Comp Cams, High Energy 268
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From: WAY DEEP INSIDE AMERICO,YES YOU LIVE HERE TO!! TX
Comp Cams, High Energy 268
Anyone run this cam without having problems with the stock converter.
Its RPM range is 1500 to 5500, and sez you dont need a stall to run this cam.. Would this cam be ok with stock 82 heads with a gasket port match???
Its RPM range is 1500 to 5500, and sez you dont need a stall to run this cam.. Would this cam be ok with stock 82 heads with a gasket port match???
Burning Brakes
Joined: Apr 2004
Posts: 847
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From: Des Allemands LA
Ran one in an '81 Z-28 with no trouble. A little heavier than our cars but I don't see any trouble running this cam, actually with the car a little lighter I think the cam would appear a tad more aggressive. Not much-but a little.
Advanced
Joined: May 2005
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From: CA
Originally Posted by LiveandLetDrive
No problem. I got it cheap but a XE260 would probably be a better choice. Some similar numbers but a more modern grind.
-Chris
-Chris
The H cams are symmetrical grinds and are therefore a bit more traditional than the XE line. I think "modern" things are good, but sometimes I feel that they are mainly good for the company that sells them, so they can get you to ditch your perfectly good old item and replace it with a "modern" one.
Why wouldn't you want to stay with something that fits the vintage of your car? I have had and still have H grind cams in a couple of cars (260 and a 280) and they both are great. It may be me, but I imagined that the idle on the 280H is more raw / classic muscle than the XE stuff I have experienced on other folks rides.
If you want to keep discussing this, you should list the exact specs of both cams, and I am sure that you will be hard pressed to see much of a difference, even in the specs. You basically said this yourself. Also, in my opinion performance will be so similar that your seat of the pants dyno won't notice a difference...
It is a no brainer. You have this cam already and it fits the vintage of your car 100%, put it in!
George
Race Director
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
i'm running an xe268 in my new engine i did the tranny swap at the same time. the 1400 rpm stall speed was a problem and went to a 2500 stall speed torque converter and it is working well.
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From: WAY DEEP INSIDE AMERICO,YES YOU LIVE HERE TO!! TX
Originally Posted by The Money Pit
I ran the 268H for years in my stock 350 with the stock tranny and converter. No problem with the converter.Top rpm was around 5500.
Sorry, I should have noted, I have a 700R-4
Team Owner
Joined: Jul 2001
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From: Here to make friends
St. Jude Donor '11, '16-'17
I have been running this cam for several years now. I have a manual transmission, so I can't help with the torque converter question, but the cam is working well for me with the stock heads.
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Le Mans Master
Joined: Jun 2002
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From: I can walk to MA
The "H" should be OK, but the XE (PowerMax by Crane, and others)
has asymmetric grind to help compensate for the small exhaust valve.
It's not about 'vintage' - so much as fixing the inadequecies
of a symmetric grind and unequal valve sizes.
With all the work you are doing ... I'd think you want a "modern" grind.
has asymmetric grind to help compensate for the small exhaust valve.
It's not about 'vintage' - so much as fixing the inadequecies
of a symmetric grind and unequal valve sizes.
With all the work you are doing ... I'd think you want a "modern" grind.
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From: WAY DEEP INSIDE AMERICO,YES YOU LIVE HERE TO!! TX
Originally Posted by NHvette
With all the work you are doing ... I'd think you want a "modern" grind.
i know diddly about cams
I have the weiand stealth manifold with a holley 750
I was also thinking of the VOODOO line up
Last edited by MEGLADON; May 18, 2005 at 02:24 PM.
Melting Slicks
Joined: Jul 2002
Posts: 3,128
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From: Deltona (son of Deland and DAYTONA) FL
270H cam here. 1800 stall converter feels stock. Very tight. No problems with idle here. In drive sounds like glug-glug-glug. In park or neutral, slightly rumpity-rumpity, but it doesn't shake the car like my 383.
Last edited by isosceles; May 18, 2005 at 03:04 PM.
Melting Slicks
Joined: Mar 2005
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From: Austin TX
Can't respond to the converter question, but I agree with those who support the "H" series line...I'm using a 270H in a 69 and a 280H in another...love them both. Do a seach on camaros.net (I did) and you'll learn of valve train noise and problems with the XE line. It's thought the ramps are too steep for flat tap cams.
Good luck,
Wes
Good luck,
Wes
Le Mans Master
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From: I can walk to MA
Originally Posted by MEGLADON
Like what???? help me out here
i know diddly about cams
I have the weiand stealth manifold with a holley 750
I was also thinking of the VOODOO line up
i know diddly about cams
I have the weiand stealth manifold with a holley 750
I was also thinking of the VOODOO line up
New grinds are "assymetric" between the intake and exhaust.
From what I understand, leave exhaust valve open longer to help
overcome the small valve size.
Here is the cam I was considering when I finally bump up the compression:
http://www.cranecams.com/?show=brows...tNumber=113802
Here is their latest line ... http://www.cranecams.com/?show=promo...7964d5cfc38e25
This one looks like a nice street/performance candidate:
http://www.cranecams.com/?show=brows...tType=camshaft
There was a formula in a recent post ... to determine if the lobe ramp
is too aggresive and prone to wiping. The XE line eclipsed the threshold,
where the Crane Powermax was close - but still considered safe. I'm not
sure about the new Zcam series.
Last edited by NHvette; May 19, 2005 at 09:58 AM.
