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I've decided to go with the Comp Cams XE274H-10 cam swap for my new Edelbrock heads. Anyone else using this cam or have an opinion on it?
Comp Cams XE274H-10
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Umm on your 350ci with 700R4 and 3.55 gears?
You do realize this XE274H is for racing right? Its too lopey for a driver, let alone one with an overdrive! Vacuum is only 11 which might not be enough for your power brakes?
Recommend the XE262H for your application, 17.5 vacuum, 5ft lbs more torque at 3700 rpm instead of 3900 rpm (XE274H).
That extra 20hp is at 5900 RPMs with the XE274H, you won't be ever running your engine to 5900 rpms....
XE262H : HYDRAULIC: Excellent response, good mid-range, noticeable idle.
Duration @ 0.050" 218 / 224
XE274H : HYDRAULIC: Very strong mid-range, torque and throttle response, 2200+ stall
Duration @ 0.050" 230 / 236
You do realize this XE274H is for racing right? Its too lopey for a driver, let alone one with an overdrive! Vacuum is only 11 which might not be enough for your power brakes?
Recommend the XE262H for your application, 17.5 vacuum, 5ft lbs more torque at 3700 rpm instead of 3900 rpm (XE274H).
That extra 20hp is at 5900 RPMs with the XE274H, you won't be ever running your engine to 5900 rpms....
XE262H : HYDRAULIC: Excellent response, good mid-range, noticeable idle.
Duration @ 0.050" 218 / 224
XE274H : HYDRAULIC: Very strong mid-range, torque and throttle response, 2200+ stall
Duration @ 0.050" 230 / 236
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Thanks for the input Brian ....
I'm trying to do the best research I can, but cams are a HUGE mystery to me. I WON'T be doing this again, so I don't wanna screw up with a bad cam choice
I'm trying to do the best research I can, but cams are a HUGE mystery to me. I WON'T be doing this again, so I don't wanna screw up with a bad cam choice
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Most people OVERCAM their engines.
An XE274H is great for a 408 on the street, but not a 350.
Every 25 cu inch difference you should lower the duration 5
Since you are 53-58 cu inch less than 6D9's 408, for your engine to idle and have the same throttle response as the 408, you should run 11 less on duration, so an XE262H would be perfect.
I run a 327 on my 63 Nova, with an XE256H, thus I am running 25 cu inch less than you and so I am also running 6 less on duration. My 327 idles and has the same characteristics as a 350 running an XE262H
If you had a 383 you would probably consider an XE268H
As you increase your duration, your power band moves up higher in the RPMs, your drivetrain with a 700-R4 Overdrive + 3.55 wants more low end than high end. If you were running a TH350 + 3.73 or 4.11 you would possibly want to cam up just a tad to move the powerband up a little.
If this car was just for racing then thats a different matter, if you didn't care how it drove and just wanted the maximum 0-60 or quarter mile then the XE274H might work for your needs, but I am pretty sure your car is going to see the road 99% of the time and the track 1% of the time, so stick with the XE262H, you'll love it.
An XE274H is great for a 408 on the street, but not a 350.
Every 25 cu inch difference you should lower the duration 5
Since you are 53-58 cu inch less than 6D9's 408, for your engine to idle and have the same throttle response as the 408, you should run 11 less on duration, so an XE262H would be perfect.
I run a 327 on my 63 Nova, with an XE256H, thus I am running 25 cu inch less than you and so I am also running 6 less on duration. My 327 idles and has the same characteristics as a 350 running an XE262H
If you had a 383 you would probably consider an XE268H
As you increase your duration, your power band moves up higher in the RPMs, your drivetrain with a 700-R4 Overdrive + 3.55 wants more low end than high end. If you were running a TH350 + 3.73 or 4.11 you would possibly want to cam up just a tad to move the powerband up a little.
If this car was just for racing then thats a different matter, if you didn't care how it drove and just wanted the maximum 0-60 or quarter mile then the XE274H might work for your needs, but I am pretty sure your car is going to see the road 99% of the time and the track 1% of the time, so stick with the XE262H, you'll love it.
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Thank you sir ...
That's the advice I'm looking for
The XE262H it is
That's the advice I'm looking for
The XE262H it is
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Thinking of running the hydra roller version of this cam , down one from my XE282HR on my 383. Trying to preserve a little more of my compression. Talked to Comp about it, they talked me into keeping what I had. Desktop dyno curves mirrored each other mid to top range but bottom end the 274 had more torque. The 262 or 268 sounds more of what you need.
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Brian quick question ....
