Question about what cam to use

[cholag]

Hello, I want to start off saying that I have searched what I am about to ask and can’t really find the exact answer, but I have a 1983 280zxt with a P90A head. I have noticed a lot of valve train noise and took it to a shop, they said all my hydro lifters are collapsed. So I want to switch to solid lifters, I know I need a solid lifter cam, my question is what is a good stock solid lifter cam to use on a p90a head where I won’t notice a lot of power loss?

 

I did read somewhere, I don’t know if it was this forum or somewhere else, that the n47 cam would work good, if I were to use that cam do I need to degree it or will it be within range of the stock settings or should I get the p90 solid lifter cam?

[ctc]

My posting is incorrect as noted by by BRAAP below. Thank you for the correction

 

...

Edited December 15, 2010 by BRAAP
It's all good. ;-)

[BRAAP]

.... Do not use a mechanical cam in a P90a that has Hydraulic slack adjusters. The opening and closing ramps are different. If installing mechanical adjusters, then use a mechanical cam, if retaining the hydraulic adjusters, keep the hydraulic cam. There has been some discussion on here about performance hydraulic cams for the P90a, not sure if anyone ever followed through and had one ground.

 

...There is a factory N/A cam that that produces more power on the same boost pressure and spools the turbo sooner vs the stock Turbo cam.

Edited December 15, 2010 by BRAAP
All good. ;-)

[mario_82_ZXT]

BRAAP I can't seem to find any of those threads, just "mentionings" that say the NA cam is better (500rpm more usable power).

 

I thought there were different stock cams?

 

Someone said it's good for a mild turbo build. Would it be a step up from the stock cam on a 20psi T4 turbo build? Or a step back?

And out of which years are they talking about?

[cholag]

Thanks BRAAP! Your response answered my question perfectly! I am installing mechanical adjusters as well, I was going to suggest the n42 cam but found out that it isn’t internally oiled and would have more rotational mass then the n47 which is internally oiled.

 

I'll order everything from zbarn tomorrow and I should have it all installed by tuesday, then I'll make a youtube video after the megasquirt gets tuned. I've been working on this build for a while and I hope it will put some power down!

 

Also I will be pushing 14lbs of boost on a rebuilt motor with ARP hardware and rebuilt head plus a lot more.

Edited December 14, 2010 by cholag

[SHADY280]

mario its an "a" or "k" stamp, but cant remember, sold my last one to hoov, he would know.

[BRAAP]

BRAAP I can't seem to find any of those threads, just "mentionings" that say the NA cam is better (500rpm more usable power).

 

I thought there were different stock cams?

 

Someone said it's good for a mild turbo build. Would it be a step up from the stock cam on a 20psi T4 turbo build? Or a step back?

And out of which years are they talking about?

 

 

Howdy Mario. Yes there are few different N/A grinds Nissan used through the years. The stamp on the very back of the cam indicates the grind, the "A" grind seems to be the grind of choice.

 

...

I keep in touch with Rebello Racing on a semi regular basis, in those talks with the owner, the discussion of L-series heads is always the core topic. Being as he has probably more L-6 dyno time than anyone in the country, I personally put a lot of faith in his opinion regarding what does and does not work on the L-6. Regardless of the absolute numbers his dyno declares, it is within those numbers of what combo produces more and most consistently that I’m interested in. In his playing and tinkering with the Turbo L-6’s on the Dyno, he has developed an affinity for the "A" grind N/A cam, even over the stock Turbo grind and even the other over the counter Turbo grinds he has tested. At that there is still room on the table for more depending the specifics and custom cam can be ground to take advantage of the combination as a whole. Ron Iskendarian is a good place to go for the custom Turbo grinds. ....

 

TonyD mentioned in one of those "A" grind discussions, experiencing similar results using that cam in a mild Turbo application.

[mario_82_ZXT]

Interesting...

We might try this out. It's kind of a frankenbuild. 3l turbo build on a cheap chinacharger (61mm compressor with new US made bearings).

 

We had the injectors maxed out at 20psi of boost with 47 lbs base fuel pressure, car was scooting pretty good. Held up for a few months, we just spun #6 rod bearings, broke the rings on that piston, and broke the skirt on #3. Would this cam be a benefit to us, or should we go custom now?

[mario_82_ZXT]

Oh yea, with the carnage I just said there seems to be no damage to the stock piston tops. Is it safe to assume this wasn't detonation damage?

[rayaapp2]

Food for thought,

 

I have been looking into changing my cam for a L24, as Paul knows. I have discovered that sending off your old stock cam(if its still a usable core) to get it reground is uber cheap. In my ignorance I just assumed it was a really expensive thing to have done. Its about half the cost of a new cam depending on cam company. What are you willing to pay for an "A" cam? $100 plus shipping? Delta Cams just quoted me $95 plus shipping. They also offered to do my rocker wipe pads for $3.50 ea. as well. Its been a while since I last bought a good "A" cam though so unless you already have one laying around to play with, you might try calling one of the cam companies for a custom grind quote and see what they offer.

[Tony D]

Oh yea, with the carnage I just said there seems to be no damage to the stock piston tops. Is it safe to assume this wasn't detonation damage?

 

Broken Skirt=detonation

Spun Rod Bearing and Broken Skirt on same Piston=DEFINATE detonation!

 

The things break due to excessive, uneven loadings in the combustion chamber. You split the rods on the main beam when it detonates if you are making enough power and there is a flaw or stress riser---generally if you split a rod, you break a skirt AND usually the rod bearing spins because the oil wedge is jumped and the bearing is pushed hard metal-to-metal.

[cholag]

Ryaapp2, I have an n47 A cam coming, it was cheaper then sending my cam to delta. I did send my cam and rockers to delta when I was doing my build but it looks like it was money wasted, oh well. Overall this whole swap is costing me $200, that's including the timeserts, cam, lifters, and adjusters.

 

My only other question is will I have to shim my cam towers?

[Raami]

This is making me wanna change my F-cam to my other cam which is A.

Is there really big difference?

Both are stock cams as far as I know.