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Re: Comp Cams XE268H vs. XE274H? Opinions?
[Re: ohiodemon]
#452321
08/28/09 10:37 AM
08/28/09 10:37 AM
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Joined: Mar 2006
Posts: 426
Mid-Atlantic
Scatransit
OP
mopar
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OP
mopar
Joined: Mar 2006
Posts: 426
Mid-Atlantic
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Thanks, no other mods planned. I'm ready to buy the 268, just curious about the 274 since the comp website says it can use the same 911-16 springs.
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Re: Comp Cams XE268H vs. XE274H? Opinions?
[Re: Dodgem]
#452324
08/28/09 11:51 AM
08/28/09 11:51 AM
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Joined: Mar 2006
Posts: 426
Mid-Atlantic
Scatransit
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mopar
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OP
mopar
Joined: Mar 2006
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Stock all the way...cast iron...numbers...that sorta thing...The bore is .030, but comp ratio is 10:1...I realize that a stock cam is the safest bet, but I would like to take advantage of todays technology, keep the idle reasonable, and maybe gain a little performance...
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Re: Comp Cams XE268H vs. XE274H? Opinions?
[Re: Scatransit]
#452325
08/28/09 01:06 PM
08/28/09 01:06 PM
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Joined: Mar 2006
Posts: 426
Mid-Atlantic
Scatransit
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mopar
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OP
mopar
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I'm curious about the 274 too...Anyone have any experience with it?
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Re: Comp Cams XE268H vs. XE274H? Opinions?
[Re: Scatransit]
#452326
08/28/09 01:19 PM
08/28/09 01:19 PM
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Joined: Jul 2006
Posts: 383
Essex, Ont., Canada
Fishmarket
enthusiast
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enthusiast
Joined: Jul 2006
Posts: 383
Essex, Ont., Canada
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I have the XE268 in mine and I like it but I wish I would have went with the XE275HL now. They are a tad on the noisy side but for you app. the 268 would probably be perfect.
1972 Plymouth Cuda 340 4 speed
1971 Plymouth Road Runner 383 Auto
1970 Plymouth Duster /6 Auto
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Re: Comp Cams XE268H vs. XE274H? Opinions?
[Re: Fishmarket]
#452327
08/28/09 01:34 PM
08/28/09 01:34 PM
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Joined: Jan 2003
Posts: 3,920
n.e. pa.
65rbdodge
master
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master
Joined: Jan 2003
Posts: 3,920
n.e. pa.
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i have the 274 in the 400 in my dart. i like it, i pulls pretty hard through all the rpm range and has a lumpy idle. my combo is eddy. rpm intake, holley 750, 84cc eddy heads milled .040(.74cc), KB pistons at 0 deck, headers, 2.5"duals w/x pipe, 2600rpm converter, 355 gears.
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Re: Comp Cams XE268H vs. XE274H? Opinions?
[Re: Scatransit]
#452328
08/28/09 03:40 PM
08/28/09 03:40 PM
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Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
patrick
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
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Quote:
Stock all the way...cast iron...numbers...that sorta thing...The bore is .030, but comp ratio is 10:1...I realize that a stock cam is the safest bet, but I would like to take advantage of todays technology, keep the idle reasonable, and maybe gain a little performance...
do you have dome pistons and/or milled heads? if not, then you probably aren't at 10:1. I'd go XE268 or Lunati voodoo 60303, and use the same comp springs.
1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
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Re: Comp Cams XE268H vs. XE274H? Opinions?
[Re: patrick]
#452329
08/28/09 04:14 PM
08/28/09 04:14 PM
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Joined: Mar 2006
Posts: 426
Mid-Atlantic
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mopar
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Negative on both...Sealed Power .030-over flat tops...heads untouched except for new seals and springs...The comp ratio is 10:1 .
The 268 was my first choice but the 274 is tempting...
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Re: Comp Cams XE268H vs. XE274H? Opinions?
