Xe268 wiped lobes - Page 3 - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #31 (permalink)  
Old 02-19-2012, 11:07 PM
Registered User
 
Last photo:
Join Date: Jan 2009
Location: Springfield, MO
Age: 29
Posts: 1,108
Wiki Edits: 0

Thanks: 5
Thanked 0 Times in 0 Posts
Well I dont think the desktop dyno can be too terribly far off. Its only 50ft lb over what my engine is rated at stock. The engine IS stock but will be getting headers and exhaust and a K&N filter. Who knows what else. Also I might have to advance the cam a little to push the torque curve down - I am planning on doing some towing with this truck. About 6,000 worth.

Still yet, even if i only gain 30 ft lb, that puts me equal to a chevy 350 of the same year. 350s tow OK.

Big thing tho is still the fear of wiping out a cam. I know the engines are a good bit different between the SBC and SBF.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #32 (permalink)  
Old 02-19-2012, 11:51 PM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,153
Wiki Edits: 0

Thanks: 5
Thanked 380 Times in 374 Posts
Quote:
Originally Posted by Torque454
Well I dont think the desktop dyno can be too terribly far off. Its only 50ft lb over what my engine is rated at stock. The engine IS stock but will be getting headers and exhaust and a K&N filter. Who knows what else. Also I might have to advance the cam a little to push the torque curve down - I am planning on doing some towing with this truck. About 6,000 worth.

Still yet, even if i only gain 30 ft lb, that puts me equal to a chevy 350 of the same year. 350s tow OK.

Big thing tho is still the fear of wiping out a cam. I know the engines are a good bit different between the SBC and SBF.
Advancing a cam will not "push the torque curve down"

Shorter duration, will. VERRY easy to over cam a 302. a larger than stock cam requires a higher towing rpm. ( gears )

50FT/lbs difference betweent eh real and virtual simulation is huge.
You best reconsider your inputs for the engine modeling choices.

This graph shows the basic effect on a engines torque curve when the cam is advanced or retarded. A duration change basicaly moves the whole torque curve up or down the rpm range.

A torque out put GAIN increase requires a increase in total engine AIR flow.
improved volumetric effieientcy or a reduction in friction or a increase in compression or engine CID.

Last edited by F-BIRD'88; 02-20-2012 at 12:04 AM.
Reply With Quote Quick reply to this message
  #33 (permalink)  
Old 02-20-2012, 11:31 AM
1969chevyss's Avatar
Registered User
 
Last photo:
Join Date: Aug 2011
Location: Jacksonville, Fl
Posts: 129
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I called Isky this morning and they recommended the 264 Mega. This camed will give me more low end torque with a noticeble lope at idle but nothing to extreme. He said he have heard from people that the 264 Mega out perfomed some xe268h. The Mega 268 would fit my combo as well if I was planning on changing the stock gears and converter. I'm glad I brought this issue up now and not later causing me to tear the motor down for a flat cam. I know it is still up to me to break in the cam right and use the right oil additives.
Reply With Quote Quick reply to this message
  #34 (permalink)  
Old 02-20-2012, 01:51 PM
techinspector1's Avatar
Senior Curmudgeon
 
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Hemet, California, USA
Age: 72
Posts: 12,947
Wiki Edits: 326

Thanks: 760
Thanked 1,013 Times in 849 Posts
Here's a checklist to help you out.....
http://www.crankshaftcoalition.com/w...ips_and_tricks
Reply With Quote Quick reply to this message
  #35 (permalink)  
Old 02-20-2012, 04:52 PM
6426yy's Avatar
Member
 
Last photo:
Join Date: Nov 2003
Location: Macomb Il.
Age: 35
Posts: 551
Wiki Edits: 0

Thanks: 1
Thanked 1 Time in 1 Post
This is the cam I have in my pickup right now with a 355, th350 and 3.73 posi 12 bolt, summit hyper flat tops, steel shim head gasket and fresh 993 heads with small valves, Holley streetmaster intake with a divider installed and a 600 Holley it runs very well it actually surprised me and my buddies, I'm fixing to install vortec heads this spring after I clean them up and cut the guides down for positive seals, I run the cheap lifters all the time from competition products, or summit using diesel oil and Zddp and never had a problem. I have a comp 4x4 extreme in my 454 and it hasn't went flat broke it in with the outer springs only. I think cam failures are mostly installed wrong and the people don't want to admit they don't know what there doing.

