Just wiped a lobe. Wanna try a non-thumpr now. Any suggestions so I don't lose power? - 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> Hotrodding Basics
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 02-19-2013, 09:13 PM
Registered User
 
Join Date: Jun 2011
Location: USA
Posts: 44
Wiki Edits: 0

Thanks: 3
Thanked 0 Times in 0 Posts
Just wiped a lobe. Wanna try a non-thumpr now. Any suggestions so I don't lose power?

Basically, I had the hydraulic flat tappet thumpr cam. (smallest, not mutha, etc.) Here are the specs for it.

What should I look for in a non-thumpr cam to offer close to equal power as what I have now? Just make sure it has the same lift duration?

FYI It's a 350 sbc basically stock but with upgraded aluminium heads, edelbrock air gap intake, and holley 650 dp.
Reply With Quote
  #2 (permalink)  
Old 02-19-2013, 09:30 PM
33Willys77's Avatar
Registered User
 
Join Date: Jan 2013
Location: Wisconsin
Posts: 214
Wiki Edits: 0

Thanks: 2
Thanked 23 Times in 23 Posts
Are you saying the cam lobe wore off the cam?
Reply With Quote
  #3 (permalink)  
Old 02-19-2013, 09:31 PM
vinniekq2's Avatar
Registered User
 
Join Date: Jun 2012
Location: BC,Canada
Age: 55
Posts: 3,450
Wiki Edits: 0

Thanks: 98
Thanked 241 Times in 236 Posts
110941-11 CL110941-11 279 279 225 225 .465 .465 111 108 Hyd. Hyd. 1
1500-5600 Fair idle, Strong mid-range performance.
or step up to

113215-10 CL113215-10 270 278 217 225 .495 .500 110 106 Hyd. Hyd. 1,2
1300-5500 Good idle, Street Performance. Strong lower mid range. Stock converter OK.
depends on money
second choice here would be nice and idle better,but make more power
Reply With Quote
  #4 (permalink)  
Old 02-19-2013, 11:25 PM
Registered User
 
Join Date: Feb 2013
Posts: 63
Wiki Edits: 0

Thanks: 0
Thanked 9 Times in 9 Posts
Thats what I keep fearing although maybe unfounded but to have a wreck with a flat tappet cam rather then going the roller way. I assume you've been looking in the Comp catalog online and go to page 170 where it mentions getting a cam nitrided which will hopefully help with a cam starting the wear process and wiping a lobe. Worth asking about anyway.
Reply With Quote
  #5 (permalink)  
Old 02-20-2013, 01:01 AM
JeffB's Avatar
Registered User
 
Last photo:
Join Date: Jul 2006
Location: Phoenix,AZ
Age: 67
Posts: 1,305
Wiki Edits: 0

Thanks: 1
Thanked 16 Times in 16 Posts
Quote:
Originally Posted by Zerocyde View Post
Basically, I had the hydraulic flat tappet thumpr cam. (smallest, not mutha, etc.) Here are the specs for it.

What should I look for in a non-thumpr cam to offer close to equal power as what I have now? Just make sure it has the same lift duration?

FYI It's a 350 sbc basically stock but with upgraded aluminium heads, edelbrock air gap intake, and holley 650 dp.
Howard has been known for a harder surface core this should be a good match: Howards Cams Hydraulic Flat Tappet Camshaft and Lifter Kits CL110041-12 - SummitRacing.com
Reply With Quote
  #6 (permalink)  
Old 02-20-2013, 01:55 AM
Registered User
 
Join Date: Jun 2011
Location: USA
Posts: 44
Wiki Edits: 0

Thanks: 3
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by 33Willys77 View Post
Are you saying the cam lobe wore off the cam?
Yes. Noticed a ticking and saw that one rocker wasn't moving as far as the rest. Pulled the lifter out and it was beat to hell and domed. Looked down at the cam and that lob was basically gone.

Thanks for the good suggestions, guys. All I want is a cam that will (at least) match the power that I got from the thumpr, but without the whole "give up driveability for a cool sound" aspect.
Reply With Quote
  #7 (permalink)  
Old 02-20-2013, 10:19 AM
S10xGN's Avatar
Gotta love a turbo!
 

Last journal entry: Body on Frame today.
Last photo:
Join Date: Aug 2004
Location: Port Neches, TX
Age: 59
Posts: 1,306
Wiki Edits: 0

Thanks: 0
Thanked 9 Times in 9 Posts
It's prolly gonna be more about what oil and additives you're using than just replacing the cam. If you don't have enough zinc, ZDDP, phosphorus, etc in your oil, the new cam will meet the same fate as the current one.

Russ
Reply With Quote
  #8 (permalink)  
Old 02-20-2013, 10:40 AM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 58
Posts: 4,203
Wiki Edits: 1616

Thanks: 86
Thanked 389 Times in 357 Posts
Quote:
Originally Posted by Zerocyde View Post
Yes. Noticed a ticking and saw that one rocker wasn't moving as far as the rest. Pulled the lifter out and it was beat to hell and domed. Looked down at the cam and that lob was basically gone.

