Avoiding Flat Cam Syndrome-Engine Builder - 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 10-21-2012, 05:47 AM
1Gary's Avatar
Registered User
 

Last journal entry: 383 dyno sym
Last photo:
Join Date: Oct 2010
Location: Roch,NY
Age: 66
Posts: 1,514
Wiki Edits: 0

Thanks: 201
Thanked 153 Times in 139 Posts
Avoiding Flat Cam Syndrome-Engine Builder

I saw this article in Engine Builder Mag and thought maybe you guys know this already and may be not. Want to give credit to Engine Builder Shop solutions and to Norm Johns.


Along with the use of assembly lubes, break-in oils with ZDDP (Zinc Dialkyl Dithiosphate), and a lifter bore grooving tool our shop does this; on all flat tappet cam engines our shop has added one step before final assembly.

With the block in a bare and clean state we’ll put in the two end cam bearings and install the cam with only light oil. Next we install the lifters with only light oil. Install a bolt in the front of the cam and spin it quickly clockwise with a speed handle and observe each lifter’s spinning action when the engine is running. You can use a felt pen to mark the lifters so it’s easier to see them spinning. If you find any of the lifters not spinning, this could be a potential problem if it leaves your shop like that. Lifter bore or even cam bore alignment could be the problem.

Many times the cam bearing bores get closer (fall) towards the crank centerline going front to back, (especially on BB Chevys) which in turn causes the taper on the cam lobe to be lessened towards the back of the motor. Zero or too little taper can keep the lifter from spinning, and this can cause the cam to fail shortly after fire-up.

To remedy this problem without reboring lifter or cam bores check local listings or the internet under custom cam grinding to have the cam reground with more taper grind into the lobes. After regrinding we do the test again. We’ve had great luck and no flat cams when all of the lifters spin before we fully assemble the engine, even with today’s lousy oils! Yes this will cost more, but what will really cost more – an extra cam grind, or a flat cam, or a comeback and angry customer? Thanks and good luck.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 10-21-2012, 08:44 AM
Registered User
 
Last wiki edit: General Motors transmissions Last photo:
Join Date: Mar 2006
Location: near Yellowstone park
Posts: 4,211
Wiki Edits: 27

Thanks: 11
Thanked 233 Times in 219 Posts
flat cam

My room mate in college rebuilt his Ford Fe and the cam went flat in 100 miles, he pulled it apart at their farm shop and got another new cam from the dealer and it went flat again in about 100 miles. I went to his house for weekend to help and found that the cam was catching two lifters with the same lobe. Factory replacement cam and original block, it only got new rings and bearings the first rebuild. I ended up getting a transmission thrust washer from a box of spare pieces the dealer had in their parts room, and every since then I drop in one lifter at a time and rotate tthe cam to check.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 10-21-2012, 09:46 AM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,540
Wiki Edits: 0

Thanks: 3
Thanked 331 Times in 328 Posts
Good post. Correct cam manufacture process is critical. (correct lobe taper included)
This why I use and recomend Isky cams for flat tappet camshafts.
Not made by a contracted "out sourced" cam grinder at the lowest bid price, as many popular high volume
catalog cams are.

How the cam is actually ground, matters.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 10-21-2012, 11:10 AM
hcompton's Avatar
Old & Furious
 
Join Date: Oct 2012
Location: MD
Age: 41
Posts: 1,074
Wiki Edits: 0

Thanks: 6
Thanked 87 Times in 84 Posts
Quote:
Originally Posted by F-BIRD'88 View Post
Good post. Correct cam manufacture process is critical. (correct lobe taper included)
This why I use and recomend Isky cams for flat tappet camshafts.
Not made by a contracted "out sourced" cam grinder at the lowest bid price, as many popular high volume
catalog cams are.

How the cam is actually ground, matters.
Most cams factory oem and aftermarket are made by Camshaft Machine Corperation in michigan. They are top quality manufacturer of cams. Most bad grinds come from old templates and in house ground cams. Not sure about the lifters but they usally fail and wipe out the cam. For most cases of failure its either inproper installation or bad lifters. Possibly before and after the heat treatment.

Since they are mostly cnc ground. Its kind of hard to convince your cnc not to do what its told. They are also scanned with lasers to make sure grind was correct. This is the same process and companies that ford and chevy use.

that being said there is alot of junk out there. With a big lathe and some skill you can make your own cams. Regrinds are even easier. And alot more common than you may think. This where you get into trouble.

