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Author
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Topic: Boy was I barking up the wrong tree!
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Butch Jennings
Gearhead Posts: 633
From: No. California
Registered: Apr 2000
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posted 06-25-2002 05:10 AM
   
I did the test that Alex told me to do to check my converter and it seemed to be down on power. I got a set of Jomar stud girdles (long overdue) off of Ebay that showed up today and was putting them on tonight. As I was adjusting the valves I noticed I've got an intake rocker that is moving a lot less than the rest  ....flat cam! That pretty much explains away everything that was going on with the car Friday night. It's pretty ironic, we were really puzzled at why the car didn't react to what we were throwing at it like we figured it should. I remember telling Larry that maybe we were tuning around something that was going away (I thought converter  )and we were actually doing pretty good to keep it stepping up. 10.62 with a cam going away is pretty encouraging actually. I've got an appointment to align the front end on Wednesday that I'm going to keep, but I think I found the problem. Thanks for all of your help guys  . ------------------
Butch
460 powered 1967 Comet Cyclone
10.271 @ 130.231
Butcher's Home Page
"Friends don't let friends drive Chevys"
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bluestreek
Gearhead Posts: 1724
From: Athens,GA
Registered: Jul 2001
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posted 06-25-2002 10:26 AM
I should have thought about that! My bro-in-law just went through the same thing with a freshly rebuilt motor. When the motor didn't run to expectations and sounded noisier than usual, he took it down and found 3 wiped lobes on the cam. He used a "good old" cam with new lifters and after I asked him about it, he admitted that he didn't use any cam break-in lube because the cam was already broke in. Not sure if that is what caused it, but it didn't help.
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SteveLaRiviere
Administrator Posts: 45869
From: Saco, Maine
Registered: May 99
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posted 06-25-2002 10:36 AM
Butch, what was the converter test?Also, were these Crane cams? I know of three Crane cams that wiped out cam lobe really early. They must be using pencil lead... ------------------
'70 Mustang Mach 1, '72 Mustang Sprint, '94 F-150
Pics
MCA Member # 47773
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Moneymaker
Administrator Posts: 27499
From: Lyons, IL, USA
Registered: May 99
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posted 06-25-2002 11:45 AM
I'll tell you guys.  I have seen every type of cam known to man flatten and hypothosised or scienced every reason in the world. Bad material, too much spring pressure, not enough spring pressure, too much lube, not enough lube, the wrong lube,not enough oil, too much oil, wrong lifters, old lifters, etc, etc.
I have had .650 lift solid cams last forever, and have had .490 lift hydraulic cams go flat before my eyes.
The only expanation I have is that years ago there were 2-300 cam manufacturers/grinders and only THREE (3) prime core/blank suppliers.
Anyone with a grinder started a cam company.
Now we are down to a hand full of cam companies by comparison (25-30) and still have only 3 prime core suppliers. I feel that the workmanship at the grinders has been raised to higher standards because of competition and the heat treating processes that were often "skipped" in the past to save money have a lot to do with it. I rarely have or see a cam go flat anymore unless it is due to contamination, or lack of lubrication. Especially when using a premium synthetic lubricant like Royal Purple.
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Alex Denysenko
Co-Administrator and Moderator/ non 65-66 Mustang owner sensitivity co-ordinator NHRA/IHRA/SRA member
NHRA and IHRA SS/LA National Record Holder '00, '01, & '02
Fleet of FoMoCo products including 88 ASC McLaren Mustang #28
Part time secret agent license #0089
Professional Manwhore
The Barry of BarrysGrrl
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SteveLaRiviere
Administrator Posts: 45869
From: Saco, Maine
Registered: May 99
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posted 06-25-2002 12:30 PM
Alex, you're an old guy like me. Remember all those sbc cams that would flatten out? {maybe from '68-'75 or so?} Those suckers must have been whittled outta alka-seltzer! ------------------
'70 Mustang Mach 1, '72 Mustang Sprint, '94 F-150
Pics
MCA Member # 47773
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bluestreek
Gearhead Posts: 1724
From: Athens,GA
Registered: Jul 2001
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posted 06-25-2002 01:05 PM
So Alex, what your saying is that any new or old cam and lifters, on any given break-in, can just eat itself up and the reason is rarely ever found? Dan
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Moneymaker
Administrator Posts: 27499
From: Lyons, IL, USA
Registered: May 99
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posted 06-25-2002 01:34 PM
Steve, when you and I were turning wrenches for a living, two GM engines were notorious for eating cams. ANY V-8 Pontiac and the original 305 chebbies.
