xe 262 vs. 268. [Archive] - Chevy Nova Forum

: xe 262 vs. 268.


danthegeek
20th-June-2008, 01:22 AM
Well, i can not go with a Lunati cam because of the high lift rates and I have pressed in studs. they told me they wouldnt guarantee anything unless I had threaded studs with guide plates, so Im going the cheap route for now.

Since Im putting in a 3000rpm stall torque converter in my th350 and i will eventually replace my 3.08s with 3.73s, should i go with a Comp cams xtreme energy 262 or 268. The 262 is supposed to have more low end torque, but since I have a relatively high stall rpm, The torque seems to be almost the same above 3000 rpm and actually peaks with more with the 268. My compression is low at 8.88:1 in my 355. Its a weekend cruiser and fun at the drag strip a couple times a month.

Also, which is your guess that would give me the best E.T. I called Comp and they suggested I use the 268 with the rest of my setup and make about 10-15 more Hp over the 262. They also said it would work great with a set of vortecs if I eventually change heads.

Thanks again for everyones help. I know these questions must be getting old by now :D

teddisnoke
20th-June-2008, 01:33 AM
For many years, I ran the XE-268. With a 350- it had quite a little lope to it, mellowed a bit with the 400. Great cam, pulled hard and produced decent low end torque numbers. I had this cam with my Vortec heads. I never had them re-worked for bigger springs, but ran Comps number 981-16 valve spring. Never seemed to have issues. Well, except for the cam going flat. But many had that problem, and Comp attributed it to a bad run of cams. Still- I have great memories with that grind!!

GerryLP
20th-June-2008, 10:06 AM
I have used the XE268 on my 0.040" over 350 block, and I have it installed currently in my 81 Corvette's engine.

If you have a low compression ratio (CR) on your engine, I would recommend the 262. But if you plan to bump-up the CR (i.e. change heads to smaller chamber sizes), then the 268 is the way to go.

The 268 with a CR lower than 9.5 is tedious to tune, and with CR below 9.0, you're not going to see measurable improvements.

I recommend also paying to have the CR accurately measured (or if you have the tools, then do it yourself), for later on, when you run out of tuning options, you'll be left wondering what's going on, but in fact what you would be probably doing is tuning for the wrong CR. KNOWING WHAT YOUR CR REALLY IS WIL SAVE YOU SOME SECOND GUESSING LATER ON.

GerryLP:cool:

danthegeek
21st-June-2008, 01:13 AM
Thanks for the responses. I appreciate your time. Im starting to lean towards the 268. I didn't want to go with anything to big, but when I put new heads on, I think the 268 would wake things up a bit more. The 262 seems to be awesome in heavy cars with low rear gears, but I want to run 3.73s. Im not to worried about real low end torque since I only drive it once a week or less :o. Lately its been spending more time at the drag strip then cruising. Some say i have "The Fever." :D. I guess worse case, If I order the 268 and dont like it, I could throw in a 262 and save the 268 when I get some worked vortecs.

Thanks again, and if anyone has any input, I greatly appreciate it.

-dan

danthegeek
21st-June-2008, 02:58 AM
Ok, after getting some dyno results from comp's website, I think I will go with the 262. It actually outperformed the 268 :rolleyes: according to comp in the exact same engine.

There dyno sheets are here: http://www.compcams.com/Technical/DynoSheets/

Thanks again for all of the help.

-dan

youngin69nova
21st-June-2008, 06:19 PM
the 262 does out perform it on that engine but the 268 will leave more room for growth

danthegeek
21st-June-2008, 08:54 PM
the 262 does out perform it on that engine but the 268 will leave more room for growth

Yah, I think the 268 would work better with more compression then the 262. Since i have around 8.8:1, I think the 262 would perform nicer and be easier to tune just like Gerry said. That may even be why the 268 didnt do as well as the 262 in that motor, they couldnt tune it. Comp told me i may have some trouble getting the 268 just right, but it would scream :rolleyes:. The 262 should peak around 5000 and pull hard to 5500 (current cam should peak around 4500 and falls flat at 5100 at the track) . They even told me I would gain 20 hp but only loose 5 ftlbs at 3000rpm and gain it all back plus some after 3500 rpm.

Oh well, Im going to replace it when I get decent heads anyways. The 262 should be fun for now. :D

-dan

cr74hb
21st-June-2008, 11:07 PM
If you still want to use the lunati you could just roll pin the studs its pretty cheap and easy you could do it yourself too:)

danthegeek
22nd-June-2008, 01:41 AM
If you still want to use the lunati you could just roll pin the studs its pretty cheap and easy you could do it yourself too:)

They told me even if I pinned the studs they wouldn't guarantee it would work. They said it isnt guaranteed to work unless I had screw in studs and guide plates. Besides, their customer service was rather rude :mad:. But if the comp cam wipes during break in, they said they would cover the cost of a new one as long as the proper springs, retainers, etc were used and it all comes in a kit they offer. The spring pressures are much lower (around 273 open) then the lunati as well. I would have like to try it but it going to cost much more in the long run. So Im going to wait and get a 268 lunati when I get vortec heads. For right now the 262 should be fine and should be a huge improvement over my cheap 70's Rv style cam.

So, anyone have a cheap engine hoist they dont want :D

Mark Keenum
22nd-June-2008, 12:03 PM
I know we're talking cams here, but, you might want to change those rear gears before you upgrade your cam to a longer duration model.
The car would be a lot more fun to drive on the street.