Timing and performance cam
Thread Starter
Senior Member
Joined: Mar 2011
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Timing and performance cam
Anyone know how a non stock cam affects timing? My 95 5.0 has a Crane Cams sticker under the hood, so it apparently had a performance cam installed when the previous owner had it rebuilt. It doesn't lope, so it's probably pretty mild. Does a cam require any compensation one way or the other timing wise? Everything is in place for the timing bump, but haven't advanced it just yet
Thread Starter
Senior Member
Joined: Mar 2011
Posts: 103
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I would agree if the sticker were outside the vehicle on a window or bumper, however, it is on the underside of the hood right next to the engine and vacuum stickers from the factory. I know the previous owner pulled a construction trailer with it both before and after it was rebuilt, so it would make sense he wanted better performance and had a mild cam installed.
His FIL had the truck when I bought it, so I never spoke directly with the owner
His FIL had the truck when I bought it, so I never spoke directly with the owner
Hi-Rev Motorsports
Joined: Aug 2009
Posts: 4,898
Likes: 65
From: Northern Indiana
you dont have to pull it down.... you can very easily profile the cam using a dial indicator and pulling a valve cover....
The easiest way to tell would be to hook up a vacuum gauge and check idle vacuum... anything bigger than stock will have lower idle vacuum...
Other than that the answer to your question is NO it doesnt affect timing much... it can however make it more sensitive to timing...as in how much it can handle... no different than other things though like engine temperature, Fuel charge, dirty injectors, operation of the EGR valve and so on.... and the fact that every engine is different and other may like more timing that others and some wont tolerate near as much.... type of fuel used plays a role too...
The easiest way to tell would be to hook up a vacuum gauge and check idle vacuum... anything bigger than stock will have lower idle vacuum...
Other than that the answer to your question is NO it doesnt affect timing much... it can however make it more sensitive to timing...as in how much it can handle... no different than other things though like engine temperature, Fuel charge, dirty injectors, operation of the EGR valve and so on.... and the fact that every engine is different and other may like more timing that others and some wont tolerate near as much.... type of fuel used plays a role too...
Thread Starter
Senior Member
Joined: Mar 2011
Posts: 103
Likes: 1
you dont have to pull it down.... you can very easily profile the cam using a dial indicator and pulling a valve cover....
The easiest way to tell would be to hook up a vacuum gauge and check idle vacuum... anything bigger than stock will have lower idle vacuum...
Other than that the answer to your question is NO it doesnt affect timing much... it can however make it more sensitive to timing...as in how much it can handle... no different than other things though like engine temperature, Fuel charge, dirty injectors, operation of the EGR valve and so on.... and the fact that every engine is different and other may like more timing that others and some wont tolerate near as much.... type of fuel used plays a role too...
The easiest way to tell would be to hook up a vacuum gauge and check idle vacuum... anything bigger than stock will have lower idle vacuum...
Other than that the answer to your question is NO it doesnt affect timing much... it can however make it more sensitive to timing...as in how much it can handle... no different than other things though like engine temperature, Fuel charge, dirty injectors, operation of the EGR valve and so on.... and the fact that every engine is different and other may like more timing that others and some wont tolerate near as much.... type of fuel used plays a role too...
I did hook up a vacuum gauge and did notice lower than usual vacuum. My gauge has no measurement between 15 and 20 inches, just the red and green sections on the dial. Vacuum holds steady at the bottom edge of the green, so I'm guessing just about 18 inches at 10° BTDCYou think it would be ok to go ahead with the timing bump with the mild cam? Plugs are gapped at .055 new wires and HE coil in place. just haven't tried advancing the timing yet