NISMO 46cc Heads inspected... to be installed \m/, ^_^ .\m/
04-25-2004, 08:17 PM
#123
Found out some useful info on these NISMO heads in regard to installing them onto your 350z. From someone who has actually installed them onto his car.
You cant just stick the NISMO heads(actually a VQ30 head with VQ35 valve seats) on and off you go, because the compression ratio is raised you need to change your pistons, rods and rod bolts as well because of the increased heat and pressure exerted on them. The cams would also need changing to any of the aftermarket ones because the stock VQ35 ones dont work with the head. Also because the location of the valve openings is futher down in the VQ30 heads the VQ35 or titanium FX45 valves which are sold through performance nissan arent long enough to be hit by the camshaft lobe. Therefore you'll also need to buy larger tapets and possibly modify them to the correct size enabling the lobe to make perfect contact. High lift valve springs, retainers, ecu tuning and possibly a few other bits would also be required.
You cant just stick the NISMO heads(actually a VQ30 head with VQ35 valve seats) on and off you go, because the compression ratio is raised you need to change your pistons, rods and rod bolts as well because of the increased heat and pressure exerted on them. The cams would also need changing to any of the aftermarket ones because the stock VQ35 ones dont work with the head. Also because the location of the valve openings is futher down in the VQ30 heads the VQ35 or titanium FX45 valves which are sold through performance nissan arent long enough to be hit by the camshaft lobe. Therefore you'll also need to buy larger tapets and possibly modify them to the correct size enabling the lobe to make perfect contact. High lift valve springs, retainers, ecu tuning and possibly a few other bits would also be required.
Last edited by mchapman; 04-25-2004 at 08:21 PM.
04-25-2004, 10:15 PM
#124
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Would using a more aggresive cam(ie more agressive than Nismo 262 degrees) make up th distance between the cam lobe and the valves. I was hoping the Q45/FX45 titanium valves would reach and do the trick. And what size pistons.
Last edited by pimp1911; 04-25-2004 at 10:17 PM.
04-25-2004, 10:27 PM
#125
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So a VQ30 would work...... And what pistons would we need to change to? You also say something about the vq35 and fx45 valves not working with the vq30 head? So can anyone list exactly what needs to be done in this head swap.
1. You can swap to more aggressive cams
2. Now you need new pistons, rods, rod bolts?
3. Different valves?
4. High lift valve springs and retainers?
man is this getting confusing. sounds promising though.
1. You can swap to more aggressive cams
2. Now you need new pistons, rods, rod bolts?
3. Different valves?
4. High lift valve springs and retainers?
man is this getting confusing. sounds promising though.
Originally posted by mchapman
You cant just stick the NISMO heads(actually a VQ30 head with VQ35 valve seats) on and off you go, because the compression ratio is raised you need to change your pistons, rods and rod bolts as well because of the increased heat and pressure exerted on them. The cams would also need changing to any of the aftermarket ones because the stock VQ35 ones dont work with the head. Also because the location of the valve openings is futher down in the VQ30 heads the VQ35 or titanium FX45 valves which are sold through performance nissan arent long enough to be hit by the camshaft lobe. Therefore you'll also need to buy larger tapets and possibly modify them to the correct size enabling the lobe to make perfect contact. High lift valve springs, retainers, ecu tuning and possibly a few other bits would also be required.
You cant just stick the NISMO heads(actually a VQ30 head with VQ35 valve seats) on and off you go, because the compression ratio is raised you need to change your pistons, rods and rod bolts as well because of the increased heat and pressure exerted on them. The cams would also need changing to any of the aftermarket ones because the stock VQ35 ones dont work with the head. Also because the location of the valve openings is futher down in the VQ30 heads the VQ35 or titanium FX45 valves which are sold through performance nissan arent long enough to be hit by the camshaft lobe. Therefore you'll also need to buy larger tapets and possibly modify them to the correct size enabling the lobe to make perfect contact. High lift valve springs, retainers, ecu tuning and possibly a few other bits would also be required.
04-26-2004, 12:43 AM
#126
Originally posted by pimp1911
Would using a more aggresive cam(ie more agressive than Nismo 262 degrees) make up th distance between the cam lobe and the valves. I was hoping the Q45/FX45 titanium valves would reach and do the trick. And what size pistons.
Would using a more aggresive cam(ie more agressive than Nismo 262 degrees) make up th distance between the cam lobe and the valves. I was hoping the Q45/FX45 titanium valves would reach and do the trick. And what size pistons.
Even if the higher lift cams could reach(which they dont) they wouldnt be hitting the cam at the designed location causing damage and wouldnt be able to push the valve through its entire range of motion.
Last edited by mchapman; 04-26-2004 at 12:46 AM.
04-26-2004, 01:10 AM
#127
Originally posted by x350Zx
So a VQ30 would work...... And what pistons would we need to change to? You also say something about the vq35 and fx45 valves not working with the vq30 head? So can anyone list exactly what needs to be done in this head swap.
