Ford 7.3 Gas Engine Failure
Cargo Master
Joined: Oct 2020
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What you have to remember is that roller cams have different limitations than flat tappet cams do. Flat tappet cams are velocity per degree limited based on their diameter, get too much lift per degree, run off the edge and then the lifter digs into the lobe. Any roller follower camshaft is acceleration limited. It can only increase or decrease the speed of the valvetrain per degree so quickly before the pressure angle on the wheel becomes too high and this either greatly reduces the life of the lifter or snaps the roller right off of the bottom.
It is possible for the stock cam to have accelerations that are pretty darn high and you never know until you plot it but as an example.
I just looked and it has a 1.8 rocker arm ratio so .539 takes a .300 lobe. A stock Chevy LT1 hydraulic roller lobe is 201 @ .050 with a .299 lobe lift.
It is possible for the stock cam to have accelerations that are pretty darn high and you never know until you plot it but as an example.
I just looked and it has a 1.8 rocker arm ratio so .539 takes a .300 lobe. A stock Chevy LT1 hydraulic roller lobe is 201 @ .050 with a .299 lobe lift.
Cargo Master
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I reground a cam for a customer a month or two ago from one of those 6.2 engines that can deactivate 1/2 of the cylinders and the lobe I repaired was one that has the normal lifter that doesn't shut off.
Cargo Master
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What's weird about that is on previous Ford engines with roller cams the cam cores have been excellent quality but these certainly could be lower quality. Another thing that can cause lobe failures is crankcase moisture. I think that's what cases the lobe damage on the Honda V6 cams. It always happens toward the front of the cam on the front head. That is right where the PCV valve is located.
Its Comin Right for us!
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From: GA
I know ford big block cam cores have been in short supply most of the year. Crower said they are all supplied from overseas now and the supplier runs the show.
i ended up regrinding a factory core because none of the suppliers could get one. Wouldnt be surprised if we lost some more suppliers in the cam world as a result of the flu hoax along with a dip in material quality.
id really love to know of 7.3 failures with build dates prior to march 2020
i ended up regrinding a factory core because none of the suppliers could get one. Wouldnt be surprised if we lost some more suppliers in the cam world as a result of the flu hoax along with a dip in material quality.
id really love to know of 7.3 failures with build dates prior to march 2020
Logistics Pro
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From: Everywhere and nowhere
and it was already stated that GM and Steallantis also had lifter issues. Correlations doesn't equal causation but similar issues and we never had these issues with older pushrod engines running roller lifters.
Its Comin Right for us!
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From: GA
rare with flat tappet until last 10-15 yrs
Cargo Master
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I know ford big block cam cores have been in short supply most of the year. Crower said they are all supplied from overseas now and the supplier runs the show.
i ended up regrinding a factory core because none of the suppliers could get one. Wouldnt be surprised if we lost some more suppliers in the cam world as a result of the flu hoax along with a dip in material quality.
id really love to know of 7.3 failures with build dates prior to march 2020
i ended up regrinding a factory core because none of the suppliers could get one. Wouldnt be surprised if we lost some more suppliers in the cam world as a result of the flu hoax along with a dip in material quality.
id really love to know of 7.3 failures with build dates prior to march 2020
Maybe what happened at Ford was that all of the people who got the materials and heat treat figured out so good on the roller cams for the older engines retired.
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From: The Great State of Texas
Lead Driver
Joined: Feb 2005
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From: The Great State of Texas
CWC Textron(large supplier for OEM and aftermarket camshafts and camshaft cores) isn't going to make cast iron camshaft cores for the foreseeable future so this is making new flat tappet cams hard to get. I don't know what cores Estas from Turkey has to offer but in the future they might be the only choice for cast cores besides regrinds.
Maybe what happened at Ford was that all of the people who got the materials and heat treat figured out so good on the roller cams for the older engines retired.
Maybe what happened at Ford was that all of the people who got the materials and heat treat figured out so good on the roller cams for the older engines retired.
Cargo Master
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Logistics Pro
Joined: May 2022
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From: Everywhere and nowhere
I am not sure that is the root cause, but I have read of failures that did exactly this in the 7.3L. There could have been some other failure that precipitated the rotation, like a badly worn/uneven interface between the cam and roller. From what I have read they are made of some type of plastic.
Edit: Found one.
https://www.fordtremor.com/threads/7...g-issue.15992/
Edit: Found one.
https://www.fordtremor.com/threads/7...g-issue.15992/
4wd Low
Joined: Sep 2021
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Read thru this thread;
7.3 Failures
"https://www.ford-trucks.com/forums/1749008-7-3l-engine-failure-rough-idle-low-compression-lifter-taps.html'
A few of us that have had engine replacements posted their work receipt from the dealership..........
7.3 Failures
"https://www.ford-trucks.com/forums/1749008-7-3l-engine-failure-rough-idle-low-compression-lifter-taps.html'
A few of us that have had engine replacements posted their work receipt from the dealership..........
Lead Driver
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From: Itinerant
Talking to OBS460 is like talking to a fence pole. He doesn’t want to hear what he doesn’t want to hear. No amount of documented failures will ever get him to say anything other than live in fear chicken little, blah, blah, blah. Fortunately, most people who are actually open minded will just write him off.
Some of us realize that there are bad parts out there and maybe even bad design....they are designed and made by man after all.
You can pound your chest and point fingers at manufacturer's all you want or you can be prepared with you wallet if out of warranty. Keep paperwork incase down the road there is a recall and recoupe your money later. Or maybe nothing will happen at all and you'll have a uneventful vehicle ownership. Certainly not going to worry about something that hasn't happened yet. But then I only have 163,000+ miles so far and shooting for 300,000. 🤷
