Web Camshaft

[Gollum]

Should have come to Mt. Diablo a few weeks ago.... I'm sure you could have gotten a ride in some Z cars.

 

I'll first put out there that I have very little experience with what some consider the "more agressive" stock L24. I've only ridden in 1 stock longblock 240Z and it was probably on putting around 100hp to the wheels, if that. But I've also ridden in, and driven, a few L28 equipped 240's, and it's amazing how much better they feel from a stop.

 

Point being ~ You can do all sorts of tricks to increase VE, but increasing it down low just seems like a backwards way to go. A 2.8 liter S30 will have ZERO issues with having enough torque to handle hills unless there's something seriously wrong. And no matter what, a L28 that's making a healthy 200hp at 6,000 rpm is going to feel way better all through the RPM range than a L28 making 170hp at 5,000, even if it's making more torque down low.

 

That's my .02 cents. Oh, and all that said my S30 has a L28ET... When I get it running again you can come drive it if you want to head up to vacaville sometime.

[luseboy]

Should have come to Mt. Diablo a few weeks ago.... I'm sure you could have gotten a ride in some Z cars.

 

I'll first put out there that I have very little experience with what some consider the "more agressive" stock L24. I've only ridden in 1 stock longblock 240Z and it was probably on putting around 100hp to the wheels, if that. But I've also ridden in, and driven, a few L28 equipped 240's, and it's amazing how much better they feel from a stop.

 

Point being ~ You can do all sorts of tricks to increase VE, but increasing it down low just seems like a backwards way to go. A 2.8 liter S30 will have ZERO issues with having enough torque to handle hills unless there's something seriously wrong. And no matter what, a L28 that's making a healthy 200hp at 6,000 rpm is going to feel way better all through the RPM range than a L28 making 170hp at 5,000, even if it's making more torque down low.

 

That's my .02 cents. Oh, and all that said my S30 has a L28ET... When I get it running again you can come drive it if you want to head up to vacaville sometime.

 

I know, I wish I would have gone! I had a friend that was going to come here that weekend, so I thought I wasn't going to be able to go. he ended up getting sick and couldn't come here. But then I went and picked up my engine that day so it was either get the project started or go see some Z cars. It was gonna be at least another week till I would have been able to get the engine so I went for getting it then.

 

I guess I'm used to my MINI where cams are a selection of street, semi-race, or full on race. I was under the impression that that's how all engines are. But I have realized that I am very wrong in that impression. Well I've decided to go with the one I had planned on, the web "91" grind: 260 duration.

here's the info sheet on it: http://webcamshafts.com/pages/automobile/datsun/install_data/tc_001800_001086.html

 

does this sound like a good cam? or should I go more aggressive?

Edited October 3, 2011 by luseboy

[Leon]

Too bad you missed it, I was there as well!

 

What part of the North Bay are you in? I can let you know if I'm in the area with my Z and would have no problem coming by and taking you on a ride.

[luseboy]

Too bad you missed it, I was there as well!

 

What part of the North Bay are you in? I can let you know if I'm in the area with my Z and would have no problem coming by and taking you on a ride.

 

Aww well I wish I had gone!

 

haha I'm in san anselmo, I'd love to have a ride (in your car lol). And I'd love to check it out just to get some nice ideas for my project.

Edited October 3, 2011 by luseboy

[automec]

i have a customers car in that was rebuilt elsewhere last year. and his schnider cam went bad on 1 lobe. schnider said the edge of the rocker pad had been hitting the cam, and to use a .160 lash pad with this replacement. well.... it has 170s in it(and nothing available at motorsports) so i thought i would try one and see where the geomerty looked. its bad. i have the adjuster all the way down, 1 lash pad cut to 160 and still have less than 0 clearance looking at the springs they are at proper spring installed height , but there is a .060 extra shim under the spring to do so.

looks like i get to redo someones valve job, so i can get the valve tips to a lower position.

[duragg]

I could only get .190s and 230s from MSA and I needed 140s.

Just had machine shop friend grind them down on surface grinder.

 

There aren't many of the right size around.

[luseboy]

is there any other source for lash pads? I thought rock auto sold them as well? if lash pads aren't available... then I guess I can't get a camshaft... unless by dumb luck I am able to find the right lash pads in stock...

 

isn't this a good selection of all the ones anyone would need?

http://www.thezstore.com/page/TZS/PROD/PEM02/10-2041

Edited October 4, 2011 by luseboy

[duragg]

They were sold out at MSA and didn't sound like more were coming.

Get the big ones. Determine what you need by the "method" and have a machine shop surface grind to size.