Thanks for the good suggestions, guys. All I want is a cam that will (at least) match the power that I got from the thumpr, but without the whole "give up driveability for a cool sound" aspect.
Below are a couple pages w/info that should help you have a successful cam break in. If you don't read anything else, be sure to check out the first page listed. Good luck.
Cam break in
Adjusting hydraulic lifters
Valve train points to check
Valve train geometry
Valve spring installed height
Reply With Quote
  #9 (permalink)  
Old 02-20-2013, 10:44 AM
Registered User
 
Join Date: Jun 2011
Location: USA
Posts: 44
Wiki Edits: 0

Thanks: 3
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by cobalt327 View Post
Below are a couple pages w/info that should help you have a successful cam break in. If you don't read anything else, be sure to check out the first page listed. Good luck.
Cam break in
Adjusting hydraulic lifters
Valve train points to check
Valve train geometry
Valve spring installed height
I had the cam for 3 years before the lobe wiped. I thought cam break-ins were only like 200 miles...
Reply With Quote
  #10 (permalink)  
Old 02-20-2013, 11:06 AM
vinniekq2's Avatar
Registered User
 
Join Date: Jun 2012
Location: BC,Canada
Age: 55
Posts: 3,450
Wiki Edits: 0

Thanks: 98
Thanked 241 Times in 236 Posts
why not upgrade to a small roller hydraulic like I posted?make more power with a much nicer idle
Reply With Quote
  #11 (permalink)  
Old 02-20-2013, 11:14 AM
33Willys77's Avatar
Registered User
 
Join Date: Jan 2013
Location: Wisconsin
Posts: 214
Wiki Edits: 0

Thanks: 2
Thanked 23 Times in 23 Posts
I had a roller lifter arm break and the lifter spun and took out the roller and cam. All that metal went into the motor and chewed the bearings and pump up. Take a close look and do not just throw in a new cam. You might want to consider a rebuild!
Reply With Quote
  #12 (permalink)  
Old 02-20-2013, 11:35 AM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 8,142
Wiki Edits: 0

Thanks: 0
Thanked 171 Times in 169 Posts
Change to a Isky 270H Mega cam. Isky #201271
The idle won;t be quite as rough. Lots of power.

Be sure your lifter bores a re free of burr edges especially on the bottom edge of the bore.
The lifters must be able to spin in their bores or the cam will fail.
minor bore honing many be required.
best to pull the pan and wash everythng out after a cam lobe failure.
The Isky cams are high quality.
ISKY Racing Cams - Do It Right. Race with the Legend. Camshafts, Connecting Rods, Valve Springs, Lifters This Isky 270H mega cam is available in various versions, dual pattern, different LSA etc

I use GM EOS and this stuff
Molyslip Canada Inc. :: Molybdenum Lubricants, Performance Lubricants, Copaslip Anti-Seize, EP2 Grease, Wear Reducing Lubricants, Oil Additive E oil suplement in the oil to aid cam break in and avoid scuffing
Reply With Quote
  #13 (permalink)  
Old 02-20-2013, 12:18 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 58
Posts: 4,203
Wiki Edits: 1616

Thanks: 86
Thanked 389 Times in 357 Posts
Quote:
Originally Posted by Zerocyde View Post
I had the cam for 3 years before the lobe wiped. I thought cam break-ins were only like 200 miles...
Generally the cam is broken in for at least 20 minutes w/the engine at or above 2000 rpm, varying the rpm, w/o idling. So it's not really a matter of how many miles, unless you're able to meet the above criteria while driving the vehicle. Which isn't recommended.

The oil that is available from gas stations and parts stores is not generally going to have the additives present that are needed to keep a performance flat tappet cam and lifters from wearing at an increased rate. Using an oil specifically formulated for flat tappet performance engines, or adding ZDDPlus (or other similar additives) to OTC motor oil will help in this regard.
Reply With Quote
  #14 (permalink)  
Old 02-20-2013, 06:13 PM
Registered User
 
Join Date: Feb 2013
Posts: 63
Wiki Edits: 0

Thanks: 0
Thanked 9 Times in 9 Posts
33Willys, I assume that was a retrofit style roller set then and what brand and model type were they as I know with roller cams a lot of mix and match can be done so one brand cam with another brand roller lifter and even used rollers for that matter.
Reply With Quote
  #15 (permalink)  
Old 02-20-2013, 08:15 PM
33Willys77's Avatar
Registered User
 
Join Date: Jan 2013
Location: Wisconsin
Posts: 214
Wiki Edits: 0

Thanks: 2
Thanked 23 Times in 23 Posts
They were an old style. It was more like sprung steel in an arch that held the 2 together. One little tab broke on it and it turned. Very costly when it happens to a 392 Hemi - solid roller too.
Reply With Quote

Recent Hotrodding Basics posts with photos


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

Posting Rules
You may not post new threads
You may not 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
What's equivalent (power-wise) to a thumpr? Zerocyde Engine 27 06-12-2012 11:59 AM
wanna increase power 1990 corvette alinberta88 Engine 2 05-06-2009 07:42 PM
Wiped out a cam lobe :( 66GMC Engine 25 04-28-2008 05:49 PM
Questions for wiped lobe victims & engine gurus JPhil Engine 17 09-22-2005 07:01 PM
why did the cadillac 500 lose power over the years? Macman Engine 15 07-29-2003 03:53 AM


All times are GMT -6. The time now is 03:55 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2013, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.