xe-266 and p head questions

[5.0tbirdguy]

I'm really taking my time before finishing my Explorer motor. Don't want to do anything twice. I ordered a set of rev 1.85/1.54 valves for my p heads. The stock valves had very little margin. Should I use the exhaust valves as is or cut them down to 1.5 or 1.46?

Was planning on a cheap tfs1 cam.
After all the the research on inexpensive cams I've decided they aren't worth the risk. Comp is inexpensive compared to custom, but supposedly with better quality control. They recommended the xe266 for my combo, but that was before ordering the larger exhaust valves.

With the extreme ramp of the 266 will I need screw in studs instead of pedestals? Will the valvetrain be durable for high mileage? Like I said I don't want to take anything apart to upgrade one the motor is in.

 

[aleborjas]

i'll run that can that cam its very good i dont think you need to change valves because that cam has good lift and duration.....

 

[87'GTstang]

When you are referring to screw in studs compared to pedestal, you are talking of a different rocker arm setup. If you have pedestal, you can probably stick with it if you'de like. Most convert or when they buy new heads they choose stud mount due to easier adjustment and less powerloss due to friction. If you already have it, then use what you've got from a budget standpoint.

The XE series cams are rather nice. I am currently installing an XE270HR cam in my shortblock. Basically with compcams, the higher the H/HR number, the more wilder it gets - 266 is by no means crazy. You should be fine, but what you should worry about is weather or not you have enough spring pressure to close the lobes on the XE cam. What spring pressures are you running currently do you know?

 

[5.0tbirdguy]

I haven't bought the valvetrain yet. Hence the questions.

Ran the xe266 on dyno2000 and can't find a stronger all around cam for my generic p head airflow.

The valves came today and will give a 1.750 installed height. Looks like cutting the exhaust seat bigger would be better than using a smaller valve.

I will use the comp 986 springs or a stronger equivalent with 1.750 installed height. The xe266 has .555 lift , so that is where the durability question comes in. Very short duration for such high lift. I don't care if it ticks at mid rpm as long as nothing breaks at 6000 rpm.

I'm thinking Scorpion 1.6 pedestal rockers might hold up? I'm pretty sure anything over .560 lift pedestals are out and .555 is real close. Would '89 model aluminum factory valve covers fit with studs? I've started polishing a set and really want to use them with the steel/rubber gaskets.