[JMortensen]

Wasn't www.zccjdm.com having them made?

[Gollum]

does this sound like a good cam? or should I go more aggressive?

 

I think it'll work for your goals as long as the head is healthy and you induction system is well matched. I'd suggest playing with cam timing when it comes time to tune too.

[cockerstar]

Wasn't www.zccjdm.com having them made?

 

Looks like they have them from .120-.300" for $99/set

 

http://www.zccjdm.com/catalog.php/azcarbum/dt93256/pd2126003/A_DATSUN__L4_L6_VALVE_LASH_PADS_

[luseboy]

I think it'll work for your goals as long as the head is healthy and you induction system is well matched. I'd suggest playing with cam timing when it comes time to tune too.

 

awesome! sounds like the winner! Well I'll go with that one then .

[Gollum]

What's the average weight and displacement of the MINI's you're used to?

 

Reason I ask, is that I believe the Z will have much more displacement for the weight of the vehicle, meaning that it's going to feel much more "torquey". This is something I didn't really think about much until recently but I can go back through the history of all the cars I've driven and can definitely make the correlation in the numbers.

 

A 1.8 liter CRX can actually "feel" like it's got more torque, or "power off idle", than a 4.7 liter toyota tundra.

 

I can also say it this way. Torque is nearly meaningless without context. Torque more than anything is an indicator and should be used as such. A diesel isn't powerful off idle because it makes a crap ton of torque, it's actually because it makes so much bloody HP off idle. HP moves cars, not torque. HP puts you in your seat, not torque.

 

But if I say an engine has 400lbs of torque off idle (we'll assume 1k rpm) that's over 75HP, which is a boatload when it's that low in RPM. It's going to get an object MOVING.

 

The this is though, is that torque is directly tied to displacement in NA applications. So for comparing NA vehicles to NA vehicles, we can use displacement to weight to directly compare how they'll drive at low engine speeds, even if they behave very differently at peak HP. You're not driving at peak HP all the time, so for street driving I find the displacement/weight measurement very useful.

 

So that's why I ask about the mini. The Z will weigh around 2200-2400 pounds, and 2.8 liter is more than 1 liter per 1,000 pounds, which is better than many muscle cars.

[luseboy]

What's the average weight and displacement of the MINI's you're used to?

 

Reason I ask, is that I believe the Z will have much more displacement for the weight of the vehicle, meaning that it's going to feel much more "torquey". This is something I didn't really think about much until recently but I can go back through the history of all the cars I've driven and can definitely make the correlation in the numbers.

 

A 1.8 liter CRX can actually "feel" like it's got more torque, or "power off idle", than a 4.7 liter toyota tundra.

 

I can also say it this way. Torque is nearly meaningless without context. Torque more than anything is an indicator and should be used as such. A diesel isn't powerful off idle because it makes a crap ton of torque, it's actually because it makes so much bloody HP off idle. HP moves cars, not torque. HP puts you in your seat, not torque.

 

But if I say an engine has 400lbs of torque off idle (we'll assume 1k rpm) that's over 75HP, which is a boatload when it's that low in RPM. It's going to get an object MOVING.

 

The this is though, is that torque is directly tied to displacement in NA applications. So for comparing NA vehicles to NA vehicles, we can use displacement to weight to directly compare how they'll drive at low engine speeds, even if they behave very differently at peak HP. You're not driving at peak HP all the time, so for street driving I find the displacement/weight measurement very useful.

 

So that's why I ask about the mini. The Z will weigh around 2200-2400 pounds, and 2.8 liter is more than 1 liter per 1,000 pounds, which is better than many muscle cars.

 

 

My mini has a 1.6 liter supercharged engine and weighs about 2600 lbs. It is probably putting out around 175 hp. Stock is 160 hp.

 

I can see what your saying, and I'm glad to hear it haha. Like I said, I want something that feels fast. I'm more interested in feel and driveability than the numbers. As I understand it, with my planned mods, I will be putting close to 200 hp to the wheels. so thats 10 lbs per hp, roughly, which is awesome! The throttle will also react faster (damn drive by wire),and I will absolutley love driving this car!

 

So if I did that cam I talked about, and a 5 speed tranny, which diff would I want? I want a vicious lsd out of a 300z if I can find one... But an open diff would be ok too. So what size tranny would I want? A 3.9? Or would a 4.1 suit me better? Like I said I want power a little lower than most people.

[Zmanco]

So if I did that cam I talked about, and a 5 speed tranny, which diff would I want? I want a vicious lsd out of a 300z if I can find one... But an open diff would be ok too. So what size tranny would I want? A 3.9? Or would a 4.1 suit me better? Like I said I want power a little lower than most people.

