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Discussion Starter #1
Ok i am going to do a full engine overhaul. I am getting different pistonsw to raise compression and getting webber thriple carbs(six-Pack) headers and K&N intake and getting large valves for my old E-88 and having it port and polished and port matching the intake manifold. May get a turbo exhaust, getting a cam the second grind in the Motorsports catalog and just rebuilding the engine to the best of my money's ability. What kind of horsepower can I expect to my back wheels after all that crap is done 170- 180? Can you thing of anything i missed to get more horsepower out of my old 240z? i am too cheap to buy a280zx engine or head but will use all the stuff i have around my garage. What else can i do to my engine to get the last drops of HP out of it?

Dustin Morris
 

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The only thing I saw in this post that I'd be super carefull of is having the head ported. It's real hard to find a good place to have this done. I've had 2 heads ruined this way. It's really only needed if you plan on going for a high RPM motor and race, it doesn't help much for a street car. I'd just have the ports matched to the manifold, have the valves unshrouded, this gives a good increase of flow and for the cost is a lot bigger benifit than having the head ported. Most books seem to think datsun did pretty good at the stock ports anyway. Have the darn thing balanced very well but keep in mind these L6's still arn't made for high RPM prolonged use, it's ok for short bursts but with their torsional vibrations they can waste a chankshaft. Take a look at Nissan Motorsports race header, this is one fantastic header and the best you'll see anywhere for the Z. Make real sure you don't stop by just building the engine, make sure your suspension is up to the job also. I also recomend that upper strut bar. The Z doesn't have the strongest frame setup and flexes a lot with high power engines, one reason I don't care for the V8 conversion of these cars. Get better brake pads or better and make sure the torsion bar bushings are replaced. A high volume Oil Pump isn't a bad idea either though a high pressure Oil Pump isn't really needed for the street, they can be hard on the main seals anyway. A remote oil filter setup is nice, I have a dual filter setup that does a great job. Better sway bars and bushings is a must for the Z's. I would also get a better distributor, with the Weber's it's almost a requirement. After putting Mikuni's on my 280Z it felt it was missing something till I replaced it with a Mallory unit from Victoria British. It liked the better advance curves, stock just doesn't do it with those carbs. I also got the Colortune unit and after some getting to know it find it a very usefull tool for those types of carbs. Ok, a very good sync tool for these carbs and by far the best/easy way to sync them is a Manometer (recomended by Mikuni). It is what Motorcycle shops use for multi carbed motorcycles and takes the guess work and time out of syncing the weber/mikuni carb setups. It costs around 70.00 at a local motorcycle shop and worth it. I can sync my setup in 10min or less and do a MUCH MUCH better job than with that unisync tool that fits over the carb venturi. That tool is too restrictive and you can't sync the carbs with the air cleaners on which can change the airflow between carbs if you use seperate aircleaners. With the Manometer you can sync with everything on as it will be in dayly driving for a much better sync job. Get a jet screwdriver, webers have a lot of different jets to contend with and it's just too easy to mess them up without a proper fitting tool. In the long experience with carbs this is one tool I always seem to be without till I messed up one too many. Sorry this is a long one, hope some of it helped.

> Ok i am going to do a full engine overhaul.
> I am getting different pistonsw to raise
> compression and getting webber thriple
> carbs(six-Pack) headers and K&N intake and
> getting large valves for my old E-88 and
> having it port and polished and port
> matching the intake manifold. May get a
> turbo exhaust, getting a cam the second
> grind in the Motorsports catalog and just
> rebuilding the engine to the best of my
> money's ability. What kind of horsepower can
> I expect to my back wheels after all that
> crap is done 170- 180? Can you thing of
> anything i missed to get more horsepower out
> of my old 240z? i am too cheap to buy a280zx
> engine or head but will use all the stuff i
> have around my garage. What else can i do to
> my engine to get the last drops of HP out of
> it?

> Dustin Morris
 

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Registered
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107,695 Posts
Discussion Starter #3
Unless you're setting up to race in a class that limits you to the 2.4l engine, you should consider the 2.8l block as I'm sure you've heard there's no substiture for cu in. But for sure a better distributor, I'm running a 280Z unit, it fits with no mods and no more points or condenser to change! It works well with the webers too. An electronic ignition like a Mallory, Crane, Holley or MSD helps too and they come with a reve limiter so you don't waste all that rebuild money on a missed shift. I run a HI-6 and it works great!
Have fun!

> Ok i am going to do a full engine overhaul.
> I am getting different pistonsw to raise
> compression and getting webber thriple
> carbs(six-Pack) headers and K&N intake and
> getting large valves for my old E-88 and
> having it port and polished and port
> matching the intake manifold. May get a
> turbo exhaust, getting a cam the second
> grind in the Motorsports catalog and just
> rebuilding the engine to the best of my
> money's ability. What kind of horsepower can
> I expect to my back wheels after all that
> crap is done 170- 180? Can you thing of
> anything i missed to get more horsepower out
> of my old 240z? i am too cheap to buy a280zx
> engine or head but will use all the stuff i
> have around my garage. What else can i do to
> my engine to get the last drops of HP out of
> it?

> Dustin Morris
 

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107,695 Posts
Discussion Starter #4
I have a similar combo to the one that you are talking about, but with a smaller cam. It has done a best of 15.3 at 93 mph. Power to weight to get that time would be about 150 hp. I plan on putting a bigger cam, better fuel pump and bigger fuel lines and then droping the gears to about 3.7 or 3.9 that should feel pretty quick.
 
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