Melting Slicks
Joined: Jan 2004
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From: New Cumberland PA
The cam should be good choice. It should somewhat similiar to the L-82 specs. It takes some restraint when picking cams. Since cams in the same category typically cost the same, some people will decide they'll go up a couple of notches. The XE series should make a little more power. Partly because they designed the cam for better exhaust flow, but I also think the ramps are a little more aggressive. There have been some failures on these XE cams, which get posted here. Some of that could be from improper installation and some of attributed to the manufacuter pushing the envelope of the ramp.
I don't think you'll have to change the conveter. The duration is not that long. What happens with long duration camshafts is that they also need to idle at higher rpms. In an automatic, that means idle while in gear, not just in nuetral or park. A higher stall speed while idleing in gear will better at 900 rpms then a lower stall speed converter. What that does is allow the engine to idle at a lower rpm when in neutral/park. The car will not have the 500rpm drop while going from neutral to drive or reverse.
I don't think you'll have to change the conveter. The duration is not that long. What happens with long duration camshafts is that they also need to idle at higher rpms. In an automatic, that means idle while in gear, not just in nuetral or park. A higher stall speed while idleing in gear will better at 900 rpms then a lower stall speed converter. What that does is allow the engine to idle at a lower rpm when in neutral/park. The car will not have the 500rpm drop while going from neutral to drive or reverse.
Race Director
Joined: Sep 2004
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
i'm running the XE268 and i don't buy the poor design talk.... i have seen only one post where someone wiped a lobe, everything else is second hand talk....as i have said before. a cam swap is easy to do and cheap...it becomes more expensive to do it correctly with correct springs, new lifters and to break it in correctly...i suspect most issues with these come from half *** installations and people mis matching components....Lars said he has an XE series cam that he has been trying to kill and has not been able to...
Melting Slicks
Joined: Jan 2004
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From: New Cumberland PA
Originally Posted by bobs77vet
i'm running the XE268 and i don't buy the poor design talk.
Race Director
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
Originally Posted by mandm1200
The XE series should make a little more power. Partly because they designed the cam for better exhaust flow, but I also think the ramps are a little more aggressive. There have been some failures on these XE cams, which get posted here. Some of that could be from improper installation and some of attributed to the manufacuter pushing the envelope of the ramp.
Originally Posted by 73, Dark Blue 454
...... Do a seach on camaros.net (I did) and you'll learn of valve train noise and problems with the XE line. It's thought the ramps are too steep for flat tap cams.
Good luck,
Wes
Good luck,
Wes
I based my observation on the above posts. My intention is not to start a pissing contest on cam design that i am ill equipped to argue since i do not have any technical expertise on this subject other then being an XE consumer. I will again state that there is more anectodatal evidence of XE cam failure then there is direct evidence of it...Again as i have done in the past I invite people with direct first hand knowledge of XE cam failure on there car to tell us about it . in the past there has been one maybe two people who have first hand knowledge of this failure. what I am saying is that i believe there are too many variables associated with Cam installations to castigate a whole series of cams based on annectodal and second hand information. Not to mention i seriously hope they are a good product since i have one.
edit heres a previous thread, post 34 is very informative
http://forums.corvetteforum.com/show...cam+wiped+lobe
Last edited by bobs77vet; May 19, 2005 at 03:18 PM.
Melting Slicks
Joined: Mar 2005
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From: Austin TX
If you'll notice on the spec sheets, the XE line of cams has the same intake lobe as their traditional Magnum brothers. But the exhaust lobe is considered by some to be too steep. Please note, that almost always, the XE failures occur on the exhaust lobes. That's more than anecdotal evidence of a problem.
Here's some excellent advise from Vissard, Isky, and others regarding dual-pattern cams in general:
http://www.camaros.net/forums/showth...t=dual+pattern
These are pretty solid opinions which steered me to traditional single pattern cams.
I'm still looking for a thread that referenced Isky regarding steep ramps...that anything less than 47.5% (duration @ .50/lift) was too harsh for a flat tap valve train...a test was cited. It may be on the chevelles.com page. Stay tuned.
Here's some excellent advise from Vissard, Isky, and others regarding dual-pattern cams in general:
http://www.camaros.net/forums/showth...t=dual+pattern
These are pretty solid opinions which steered me to traditional single pattern cams.
I'm still looking for a thread that referenced Isky regarding steep ramps...that anything less than 47.5% (duration @ .50/lift) was too harsh for a flat tap valve train...a test was cited. It may be on the chevelles.com page. Stay tuned.
Melting Slicks
Joined: Mar 2005
Posts: 2,838
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From: Austin TX
Sorry, the above link was abbreviated and won't work. Go to camaros.net , then to the tech discussion, and search "Dual Pattern Cams" (must use the caps...and search for the title, not the entire posts) in their performance section.
Good info from some legends.
Good info from some legends.
Race Director
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
i'll look at that website, i am a fan of Vizard's
edit .....well been there and looked at the site, interesting thks, lot of those guys love the XEseries and i saw no mention in the three pages i reviewed (from the caption you sent me to) of any wiped lobes. seems some guys complained of noise and others had no noise problems...i have no noise problem. i found one reference to Vizards book that said a single pattern cam in a certain application would produce more power. (he was not critical of the XE design )
edit .....well been there and looked at the site, interesting thks, lot of those guys love the XEseries and i saw no mention in the three pages i reviewed (from the caption you sent me to) of any wiped lobes. seems some guys complained of noise and others had no noise problems...i have no noise problem. i found one reference to Vizards book that said a single pattern cam in a certain application would produce more power. (he was not critical of the XE design )
Last edited by bobs77vet; May 19, 2005 at 09:34 PM.