Contour Enthusiasts Group Archives Forums Modifications 3.0L Duratec 3L hybrid and high lift cams??

can anyone tell me if i will bend my valves if i run a high lift cam?? the cams i want to run are cat cams 10.7 lift. ive tried to ask so many people and noone has given me a final answer. thanks

Do you have the cams in hand? Theres been some debate that they dont come with gears, but I havent seen anybody thats running them.

btw, might want to read this first before considering them.
click me

You could be in for some bad clearance issues.

The 3L clearance is much less then the 2.5L clearance to begin with and the CAT cams are made for a stock 2.5L (not even an SVT with the domed pistons)

That means they are made for the smaller valves as well.
Half of 3-4mm doesn't sound like much but when your safe working clearance is in hundredths of an inch it can be a mile.
2mm = .08" Offset that by the angle of the valve and it still means clearance is tight. (without the actual valve angle handy a guess would be around .015")
The 3L did change to relieved pistons for a reason. Clearances are terribly tight.


The maximum milling clearance of a stock 3L head is .01" and that is really pushing your luck. The safe limit is .006"


I personally know you can run a small increase in effective lift on the 3L but a 1mm jump is a lot.

Hey Demon,

Knowing the tolerances are soo tight for lift, are there any benfits for increasing the duration, or do we begin to run into increased overlap issues. I know this has been discussed, but wouldn't longer duration with adj timing gears for the V6 be of benefit, or would it?

Just thinking out loud again.

Who makes adjustable timing gears though?

Also adjustable timing gears only prolong or hasten the curve of said camshafts. They don't really alter their primary power curve shape.

For certain applications that could be benefitial. (i.e. stock or oval port cams)

For instance retarding the oval port exhaust cams on a boosted engine.

For a NA application to better using the SVT cams you really need to change to a completely different set of camshaft profiles. Like the CAT Stage 3 cams. (or Stage 3/2 combo)

Do the cat cams have a longer duration??? I can't find any info on them (or I didn't look in the right place)

www.catcams.com



They have come up numerous times. Plenty of juicy info found with the search feature.

Thanks, I think my fingers are broken or something.

partnr.
duration
duration
maximum lift
lift at TDC
parts
application

[data link]
[0.1mm+cl]
[1.0mm+cl]
[cl=0]
[cl=0]
[-]
[-]

O.E.M.
258 / 264�°
212 / 214�°
9.75 / 9.70mm
1.05 / 0.80mm
O.E.M.

HYDR: O.E.M

2394062
257 / 257�°
218 / 218�°
10.20 / 10.20mm
1.30 / 0.95mm
O.E.M.
HYDR: sport

2394064
264 / 264�°
226 / 226�°
10.15 / 10.15mm
1.75 / 1.30mm
O.E.M.
HYDR: sport

2394066
271 / 264�°
234 / 226�°
10.65 / 10.15mm
2.25 / 1.75mm
O.E.M.
HYDR: rally & cross

2394068
280 / 271�°
242 / 234�°
10.70 / 10.65mm
2.75 / 2.25mm
O.E.M.
HYDR: rally & cross

2394070
288 / 280�°
250 / 242�°
10.65 / 10.70mm
3.30 / 2.75mm
O.E.M.
HYDR: rally & race

This is off their site. It does not look like you can get a longer duration cam without increasing lift at all, without a custom regring. Maybe I'm reading it wrong but are those lifts safe???

the most aggressive ones are 106 lobe seperation which is great for NA but bad for F/I. the lesser ones are 110 which, is not to great for F/I. the optimum would be 112 to 114 for F/I.