[Re: Scatransit]
#452330
08/28/09 04:28 PM
08/28/09 04:28 PM
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Joined: Feb 2005
Posts: 5,221
Branson, Mo.
joedust451
super gas
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super gas
Joined: Feb 2005
Posts: 5,221
Branson, Mo.
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Quote:
Negative on both...Sealed Power .030-over flat tops...heads untouched except for new seals and springs...The comp ratio is 10:1 .
The 268 was my first choice but the 274 is tempting...
Depending on how far below the deck those pistons are, & you say the heads are untouched, if your running a .040" gasket, your not at 10.1, my Ross pistons sat .017" below, & i was at 9.73, but if those are the reg. cast seal power pistons, then there around .080" below, your more like 8.7.1, but if there the six pack 2255s forged units, then your around 9.6.1, so what pistons do you have??
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Re: Comp Cams XE268H vs. XE274H? Opinions?
[Re: Scatransit]
#452332
08/29/09 09:06 AM
08/29/09 09:06 AM
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Joined: Feb 2005
Posts: 5,221
Branson, Mo.
joedust451
super gas
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super gas
Joined: Feb 2005
Posts: 5,221
Branson, Mo.
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Quote:
I appreciate your interest...I understand that compression ratio is a value that needs to be factored in when determining the application of a camshaft...Suffice it to say that the pistons are advertised as .030-over replacements for the 383 HP engine...I do not know what the EXACT compression ratio is, and I frankly don't care. I would assume that it is close to what was advertised...that's good enough for me. This is not a race engine. I just wanted to hear of fellow hobbyists experiences with the cams in the subject line. Thanks
Ok, seeing you have a stock cam now, i would get the .268, it should wake it up nicely, the .274 would sound better, but with stock compression, you may not like it as much as the .268, now that thats said, you really should care about what you build, especially the compression when it comes to picking a cam, if you get defencesive about it, then knowone with any real knowhow will bother helping you, then your responces will be slim, & thats why your asking Qs, for help "right", so don't be quick to get mad, because doing the math on any build is knowledge, & ammunition for any future upgrades you may want to do.
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Re: Comp Cams XE268H vs. XE274H? Opinions?
[Re: joedust451]
#452333
08/29/09 09:12 AM
08/29/09 09:12 AM
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Joined: Feb 2005
Posts: 5,221
Branson, Mo.
joedust451
super gas
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super gas
Joined: Feb 2005
Posts: 5,221
Branson, Mo.
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Quote:
Quote:
I appreciate your interest...I understand that compression ratio is a value that needs to be factored in when determining the application of a camshaft...Suffice it to say that the pistons are advertised as .030-over replacements for the 383 HP engine...I do not know what the EXACT compression ratio is, and I frankly don't care. I would assume that it is close to what was advertised...that's good enough for me. This is not a race engine. I just wanted to hear of fellow hobbyists experiences with the cams in the subject line. Thanks
Ok, seeing you have a stock cam now, i would get the .268, it should wake it up nicely, the .274 would sound better, but with stock compression, you may not like it as much as the .268, now that thats said, you really should care about what you build, especially the compression when it comes to picking a cam, if you get defencesive about it, then knowone with any real knowhow will bother helping you, then your responces will be slim, & thats why your asking Qs, for help "right", so don't be quick to get mad, because doing the math on any build is knowledge, & ammunition for any future upgrades you may want to do. [/quot
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Re: Comp Cams XE268H vs. XE274H? Opinions?
[Re: joedust451]
#452334
08/29/09 11:39 AM
08/29/09 11:39 AM
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Joined: Mar 2006
Posts: 426
Mid-Atlantic
Scatransit
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WOW! This is why I rarely post on this forum. I only wanted to ask my fellow MOPAR enthusiasts if they had any experience with either cam mentioned in the subject line. I am sorry if you have taken things the wrong way. I was not seeking a recommendation, just experiences. Friends? 
