1300 head question

[dllubin]

Already way over my head buddy.

If you can get a measurement of the minimum radius of the lobe (base circle) and the maximum radius (lobe height) then you should be set. Here is a thought I have not tried: If you can get a good reference point on the cam box where you can measure a distance orthogonally to the cam, rotate the cam so you are measuring the base circle (180 degrees from lobe maximum) and the turn the cam 180 to measure the distance to the top of the lobe, then the gross lift should be the difference between those two numbers.

 

[CnC79X19]

If you can get a measurement of the minimum radius of the lobe (base circle) and the maximum radius (lobe height) then you should be set. Here is a thought I have not tried: If you can get a good reference point on the cam box where you can measure a distance orthogonally to the cam, rotate the cam so you are measuring the base circle (180 degrees from lobe maximum) and the turn the cam 180 to measure the distance to the top of the lobe, then the gross lift should be the difference between those two numbers.

Thanks for the advice. I’ll give it a shot

 

[Dr.Jeff]

This isn't scientific but I have a reground performance cam and the shape of the lobe peaks (apex) are very "pointy" looking. Typically a performance cam that isn't a reground one has a bit more rounded tips. But that isn't always true.

 

[Jeff Stich]

This isn't scientific but I have a reground performance cam and the shape of the lobe peaks (apex) are very "pointy" looking. Typically a performance cam that isn't a reground one has a bit more rounded tips. But that isn't always true.

The shape of the lobe tips isn't tied directly to whether the cam is a "regrind" or not, it's dependent on the desired valve duration &/or overlap (how long the valve stays open & its opening/closing relationship with the other valve in that cylinder). A "pointy" lobe opens & closes the valve quickly, while a more-rounded lobe will keep the valve open longer (for a longer duration).

A reground cam can have any lobe shape desired, as long as the initial "OEM" lobe parameters of the cam allow it.

 

[Dr.Jeff]

The shape of the lobe tips isn't tied directly to whether the cam is a "regrind" or not

Agreed, that's why I said it isn't scientific. The couple of performance Fiat cams that I have seen (which is only a couple) were very different looking between the reground one and the new casting one. So I was thinking the sharp apex on the reground lobes might be a feature necessary when attempting to get the desired profile out of a stock Fiat cam.