Camshaft Feedback???

[kenm78]

I was recomended my Comp cams to go with the XE 268 cam they offer for my 383 Stroker. I understand they are the pro's but I want to know real life opinions before I make a comentment on this cam. I have a 71 C10 WLB about 4400 lbs,3.42 rear TH350 trans with possiblilty of upgrading to a 700r4 or a gearvendor add on. I am going with the edelbrock EPS intake and going to go with the Holley 670 street avenger carb. I have MSD ignition. My heads right now are 76cc ported still working on polishing (my first time performing this boy very time consuming) , I just need a valve job and guides installed before they are completely ready. I am building this not as a daily driver but when I want to drive it, it will have decent street manners but pleanty of power to hold its own. Should I go with this cam or should I use somthing else?

[fnoblitt]

i had that same cam before . and i was not that impressed. i prefer the lunati voodoo cams. they make one with similar specs as the 268 . but with way better results. just my 2 cents.

[Billla]

This is a link to the cam card if people want to review before giving feedback:

http://www.compcams.com/Technical/Se...umber=12-268-4

[kenm78]

Billa what is your opinion?

[Billla]

Originally Posted by kenm78

Billa what is your opinion?

I made a comment on your other thread, but overall the lift is on the mild side for a 383 but very driveable. It's more suitable for higher RPM power than low-end torque, if that's what you're looking for.

[kenm78]

Good to go, Thank you.

[kenm78]

Billa What would you use for my app?

[1970 CST Short Wide]

IF you go with the Comp, I'd like to hear from you on any noise issues it may have. Every NEW (not the 10 year old ones) Comp I've tied was VERY noisy for a Hyd. I switched to Lunati and have NO noise issues at all. Just my 2c

[kenm78]

I ran a Comp Cam 280H for about 6k and it didn't make any strange noise. switching cams becouse I want more engine vacume for power brakes.

[Billla]

Originally Posted by kenm78

Billa What would you use for my app?

You need to start by really drilling down on what you want from the engine. What's your cruise RPM? What's the maximum RPM you see on a daily basis? Towing important? I'm happy to make a recommendation with a bit more background, and I HIGHLY encourage you to call CompCams or fill out their online template to get their reccomendations too - then you can balance all this information and make the right pick for you. There's a science and art to cam selection and while everyone has their opinons (me too it's important to balance what you hear as anecdotal recommendations with information from the pros.

http://www.compcams.com/Information/CamForm/camform.asp

[mnunn454]

Originally Posted by kenm78

I was recomended my Comp cams to go with the XE 268 cam they offer for my 383 Stroker. I understand they are the pro's but I want to know real life opinions before I make a comentment on this cam. I have a 71 C10 WLB about 4400 lbs,3.42 rear TH350 trans with possiblilty of upgrading to a 700r4 or a gearvendor add on. I am going with the edelbrock EPS intake and going to go with the Holley 670 street avenger carb. I have MSD ignition. My heads right now are 76cc ported still working on polishing (my first time performing this boy very time consuming) , I just need a valve job and guides installed before they are completely ready. I am building this not as a daily driver but when I want to drive it, it will have decent street manners but pleanty of power to hold its own. Should I go with this cam or should I use somthing else?

Your choice of transmissions is (IMO) perhaps the biggest factor you've listed because it makes a 30%+ difference in final drive ratio (FDR) and therefore 30% diff in highway cruising RPM. Depending on tire size, if your FDR is less than about 2200, you'll certainly want a cam that will have minimal overlap (wasted fuel) plus a manifold/intake runner combo that still has good airflow (velocity) somewhere below the highway RPM level. The larger the porting and more aggressive the cam, the more you risk sucky/inefficient performance at highway/daily driver cruising speeds.

For a rough comparison, (Granted it's a BBC) but my 70 Elky has a Comp 262-H cam with 700-R4 trans and 3.55 gearing. It pulls just fine at 55-60 MPH/2200 RPM and up, and gets approx 12MPG. The 268H is a little more aggressive than that.

One other thing. I've heard that COMPs XE series cams are specifically designed to optimize the lower RPM levels and that they do this primarily by advancing the cam centerline by about 4 degrees.

Bottom line is I think you should be fine with your current trans and the XE 268-H, but may have to change cams again (get a little more conservative grind) if/when you go to an O/D tranny.

[kenm78]

Comp Cams are the ones who recomended the XE268. I am going to drive this truck pretty good not drag on every stop light to stop light but still getting into it on a freq basis. I am crusing at 70mph at 2800 rpm. I might will tow my 16 foot boat and use it to move odds and ends but nothing really serious. I am thinking of upgrading to a overdrive so I don't know when that may happen so as of now I am stuck with the TH350. I will be operating my engine estimated 1000-5500 rpms I never went over about 5700-5800 RPM with the Comp 280H cam.

[kenm78]

Thanks for the input mnunn454

[Billla]

If that's what you got from CC, I'd go for it and stop worrying As I said, it's a bit mild on the lift side, but that helps low-end torque. My gut from the cam card was that the power band was more on the high side, but understanding that 4 degrees of advance is ground in (thanks, mnunn454) makes sense.

Originally Posted by kenm78

Comp Cams are the ones who recomended the XE268. I am going to drive this truck pretty good not drag on every stop light to stop light but still getting into it on a freq basis. I am crusing at 70mph at 2800 rpm. I might will tow my 16 foot boat and use it to move odds and ends but nothing really serious. I am thinking of upgrading to a overdrive so I don't know when that may happen so as of now I am stuck with the TH350. I will be operating my engine estimated 1000-5500 rpms I never went over about 5700-5800 RPM with the Comp 280H cam.

[kenm78]

Good to go.

[kenm78]

Has anyone every used the XE268 in a sbc or 383 if so what is its real world charictoristics? GOOD BAD UGLY???

[bryanw1968]

Originally Posted by 1970 CST Short Wide

IF you go with the Comp, I'd like to hear from you on any noise issues it may have. Every NEW (not the 10 year old ones) Comp I've tied was VERY noisy for a Hyd. I switched to Lunati and have NO noise issues at all. Just my 2c

I am running the Comp XE268 and I like the performance. However, it is a noisy ass cam!!!!! It is considered and aggressive cam and the exhaust valves slam down very quickly and make noise. Roller rockers and aluminum valve covers make it all even louder. It almost sounds like my rockers are all loose.

Great cam but loud. I would probably go with the Voodoo next time just because of the noise.

[Billla]

Originally Posted by bryanw1968

It is considered and aggressive cam

Agressive = steep ramps on the lobe profile.

[mnunn454]

Not to steal the thread, but I've been hearing a noise I can't ID with my .500 lift Comp XE262H cam on my Elky's 454. Thought at first it was lifters that needed adjusting, but they were all fine. Had never thought of the cam profile. Comp Magnum cam in the C-10 with .550 lift is quiet as a mouse. Hmmm. Thanks for the idea. I'll check it out.

[1970 CST Short Wide]

mnunn454:
I can almost guarantee you the noise is from that cam. I had 3 diff comp things in my BB and could NOT get rid of the noise. I went with Lunati Voodoo and NO noise AND I like the performance better. PLUS the warrantee guy at comp,his name is "RED", is a real, well lets just say we didn’t see eye to eye.

Good