Just to be clear, the diff won't affect where in the rev range the engine makes the most power. You want to match the characteristics of the cam with the driveline. I still see you saying you want good low end torque, but also want to wind it out and make good power at high revs too. On our L28s, you have to compromise - the better the engine makes power at high revs, the weaker its torque will be at low revs.

 

That said, I run a 4.11 diff with an 81-83 zx 5 speed and find the combination a lot of fun to drive on the street. The 4.11 means that I don't have to downshift as often as with a lower diff, and I can wind it out in 2nd gear without hitting go to jail speeds. It also spends very little time in the lower rpm range as long as I'm willing to shift. When I ran NA on the track it was great because there was always a gear where I was in the power band i.e. above 3500 rpm.

 

This site is a great way to get an idea of where your shift points will be with various combinations. You might compare to your Mini to get a frame of reference.

 

As for whether you should get an LSD, for a street driven Z I'd vote no. The LSD adds weight, cost, and makes the car push when under power, and then loosens when it unlocks from lifting the throttle. I was surprised how much of a difference it made in sweeping turns on the street. Note: this is with a CLSD. A VLSD might be less intrusive. Unless you really stiffen the rear suspension, you will probably find that you don't need it.

[JMortensen]

I gotta disagree on the LSD. The traction difference coming out of corners is way more important than understeer on a street car, and if you're carving canyons and that sort of thing, you can tune around it with suspension.

 

A 2 way LSD, like the Nissan CLSD, limits slip under power and decel, and has spring preload when feathering the throttle, the amount of lockup changes as a function of the torque sent to it, but it doesn't unlock under decel.

[luseboy]

Just to be clear, the diff won't affect where in the rev range the engine makes the most power. You want to match the characteristics of the cam with the driveline. I still see you saying you want good low end torque, but also want to wind it out and make good power at high revs too. On our L28s, you have to compromise - the better the engine makes power at high revs, the weaker its torque will be at low revs.

 

That said, I run a 4.11 diff with an 81-83 zx 5 speed and find the combination a lot of fun to drive on the street. The 4.11 means that I don't have to downshift as often as with a lower diff, and I can wind it out in 2nd gear without hitting go to jail speeds. It also spends very little time in the lower rpm range as long as I'm willing to shift. When I ran NA on the track it was great because there was always a gear where I was in the power band i.e. above 3500 rpm.

 

This site is a great way to get an idea of where your shift points will be with various combinations. You might compare to your Mini to get a frame of reference.

 

As for whether you should get an LSD, for a street driven Z I'd vote no. The LSD adds weight, cost, and makes the car push when under power, and then loosens when it unlocks from lifting the throttle. I was surprised how much of a difference it made in sweeping turns on the street. Note: this is with a CLSD. A VLSD might be less intrusive. Unless you really stiffen the rear suspension, you will probably find that you don't need it.

 

well the 4.11 sounds like the one. I'm not racing or planning to turbo or supercharge anytime soon, so one you liked for N/A will be the better one I'm sure.

Thats a good point about the lsd... i hadn't really thought about it that way. I think I'll just stick with the diff I have already for now, it will save me some cost for my build. Maybe I'll do an lsd conversion or some other diff later on.

 

Well looks like all my questions relating to this topic have been answered on this thread... once again! I love this place, best forum I've ever been on.

thanks for all the help guys!

[SleeperZ]

well the 4.11 sounds like the one. I'm not racing or planning to turbo or supercharge anytime soon, so one you liked for N/A will be the better one I'm sure.

Thats a good point about the lsd... i hadn't really thought about it that way. I think I'll just stick with the diff I have already for now, it will save me some cost for my build. Maybe I'll do an lsd conversion or some other diff later on.

 

Well looks like all my questions relating to this topic have been answered on this thread... once again! I love this place, best forum I've ever been on.

thanks for all the help guys!

I'm very interested to hear how that Web Cams grind works out for you. I'm looking at the same thing, again I don't need a top end demon, especially since I am using a BW T5 transmission and a 3.54 R200; the 280ZX original factory drivetrain. This setup worked really well on the dragstrip, I could actually use 1st gear, but the factory cam starts wheezing past 5000 rpm, and I'd like some nice torque upwards of 6500. I don't need the monster torque down low - with 16 psi on the stock cam, I made over 400ft-lbs at 2800, I think I can spare some of that for some breathing room up top, especially since my CF clutch will slip with good tire traction at the torque peak.