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Re: Comp Cams XE268H vs. XE274H? Opinions?
[Re: Scatransit]
#452335
08/29/09 02:09 PM
08/29/09 02:09 PM
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Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
patrick
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
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Quote:
I appreciate your interest...I understand that compression ratio is a value that needs to be factored in when determining the application of a camshaft...Suffice it to say that the pistons are advertised as .030-over replacements for the 383 HP engine...I do not know what the EXACT compression ratio is, and I frankly don't care. I would assume that it is close to what was advertised...that's good enough for me. This is not a race engine. I just wanted to hear of fellow hobbyists experiences with the cams in the subject line. Thanks
you might not care until you put too big of a cam in it and it runs like poo.
ok, so you have a stock rebuilt 383 HP. most 906 heads are in the 92 cc range, if you used a steel shim head gasket, those are about 5cc, if the pistons were .080 in the hole, you're looking at 7.9:1 actual compression. if you used the standard gasket in the rebuild kit, you're looking at more like 7.6:1 compression. if they were .017 in the hole like someone else mentioned, you're looking at more like 8.8:1 with the thin gasket, and 8.5:1 with the standard fel-pro engine teardown kit.
if you were at a true 10:1, I'd say go for the XE274, but you're not. you may be waaaay off of that. I'd go conservative and go with the XE268, otherwise the car might be pretty doggy until 3500 RPM or so.
1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
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Re: Comp Cams XE268H vs. XE274H? Opinions?
[Re: patrick]
#452336
08/29/09 02:30 PM
08/29/09 02:30 PM
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Joined: Nov 2007
Posts: 21,822
Kirkland, Washington
Pacnorthcuda
Too Many Posts
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Too Many Posts
Joined: Nov 2007
Posts: 21,822
Kirkland, Washington
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Quote:
Quote:
if you were at a true 10:1, I'd say go for the XE274, but you're not. you may be waaaay off of that. I'd go conservative and go with the XE268, otherwise the car might be pretty doggy until 3500 RPM or so.
 Finally someone brought up the bottom end. I too would go with the 268. Only because of maintaining a nice driveable bottom end. With Stock intake and exhaust, and no plans to mod, it very much sounds like a casual driver. I doubt you want to be hottrodding it all (or even most of the time). The powerband for the 268 should begin about 1800-2000 rpm. The 274 will be higher, probably about 300-400 higher. Having to slip the clutch at 2400 from every stop gets annoying in casual low-performance driving. Sidestepping the pedal while having fun is a different issue.
The 274 is a risky choice in your combo, and it would be held back by the intake/exhaust/compression
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Re: Comp Cams XE268H vs. XE274H? Opinions?
[Re: Scatransit]
#452337
08/29/09 04:50 PM
08/29/09 04:50 PM
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Anonymous
Unregistered
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Anonymous
Unregistered
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Quote:
I appreciate your interest...I understand that compression ratio is a value that needs to be factored in when determining the application of a camshaft...Suffice it to say that the pistons are advertised as .030-over replacements for the 383 HP engine...I do not know what the EXACT compression ratio is, and I frankly don't care. I would assume that it is close to what was advertised...that's good enough for me. This is not a race engine. I just wanted to hear of fellow hobbyists experiences with the cams in the subject line. Thanks
Your "assumption" can get you in trouble, even for a street engine. First of all, the CR of a stock 383 was less than advertised, but more importantly, when you get "stock replacement" pistons, they are gonna be generic one-size-fits-all, not duplicates of the original pistons.
It doesn't matter what year 383 you specify, what carb, or what factory CR rating, you get the SAME piston that's probably gonna end up .050-.100 below deck at TDC. Then when you put on your Fel-pro .039" head gaskets instead of the stock steel shim, you end up with maybe 7.5 - 8.0 to one CR - nowhere near close to advertised.
Your cam question really can't be answered properly without having some idea of your actual CR; that's why someone brought up the issue - they were trying to help you, not harass you.
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