Swazo, I have SVT heads PNPed with 3L valves (brand new 20k ago), thoughts on that with aftermarket cams?
With the lack of any real world data (...that I have found. Not to say people haven't done this. I'm sure I just haven't looked hard enough. I'll be searching a bit more for info from across the pond.) on anything other than OEM cams, me pointing you towards a cam at this point would be the blind leading the blind. lol Cat Cams produces these cams, I would wager people have used them.
If you had a any generation of any popular performance oriented engine out there other than Duratec V6's, cams are some of the first things people change. OEM cams are generally thought of as detuned POS. Until real world data is collected, somebody is going to have to be the test rat.
I'm going to be buying an already modified Contour that pretty much has everything I want to back a cammed 3L with. I'm going to just pay a shop to take the liability aspect out of this, (use an experienced modular engine builder) and assemble the components I've assembled together with input from the cam manufacturer and the machine shop. No rush and no timelines to meet, just a desired end product. When said engine is built, the CSVT's existing engine will get replaced with it.
I know a bit about cams, but there are a few variables when it comes to picking out an ideal, modified cam profile. The cam manufacturer is going to have the best idea of which profile to use for your application/expectations.
I'm guessing here, but if I were in your shoes and didn't want to do all of that....... SHOsource's cams stage I cams don't sound like they're deviating too far from the SVT profile. If that's the case, there is a good chance they could pop right in without any mods and just a good engine builder. It might be some additional and minor relief cutting on OEM pistons, at most.
1.
Since it seems like you know a bit about cams and such, or if there is anyone else that has some knowledge in this field feel free to chime in, would the ST220 valve springs be sufficient enough for any of the aftermarket cams out there? I thought I read something somewhere about those valve springs that they were stiffer than the SVT ones. I can't remember how much stiffer.
2.
If those cams from shosource are going to have to be re-grinded (sp?), how can they be retreated?
3.
And Swazo again (lol), I'm going to be doing a full 3L swap with an ST220 UIM and maybe some light headwork (though I'm not sure on the latter), what were your thoughts be on aftermarket cams?
Sorry for all the questions man lol. Just want to be informed
1.
I honestly would not take a chance on the ST220 springs unless you know how much lift they can handle. IIRC, their stiffer aspect makes them more desirable because there is that much less of a chance that the valves will float when engine breaking/down gearing @ higher RPMS, FI applications, etc. They're still an OEM spring that isn't likely going to be able to handle additional lift that an aftermarket performance cam will have. That's a guess though, I'm just getting back into Duratecs and have to refresh running knowledge.
2.
If they are regrinding OEM cams, there is only so much changes you can make on an existing cam. You can't add more material, you can only take away what's already there. But, from what I recall, rehardening the cams wasn't an option. This is one of many things I have on my list to verify.
3.
Head work is crucial. Untouched OEM heads are a MUCH better choice than it is to have gasket matching, all out hogging without keeping port traits intact, not CC matching EVERYTHING, not keeping intake to exhaust port size ratio damn close to OEM.....
Even with OEM cams, you can get
nice gains with good port work. The more the cam flows, the larger amount of porting is needed and eventually valve size will have to increase.
Didn't the 04+ 3L's have the same cams as the ST220? That's the route I would go for an oval port head and ST220 springs.
