Comp XE268 vs 268AH-10
- Thread starter XFX
- Start date
-
PRH
Well-Known Member
Actually the 268AH-10 is the “magnum muscle” grind
268/276-adv
222/226@.050
.464/.464 lift
110lsa
Part number 20-309-4
The 268H is the single pattern 218/218-110 cam.
Part number 20-212-2
The XE268 intake lobes are about 20 years newer designs than either of the other two grinds.
268/276-adv
222/226@.050
.464/.464 lift
110lsa
Part number 20-309-4
The 268H is the single pattern 218/218-110 cam.
Part number 20-212-2
The XE268 intake lobes are about 20 years newer designs than either of the other two grinds.
Thank you. This site has a great search feature and I was able to find the post where Ramm had some good numbers in a "stock" looking 340 build and the couple other search results seemed to show it in a good light.
Since Ive researched more it looks to me one comp 268 is a decent cam for the lower compression motors and this one seems to favor the higher like an oem 10+ 340.
Ive a build here and I can wiggle things around to hit 10.5-11:1 with head gaskets and even aftermarket valves vs the bowl like stock valves and could even clean the chambers if I needed to dumb it down. But I think at my 4k above sea level left at the 11:1 this cam may fly.
I was able to grab a cam and lifter kit of this 268AH pretty cheap and currently some sites show its either discontinued or back ordered. It comes with the questionable 822-16 lifters but I have some 80-s Johnson lifters that might be a better option.
I also noticed in Ramms build he used the 901 spring and a simple 5/16 .080 pushrod so it all seems pretty basic and it looks like he still used the oem rockers although I have better if it would make it more stable and last longer.
I have a 260AH-8 212/218 .444 here and was considering trying to drop the compression some and possibly this would make a great off idle hard hitter for what it is but the numbers seem a bit iffy just to try and have to try again. Unless someone smarter then me can give input on the idea.
Since Ive researched more it looks to me one comp 268 is a decent cam for the lower compression motors and this one seems to favor the higher like an oem 10+ 340.
Ive a build here and I can wiggle things around to hit 10.5-11:1 with head gaskets and even aftermarket valves vs the bowl like stock valves and could even clean the chambers if I needed to dumb it down. But I think at my 4k above sea level left at the 11:1 this cam may fly.
I was able to grab a cam and lifter kit of this 268AH pretty cheap and currently some sites show its either discontinued or back ordered. It comes with the questionable 822-16 lifters but I have some 80-s Johnson lifters that might be a better option.
I also noticed in Ramms build he used the 901 spring and a simple 5/16 .080 pushrod so it all seems pretty basic and it looks like he still used the oem rockers although I have better if it would make it more stable and last longer.
I have a 260AH-8 212/218 .444 here and was considering trying to drop the compression some and possibly this would make a great off idle hard hitter for what it is but the numbers seem a bit iffy just to try and have to try again. Unless someone smarter then me can give input on the idea.
Iam running the 268H at 9.91 to 1 cranking psi is 169 on 100k mile plus 68 340 short block its a great stockish cam runs good power timed on 94 octane around 16 btdc the split pattern 268 wasnt out yet when i did the top end over. I debated between the the 268H and 270H because i had 3.23s i went with the 268H now i have 3.91s think those gears would have loved the 270H
although today the split pattern xe268 would be better imo
although today the split pattern xe268 would be better imo
33IMP
Well-Known Member
I would run it lower than 11 to 1 too, but o.p. says he's at 4000 feet.
Altitude is real pain to build to. Maybe eight years ago I went and got a duster from Eastern GA and did a compression check during the inspection and all were in the 185-187 area (al head) and then sitting here in my shop it was in the 165 area and it felt a lot softer driving it here vs there.
I look at every reply and bit of advice very objectively. The build I mentioned Ramm posted with that cam in a stock 340 if his location is correct seems near 800ft above sea level and with the semi limited details I figure in many areas im close with the exception of approx 6cc more due to piston difference.
I could dumb it down to maybe 10:6 but I really dislike motors that are soft or spongy. This will break in on an engine stand so im still on the fence on just trying to and see where it lands and with my setup I can load the motor a bit.
What to do what to do. Im not used to the small cam world.
Comp does say these are for the higher compression of the time period but it seems much of the 60-70s compression ratios were a bit hyped up vs the real spec.
I look at every reply and bit of advice very objectively. The build I mentioned Ramm posted with that cam in a stock 340 if his location is correct seems near 800ft above sea level and with the semi limited details I figure in many areas im close with the exception of approx 6cc more due to piston difference.
I could dumb it down to maybe 10:6 but I really dislike motors that are soft or spongy. This will break in on an engine stand so im still on the fence on just trying to and see where it lands and with my setup I can load the motor a bit.
What to do what to do. Im not used to the small cam world.
Comp does say these are for the higher compression of the time period but it seems much of the 60-70s compression ratios were a bit hyped up vs the real spec.
-
Similar threads
