350 cam questions

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Dec 29, 2002 | 03:05 AM
  #1  
OK ive built a 350 with 305 heads (yah i know there 305 heads), but anyways, it will be carbed, headers and exhaust, and driven everyday with a 700R4 2200 stall, 3.42 gear

Im decided on two cams to get XE262 or XE268, i will also be gettin the k kit that comes with springs and everything. what i need to know is how this thing will idle with both, driveability, i want a little lump to the idle nothing radical. the head will also be stock other than being ported a little with 1.52 magnum rockers.

If you need to know more, post and ill answer. Thanks


Kevin
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Dec 29, 2002 | 03:17 AM
  #2  
Sounds real similar to what I have, unfortunately I have only started the thing up a couple of times(open headers) and the carb needs replaced so I havent really got a chance to see what it will idle at since you are supposed to run it at at around 2000 to break in the cam. From what I have been told the xe268 works pretty well in a street 350. What casting head number are you using? I just ordered my exhaust yesterday, and plan on paying for my new carb next weekend.

Good luck

Ben
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Dec 29, 2002 | 10:01 AM
  #3  
of those two, i'd pick the xe268.
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Dec 29, 2002 | 11:38 AM
  #4  
do you guys think the 268 would be better matched to my components in my sig? also is it much smaller then the cam i have now? my cam now lopes really good but it is so horrible on gas i can only drive it like once or twice a week and i need to be able to drive it every day. also what are the specs on the 268? thanks
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Dec 29, 2002 | 01:45 PM
  #5  
the heads i will be using are 081 305 heads. Will the cam work with the stock head, i will be changing the valvespring and retainters though. thanks


Kevin
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Dec 29, 2002 | 01:51 PM
  #6  
Quote:
Originally posted by 89formula#1
do you guys think the 268 would be better matched to my components in my sig? also is it much smaller then the cam i have now? my cam now lopes really good but it is so horrible on gas i can only drive it like once or twice a week and i need to be able to drive it every day. also what are the specs on the 268? thanks
the xe268h-14 is 224/230 479/480 114lsa if memory serves me correctly
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Dec 29, 2002 | 02:42 PM
  #7  
oh so its almost the same as my cam now. I guess i need to go smaller
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Dec 29, 2002 | 02:46 PM
  #8  
will this cam work with my 081 heads, with the right springs and retainers
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Dec 29, 2002 | 02:56 PM
  #9  
89:
The XE268 will likely outrun that old 280. It will certainly give the motor better low-RPM manners without hurting whatever top end it has. The newer cams open the valves so much farther and faster, you'll probably get about the same "area under the curve" of valve motion from the XE268 as from that older 280, but with 12° less of "advertised" duration.

Deep:
I'd go with the 268 in your setup too, it's a reasonable match for what you've got. Port those heads, and use a thick head gasket, at least .039", to keep your compression under control. If you leave the stock 1.84" valves in the heads, they'll be your bottleneck.
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Dec 29, 2002 | 03:05 PM
  #10  
so you think ill be ok, i mean as in no maching to the heads go, cuz at the moment im taking what was given to me, sooner or later i plan on getting better heads tho. thanks


Kevin
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Dec 30, 2002 | 01:36 AM
  #11  
am i going to have any problems with hitting the valve guides with the xe268 (.477 , .480), if i use the retainers that im getting with the kit, with 1.52 rockers. thanks


Kevin
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Dec 30, 2002 | 07:07 AM
  #12  
I replied to you pm. I dont think what you have is ideal, unless you do your own porting on those 305 heads but it will work. If you plan on putting aftermarket heads on eventually I would do the best you can for now without putting to much money into it and then spend your money on the new heads instead.

Ben
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Dec 30, 2002 | 11:02 AM
  #13  
Quote:
Originally posted by RB83L69
89:
The XE268 will likely outrun that old 280. It will certainly give the motor better low-RPM manners without hurting whatever top end it has. The newer cams open the valves so much farther and faster, you'll probably get about the same "area under the curve" of valve motion from the XE268 as from that older 280, but with 12° less of "advertised" duration.

Deep:
I'd go with the 268 in your setup too, it's a reasonable match for what you've got. Port those heads, and use a thick head gasket, at least .039", to keep your compression under control. If you leave the stock 1.84" valves in the heads, they'll be your bottleneck.
But isn't the XE268's lift too much for stock springs in the heads?
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Dec 30, 2002 | 11:32 AM
  #14  
.479/.480 its like right on the line. but if your springs are old yea then you should replace them anyways. no sense in buying a cam and doing all that work if your not willing to change your valve springs. doesnt make much sense to me.
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Dec 30, 2002 | 12:12 PM
  #15  
do you think i would get any better gas milage with the xe268 then the cam in my sig? i was thinking ofputting on a 650 with the xe262, do u think it would be around 15-18 mpg? also do your think i coudl hit 13's?
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Dec 31, 2002 | 12:02 AM
  #16  
Quote:
Originally posted by 89formula#1
do you think i would get any better gas milage with the xe268 then the cam in my sig? i was thinking ofputting on a 650 with the xe262, do u think it would be around 15-18 mpg? also do your think i coudl hit 13's?
Town or country?

For better mileage the XE262 would be the choice. Any decently built 350 with heads, headers and an XE262 should crack the 13s.
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Dec 31, 2002 | 02:13 PM
  #17  
any other opinions on which one i should get for daily driving, with some action at the track. if you got either cam what is your mpg, and setup, thanks


Kevin

p.s. I will be changing every thing that goes along with cam swap, with matched parts
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Dec 31, 2002 | 03:02 PM
  #18  
i dont think they'll be too much mpg diff between the 262 and 268
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Dec 31, 2002 | 05:38 PM
  #19  
Re: 350 cam questions
Quote:
Originally posted by deepstage69
OK ive built a 350 with 305 heads (yah i know there 305 heads), but anyways, it will be carbed, headers and exhaust, and driven everyday with a 700R4 2200 stall, 3.42 gear

Im decided on two cams to get XE262 or XE268, i will also be gettin the k kit that comes with springs and everything. what i need to know is how this thing will idle with both, driveability, i want a little lump to the idle nothing radical. the head will also be stock other than being ported a little with 1.52 magnum rockers.

If you need to know more, post and ill answer. Thanks


Kevin
I'd go with the smaller cam with what you have.
the 268Xe needs a higher stall and more gear to get the best out of it.
Dyno comparisions between the two cams show the considerable loss in low end torque below 3000 rpm with the 268XE. Unless you will get a 3000+ converter, the smaller one will be better overall.
Take those 305 heads off and port them more.
Don't be shy here. You can't port these heads too much.

There is much more power in doing that than in the bigger cam.

Don't even consider the 268Xe if you've still got the 1.84" intake valves.
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