http://www.competitionproducts.com/E...ctinfo/E1065P/
It's close to the comp 268H and has a very nice idle.
Reply With Quote Quick reply to this message
  #36 (permalink)  
Old 02-21-2012, 05:37 AM
stich626's Avatar
gearheadslife
 

Last journal entry: The TwoTonShu #10
Last photo:
Join Date: Aug 2011
Posts: 372
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
Quote:
Originally Posted by 6426yy
This is the cam I have in my pickup right now with a 355, th350 and 3.73 posi 12 bolt, summit hyper flat tops, steel shim head gasket and fresh 993 heads with small valves, Holley streetmaster intake with a divider installed and a 600 Holley it runs very well it actually surprised me and my buddies, I'm fixing to install vortec heads this spring after I clean them up and cut the guides down for positive seals, I run the cheap lifters all the time from competition products, or summit using diesel oil and Zddp and never had a problem. I have a comp 4x4 extreme in my 454 and it hasn't went flat broke it in with the outer springs only. I think cam failures are mostly installed wrong and the people don't want to admit they don't know what there doing.

http://www.competitionproducts.com/E...ctinfo/E1065P/
It's close to the comp 268H and has a very nice idle.
x2
easier to blame the maker of the cams
Reply With Quote Quick reply to this message
  #37 (permalink)  
Old 02-21-2012, 02:06 PM
techinspector1's Avatar
Senior Curmudgeon
 
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Hemet, California, USA
Age: 72
Posts: 12,947
Wiki Edits: 326

Thanks: 760
Thanked 1,013 Times in 849 Posts
Quote:
Originally Posted by 6426yy
I think cam failures are mostly installed wrong and the people don't want to admit they don't know what there doing.
I agree. Most people cannot admit it when they're wrong.
Reply With Quote Quick reply to this message
  #38 (permalink)  
Old 02-21-2012, 04:39 PM
Registered User
 
Last photo:
Join Date: Jul 2004
Location: At Speed
Age: 51
Posts: 1,347
Wiki Edits: 0

Thanks: 2
Thanked 30 Times in 30 Posts
I bailed on Comp years ago.
If you're building a SBC, they probably make fine street cams.
If you want your junk to run like its supposed to, then look elsewhere.
For catalog cams, I only use Isky.
For race engines, I only use custom grinds.
Reply With Quote Quick reply to this message
  #39 (permalink)  
Old 02-22-2012, 06:18 PM
lust4speed's Avatar
Member
 
Last photo:
Join Date: Oct 2003
Location: Inland Empire, SOCAL
Posts: 424
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Well, you can say what you want about failures being caused by incorrect installation, but how do you justify the professional engine builders that went from no failures to several failures overnight? Then just about as quickly as the failures started, they have went away. There's still old stock from a couple of years ago being sold that should have been trashed, so we are still seeing a few failures with everything done right.

I don't believe that the cam blanks were the problem, but the white box lifters being sold during that time period. A crap lifter will take out even a good cam quickly. I may be wrong, but anyone heard of an installation with a set of Rhoads lifters going bad during that time period? Same cams, but different lifters didn't seem to have any problems.

Many years ago I ran a 268H cam in my (Pontiac) 455. Really great mid-range, but power flattened out about 4,500 RPM. Cam specs seemed like the power curve should have went much higher before running out of steam. Installed a Crower cam with close to the same specs and the power curve went 1,000 RPM higher before leveling off.
Reply With Quote Quick reply to this message
  #40 (permalink)  
Old 02-22-2012, 06:59 PM
1969chevyss's Avatar
Registered User
 
Last photo:
Join Date: Aug 2011
Location: Jacksonville, Fl
Posts: 129
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I'm going to take all the factors into consideration but I've already ordered the isky mega 264 with lifters. The xe268 probably would have been good for me with my mild build but why take chances especially at this stage in the build.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Cam lobes grinding down!?!? chevycarlo91 Engine 11 08-05-2009 06:01 PM
Wiped out a cam lobe :( 66GMC Engine 25 04-28-2008 05:49 PM
what lenght pushrods? wiped out cam? 78 ford 302 Warrant Engine 2 03-19-2007 11:26 AM
Article on Oil, Wiped Lobes HawkZ28 Engine 8 06-08-2006 10:33 AM
Questions for wiped lobe victims & engine gurus JPhil Engine 17 09-22-2005 07:01 PM


All times are GMT -6. The time now is 08:26 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.