What is more important, lift or duration?
Again ... cams baffle me
What is more important, lift or duration?
Again ... cams baffle me
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Ok gotcha ....
Looks like that's the way I'm gonna go.
Now .... keeping on the 600 cfm carb is the smart way to go right?
I've heard a few times over that a 750 is overkill for a street motor???
Looks like that's the way I'm gonna go.
Now .... keeping on the 600 cfm carb is the smart way to go right?
I've heard a few times over that a 750 is overkill for a street motor???
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I recommend, on a 350 'street' motor with 10.1, 170/190 cfm heads, the 268 from COMP. I chose a 274 for my motor cuz I liked it better for my setup. A 350 9.5:1 184/150 valves, torker intake an 650 VAC SEC holley. Motors runs like a russian race horse. I like a little more cam in my motors. I have always traded up, heads intake an such, that keeps me from swappping cams also. but my motor happens to like that cam just fine. I outran a 99 GT fairly easily...
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With the blower?
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DesktopDyno2000 estimates
Cruise (75mph) RPM (26.1" tire / 3.55 rear) - 3rd gear 3429 rpm, overdrive 2400 rpm
XE262H - 352 hp at 5500 rpm 385lb torque at 4000 rpm
Cruise (2400rpm) - 361 lbs torque
Jump to Third from Cruise - (3429 rpm) - 381 lbs torque
XE274H - 369 hp at 6000 rpm (ENGINE CAN'T GO THIS HIGH!!), 375 torque at 4500 rpm
Cruise (2400rpm) - 330 lbs torque
Jump to Third from Cruise - (3429 rpm) - 360 lbs torque
See what happened when you bumped up the duration? You lost 31 lbs of torque at cruise!
Same with your Acceleration Gear (3rd gear), when you cruise at 2400 and step on the gas you jump to 3rd, at 3430 rpm, well at that rpm you get 20 lbs less torque by going with the XE274H!!!
XE274H peak HP is too high, 6000 rpm, your engine will never get that high, 5500 max, most likely 5000-5200 with hydralic lifters.
This is why going up any higher than the XE262H is going to diminish your driveability. Sure it might rev higher but unless you sit in 3rd gear with a 4.10 out back it makes no difference because its outside your normal operating range. Leave the larger duration for the drag racers…. That is what they were designed for!
Cruise (75mph) RPM (26.1" tire / 3.55 rear) - 3rd gear 3429 rpm, overdrive 2400 rpm
XE262H - 352 hp at 5500 rpm 385lb torque at 4000 rpm
Cruise (2400rpm) - 361 lbs torque
Jump to Third from Cruise - (3429 rpm) - 381 lbs torque
XE274H - 369 hp at 6000 rpm (ENGINE CAN'T GO THIS HIGH!!), 375 torque at 4500 rpm
Cruise (2400rpm) - 330 lbs torque
Jump to Third from Cruise - (3429 rpm) - 360 lbs torque
See what happened when you bumped up the duration? You lost 31 lbs of torque at cruise!
Same with your Acceleration Gear (3rd gear), when you cruise at 2400 and step on the gas you jump to 3rd, at 3430 rpm, well at that rpm you get 20 lbs less torque by going with the XE274H!!!
XE274H peak HP is too high, 6000 rpm, your engine will never get that high, 5500 max, most likely 5000-5200 with hydralic lifters.
This is why going up any higher than the XE262H is going to diminish your driveability. Sure it might rev higher but unless you sit in 3rd gear with a 4.10 out back it makes no difference because its outside your normal operating range. Leave the larger duration for the drag racers…. That is what they were designed for!
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275 Posts
Thanks Brian ...
Sounds like a good match for me.
It's a far cry from the 205 rwhp I dyno'd at last summer.
Although I still don't think the idiot running the dyno software knew what he was doing ;-)
Sounds like a good match for me.
It's a far cry from the 205 rwhp I dyno'd at last summer.
Although I still don't think the idiot running the dyno software knew what he was doing ;-)
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2,108 Posts
Ok this Crower 241 camshaft on 64cc (9.5:1 compression) does in a perfect world
378 torque at 4000 rpm, 357 hp at 5500 rpm
2500rpm cruise is 344 torque
3500rpm acceleration is 370 torque
the XE262H was 361 torque at 2500 rpm and 381 torque at 3500 rpm, so the XE262H will give you 17 more torque at cruise and 11 more torque on acceleration. So you will notice a difference between both camshafts in terms of power. And with the switch from 76cc to 64cc you will are going from a compression of probably 8:1 to 9.5:1 !!!! (76cc with .039 gasket, 64cc with .015 gasket)
That’s HUGE!!
