Turbo Cam Spec's

[Lockjaw]

Hey,

 

Does anyone out there have the spec's on the 3 turbo grind cams Nissan put in the ZX's. I think they are B, J, & M. I have the B grind, and I know the M grind is 83 only manual and auto. B grind is Auto 81-82, and J (not sure if right) is 81-82 manual.

 

Any idea where I could find out? Need the specs to play around with the Drag program.

 

Thanks.

[scottyMIz]

wow they made different cams????? i do learn something new everyday What are the diff in them?

[Lockjaw]

Well I am not sure, which is why I would like the spec's. I know they went to the trouble to stamp 3 different letters on the backside, and I have heard the 83 cam is the best one, but without having the 3 cams and sending them to Crower or somebody, I don't know.

 

My friend has a shop with lots of Z cams laying around, and I could not find a single J grind, I found a few F's, several M's, and a B, which I put in my car. I had an old BAE kit with a rotomaster turbo, and I knew it would not spool very quickly, so I wanted a cam that had more bottom end. I figured since it went in the auto, it had to be slightly milder.

 

I have tried a regular stock ZX cam, and did not like it, and I tried a Schneider cam that I had for an NA engine, and it sucked as well.

 

But you have to have the specific specs on the cam to dial in the desktop drag program, and I have no idea what the specs are. I just would like to play around with the thing and see what it thinks I need to try for more power.

 

I guess I could call Nissan Motorsports, but that is always such an ordeal. It took me forever to convince the guy I spoke with last time that there were different cams. He said they were all the same. I told him politely that he was mistaken.

 

Anyway, just thought I would take a shot before having to waste my major long distance talking to Nismo.

[Guest Anonymous]

Well, the '83 had hydraulic rockers, as you probably know, I wouldn't doubt it if nissan changed the specs too.. as far as the best cam, I've heard the stock cams fall short around 4800 rpms (dunno which model), which makes sense because of the small stock turbo. I don't mind using the stock one for a while, to see how it works out. everything on my motor comes from a manual '82.. BUT I don't have the cam- here. That's right, I will be getting it sent to me soon..

Nismo would be good, but perhaps MSA could get you the information faster, they've answered all of my nichest of niche questions on the tech line. Anyway, if you find out, please post them, I'd like to know myself

good luck

-980mak

[Lockjaw]

You can run any cam in the "non-hydraulic" head, it doesn't matter if it is the hydraulic cam.

 

I will see what I can find out, and I will post the results. I would like to know the spec's so I can have a larger one made.

[Lockjaw]

Well I sent an email off about the cams so we shall see what I get back. I also ordered the NISMO adjustable cam sprocket, and am going to try retarding the cam and see what happens. I can retard it up to 9 degree, or advance it up to 12 degree's in increments of 3 degree's.

 

I think retardation is the way to go.

 

Not very PC was it?

[Guest Tom Scala]

I had a link to a page that listed specs for all the factory cams but it doesn't work anymore. I'm pretty sure I printed it out so I'll have to look around for it. From what I remember though the 81 turbo cam had a dual pattern with more exhaust duration and was essentially the same grind as the early 1976 280Z cam. The second version was a single pattern using the intake duration of the 81 cam on both events. The 1983 P90A cam had identical duration to that one but was advanced 4 degrees,maybe for emissions reasons? I think it had a 104 ICL on a 109 LCA compared to 108ICL on 109LDA for the solid lifter 1982 head. All had around .380" lift and LCA's of 109. Thinking my old timing chain was starting to stretch I advanced my P90A cam one notch to the no.2 hole before I knew about the different timing of the 1983 cam. It's probably way over advanced and the reason the motor doesn't want to pull hard over 5K RPM. BTW I'll look for that page and post it if I find it.

[Lockjaw]

So you are saying the 83 cam had 4 degree's of advance ground into it? Is that right?

 

See I am thinking I could send the factory cam to crower and have them grind me a new billet cam with more lift and duration, without getting to the point where it lopes. Then it should pull cleanly to about 6500 or so, with good power when the cam came up and the turbo spooled up.

 

I would go up to about 420 or so lift, maybe as high as 450, and add about 15 to 20 degree's of duration, and leave everything else alone. What I don't want to do it get some big old cam that lopes and kills the response down low.

 

Maybe I should short shift my car at the drags next time and see if it runs better.

[yo2001]

go with high lift, small duration, the turbo would like that set up. .500" lift and around 240-260 duration maybe? Turbo car will do good with NOS cam too I think. There is an adjustable cam spocket at arizona Z for $120. Cheaper than Nismo. By backing the cam, you might have spooling problem. I guess that's the destiny of SOHC. BTW, do you have 300zx TPS handy? My TPS is dead.

[Lockjaw]

OK, we will try to go in oder here. Yo2001, I odered an adjustable sprocket today for 93.00, and I posted the link to the place in the head gasket post. I sent you an email about the tps.

 

As far as lobe centerlines, I need to do some research in that area because I am not a fan of a wide centerline. Of course most of my cam playing was done with normally aspirated Z motors, but I will look around some and see. I am not doubting you mind you, just one of those things if you know what I mean.

 

I have seen the Scneider cam in the Motorsports catalog, but have never heard of anyone running the turbo cam. I have run two different NA Scneiders, and liked them both. I have heard bad things about Schneider from JWT people, mainly involving their customer service.

