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
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,