Flat new lifters

[Little Mouse]

Solid flat tappet cam using non chamfer lifters. Have always thought the lobe taper and the chamfer of the lifter combined to rotate the lifters. What is the advantage or disadvantage of a cam and lifters like this.

[PackardV8]

We also would like to learn what's changed in lobe taper and lifter radius.

With our tappet grinder, there is an adjustment for radius and the Operator's Manual has a table delineating the 0-to-8 setting to produce a lifter radius to the OEM spec for all US '50s-'60s engines.

Today, when we buy replacement lifter from Johnson, et al, for some of our obsolete engines, the radius is visibly larger (flatter) than the OEM spec. I asked Johnson what had changed and the the tech guy claimed it hadn't; that they were still using the same blueprints. Not true.

[Little Mouse]

Crower has a series of cam they call the 220, down at bottom of page it gives a part number and says must use this non chamfer lifter, other cams they make in other series are not using a non chamfer lifter. So my guess without calling them the taper there using on the cam maybe the difference and maybe the non chamfer lifter allows the lobe to sweep a bit further across the lifters face. So if say the lobe has more taper to help spin the non chamfer lifter, would more taper if that's the case make the cam more likely to wear the taper on the lobe then less taper.

[enigma57]

Not something I would want in my engine. Why change what has worked so well since the dawn of internal combustion engines? Would be interesting to hear Mike's take on this.

Happy Motoring,

Harry

[Little Mouse]

Crower has had this 220 series for a long time not something new it is off a pro 55 core. From info on crower it says it is high rev and easier on the valve train, makes me believe it's not a real high ramp rate cam. They all seem to be on 10 degree duration split for the exhaust tight 107 to 108 seperation.

[PRH]

The “chamfer” is referring to just that.
The breaking of the edge from the bottom to the side of the lifter.

Not the radius on the bottom.

The chamfer on the lifters can vary quite a bit, and if you’re using a profile that needs the entire diameter to keep it from running off the edge...... you want lifters with basically no chamfer.

[CamKing]

Crower has a series of cam they call the 220, down at bottom of page it gives a part number and says must use this non chamfer lifter, other cams they make in other series are not using a non chamfer lifter.

You're confusing chamfer with crown.
The "non-chamfered" lifter is still crowned, bit it doesn't have a chamfered edge. The edge of the face is square.
A standard lifter have the edge chamfered, so it doesn't chip. That's good, but it reduces the diameter of the actual lifter face.
The diameter of the actual lifter face is what dictates the maximum velocity you can move the lifter, without the lobe over-riding the lifter face.
The Crower 220 lobe designs and designed with a slightly higher maximum velocity, then their std profiles, so they'll over-ride the lifters with the chamfered edges, and require non-chamfered lifters. This is something we were doing in NASCAR in the 80's. We had the lifters made with no chamfer on the edge, and we designed to lobe profiles to take advantage of the extra usable face diameter.

[Little Mouse]

Ok thanks mike now it makes sense. Have never taken a close enough look at a flat tappet to notice what you talked about.

[pdq67]

The “chamfer” is referring to just that.
The breaking of the edge from the bottom to the side of the lifter.

Not the radius on the bottom.

The chamfer on the lifters can vary quite a bit, and if you’re using a profile that needs the entire diameter to keep it from running off the edge...... you want lifters with basically no chamfer.

UDHarold once told me that he designed his cams to run within .016" of the outside edge of the lifter to gain max. design characteristics.

I figure a no chamfer lifter should to be used.

pdq67

[Geoff2]

The Chrs 440 Magnum [ 4bbl ] had the same cam specs as the cam used in the 440 six pack. The six pack had stronger v/springs. To control lobe wear, the six pack cam had special low[er] taper lifters, which I presume means that the radius was larger.

[Geoff2]

I have often wondered whether some of the FT cam/lifter failures are due to aggressive lobes that require the full diameter of the lifter, being used with lifters with too much chamfer & the result is the lifter digging into the lobe.

Here in OZ, we re-face FT lifters, & they are then as good as new, if they are good factory lifters or lifters made prior to the crap lifter era. I always get the lifters re-faced with no chamfer.

[pdq67]

I have often wondered whether some of the FT cam/lifter failures are due to aggressive lobes that require the full diameter of the lifter, being used with lifters with too much chamfer & the result is the lifter digging into the lobe.

Here in OZ, we re-face FT lifters, & they are then as good as new, if they are good factory lifters or lifters made prior to the crap lifter era. I always get the lifters re-faced with no chamfer.

I would reface the stellite footed flat tappet solid lifters and go.

pdq67

[Geoff2]

Pdq,

The machinist that refaces my lifters claims that even NEW Stellite lifters should be re-faced. He reckons the radius & centering is all over the map. Accordingly, every set I get from Summit go to him for refacing before going into an engine.....

[pdq67]

Pdq,

The machinist that refaces my lifters claims that even NEW Stellite lifters should be re-faced. He reckons the radius & centering is all over the map. Accordingly, every set I get from Summit go to him for refacing before going into an engine.....

Good point Geoff2!!

pdq67

[CamKing]

Pdq,

The machinist that refaces my lifters claims that even NEW Stellite lifters should be re-faced. He reckons the radius & centering is all over the map. Accordingly, every set I get from Summit go to him for refacing before going into an engine.....

Have you had your lifter bores "true'd" ?
If the lifter bore isn't perpendicular to the cam, and/or the centerline of the lifter bore doesn't cross thru the centerline of the cam, what you do to the lifter face is meaningless.