Isky is a great cam but i bet they make just as many bad ones as anyone else. But they do alot of quaility control to make sure they never reach the public. And that makes a world off diference. I did not see anything on isky site saying they make them in house. But that is fine.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 10-21-2012, 12:33 PM
Registered User
 
Last photo:
Join Date: Apr 2007
Location: Seattle, Wa
Posts: 6,692
Wiki Edits: 0

Thanks: 3
Thanked 404 Times in 349 Posts
Quote:
Originally Posted by 1Gary View Post
I saw this article in Engine Builder Mag and thought maybe you guys know this already and may be not. Want to give credit to Engine Builder Shop solutions and to Norm Johns.


Along with the use of assembly lubes, break-in oils with ZDDP (Zinc Dialkyl Dithiosphate), and a lifter bore grooving tool our shop does this; on all flat tappet cam engines our shop has added one step before final assembly.

With the block in a bare and clean state we’ll put in the two end cam bearings and install the cam with only light oil. Next we install the lifters with only light oil. Install a bolt in the front of the cam and spin it quickly clockwise with a speed handle and observe each lifter’s spinning action when the engine is running. You can use a felt pen to mark the lifters so it’s easier to see them spinning. If you find any of the lifters not spinning, this could be a potential problem if it leaves your shop like that. Lifter bore or even cam bore alignment could be the problem.

Many times the cam bearing bores get closer (fall) towards the crank centerline going front to back, (especially on BB Chevys) which in turn causes the taper on the cam lobe to be lessened towards the back of the motor. Zero or too little taper can keep the lifter from spinning, and this can cause the cam to fail shortly after fire-up.

To remedy this problem without reboring lifter or cam bores check local listings or the internet under custom cam grinding to have the cam reground with more taper grind into the lobes. After regrinding we do the test again. We’ve had great luck and no flat cams when all of the lifters spin before we fully assemble the engine, even with today’s lousy oils! Yes this will cost more, but what will really cost more – an extra cam grind, or a flat cam, or a comeback and angry customer? Thanks and good luck.
It's looking like the days of running a flat tappet cam, on the street at least, are about closed. Around the Seattle area it's getting increasingly difficult to find heavier weight oils including 15-40 and 20-50 as the EPA wants all the ZDDP carrying oil off the market plus these new engines use very light weight oils with no ZDDP. We just put in a supply of 15-40 DELVIC cause our local distributor says when that's gone boys there ain't gonna be any more.

I'm thinking the race sanctioning bodies are going to very shortly have to rethink their ban on roller lifter cams as well. I guess the 60's truly are over.

I have for decades used a cam button on Chevy flat tappet cams, I feel the lobe and lifter, as well as the distributor gear have plenty enough to do without also holding the cam in the block. The two things that come out of this is that we hardly ever experience wiped lobes and lifters even with today's low ZDDP oils while the so called spark scatter problem even with the 7 tooth SBC oil pump is mostly gone. We, also, do not use oil restrictors even with solids and we use standoff vents rather than closing the drain back holes in the valley along the cam. This does shut off the mid block drain back from raining on the crank while allowing some breathing space so all the blow by isn't trying to get into the valley on the ends where I'm also trying to get the drain back oil to drop into the pan.

Bogie
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 10-21-2012, 07:03 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: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Camshaft install tips and tricks
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 10-21-2012, 08:23 PM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,540
Wiki Edits: 0

Thanks: 3
Thanked 331 Times in 328 Posts
It's looking like the days of running a flat tappet cam, on the street at least, are about closed.

I highly doubt that.

i agree must of the flat tappet cam lifter premature deaths are from improper installation/break in method.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 10-22-2012, 12:12 AM
Registered User
 
Join Date: Oct 2008
Location: Mora,MN
Posts: 414
Wiki Edits: 0

Thanks: 0
Thanked 6 Times in 6 Posts
Quote:
Originally Posted by hcompton View Post
Most cams factory oem and aftermarket are made by Camshaft Machine Corperation in michigan. They are top quality manufacturer of cams. Most bad grinds come from old templates and in house ground cams. Not sure about the lifters but they usally fail and wipe out the cam. For most cases of failure its either inproper installation or bad lifters. Possibly before and after the heat treatment.

Since they are mostly cnc ground. Its kind of hard to convince your cnc not to do what its told. They are also scanned with lasers to make sure grind was correct. This is the same process and companies that ford and chevy use.

that being said there is alot of junk out there. With a big lathe and some skill you can make your own cams. Regrinds are even easier. And alot more common than you may think. This where you get into trouble.