1. You can swap to more aggressive cams
2. Now you need new pistons, rods, rod bolts?
3. Different valves?
4. High lift valve springs and retainers?
man is this getting confusing. sounds promising though.
So a VQ30 would work...... And what pistons would we need to change to? You also say something about the vq35 and fx45 valves not working with the vq30 head? So can anyone list exactly what needs to be done in this head swap.
1. You can swap to more aggressive cams
2. Now you need new pistons, rods, rod bolts?
3. Different valves?
4. High lift valve springs and retainers?
man is this getting confusing. sounds promising though.
You dont need different valves, you can use the VQ35 or FX45 valves but you need larger tapets which sit on the end of the valve to make up the distance between the valve and the camshaft lobe. I dont know the exact measurements needed but you should take this into consideraton before you order the head because you wont have all the parts needed for the install otherwise. The person who has done this actually bought oversize tappets because it takes a while to get the parts here to Australia from Japan and ground them down to the correct size to get them to work.
I dont know the exact list down to every bolt needed for the NISMO head to work, but im sure after performance nissan try to put it into their car they will have to figure this out and will inform everyone of any troubles they have and what additional parts are required.
04-26-2004, 03:51 AM
#128
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Originally posted by Resolute
The VQ30 heads do not flow as well as the VQ35 heads do. The VQ35 heads stock are close to what these RZZ heads will flow, but the VQ30 will not come close to these NISMO heads. This swap will also require the front chain cover to be replaced and yes, you will lose the CVTCC system on the VQ35. Second, the wiping pad on the VQ30 buckets are not as large as the what can fit on the VQ35 or the RZZ, which is a damn good reason why the Formula Nissan series do not use ported VQ30 heads on the VQ30 blocks when they rev to 10,000 rpm. Food for thought.
The VQ30 heads do not flow as well as the VQ35 heads do. The VQ35 heads stock are close to what these RZZ heads will flow, but the VQ30 will not come close to these NISMO heads. This swap will also require the front chain cover to be replaced and yes, you will lose the CVTCC system on the VQ35. Second, the wiping pad on the VQ30 buckets are not as large as the what can fit on the VQ35 or the RZZ, which is a damn good reason why the Formula Nissan series do not use ported VQ30 heads on the VQ30 blocks when they rev to 10,000 rpm. Food for thought.
04-26-2004, 04:29 AM
#129
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Originally posted by ether
clarification question, will the CVTCC system work with the nismo heads? or is it that i will not work with the VQ30 heads but will work with the nismos?
clarification question, will the CVTCC system work with the nismo heads? or is it that i will not work with the VQ30 heads but will work with the nismos?
04-26-2004, 02:26 PM
#130
Some clarification needed.
I am using the Nismo RRZ cyinder heads on my Z & you can not use them with any of the available aftermarket camshafts ( JWT, Nismo, Tomei etc) if you use the titanium Infiniti VK45 valves.
Reason being that the valves seats in the RRZ head sit aprox 1.8mm further into the combustion chamber than the stock head and the VK45 valves are the same length as the stock valves.
All of the above cams are ground with the same base circle as stock cam so you have a problem setting the valve clearance as none of the available cam buckets (tappets) are thick enough.
Nismo have available blank cams that can be ground with a bigger
base circle.
Or you can do what I did and get shims made up to make up the 1.8 mm gap.
I am using the Nismo RRZ cyinder heads on my Z & you can not use them with any of the available aftermarket camshafts ( JWT, Nismo, Tomei etc) if you use the titanium Infiniti VK45 valves.
Reason being that the valves seats in the RRZ head sit aprox 1.8mm further into the combustion chamber than the stock head and the VK45 valves are the same length as the stock valves.
All of the above cams are ground with the same base circle as stock cam so you have a problem setting the valve clearance as none of the available cam buckets (tappets) are thick enough.
Nismo have available blank cams that can be ground with a bigger
base circle.
Or you can do what I did and get shims made up to make up the 1.8 mm gap.
04-26-2004, 04:43 PM
#131
Originally posted by ether
clarification question, will the CVTCC system work with the nismo heads? or is it that i will not work with the VQ30 heads but will work with the nismos?
clarification question, will the CVTCC system work with the nismo heads? or is it that i will not work with the VQ30 heads but will work with the nismos?
04-26-2004, 05:47 PM
#132
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Nathan,
So far you're the only one that I've heard of to install the RZZ heads. Did you flow bench them vs a stock head (with or without port and polish, doesn't really matter much)?
Also, I just found all your posts in the Australia posts and my biggest observation is that the VQ could rev a lot more than Nissan is letting it. In your opinion, would a cam profile that kept making power all the way up to 7k or 7.5k rpm mean substantial losses down low? Or is there some way to work the intake and CVTCS to maintain at least stock levels of torque on the bottom end?
So far you're the only one that I've heard of to install the RZZ heads. Did you flow bench them vs a stock head (with or without port and polish, doesn't really matter much)?
