Question about J-Spec Intake cam upgrade

Gavin

Member
Ive purchased an FS-ZE intake cam from CorkSport thats on its way to me now. My question is in regards to what I should do with my stock intake cam once the J-Spec unit is installed? After doing a quick search Ive read that some people have re-pined it and used it as an exhaust cam (since it has better lift). But after looking here: http://web2.airmail.net/theman/protegefaq/

I read the following:

Note that the stock intake cam has lift of .341, and a duration of 198 @.050. While the stock exhaust cam has lift of .322, and a duration of 200 @.050.

If using the stock intake cam as an exhaust cam nets me slightly better lift, but does so at the cost of 2 of duration, am I going to wind up improving my power at all in the end? If anyone on this board has set their car up both ways (i.e. installing a J-Spec intake cam by its self first - and then later re-pinning and swapping the previously removed stock intake cam into the exhaust cam slot) Id love to hear your feed back on J-Spec intake & stock exhaust cam performance vs. J-Spec intake & re-pinned stock intake (used as exhaust) cam performance.

Also Ive read that there is a possibility of using an adjustable cam gear (taken apart and rotated approximately 180) to get around having to re-pin the intake cam, if you swap it to the exhaust side. Has anyone successfully done this yet?
 
the lift more than accounts for the 2 degree loss in duration.

the exhaust pin isnt 180 degrees opposite. i wouldnt recommend doing it that way. best way is to take the old intake and exhaust cam to a cam shop and have them put in a pin in the intake cam that's the same spot as the exhaust cam. far more accurate
 
What about buying a second J-spec intake cam and having that re-pined as an exhaust cam? Better lift, better duration, seems logical. Anyone see any drawbacks to a set up like that (aside from the fact that I could have ordered both at once and saved myself a second shipping fee)?

I suppose cold weather idle could be a bit rough perhaps?
 
twilightprotege said:
the lift more than accounts for the 2 degree loss in duration.

the exhaust pin isnt 180 degrees opposite. i wouldnt recommend doing it that way. best way is to take the old intake and exhaust cam to a cam shop and have them put in a pin in the intake cam that's the same spot as the exhaust cam. far more accurate

I'm a little lost on this, I also have the intake and want to understand this better. Do u have any diagrams?
 
gavin - a j-spec intake cam repinned = mazdaspeed exhaust cam. it's what shaneracing does for the mazdaspeed exhaust cam they sell.

crazee - if you have your old intake cam lying around, take it and your current exhaust cam to a cam shop. tell them to make the pin on the intake cam the same as the exhaust cam and that's basically it. real easy
 
Thanks twilightprotege, I think a repinned Jspec intake to exhaust cam is the way I'll go. I wish I had figured this out before I placed my order for just 1 Jspec cam though
 
twilightprotege said:
gavin - a j-spec intake cam repinned = mazdaspeed exhaust cam. it's what shaneracing does for the mazdaspeed exhaust cam they sell.

crazee - if you have your old intake cam lying around, take it and your current exhaust cam to a cam shop. tell them to make the pin on the intake cam the same as the exhaust cam and that's basically it. real easy

I wish I knew if there were these "cam shops" around here. I bet my dad would be able to do it, he's a toolmaker. I assume he can do steel, he mainly works with carbide but does some aluminum and steel.
 
KanseiZM said:
I wish I knew if there were these "cam shops" around here. I bet my dad would be able to do it, he's a toolmaker. I assume he can do steel, he mainly works with carbide but does some aluminum and steel.

Or you can send your cams to Crower Cams for a regrind, that is if you have an extra set in the garage.

I don't have my exact specs with me at the moment for my regrinds.
 
65racecoupe said:
Or you can send your cams to Crower Cams for a regrind, that is if you have an extra set in the garage.

I don't have my exact specs with me at the moment for my regrinds.

(shrug) I have my FS-DE intake cam sitting in the garage, let me know about your regrinds.
 
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