Ponchos required 6 quarts of oil and most service garages used to miss that. They would only install 5 with an oil change. Run a Poncho V-8 low on oil (and they all used some) and you will flatten the cam and/or eat the timing gear in no time.
When GM introduced the 305 in 1975 it was a wonderful design for fuel economy. Small bore, long stroke. The engineers designed a pee pee cam to barely hang the valves open. GM's supplier at the time for cams was Melling and they could not tool up and meet the supply demand in time. GM outsoursed to another vendor and that vendor came through with several hundred thousand cams. THEY WERE ALL BAD! Even if the engine was well maintained, the cams went flat. Even though I was never a GM tech, I must have replaced hundreds of 305 chebbie cams on used cars and side jobs. Biggest mistake made was installing a normal TM-274 283-350 cam because an aftermarket 305 cam was unavailable. GM recalled all stock on hand and was waiting for Melling to ship higher quality replacement product. The 350 cam had more lift and duration, which caused the 305's to idle rough and killed the fuel economy.
Dan, in a word...yes. I have sent them back to cam companies, sent them to foundries, heat treating shops for evaluation, and always got some sort of an answer which never made sense.
Most often, the cam company claimed too much spring pressure on brake in, and the heat treating shops claimed oil contamination or break down. BULL$HIT! 
I have tried using damn near carb return spring tension springs for break in, and flushed NEW engines with 3 gallons of oil before start up. Still they would go flat! Back in the 70's, they just did not have the lifter or cam technology we have today. That's why 9 out of 10 times a cam company would replace the cam and lifters.
Today with premium lifters and cores, it is very rare that I se a cam go flat, unless it is on a NHRA/IHRA stocker engine. That usually happens only when oil is drained out to go fast, or if the lifters are poor quality. 
By the way, I don't know if I told you all , but the worlds largest supplier and manufacturer of lifters, Johnson Tappet Co. went out of business a month or so ago. They supplied 75% of the lifters, solid, hydraulic, and hydraulic roller in the USA!
There is a significant reason for their failure and closing which directly relates to this thread. Next time.
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Alex Denysenko
Co-Administrator and Moderator/ non 65-66 Mustang owner sensitivity co-ordinator NHRA/IHRA/SRA member
NHRA and IHRA SS/LA National Record Holder '00, '01, & '02
Fleet of FoMoCo products including 88 ASC McLaren Mustang #28
Part time secret agent license #0089
Professional Manwhore
The Barry of BarrysGrrl
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Dad Vishus
Gearhead Posts: 1064
From: Moscow, Iowa, USA
Registered: Dec 2001
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posted 06-26-2002 10:55 AM
Butch: Glad you figured out the problem.I kindof thought there must be something else going on. Changing over to alchohol should have made your car pick up quite a bit, all things being equal otherwise. 2 years ago, Kid put a backup motor in the 69 that was basically a street motor. It had a bunch of leftover parts in it and was done on an extremely small budget. The thing ran like crap on gas. It was about 10.25 to 1 compression and had a fairly mild solid cam in it. We decided we didn't have much to lose by trying alky so we did. That motor sounded great on methanol and picked 3 tenths and almost 5 MPH in the eighth mile. Just changed to the alchohol carb and bumped up the timing a bit. That motor ran the rest of the season (over half of it) and got us a 2nd place in points for the year. Not bad for a $150 motor. Anyway, when you get everything back as it should be, you should pick up substantially. I think you'll be pleased. 
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TomP
Gearhead Posts: 6120
From: Delta BC Canada
Registered: Dec 99
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posted 06-26-2002 08:02 PM
Yeah, i heard about Johnson closing. How will this affect near-future lifter supplies? I just got robbed for bearings today... i used to be able to buy whole rebuild sets with rings/bearings/gaskets/lifters/timing chain &oil pump cheaper than just the rod/main bearings cost me. Nowadays the Taiwanese garbage is taking over
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