Roller to flat tappet
Thread Starter
Safety Car
Joined: Sep 2005
Posts: 4,213
Likes: 643
From: Orange County Ca
Roller to flat tappet
While watching a diesel mechanic youtube show, I heard them mention a roller cam to flat tappet cam conversion.
It appears that newer Cummins straight 6 engines have/had some problems with their roller cams, and that there are kits out there to replace them.
Interesting, right??
On gas engine restomods, everyone wants the rollers.
These may even be solid lifters.
I realize that diesels are different, but does anyone know the story on these?
https://dnrcustoms.com/products/cumm...47273901916440
" emission compliant except in California" of course.
It appears that newer Cummins straight 6 engines have/had some problems with their roller cams, and that there are kits out there to replace them.
Interesting, right??
On gas engine restomods, everyone wants the rollers.
These may even be solid lifters.
I realize that diesels are different, but does anyone know the story on these?
https://dnrcustoms.com/products/cumm...47273901916440
" emission compliant except in California" of course.
Drifting
Joined: Jun 2020
Posts: 1,694
Likes: 728
From: Stay dangerous my friends
The advantage for roller lifters is performance with more aggressive cam profiles, and perhaps less cam break-in risk. Longevity/endurance maybe not so much.
Another note for longevity... Use a flat tappet cam for flat tappet lifters, and a roller cam for roller lifters, and they are not interchangeable. The flat tappet cam rotates the flat tappet lifter. Also despite what people do, a hydraulic lifter cam should not be interchanged with a solid lifter cam, the solid one has a ramp to close the lash before valve open, and a hydraulic lifter cam typically has vary minimal ramp.
Another note for longevity... Use a flat tappet cam for flat tappet lifters, and a roller cam for roller lifters, and they are not interchangeable. The flat tappet cam rotates the flat tappet lifter. Also despite what people do, a hydraulic lifter cam should not be interchanged with a solid lifter cam, the solid one has a ramp to close the lash before valve open, and a hydraulic lifter cam typically has vary minimal ramp.
Cruising
Joined: Oct 2024
Posts: 13
Likes: 8
yeah kinda wild seeing people go backwards on tech my cousin has a 5.9 cummins and he said the roller lifters can grenade when they wear out and send metal everywhere so some guys swap to flat tappets for reliability since theyre simpler and dont self destruct as bad it’s more of a diesel thing tho gas builds still love rollers
if you want some background on cam types check this https://en.wikipedia.org/wiki/Camshaft
if you want some background on cam types check this https://en.wikipedia.org/wiki/Camshaft