Isky is a great cam but i bet they make just as many bad ones as anyone else. But they do alot of quaility control to make sure they never reach the public. And that makes a world off diference. I did not see anything on isky site saying they make them in house. But that is fine.

there is so much misinformation in this post, I'm not even sure where to start.
isky, comp, bullet, elgin, erson, crane. that's a large amount of the aftermarket and they are NOT ground at that place. and I'm not even mentioning any of the smaller custom grinders that do their own in house. not saying anything bad about it, but they certainly don't grind cams for these places.
next, you cannot, no way, not physically possible, make a camshaft on a lathe.
i have been a machinist for many years, run everything from small lathes to
mills bigger than a house, and a lathe simply can't make a cam. maybe you could rough one out, but without getting into the technical aspects of it, it just can't be done.
and just to clarify, isky does manufacture in house, and is among the top cams out there.
they all have issues, any manufactured part will to some extent, but their stuff is top quality and i see very few issues with them.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 10-22-2012, 12:43 AM
spinn's Avatar
I Wear 1 Pair of Sox at a Time
 

Last journal entry: This makes a huge difference
Last photo:
Join Date: Oct 2004
Location: midwest
Posts: 2,363
Wiki Edits: 0

Thanks: 5
Thanked 78 Times in 76 Posts
My engines have never had a cam go flat. Never use assembly lube just 30wt oil. Prime good while rotated and have a break in procedure. The thick pastes might impede the lifter rotation and cause the failures I read about. There is alot happening and the hobbies regulating itself, slowing to a standard. Hydraulic flat tappets are long term and not going anywhere.

Nothing i build sees more than 5500rpm, and not per say, raced.

Flat hydraulic cams from edelbrock, comp and lunati have beem my choice. Almost always staying under .500" cam lift and racing high seat spring pressures. That could have something to do with the margin for error.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 10-22-2012, 06:09 AM
hcompton's Avatar
Old & Furious
 
Join Date: Oct 2012
Location: MD
Age: 41
Posts: 1,074
Wiki Edits: 0

Thanks: 6
Thanked 87 Times in 84 Posts
Quote:
Originally Posted by Plaintoast View Post
there is so much misinformation in this post, I'm not even sure where to start.
isky, comp, bullet, elgin, erson, crane. that's a large amount of the aftermarket and they are NOT ground at that place. and I'm not even mentioning any of the smaller custom grinders that do their own in house. not saying anything bad about it, but they certainly don't grind cams for these places.
next, you cannot, no way, not physically possible, make a camshaft on a lathe.
i have been a machinist for many years, run everything from small lathes to
mills bigger than a house, and a lathe simply can't make a cam. maybe you could rough one out, but without getting into the technical aspects of it, it just can't be done.
and just to clarify, isky does manufacture in house, and is among the top cams out there.
they all have issues, any manufactured part will to some extent, but their stuff is top quality and i see very few issues with them.
Its very accurate. Just look it up. or try giving them a call. Most are very honest as a cam made by CMC is top of the line stuff.

So you have never used a pattern cutter with a grinder on a lathe. This will cut a cam for sure and not that hard to make your own pattern cutter. Kinda works the same way table legs are made. Sep they use very accurate machines. I have a lathe and mill in my garage. I have seen people making cams in realy life they are made on a lathe. A cnc machine designed to cut cams looks just like a lathe just designed to grind and not cut. Very simple device nothing to it. Just make a pattern by hand or by cnc or by enlarging another cam lobe to be your stating point. Most of the cheap regrinds only grind the back of the cam the base circle.

Here is a video from comp cams you can see a guy making a cam. Yes it is cnc ground but you can see how easy it would be to have it made by pattern. Also note how small the heat treating machine is what does it hold 10 cams at once? not high productions.

here is a link where comp is talking about bringing work in house with just one machine for one off cams. They even say they do not focus on making cams just the lobe profiles.
More Effective Camshaft Machining : Modern Machine Shop

I believe you isky does in house stuff. But is your cam you got from them in house or just one of the many grinds found setting on the shelf at CMC. As you can imagine most cams designs were probably thought of and pattened the day after the v8 was invented at gm. Since the math has not changed you can figure they had come up with all the same ideas as everyone else. It is modern metals and cnc manufacturing that has made some newer cam grinds more effective.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 10-22-2012, 10:41 AM
Registered User
 
Last photo:
Join Date: Apr 2007
Location: Seattle, Wa
Posts: 6,692
Wiki Edits: 0

Thanks: 3
Thanked 404 Times in 349 Posts
Quote:
Originally Posted by spinn View Post
My engines have never had a cam go flat. Never use assembly lube just 30wt oil. Prime good while rotated and have a break in procedure. The thick pastes might impede the lifter rotation and cause the failures I read about. There is alot happening and the hobbies regulating itself, slowing to a standard. Hydraulic flat tappets are long term and not going anywhere.

Nothing i build sees more than 5500rpm, and not per say, raced.

