HD4mula

I need to make a decision quick because my final engine refresh is being held by this. My old setup had stock intake, stock heads, cam below, close to 10:1 compression, short 1 5/8 headers with 2.5" true dual exhaust. It made 236rwhp/344rwtq. Now I am adding 52mm TB, plenum ported by Corvette Plenums, AS&R runners, Edelbrock base matched to runners, AFR Eliminator 180 heads with 1.6 full rockers. I need to decide to either keep the current Crane cam or go to the XFI 268 (or even the 260). This is a semi daily driver and with the current cam it has very good manners. I can sacrifice a little of HP for good TQ low end. Do you think changing to the XFI268 will add significant HP/TQ to justify the $298 versus keeping the Crane? I'm targeting 300+rwhp/330rwTQ. Your opinions will be greatly appreciated. Thanks

From:
Crane HR 276-2S-12
109821
Operating Range: 2000-5500 RPM
Duration Advertised: 276° Intake / 284° Exhaust
Duration @ .050'' Lift: 214° Intake / 222° Exhaust
Valve Lift w/1.6 Rockers: .520'' Intake / .542'' Exhaust
Lobe Separation Angle: ??°

To:
Comp Cams XFI 268 Hydraulic Roller Camshaft
249-12-466-8
Operating Range: 1800-5800 RPM
Duration Advertised: 268° Intake / 276° Exhaust
Duration @ .050'' Lift: 218° Intake / 224° Exhaust
Valve Lift w/1.6 Rockers: .570'' Intake / .565'' Exhaust
Lobe Separation Angle: 113°

PS: Tune will be custom of course

GOY

Wow that's an aggressive lobe ramp on that XFI cam.

Personally, I do think there would be noted gains from using it, based on spending longer amounts of time in high lift areas with the AFR heads. But, I have no way of really quantifying how much.

1989GTATransAm

iTrader: (3)

The Crane cam is very lazy. You can tell by taking the advertised duration and subtracting the duration at .050 inch. The XFI cam has a 50 and the Crane has a 62. The XFI has 8 degrees less seat to seat duration so it will idle better and have more vacuum for the brakes etc. I would choose the XFI cam without hesitation. I would also use the Comp Cams 918 beehive valve springs for a real winning combination.

Guest

I kinda agree with the adv-.050 theory above. I went from a 224/232 @ .050 280/288 adv. .497/.517 112LSA to an XFI with 230/236 @ .050 280/288 adv. .576/.570 113LSA and the idle is pretty similar. I'm happier with the power and mileage from the XFI cam. I swapped from AL L98 heads to ported AFR 190's so I just couldnt leave that other cam in there.

The cams you posted are more similar than what I changed from/to so its more a matter of your pocketbook I think. Probably will pick up a little power but how much is hard to say. The added lift doesnt hurt though, and like they say its the area under the curve that counts.

zz4monte

I don't know anything about the XFI cam but the crane 276 is a good street cam for a daily driver. I have told this story about 10times know but a buddy of mine has a zz4 shortblock,180AFR street heads,Performer RPM intake and a 750DP,1 5/8 true dual exhaust with the GM 845 which is the same thing as the crane 276 and he made 408hp on the engine dyno before he put it in the car.I think you might get 15-25hp from that cam if you need the extra lift.Which I am sure the AFR's could use but it won't be a huge power gain.It would be noticable up top more than likely.I have a zz4 and I dynoed 271rwhp and 368rwtq totally stock.Your heads are far superior to mine and your cam is worth 10-15hp over mine.I think your induction will run similar to mine considering mine is only a gm version of a performer.You will more than likely make 290-310rwhp with that combo.But the cam is not a lopey cam if that is what you are looking for.

HD4mula

Well thanks to all. I talked to my guy at the machine shop and he too agrees the XFI268 would be better. Jegs has my order for it already