Also, I just found all your posts in the Australia posts and my biggest observation is that the VQ could rev a lot more than Nissan is letting it. In your opinion, would a cam profile that kept making power all the way up to 7k or 7.5k rpm mean substantial losses down low? Or is there some way to work the intake and CVTCS to maintain at least stock levels of torque on the bottom end?
04-26-2004, 08:52 PM
#134
UsafaRice
No I did not get them flow tested but I saw a flow graph at the 2003 Tokyo Auto Salon comparing the stock heads to the RZZ head & the JGTC race motor heads & the RZZ heads were close to the race head in flow.
With a big lift cam which these heads can accomadate there will be no loss of TQ low down & good power increases accross the revs up to about 7K but they will not make as much power as a big duration cam in the upper revs.
This motor is the basis of the new Fran Am racing series & with only 11.1 CR they are good for 400+HP at the flywheel at 7000rpm.
This motor was made at a cost for everything from a Pathfinder to an Infiniti.
If Nissan were to put a better bottom end in it there is no reason why it could not be made to make a reliable 350HP at say 7500 to 7800 RPM.
Remember the Z motor at its max TQ RPM of 4800, is putting out more HP than the BMW M3, Porche 3.6 996 & about the same as the 360 Ferrari.
No I did not get them flow tested but I saw a flow graph at the 2003 Tokyo Auto Salon comparing the stock heads to the RZZ head & the JGTC race motor heads & the RZZ heads were close to the race head in flow.
With a big lift cam which these heads can accomadate there will be no loss of TQ low down & good power increases accross the revs up to about 7K but they will not make as much power as a big duration cam in the upper revs.
This motor is the basis of the new Fran Am racing series & with only 11.1 CR they are good for 400+HP at the flywheel at 7000rpm.
This motor was made at a cost for everything from a Pathfinder to an Infiniti.
If Nissan were to put a better bottom end in it there is no reason why it could not be made to make a reliable 350HP at say 7500 to 7800 RPM.
Remember the Z motor at its max TQ RPM of 4800, is putting out more HP than the BMW M3, Porche 3.6 996 & about the same as the 360 Ferrari.
04-26-2004, 08:56 PM
#135
Originally posted by Nathan
Some clarification needed.
I am using the Nismo RRZ cyinder heads on my Z & you can not use them with any of the available aftermarket camshafts ( JWT, Nismo, Tomei etc) if you use the titanium Infiniti VK45 valves.
Reason being that the valves seats in the RRZ head sit aprox 1.8mm further into the combustion chamber than the stock head and the VK45 valves are the same length as the stock valves.
All of the above cams are ground with the same base circle as stock cam so you have a problem setting the valve clearance as none of the available cam buckets (tappets) are thick enough.
Nismo have available blank cams that can be ground with a bigger
base circle.
Or you can do what I did and get shims made up to make up the 1.8 mm gap.
Some clarification needed.
I am using the Nismo RRZ cyinder heads on my Z & you can not use them with any of the available aftermarket camshafts ( JWT, Nismo, Tomei etc) if you use the titanium Infiniti VK45 valves.
Reason being that the valves seats in the RRZ head sit aprox 1.8mm further into the combustion chamber than the stock head and the VK45 valves are the same length as the stock valves.
All of the above cams are ground with the same base circle as stock cam so you have a problem setting the valve clearance as none of the available cam buckets (tappets) are thick enough.
Nismo have available blank cams that can be ground with a bigger
base circle.
Or you can do what I did and get shims made up to make up the 1.8 mm gap.
Last edited by mchapman; 04-26-2004 at 09:06 PM.
04-27-2004, 10:19 AM
#137
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Originally posted by turbo-maxima
If you use the stock valves, can you use aftermarket cams like nismo, JWT, or Tomei?
If you use the stock valves, can you use aftermarket cams like nismo, JWT, or Tomei?
Regardless, if you're going to all the trouble to buy thousands of dollars of heads and cams, I would go ahead and get the titanium valves as well...
04-27-2004, 01:19 PM
#138
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So basically the cam is a custom cam. You would have to purchase the camshaft blanks to get the unground lobes. Why would Nismo issue a head that doesnt work with the cams they sell.
04-27-2004, 02:04 PM
#139
More clarification.
The Nismo head has 1mm smaller valve seat than the stock head & the exhaust is the same size as stock.
The VK45 inlet valve is 1mm smaller than stock & fits straight in Nismo head.
This head is not being marketed as a bolt on application for road cars but as a high flow head for race engine builders & with cam blanks for the engine builder to do with what he wants.
The available aftermarket cams were all designed as drop in replacements for the stock head.
The Nismo head has 1mm smaller valve seat than the stock head & the exhaust is the same size as stock.
The VK45 inlet valve is 1mm smaller than stock & fits straight in Nismo head.
This head is not being marketed as a bolt on application for road cars but as a high flow head for race engine builders & with cam blanks for the engine builder to do with what he wants.
The available aftermarket cams were all designed as drop in replacements for the stock head.