Hi mate, Look accoarding to Mr Wolf the JWT cams can be fitted with the cams in situ. In fact they are designed with smaller base circle to allow for this, and the hydraulic lifters are supposed to take up the extra clearance. Whether or not you think this is a good idea is up to you, but that's their line. Why are you fitting upgraded valve springs if you're running standard cams? You'll make plenty of power (and smooth, easy to tune, nice idle etc etc) with standard valve train and standard manual cams.
See this is what I'm stuck on, exactly what work to the Heads needs to be done to be able to install JWT +400 Cams (if there needs to be, see next bit), either now or later down the road? And to clarify, you're saying I can just install the JWT with no dramas later on and that they're actually designed for it? Because if that's so BEAST is saying otherwise or did I misunderstand you? Reason I'm going with the chosen kit as it'll best match the extensively ported heads. I can't use standard valves anymore, inlet and exhaust have been open up by 1mm. Happy to be told otherwise...? From first post in link to Heads: MoulaZX
Here's something to help with that / those voices: Sell off the Ferrea kit & stick to the stock manual cams & valve springs - keep the power band low, not shift it higher. As I've said before - there's only about 10hp peak gain by going from the stock manual cams to the JWT 400+ - as told to me by Greg Dupree after running back to back dyno tests. You saw how my car went when it was only on low boost - I had a fair bit of traction issues. How much power do you need? Also, what's the total cost of getting the 400+ cams (if you do go that route), combined with what you've paid for the valve & spring kit? there's 2 and a half grand man - for what? 20hp? - save yrself the money man! If you haven't already purchased the valve & springs kit, I would just stick to manual cams & stock cam gears & not worry about the stiffer valve springs - as you can see this caused cam gear chatter on start up on mine. Have a few more drives of my beast this wkend at Arv's & make up yr mind from there. My 2 cents
I would go 100% along with you if I haven't been kinda forced to now go 1mm over sized valves. Ideally I would love to be able to run larger valves with Standard Springs, Cams and Cam Gears and still achieve similar power. And yea, mate I'm counting down the minutes lol... don't believe me? At this very moment, theres 3781 minutes to go, assuming I drive it on the dot at noon on Sunday MoulaZX
problem with the other advice given is that you have big ported heads and have to run oversize valves ..no turning back So R4+ is better than stock cams in this application
I'll give you the cliff notes version If you fit new high lift cams from Jun or Tomei (or other Japanese derivatives) you need to relieve the recess that the cams sit in to accomodate the larger lobes. This means that fitting new cams is an engine out, heads in pieces job. If you have a look through my build thread there is a pic somewhere that shows exactly how much material (not much) had to be removed to fit Jun .272 cams. Now the JWT cams have a smaller base circle (at the base of the lobe) so as you can fit the high lift cams in without needing to take an material off the head. Effectively this means that changing the cams can be done with the engine in place. Now here's the rub. Reducing the base circle radius increases the gap between the cam and the lifter. Now JWT say this is not a problem and that the increased clearance is still within range of what the hydraulic lifter setup can adjust for. There have been a few threads about noisy valvetrains where JWT cams have been used on twinturbo.net and I suspect this may have something to do with it. Others do too! There are two was around this issue. One is to machine the valve recess so that the valve sits in a little further, effectively moving the installed height of the valve stem and thus returning the cam/lifter clearance to factory spec. The other is by extending the valves. Either of these options brings you back to the "heads in pieces" scenario. My personal opinion is that if you must upgrade the cams (and it sounds like you would be better off for doing it) then the best time to do it is while the heads are apart and you can do your valve job. Cams are cheap (well cheaper than when I was buying them anyway!) and even if it puts the the build back another month at least you know it's been done right and you won't have to pull it down again.
Thanks, thats exactly what I was looking to hear. Looks like I'll be digging for some more pocket change soon for the +400 and adapter kit. Fark, my Heads are going to be worth multiple thousands... ... hope nothing goes wrong Also just realized something, given the extensive work done to my heads, one would think chances of having the option to still even use factory Cams would be slim seeing as the previous owner shelled out this much for the porting work that they too would have gone with aftermarket Cams... hrm, need to have another look at those heads and talk to Chad again. Now with the +400, where do I stand with any VTC related stuff? Will they still plug in and function correctly? I'm assuming the VTC setting should / will be altered while its being tuned, is this right? Cheers! MoulaZX
Chad! Before I PM ya, do you happen to know what Cams your mate was running in these Heads? If you don't, could you find out somehow pretty please? MoulaZX
There's nothing preventing you from using factory cams, the motor just won't perform as well as it could. If you run the 400+ cams, cam sprocket adapters, and keep your factory VTC cams then yeah you'll be fine. I can't remember if you have posted what ECU you plan to use but most of the "plug in" type for Z32 retain VTC function and yes allow you to program where it cuts in/out. Here's another spanner in the works, if you go h/d valve springs and high lift cams there is a good chance your OEM intake sprockets will chatter (like Sav). Maybe not right away, but it would be worth budgeting for a Brett Dempsey rebuild. See how quickly we can spend your money?!?
Its in the first post of the thread, I'll be sticking for Nistune for now so I believe I should be fine for the VTC Aside from being mildly annoying, does the chatter cause any damage? And if Std Cams were fitted with the 1mm Over sized Ferrea Kit I want to order, will there be any issues (such as chatter or other), aside from a performance limitation? I'm teetering on an edge of either path at the moment. Either throwing my hands in the air and going 'f*ck it, I'm not trying to squeeze every last drop of power out of this, its still going to be a strong build even with Std Cams' and going 'point taken, while I don't mind pulling the engine out again later to fit better Cams, guess it makes sense to do it all now (despite being a harder financial-point-of-view pill to swallow)'. Just would like a safe, reliable build that can break 350RWKW. Can my originally proposed build do this? And also, would it possible to fit just the Ferrea 1mm Oversized Valves with Std Springs, Cams and everything else? Essentially having 'stock' Head components but with the Oversized valves...? Reason for asking, no simpler then $$$, just trying to save some dosh as we all would like to lol. And yea, so easy to spend other people's money huh... (got a good chuckle out of that ) Appreciate all the information by the way! Sorry for all the questions... MoulaZX
Cool, yeah you'll be fine for vtc. I don't think cam sprocket chatter has any adverse effect on the actual motor but I don't think the over rotation can be good for the vtc gears. No issues at all, there's no need to fit the cams, but they would be nice! Everything will fit and function just fine with standard cams though. For sure, and it would be a great car to drive!
just to let you know , what you are doing in my eyes , sounds good . i would put the +1 valves in it , i would leave the stock manual cams . i would open the heads to cater for the big jun came ( just for size ) that is what i have in my zed and im making a healthy 360 RWKW @ 18 19 psi ( it was built to go 25 psi ) im still running the stock valve springs .. .. bigger is not always better . and in my opinion i would not even look at jwt cams.
some good responses for you to think about although regardless of all the opinions it means nothing untill you get these heads into a machine shop and actually get them to check everything and tell you what you can and cant put in there... the heads youve got are ported heads. either way they need to go into a machine shop and everything checked and machined etc... do not go buying stuff unless you have got them into a machine shop first. he will be the only one to tell you exactly what you can fit and cant etc... ofcorse take unboard the information you have got from here but in the end it will all fall down to what the machine shop say about them and can do etc... he doesnt know what cams where used previously with these heads but if you need more information pm me and ill give you his number to call him. dont go doing anything untill the heads are in the machine shop...
