Cams

[drew_shipley]

So I won a set of Patriot Performance Billet Cams for my Bullitt. From the look of their website I'm assuming this is the specs on them:

233/237 @ .050 Duration .545"/.550" Lift 113 LSA

I was wondering if anyone had them and what they thought of them? What kind of power gains should I be looking at? I'm considering installing them myself, but I'm sure I'll need a tune afterwards. How hard is a cam install on the 4.6 SOHC? How long does it typically take?

 

[TGJ]

To install the cams correctly, which means degreeing them in and checking for PTV before you start the car will take some time. At least 6 hours, and probably more. I know a lot of people can say you can just drop cams in, especially VT and not have any problems. However that is a gamble I wouldn't want to take.

There is now quite a few cases of PTV contact with cams installed that were not degreed in, including VT's. Some of the cars did not show any sign of PTV until, parts of the heads or the heads were destroyed. Some of the cam grinds installed with PTV that showed no signs until serious damage was done are:

Comp 262AH
Comp 270AH
VT Stg II N/A cams

The cases with the VT's destroyed the heads.

 

[hotmustang331]

And it should be noted that the reason the comps do it, is because of their ground in advance (like 4*s) then the factory gears can be off like 3*s, so you are looking at a possable 7+*s of advance if your the unlucky one with the cam gears that are 3+. That will easily cause PTV contact.

I have heard of 0 PTV contact with VT stg 2s, and its pretty much impossable with stg 1s.

 

[TGJ]

And it should be noted that the reason the comps do it, is because of their ground in advance (like 4*s) then the factory gears can be off like 3*s, so you are looking at a possable 7+*s of advance if your the unlucky one with the cam gears that are 3+. That will easily cause PTV contact.

I have heard of 0 PTV contact with VT stg 2s, and its pretty much impossable with stg 1s.

You can order the Comps without the advance and if you install them properly( Degree them in ), you can retard the advance out.

I have seen the Cam gears out as much as 6 degrees. This is the reason that you degree the cams in, or at least check them.

I know of quite a few cars having PTV with VT Stg II cams. There is 4 cases of it on MD. Now after the recent case of PTV of VT Stg II N/A cams, I am wondering how many other VT stg II cammed cars have PTV and do not know it. This car had ran fine for months, then one day, the car ran like crap. Upon teardown the car had destroyed one head and every piston on that side had valve marks on the piston. Taking apart the other side, the car had bent valves and PTV.

Now as people continue to install cams without degreeing them in, it is going to happen more and more, regardless of who makes the cam. Some of those cars that have been "Lucky" are going to break. All I am telling people is to degree the cams in, regardless of who makes it. I am not going to argue with people who thinks it is not important to do it right, it is their car and their money. I will have no sympathy for someone who took the shortcut and break later.

 

[VividDreams]

ok, i think i have a general idea, but how do you degree the cams in? need any special tools?

 

[TGJ]

An excellent thread on MD on how to degree cams and the tools needed.