 

I have seen in some of the old Nopi ads that Gude made a turbo cam for the z motor, but I checked his web site and did not see anything that looked good, and no real specs or stuff on the L series cams.

 

Rocker arms are another issue. That is why I wanted to get a cam sort of larger that stock but on the smaller side so I did not have to get springs and retainers and lash pads too. If I got one ground on a billet, I could keep the same base circle as stock, and then i should not have to change lash pads.

 

In reality though, if the cam manufacturer changes the base circle, it is pretty simple math to arrive at the correct lash pad thickness. I did it with a crower regrind and hit it dead on.

 

I heard some folks we having some success retarding the stock cam some, like 30 to 40 hp worth, which is why I wanted the adjustable sprocket.

 

I wish I had gotten my dyno pull on a disk so I could post it. I have larger injectors, and my torque and hp figures spiked pretty hard, and then torque dropped immediatley, while horsepower stayed pretty flat but declining thru about 6k. I make my major power between 3k to 4.5k or so. I would have been easier if the guy had me set up as a 6 cylinder rather than a 4. I was like, I know I wasn't turning my engine to 10k rpms.

 

I think the cam would help extend the power band further, and especially once the torque and hp lin cross at 5250 or so.

 

So lets say it hits hard about 3.2 k or so, and stayes pretty flat out to 6 or 6.5k. I could live with that. I don't want to be turning mine to 7.5k. I like my stuff to stay together and went thru enough piston rings when I was normally aspirated.

 

What we really need is to get someone to make us some roller rocker arms, and a cam that will work with them. I think there is plenty of room in the head to do that. and probably power to gain, not to mention friction to lose. Imagine how quickly we could snap the valves open and closed with a roller profile. It can't be that hard to do for someone like crower.

 

As you can see, I have a lot of time to think up idea's.

 

If I hear anything, I will let ya'll know. I may have to break down and call Clark at JWT. It would be handy to come up with the spec's on all the L series cams though. I bet some people in SCCA would know or would like to know.

[Lockjaw]

Hey sleeper, do you have a stock 280zxt ecu? If you do, I hate the way those shut down.I had a stock ECU that would go to 7k or better, but usually only right after I changed the cap and rotor. Go figure. The way those things shut down, you hit and you lose the race unless it is a really slow car.

 

My JWT box has a 7k one, although Clark told me he could set it anywhere I wanted. I may change it a little if I get a larger cam. It is much softer when I hit it than the stock ecu.

[Guest Tom Scala]

Lockjaw,you are correct. The 83 cam is identical to the 82 but has 4 degrees advance ground into it. It would have been easier to understand if I'd just said it that way in the first place. I thought about going with an aftermarket grind but the cost of new Nissan rockers scares me off. I don't know if it would be worth it in $/HP. If I did go that route I'd like to try a wider lobe spread than what is currently available for the L6. Most blower cams have 112-114 LDA's compared to the tight 108-110 you see for our motors. The wider angle would keep overlap down and let you run more duration without hurting the idle. It would also have a broader power curve and RPM higher. Maybe someday...

[SleeperZ]

Very interesting stuff about the stock turbo cams. The one I'm using now with intercooler and 12 psi really seems to run out of breath over 5000 rpm, especially compared with the cam in the P90 I ran last year. The turbo cam (Schneider) would pull hard to redline - I hit the fuel cut on the ECU many times.

 

BTW, the specs on the Schneider I used last year (and will again, soon as I swap off the head) is 114 degree lobe separation, with intake/exhaust duration (0.050" cam lift) of 240/230 with valve lift of 0.460" (intake and exhaust). I'm really happy with the cam now that I've compared it to factory. Of course the cam needs special lash pads and springs along with valve geometry re-setup.

[Lockjaw]

Comp cams has come back and said they would rec that I run one they offer, although the felt like opening up the lobe centerline to 112 deg would be better. It spec'd out at 214 deg at 50 with .420 lift. Said would give me power from about 1000 up to 5500rpms, which would have to be better than stock.

 

189.00 and it takes 3 weeks to do it since it has to be nitrided or something. I am thinking about trying it.

 

I told them I did not want one that loped at idle, and I wanted to be able to pull cleanly to about 6500rpms.

[yo2001]

I found this on the web. JUN

 

I don't know how much this helps but it's got numbers. I called Topend and they have turbo cam kit for turbo too. I didn't get the spec.

[randy 77zt]

i have not tried this yet but 90's ford ranger 2.3 had rollar cam followers.i will have to get a ford part and try it on my spare motor.

[Lockjaw]

Yo2001 I would be curious to see what the Jun specs are, and the price.

 

TEP cams are big, and what I was after was a cam that would go in the head without needing a spring and retainer swap.

 

As far as that roller follower, I am very interestd in that idea. If it was a ford part, that would be cool too. I better not get my hopes up, because that would rock, roller rockers in a Z motor. That would have to really reduce friction, and should be quieter too. I wonder if I would have to have someone grind a cam for it that is diff than the stock type cams.

 

PLease let me know about the rocker arm deal.

[Lockjaw]

I was told this weekend that Malvern Racing has roller rockers, and they are expensive. Unverified at this point.

[Lockjaw]

Verified, and my source is evidently a not so brite 240Z owner. You would think someone who had a turbo engine and an SDS engine management set up would know his stuff. I guess someone else could have put the SDS and engine in there.

 

Oh well, the rocker arms are not for the L series engine.