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Discussion Starter · #1 ·
I have a 1978 280Z which i bought that had no engine or tranny, i bought a new remanufactured engine from Motorsport Auto and a 5-speed from a Z wrecking yard in Arizona. I'm going to get the 4bbl carb manifold, 3-into-2 headders, 2.5 turbo exahust, 240Z European Distributor, with a solid poit breaker plate,8mm performance wires, Crane HI-6 ignition and coil, a Holley 390cfm 4bbl with 50cc accelerator pump, vacuum advance. I'm also going to get a performance cam from Motorsport Auto with the specs .480 lift @.50 lash, and 260 deg duration. Motorsport auto perfromance valve spring and lash pads, Oil cooler kit, high volume oil pump, Short throw shifter, limited slip differential, Centerforce II clutch and a HKS 10lbs lightweight flywheel. How many horsepower should i expect from this motor?
Thanks for your attention -->Alan :eek:)
 

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Re: How much performance will i get from these mod

> I have a 1978 280Z which i bought that had
> no engine or tranny, i bought a new
> remanufactured engine from Motorsport Auto
> and a 5-speed from a Z wrecking yard in
> Arizona. I'm going to get the 4bbl carb
> manifold, 3-into-2 headders, 2.5 turbo
> exahust, 240Z European Distributor, with a
> solid poit breaker plate,8mm performance
> wires, Crane HI-6 ignition and coil, a
> Holley 390cfm 4bbl with 50cc accelerator
> pump, vacuum advance. I'm also going to get
> a performance cam from Motorsport Auto with
> the specs .480 lift @.50 lash,
> and 260 deg duration. Motorsport auto
> perfromance valve spring and lash pads, Oil
> cooler kit, high volume oil pump, Short
> throw shifter, limited slip differential,
> Centerforce II clutch and a HKS 10lbs
> lightweight flywheel. How many horsepower
> should i expect from this motor?
> Thanks for your attention -->Alan :eek:)

Alan,
you picked a lot of good things. I think it is reasonable to expect ~170-180 hp from that. You can expect to see 135-150 at the wheels. That is nothing to laugh at. A lot of people just don't understand how just a little like that makes a big difference in how the car drives. My only recomendation would be to change the 4bbl out for dual SU's. I realize you may have already spent the money on the manifold and carb, but you really will see better overall performance and fuel economy from the original round-top dual SU's. take a look at the 4bbl manifold. what ends up happening is it pools the fuel at the sharp 90 degree turn, then it tends to run the middle two cylinders rich, the next two ok, and the front and rear lean. it is a function of the design of the manifold. The carb was designed for a v8, not a l6. you will not be unhappy, but you will actually see better from the su's.
-bob hanvey
 

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Discussion Starter · #3 ·
Re: How much performance will i get from these mod

> First, does your state have a smog test if so you might have problems passing it. Second, I only heard bad stories about using a 4bbl carb on a Z engine. You see the 4 bbl carbs are for engines that have their intake manifold on top of the engine like V6 or V8. Third, if you wanted to use 4 bbl carb you could have done a V8 conversion
using a small block chevy. How much did your
light weight flywheel cost?

I have a 1978 280Z which i bought that had
> no engine or tranny, i bought a new
> remanufactured engine from Motorsport Auto
> and a 5-speed from a Z wrecking yard in
> Arizona. I'm going to get the 4bbl carb
> manifold, 3-into-2 headders, 2.5 turbo
> exahust, 240Z European Distributor, with a
> solid poit breaker plate,8mm performance
> wires, Crane HI-6 ignition and coil, a
> Holley 390cfm 4bbl with 50cc accelerator
> pump, vacuum advance. I'm also going to get
> a performance cam from Motorsport Auto with
> the specs .480 lift @.50 lash,
> and 260 deg duration. Motorsport auto
> perfromance valve spring and lash pads, Oil
> cooler kit, high volume oil pump, Short
> throw shifter, limited slip differential,
> Centerforce II clutch and a HKS 10lbs
> lightweight flywheel. How many horsepower
> should i expect from this motor?
> Thanks for your attention -->Alan :eek:)
 

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Re: How much performance will i get from these mod

I've decided to put twin SU's on mine. I did'nt purchase the 4bbl setup yet. They don;t check emmission, as a matter of fact your lucky if they check your brake pads :) The lightweight flywheel cost me $310. What else can i do to boost power, without a turbo? i'd like to get 225hp, without a turbo if can.

