new extreme compcams
- Thread starter 18x10roushes
- Start date
Hey, just want to worn you about them, they sound alot like the 270s that we had( as far as lift and all). Make SURE that you will not have ptv. You may have to have valve releifs cut in your pistons. Just check everything, all numbers, and make sure. Don't want to make the same mistake we did.
nickthegenius
Active Member
18x10roushes said:
Unless you have some nice-sized dishes on your pistons, you may need to pull the pistons to have them flycut.
I have a 302 stroker with ported heads and comps XE278 cams and love them. They make the same power as VT's, if not a little more. I have no piston to valve issues, but am running 21cc dished pistons. Valve reliefs wont make a difference either. PTVC occurs at the edge of the piston on mod motors, not in the middle like pushrod motors. For racing, I recomend XE278, for street, XE270. XE278 are crap below 3,000 rpm, but make huge power up top!
billyfe390 said:
If you install the chains properlly, there is no need to degree the cams. I do reccomend checking the base circle on comp cams though. On some of the older cams (older than 2 years), the base circle was off. I have the XE278's, and have no PTVC problems. There is no need to have valve reliefs on mod motors. The valves will hit the edge of the piston, not the center like pushrod motors.
XE278's run great up top, but suffer below 3,000RPM. VT and Comp both make great cams, and if you look at the specs, they are very similar. It is just personal preference, thats all. Comp has been around a lot longer than VT though.
98 convertable said:
Installing a aftermarket cam without degreeing it in is just stupid. You may not get any more power out of it but you definately know that you didnt slip up timing the cams also you know dam sure that the cams are dead on with the card.
You may take the chance on someone elses workmanship but for me I am not made of money and I dont feel like replacing a short block simply because I was too lazy to do some measuring.
nickthegenius
Active Member
billyfe390 said:
I've heard of people doing this, but how do you keep the cam from turning in the keyway after its been ground out to be degreed? It looks like at some point, the cam could turn inside the sprocket
Or do you just have to torque the bejeezus out of it?Fidanza is releasing adjustable sprockets that would make it much easier, though.
white99gt
Founding Member
nickthegenius said:I've heard of people doing this, but how do you keep the cam from turning in the keyway after its been ground out to be degreed? It looks like at some point, the cam could turn inside the sprocket
Fidanza is releasing adjustable sprockets that would make it much easier, though.
If its torqued correctly it will not move.FYI-cams on the 200 cobra "R" do not have keyways because they are degreed.
Like the others said,if its a new motor check EVERYTHING..
98 convertable- the 270's have showed some PTV contact on ALL year motors.It depends on the piston maker(ford) they used..
im haveing bigboyracing build me the wholr block so they know what there doing. check them out www.bigboyracing.com
cobranos
Founding Member
Ditto on the Comp XE278's.......I run them in a 306 stroker with 16cc dished pistons..........Just do not use these unless you want an extreme lopey idle and tons of power after 2500 rpm........ 
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