Let me show you
76cc/.039 gasket, low performance heads stock porting, 8.0:1 compression, Crower 00241
2500rpm cruise is 320 torque
3500 rpm acceleration is 337 torque
Peak HP : 284 at 5000
Peak Torque : 337 at 3500
64cc/.015 gasket, performance heads, large valve, 9.5:1 compression, Crower 00241
2500rpm cruise is 344 torque
3500 rpm acceleration is 370 torque
Peak HP : 357 at 5500
Peak Torque : 378 at 4000, 379 at 4500
64cc/.015 gasket, performance heads, large valve, 9.5:1 compression, CC XE262H
2500rpm cruise is 361 torque
3500 rpm acceleration is 381 torque
Peak HP : 352 at 5500
Peak Torque : 385 at 4000
So just changing the heads/gasket you gain 24 torque at cruise, 33 torque on acceleration, 41 torque at peak
Changing the camshaft as well gives you 41 torque at cruise, 44 torque on acceleration, 48 torque at peak
Given the dyno software says 284 peak hp and you got 205 rwhp that sounds about right.
Dyno software shows a jump from 284 to 352, a whopping 68 peak HP by changing the cam, heads, and gasket!!
378 torque at 4000 rpm, 357 hp at 5500 rpm
2500rpm cruise is 344 torque
3500rpm acceleration is 370 torque
the XE262H was 361 torque at 2500 rpm and 381 torque at 3500 rpm, so the XE262H will give you 17 more torque at cruise and 11 more torque on acceleration. So you will notice a difference between both camshafts in terms of power. And with the switch from 76cc to 64cc you will are going from a compression of probably 8:1 to 9.5:1 !!!! (76cc with .039 gasket, 64cc with .015 gasket)
That’s HUGE!!
Let me show you
76cc/.039 gasket, low performance heads stock porting, 8.0:1 compression, Crower 00241
2500rpm cruise is 320 torque
3500 rpm acceleration is 337 torque
Peak HP : 284 at 5000
Peak Torque : 337 at 3500
64cc/.015 gasket, performance heads, large valve, 9.5:1 compression, Crower 00241
2500rpm cruise is 344 torque
3500 rpm acceleration is 370 torque
Peak HP : 357 at 5500
Peak Torque : 378 at 4000, 379 at 4500
64cc/.015 gasket, performance heads, large valve, 9.5:1 compression, CC XE262H
2500rpm cruise is 361 torque
3500 rpm acceleration is 381 torque
Peak HP : 352 at 5500
Peak Torque : 385 at 4000
So just changing the heads/gasket you gain 24 torque at cruise, 33 torque on acceleration, 41 torque at peak
Changing the camshaft as well gives you 41 torque at cruise, 44 torque on acceleration, 48 torque at peak
Given the dyno software says 284 peak hp and you got 205 rwhp that sounds about right.
Dyno software shows a jump from 284 to 352, a whopping 68 peak HP by changing the cam, heads, and gasket!!
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I dont think it had a blower....never heard it whine, it was behind me...:thumbsup:
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Just thinking about apples to apples comparisons, New mustang gt is what 4.6 injected and the blower version is the what 351? So a 350 is no comparison to 4.6 but is to 351, but dont think the new cobra comes without a blower. Maybe some day I will find one at a light.
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I talked to the guy that owns it, yep, it is an aftermarket motorcraft turbo w/ 7psi boost. He also has a 04 Cobra. He says I cant touch that one, hehe, we'll see.
My understanding is the cobra is blown and the GT is not. Of course I could care less about the fords....
My understanding is the cobra is blown and the GT is not. Of course I could care less about the fords....
I ran the XE274 for years in my 10:1 350 and I would not hesitate to use it again. It idled quite tame and pulled like 14" of vacuum @ 800RPM idle. With a set of Vortecs, RPM intake, 750 Demon, 3.92's, 27" tall tire, 3000 stall, and single 3" exhaust pipe it went 12.52 @ 108mph effortlessly.
I drove it all over the place... one time I drove it about 2 hours from my house and it got 14mpg with the TH350.... That means my "race car" gets better mileage than my 1500 truck! You could definitately drive the XE274 every day if you wanted to.
I drove it all over the place... one time I drove it about 2 hours from my house and it got 14mpg with the TH350.... That means my "race car" gets better mileage than my 1500 truck! You could definitately drive the XE274 every day if you wanted to.
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