Cams and lifters

[Smiliesafari]

Something I've been wondering about for some time. Is there any reason why you can't put roller lifters on a flat tappet cam?

[akforceten]

The flat tappit cam has to aggressive lobe profile the roller lifter wouldjump off the lobe

[Smiliesafari]

Thank you. I hadn't thought of that. After looking at the difference in lobe profiles it makes perfect sense.

[WoodButcher]

If your in the engine that deep you might as well replace the cam too. That is what was done to my '93 350 when it was rebuilt. The block had all the right bolt holes and was made for it so why not? We went with a little more aggressive cam and rollers which added a nice little kick to the go pedal.

[Smiliesafari]

Did you put a roller cam in or a flat tappet cam with roller lifters?

[Mmusicman]

The cam type MUST match the lifter type!!!
A flat-tappet lifter rides on a cam profile MUCH differently than the narrower point of a roller lifter.
The cam timings of a mis-match would not even be close!

Two different cam types with identical lift and duration:

Lobes.jpg (32.28 KiB) Viewed 5211 times

Contact points of lifters with identical cam shaft timing (lift timing is completely changed):

Ft_vs_roller.jpg (15.21 KiB) Viewed 5211 times