a mile from my house (as is Jet Hot) but I just was wondering who you have used for the actual pipe bending/fitting/welding for the run of exhaust between the header and the muffler.
 
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