Flat hydraulic cams from edelbrock, comp and lunati have beem my choice. Almost always staying under .500" cam lift and racing high seat spring pressures. That could have something to do with the margin for error.
You must be living in an alternate universe, the SBC has had so much trouble with wiped lobes/lifters it became the foundation of a class action law suit which the consumers lost to GM but never-the-less it was a huge problem up till GM started using roller cams in car engines in 86 and they neutered the truck cams to very low lifts less than .4 inch and durations of less than 170 degrees till the roller Vortec came on line in 96 with baby buggy valve springs to reduce the load between the lobe and lifter.

Bogie
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 10-22-2012, 02:49 PM
1Gary's Avatar
Registered User
 

Last journal entry: 383 dyno sym
Last photo:
Join Date: Oct 2010
Location: Roch,NY
Age: 66
Posts: 1,514
Wiki Edits: 0

Thanks: 201
Thanked 153 Times in 139 Posts
There are shops that turn down jobs that are not rollers. With the potential of customers bad mouthing the shop and the losses due to comebacks,it just isn't profitable to do flat tappets.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 10-23-2012, 06:49 AM
Registered User
 
Join Date: Nov 2011
Location: Virginia
Posts: 705
Wiki Edits: 0

Thanks: 0
Thanked 75 Times in 75 Posts
CMC DOES grind most of the flat-tappet hydraulic cams ground in the USA today. Comp AND Lunati have told me this. CMC was the main "vendor" to the car companies prior to the advent of rollers. It made perfect "sense" to use their equipment. Comp, Crower, Lunati, etc. (the "big" cam companies) own their own "masters" and CMC uses them for propietary grinds (like XE and VooDoo). Most of the generi-grinds (Elgin, Wolverine, Edelbrock...) are "re-hashes" from older grinds.

There are MANY applications for flat-tappet hydraulics. We still sell a bunch. The cost of rollers runs many people away. Pop had a "saying" that fits here. "When all else fails, follow instructions!" If one were to follow specifically, the instructions for "break-in" provided by Comp, Crower, Lunati, etc., most "flat lobes" wouldn't have happened. Excessive spring pressure is another cause. Many believe you "need" more spring than you really do...

FWIW

Jim
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 10-23-2012, 07:02 AM
Registered User
 
Last photo:
Join Date: Jun 2010
Location: Syracuse, NY
Posts: 2,081
Wiki Edits: 0

Thanks: 374
Thanked 206 Times in 185 Posts
Quote:
Originally Posted by oldbogie View Post
You must be living in an alternate universe, the SBC has had so much trouble with wiped lobes/lifters it became the foundation of a class action law suit which the consumers lost to GM but never-the-less it was a huge problem up till GM started using roller cams in car engines in 86 and they neutered the truck cams to very low lifts less than .4 inch and durations of less than 170 degrees till the roller Vortec came on line in 96 with baby buggy valve springs to reduce the load between the lobe and lifter.

Bogie
I vividly remember my father and uncles replacing several broomstick cams in 307s; that and the plastic geared "silent running" timing sets used to drive people nuts around here
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 10-23-2012, 11:52 AM
Member
 
Last photo:
Join Date: Aug 2003
Location: surrey bc canada
Age: 74
Posts: 642
Wiki Edits: 0

Thanks: 0
Thanked 9 Times in 9 Posts
fe cam isues

Quote:
Originally Posted by timothale View Post
My room mate in college rebuilt his Ford Fe and the cam went flat in 100 miles, he pulled it apart at their farm shop and got another new cam from the dealer and it went flat again in about 100 miles. I went to his house for weekend to help and found that the cam was catching two lifters with the same lobe. Factory replacement cam and original block, it only got new rings and bearings the first rebuild. I ended up getting a transmission thrust washer from a box of spare pieces the dealer had in their parts room, and every since then I drop in one lifter at a time and rotate tthe cam to check.
if the engine is 1963 and older it should have a spring and buton on the end,had a simler isue and builder had left them out.1964 and up have a thrusr plate and a diferent gear that holds the cam in place.pre 64 fes can be easly converted as hard to find the spring and button as well as clip'i have 1 left cliff
Reply With Quote Quick reply to this message

Recent Hotrodding Basics 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
roller cam vs Hyd. flat tapper cam Dannyringo Hotrodding Basics 48 04-12-2012 05:03 PM
Question for Cam Expert or Engine Builder 69chevyLWB Engine 5 03-02-2011 10:20 PM
I need a engine builder F3RR3T Engine 5 10-02-2008 06:06 AM
Roller cam vs. Flat Tappet cam Half Breed Engine 4 01-11-2006 08:31 PM
Looking For AZ Engine Builder Alejake Engine 0 06-22-2002 06:25 PM


All times are GMT -6. The time now is 01:19 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.