Thanks
Alan
 

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Discussion Starter · #6 ·
Re: How much performance will i get from these mod

> You will have to rise the compression of the engine. You can do this two ways. Buy pistons
that rise the compression or you can shave the
head. You can also port and polish the head.
Buy your self a electric fan and ask around about
triple SU carbs.Go to this web page it will tell you how to shave the head and you can Email him if you have any other questions.
Good luck
 

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Becoming a stock holder in Motorsports Auto???? :)

> I have a 1978 280Z which i bought that had
> no engine or tranny, i bought a new
> remanufactured engine from Motorsport Auto
> and a 5-speed from a Z wrecking yard in
> Arizona. I'm going to get the 4bbl carb
> manifold, 3-into-2 headders, 2.5 turbo
> exahust, 240Z European Distributor, with a
> solid poit breaker plate,8mm performance
> wires, Crane HI-6 ignition and coil, a
> Holley 390cfm 4bbl with 50cc accelerator
> pump, vacuum advance. I'm also going to get
> a performance cam from Motorsport Auto with
> the specs .480 lift @.50 lash,
> and 260 deg duration. Motorsport auto
> perfromance valve spring and lash pads, Oil
> cooler kit, high volume oil pump, Short
> throw shifter, limited slip differential,
> Centerforce II clutch and a HKS 10lbs
> lightweight flywheel. How many horsepower
> should i expect from this motor?
> Thanks for your attention -->Alan :eek:)

Wow, that's like a grocery list of mods you intend on doing. Motorsports Auto must love you. But, since you asked, here's my .02.

If you have install everything as stated, you can expect @200hp (gross).

I hope you haven't bought everything yet, because there are alternatives.

First of all I'd get the 6-1 Motorsports headers instead of the 3-2. The 6-2 is slightly better tuned IMO. Of course I'm bias towards Nissan Motorsports headers. These are the best bar none. Although they cost $300. But if you're willing to spend $300 on a flywheel, why not $300 on a header??

Second, the Holley 4bbl is not a good idea. Although it may sound good, because it has a high cfm rating and such, it was NOT designed for side induction. These type of carbs were designed to sit in the middle of a V8, where fuel can be drawn directly down. When adapted to the L6, it needs to make a sharp 90 degree turn, along with unequal length runners provides for fuel pooling and uneven fuel distribution. Scrap this idea if you haven't bought this yet. Go with either the stock SU's, or for all out performance triple weber/mikuni. Although the triples require alot more tuning and knowledge. So if you don't have any prior exposure to them, try and stay away until you familiarize yourself with your car.

Third, in regards to the cam. I would recommend a cam with longer duration (270-275) and .450-.460 lift. The duration is really what affects performance, unless you've ported/polished the head where you can benefit from a higher lift cam. The longer duration is the best way to go. But, don't go more than 275, as you'll start to get a lopey idle, and lose low end. I'd say a 270 with .460 will give you the best performance. Of course you should get the proper lash pads, springs (if necessary), etc....

Fourth, the HKS flywheel might sound great, but it may be too light for your application. Unless you are expecting to operate at high rpm (4500+), the light flywheel will rob too much low rpm power. Why not lighten a stock 240 flywheel to 16-18lbs?? It's lighter than the 24lb stock 280, and still heavy enough to provide some needed inertia when you try to start rolling. I run a centerforc II clutch, and have no complaints. Hooks up great, and doesn't feel too stiff. Definetely a good idea.

Just my .02 and change,
240Dave
 

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Re: what about emissions?

> Wow, that's like a grocery list of mods you
> intend on doing. Motorsports Auto must love
> you. But, since you asked, here's my .02.

> If you have install everything as stated,
> you can expect @200hp (gross).

> I hope you haven't bought everything yet,
> because there are alternatives.

> First of all I'd get the 6-1 Motorsports
> headers instead of the 3-2. The 6-2 is
> slightly better tuned IMO. Of course I'm
> bias towards Nissan Motorsports headers.
> These are the best bar none. Although they
> cost $300. But if you're willing to spend
> $300 on a flywheel, why not $300 on a
> header??

> Second, the Holley 4bbl is not a good idea.
> Although it may sound good, because it has a
> high cfm rating and such, it was NOT
> designed for side induction. These type of
> carbs were designed to sit in the middle of
> a V8, where fuel can be drawn directly down.
> When adapted to the L6, it needs to make a
> sharp 90 degree turn, along with unequal
> length runners provides for fuel pooling and
> uneven fuel distribution. Scrap this idea if
> you haven't bought this yet. Go with either
> the stock SU's, or for all out performance
> triple weber/mikuni. Although the triples
> require alot more tuning and knowledge. So
> if you don't have any prior exposure to
> them, try and stay away until you
> familiarize yourself with your car.

> Third, in regards to the cam. I would
> recommend a cam with longer duration
> (270-275) and .450-.460 lift. The duration
> is really what affects performance, unless
> you've ported/polished the head where you
> can benefit from a higher lift cam. The
> longer duration is the best way to go. But,
> don't go more than 275, as you'll start to
> get a lopey idle, and lose low end. I'd say
> a 270 with .460 will give you the best
> performance. Of course you should get the
> proper lash pads, springs (if necessary),
> etc....

> Fourth, the HKS flywheel might sound great,
> but it may be too light for your
> application. Unless you are expecting to
> operate at high rpm (4500+), the light
> flywheel will rob too much low rpm power.
> Why not lighten a stock 240 flywheel to
> 16-18lbs?? It's lighter than the 24lb stock
> 280, and still heavy enough to provide some
> needed inertia when you try to start
> rolling. I run a centerforc II clutch, and
> have no complaints. Hooks up great, and
> doesn't feel too stiff. Definetely a good
> idea.

> Just my .02 and change,
> 240Dave

doesn't this car have ANY emission reqirements where you live?? a 280 at least had fuel injection to pass minimum.
 
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