Well, here's the spec on the current engine in my '72 240Z.
Block: '77 280Z
Crank: Stock 79mm Balanced to flywheel and pulley.
Rods: Stock 280Z Balanced
Pistons: 86mm Balanced
Rings: Stock Nissan (New)
Head: '72 E88 shaved .050 Match Ported to intake and valve unshrouding and minor bowl porting. Competition 3-angle valve job, chrome moly seats, heavy duty springs. Semi-polished surface.
Head Gasket: Stock (1.2mm thk)
Compression ratio 9.3:1
Cam: L7 NISMO .475/270 duration
(Planning on .445/290 duration)
Intake: Cannon long manifold, fully port matched and semi-polished.
Carbs: Triple 45mm Webers with 36mm chokes and air horns (36mm chokes are HUGE)
Ignition: Pertronix igniter unit with MSD-6AL
(upgrading to magnecor wires soon)
Headers: 6-2 NISMO 1.625 primaries
Exhaust: 2.5 custom made with Dynomax straight through muffler
Clutch: Centerforce II
Transmission: Stock '78 280Z 5spd
Differential: Stock R180 3.364:1
This engine runs strong, and pulls to 6500rpm. Power begins at 3500 and climbs until 6500rpm. The reason I have so much top end, is that I have such huge venturis. This engine can flow alot of air/fuel. But, the problem with such big carbs is the main circuit (carb) doesn't kick in until past 3000rpm, so anything below that really bogs the engine down. There just isn't enough airflow to suck gas out of the carb. It takes alot of practice to drive around town. But, once 3000 is hit, it pours on the power, and doesn't quit. My main problem is drivetrain. The gearing is way too low for this setup with the R180. And, my diff mount is ripped and u-joints are worn. I'm going to replace all that stuff while on vacation toward the end of Dec.
I don't have dyno figures for this engine, but compared to others similar to it, it is estimated at 220-240hp. My best run at Sears Point was a [email protected] I'm expecting at least high 13's, depending on what ratio R200 I use, and after fixing all the broken parts. By the way, I didn't really build this car for drag racing. It's built for road racing. It's lowered into the weeds and has 225/50/15 tires on 15x7 panasports all around. I can outhandle almost anything on the road today. People that ride with me are totally amazed at how fast I can take turns. The main comment people make to me is; My car would flip over if I took that turn like that!
P.S. The post below was a fictitios example. I just used numbers that closely relate to a Z engine, they were not exact numbers from a dyno run. I was just trying to show how gearing plays a role in when you shift, even though power drops off at a higher rpm. But, like I said, closer gearing would eliminate the need to rev so high, because the shift drop would not be so much. I would imagine a close ratio 5spd with 3.1L would be quite fast.
What are your specs??
240Dave
Block: '77 280Z
Crank: Stock 79mm Balanced to flywheel and pulley.
Rods: Stock 280Z Balanced
Pistons: 86mm Balanced
Rings: Stock Nissan (New)
Head: '72 E88 shaved .050 Match Ported to intake and valve unshrouding and minor bowl porting. Competition 3-angle valve job, chrome moly seats, heavy duty springs. Semi-polished surface.
Head Gasket: Stock (1.2mm thk)
Compression ratio 9.3:1
Cam: L7 NISMO .475/270 duration
(Planning on .445/290 duration)
Intake: Cannon long manifold, fully port matched and semi-polished.
Carbs: Triple 45mm Webers with 36mm chokes and air horns (36mm chokes are HUGE)
Ignition: Pertronix igniter unit with MSD-6AL
(upgrading to magnecor wires soon)
Headers: 6-2 NISMO 1.625 primaries
Exhaust: 2.5 custom made with Dynomax straight through muffler
Clutch: Centerforce II
Transmission: Stock '78 280Z 5spd
Differential: Stock R180 3.364:1
This engine runs strong, and pulls to 6500rpm. Power begins at 3500 and climbs until 6500rpm. The reason I have so much top end, is that I have such huge venturis. This engine can flow alot of air/fuel. But, the problem with such big carbs is the main circuit (carb) doesn't kick in until past 3000rpm, so anything below that really bogs the engine down. There just isn't enough airflow to suck gas out of the carb. It takes alot of practice to drive around town. But, once 3000 is hit, it pours on the power, and doesn't quit. My main problem is drivetrain. The gearing is way too low for this setup with the R180. And, my diff mount is ripped and u-joints are worn. I'm going to replace all that stuff while on vacation toward the end of Dec.
I don't have dyno figures for this engine, but compared to others similar to it, it is estimated at 220-240hp. My best run at Sears Point was a [email protected] I'm expecting at least high 13's, depending on what ratio R200 I use, and after fixing all the broken parts. By the way, I didn't really build this car for drag racing. It's built for road racing. It's lowered into the weeds and has 225/50/15 tires on 15x7 panasports all around. I can outhandle almost anything on the road today. People that ride with me are totally amazed at how fast I can take turns. The main comment people make to me is; My car would flip over if I took that turn like that!
P.S. The post below was a fictitios example. I just used numbers that closely relate to a Z engine, they were not exact numbers from a dyno run. I was just trying to show how gearing plays a role in when you shift, even though power drops off at a higher rpm. But, like I said, closer gearing would eliminate the need to rev so high, because the shift drop would not be so much. I would imagine a close ratio 5spd with 3.1L would be quite fast.
What are your specs??
240Dave