I'm about to pull the cams out of my P5 and send them to Crower for a build up and agressive regrind, but if anyone has swapped out their OEM cams for the J-spec and still has the OEMs laying around, I'll buy them and send those instead. That'd cut down on the time I'd be without the car. How's $40 a piece sound. I'd even send my OEMs back to you when I'm done.

I'd also will need to give Crower the profile specs to grind to. Does anybody have an idea of how much lift I can get on the stock valve springs without float or bind? How about duration and over lap? I'm thinking about 233 intake/225 exhaust, and adjusting in about 6 degrees lap for starters. The head will be cc'd and decked for 10.5:1, and lightly ported, maybe extrude honed too. Any ideas?

 

you should get the j-spec intake cam from the fsze and mazda motorsports exhaust cam. Mazda motor sports has them both . Ive installed both in my car . My p5 rips. Im in the proccess of installing the 10.5.1 fsze pistons soon. but of course to each is own, good luck.

 

Well Boost, if you installed the J-spec cams, what happened to your stock cams? Doesn't $80 for the pair sound good? It'll amost pay for the pistons.

As for the fsez and Mazda cams, I'm sure they're better than stock, but done right some extra diration would be even better. If the lift and ramp remain no more aggesive than the stock or J-spec cams, there'd be no more float or spring compression then there is now. Being able to add overlap will really wake up the top end too, but redline would still be the same.

And there's nothing wrong with decking the head to raise compression, it's a whole lot easier than swapping pistons, and cast ones at that. Of course I'll have to get the head off and check the cc's first, but I think there will be enough volume.

I know what i'm doing, but even so I'll will still be waiting on a good header before donig anything.

 

did you replace the valve springs too??....do you have to if you get the fs-ze cam?

 

Boost--
How hard is that install? I've done it on other v8's but not an dohc engine/

 

Its not hard with the proper knowledge and tools. if you know about top dead center and timing then its cake if you dont stay away and let a pro do it. As for the springs i'm using stock fs-de springs with fs-ze intake cam and mazda motorsport exhaust cam no problems yet . cams make big dif with good intake and exhaust.

 

What about setting the timing? Is TDC marked? Are the cam sprockets adjustable? I agree that the job is not that hard but how is the time set? Also do the valve springs from the hotter engine have an increased weight? Just too many darn questions!

 

Yes, there are markings on both cam sprockets. The sprockets are not adjustable, and they have a trigger for our engines' cam position sensor. A specific application would need to be made for us to get adjustable cam gears. The difference in weight of the valve springs would be insignificant. They would have stiffer springs rates, that would allow the engine to rev higher without experiencing valve float.

 

If someone can give me the following specs of the FS engine:

-bore and stroke
-hydraulic or solid lifters
-stock cam duration and overlap, and opening angle if available
-FS-ZE cam duration and overlap, and opening angle if available
-stock revlimit (6750 rpm?)

I can run it on my Dyno2000 engine simulator.

It may come up with a suggested cam duration .
Zeus, what is your desired revlimit?

 

Bore & Stroke: 83 x 92mm

Hydraulic or solid???

Stock US (intake/exhaust)
Valve lift .341/.323, Duration @.050 198°/200°
Japanese version
Valve lift .344/.323, Duration @.050 210°/200°

Stock revlimit ~7000

 

TheMAN, stick this in the FAQ, when you get a chance.

 

Where did you get the specs on the FS-ZE intake cam? Even Mazda Motorsports told me they didn't know what they were.

 

It was in a previous post. Obtained from a aftermarket cam company, I think.

 

i had those specs sent to me by webcams.

 

Thanks for the replies. I need some more info so I can run the simulation:

-Valve diameters
-Compression ratio
-Peak power @ ?rpm
-Peak torque @ ?rpm

Ditto for the Japanese version.

Thanks!
Jason