heads for 11.5:1 compression ratio
04-20-2004, 08:27 AM
#21
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why would the car need oversized valves for an NA setup? At the power levels even the most extreme NA car can dish out, the stock valves are fine.
GY-Z - rather than going off of internet knowledge, you need to sit down with a reputable engine builder and go over your goals, budget, etc etc.
GY-Z - rather than going off of internet knowledge, you need to sit down with a reputable engine builder and go over your goals, budget, etc etc.
04-20-2004, 02:05 PM
#24
Do the oversized valves fit the NISMO head perfectly or do you need heavy porting before they would fit?
The Alu valves would wear downe quicker than the Ti ones due to steep angled camshafts, so strength would be a benefit for running the Ti ones. Alu is probabally about as lite as Ti so I dont think weight would be as much of an issue in our case.
The Alu valves would wear downe quicker than the Ti ones due to steep angled camshafts, so strength would be a benefit for running the Ti ones. Alu is probabally about as lite as Ti so I dont think weight would be as much of an issue in our case.
Last edited by mchapman; 04-20-2004 at 02:07 PM.
04-20-2004, 06:15 PM
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Originally posted by turbo-maxima
Yes it will increase compression to 11:5:1 and if you want it to go higher us VQ35 head gasket which is thinner. It is 2 layers instead of the 350z 3 layer head gasket. That would bump it up to almost 12:1:1 and that would probally require race gas. On the 11:5:1 you should get an 8% increase in power and 12:1:1 you should get 12% increase in power. So 8 % would be about 25 crank hp and 12% should ake about 35 crank hp. And the cams should add about 30 crank hp at stock redline. Then about 10-15 crank hp for the port and polish.
A ecu reflash would help with all this, a richer fuel program to help with detonation from the high compression, an extended redline would even increase the power from the cams and port and polish. The high compression, port and polish, cams, and ecu should be about 50 whp.
Yes it will increase compression to 11:5:1 and if you want it to go higher us VQ35 head gasket which is thinner. It is 2 layers instead of the 350z 3 layer head gasket. That would bump it up to almost 12:1:1 and that would probally require race gas. On the 11:5:1 you should get an 8% increase in power and 12:1:1 you should get 12% increase in power. So 8 % would be about 25 crank hp and 12% should ake about 35 crank hp. And the cams should add about 30 crank hp at stock redline. Then about 10-15 crank hp for the port and polish.
A ecu reflash would help with all this, a richer fuel program to help with detonation from the high compression, an extended redline would even increase the power from the cams and port and polish. The high compression, port and polish, cams, and ecu should be about 50 whp.
04-20-2004, 06:16 PM
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Originally posted by Z1 Performance
why would the car need oversized valves for an NA setup? At the power levels even the most extreme NA car can dish out, the stock valves are fine.
GY-Z - rather than going off of internet knowledge, you need to sit down with a reputable engine builder and go over your goals, budget, etc etc.
why would the car need oversized valves for an NA setup? At the power levels even the most extreme NA car can dish out, the stock valves are fine.
GY-Z - rather than going off of internet knowledge, you need to sit down with a reputable engine builder and go over your goals, budget, etc etc.
04-21-2004, 06:15 AM
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I would just change the heads, why spend more money than you need too. It is up to you. But switching head is alot easier than swapping pistons. Can you do the work yourself on the piston swap? I am sure you can do the headswap.
04-21-2004, 06:53 AM
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Originally posted by downforce
Does anyone have more info on the VQ30 head?
Does anyone have more info on the VQ30 head?
04-21-2004, 08:03 AM
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nismo 46cc heads
Originally posted by Jason@Performance
$3000 for the 46cc heads w/ all parts needed for the install...
can be used with the NISMO or JWT cams or any cams that will work with the stock heads...
it comes with the VK45 Titanium Valves, High Lift Valve Springs, Retainers, Spring Seats...
$3000 for the 46cc heads w/ all parts needed for the install...
can be used with the NISMO or JWT cams or any cams that will work with the stock heads...
it comes with the VK45 Titanium Valves, High Lift Valve Springs, Retainers, Spring Seats...
Originally posted by UsafaRice
I don't know if Nismo has put out the stated CR, but I come out to 12.6:1 with a 46cc chamber in them. This is using the engine volume of 3,498 cc. I don't know what the piston top is shaped like, but the Nismo head will definitely be between 12.4 and 12.7 to 1.
I don't know if Nismo has put out the stated CR, but I come out to 12.6:1 with a 46cc chamber in them. This is using the engine volume of 3,498 cc. I don't know what the piston top is shaped like, but the Nismo head will definitely be between 12.4 and 12.7 to 1.
Originally posted by pimp1911
Would the stock pistons have to be changed. And with compression that high. Would you have to switch to race gas. I am sure the ECU would have to be flashed.
Would the stock pistons have to be changed. And with compression that high. Would you have to switch to race gas. I am sure the ECU would have to be flashed.
Originally posted by turbo-maxima
You might be able to get away with ecu tuning but I doubt it will run on 93 octane. You might be able to get away with a N/A alchohol/water injection system. Those can be bought for 200 dollars. I think I have a link at my website, one sec. http://www.racetep.com/wik.html $300 dollars my bad. Good price though.
You might be able to get away with ecu tuning but I doubt it will run on 93 octane. You might be able to get away with a N/A alchohol/water injection system. Those can be bought for 200 dollars. I think I have a link at my website, one sec. http://www.racetep.com/wik.html $300 dollars my bad. Good price though.
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