what sthe difference between a regrind cam and a roller hydraulic lifter camshaft?

and whats a billet cam?

thanks guys!

regrind is a reground factory cam and needs shims to accodate for the amount ground off.

a billtet cam is a new cam that doesnt need shims

Ok Regrind cam is a stock cam that has had extra metal welded onto it and then has been ground into a new profile. Cheaper than getting a new cam machined from scratch. A billet cam is essentially a cam that has been machined out of a solid chunk of steel. Its stronger than a regrind but it is a s**t more expensive. If you're not pushing huge RPM you don't need a billet.


Ok now a roller hydraulic cam reffers to the profile of the cam lobes (they are the lumpy off center things on your cam).

You have 2 types of profile. The most common is a flat tappet. The cam lobes on a flat tappet cam look like an egg shape. Slightly pointy at the tip and a big round bulge at the bass. These have been in use since the begining of time prety much.

The second type is the roller cam. The lobes on a roller cam look like a circle that has been stretched in the middle. Or a rectangle with a semi circle on each end. Up untill the last few years these were seen as a race use only part untill ford had them in their EFI windsors from 1986 (or there ablouts) onwards, our EB to AU windsors have them, and holden had them in the last mdel True holden V8, the VT series 1 304. Reason being that a roller cam opens the valves up heaps quicker. As far as I know all the overhead cams are flat tappet profiles.

Now within these 2 types of profile (flat tappet and roller) you have both solid and hydraulic profiles. A solid cam needs solid lifters which act driectly on the pushrods (or rockers in an OHC motor). It is a direct mechanical linkage to the valves. Its main drawback is that its prety high maintanance. you gota check the valve lash so that its spot on, otherwise it wears out pretty quick.

The other type is a hydralic cam. This is designed for hydraulic lifters. Hydraulic lifters require no maintanance and us oil pressure to pump them up so you get the correct amount of pushrod travel.

So therefore the 4 types of cam in order of basic to most high performance are:

Hydraulic flat tappet
Solid flat tappet
Hydraulic roller
Solid roller.

Also remember the parts of the valve train in order

OHC motor (like out 4.0 Litre's)
cam, lifters, rockers valves

Pushrod engines (XF and earlier 6 cylinders and pre BOSS V8's)
cam, lifters, pushrods, rockers valves.

Hope that points you in the right direction.

Isn't it more like:
Cam, rocker, lifter, valve ?


And isn't the 4.0 a roller cam? is that what it means when there is a roller on the cam shaft end of the rocker?

That's what I always thought to.
A roller cam was one designed for roller rockers ?
And flat tappet is just a flat metal face that follows the cam, hence why cams in those need to be 'run in'?

I know a regrid is as the name suggests, re ground. But I didn't know they welded metal on to them, thats why you need to add extra shims to make up for the lack of meat on them.

our 4L 6 cyl is OHC and it's a roller cam.
mitsubishi GTO is OHC and is a roller cam. the BA 6cyl is also a roller cam.
there are lots of roller OHC engines.

i haven't taken the rocker cover off my OHC I6's yet to have a look.

And steedy you can have roller rockers on a flat tappet cam. just as you can have a non roller type of rocker in an angine fitted with a roller cam (i don't know why on earth you would though unless you ran out of moiney). Tear your sprint engine apart and I bet my left nut you won't find roller rockers there, even though your engine has a hydraullic roller cam.

And hornet. And as for regrinds yes they do weld extra metal on but only on the tops of the lobes and not the base of the lobes (i.e the zero lift region). If they didn't then how on earth would they maintain stock or greater than stock lift with a more agressive duration and overlap. They have to weld the extra metal on otherwise a a stock cam would have bigger lift then your wade regrinds.

Also as for the order of the parts of the valvetrain I am only familiar with pushrod engines. Animal ef didn't specify which engine he wanted to know about. Just the different types of cams out there.

I was under the impression they ground down from the standard lobes and the shims made the cam look "bigger" so that in effect while the cam has "less" lift than standard, it acts as if it has more?

Sounds pretty dodgy. There would have to be zome metal taken off the zero lift range for that to work properly. Hence why you need shims. I saw a pic of a cam getting regrounded once and i could clearly see where the extra metal had been welded on.

well i would like to know what would be the best for the ford 4.0 inline 6, sorry for not sayin dat earlier but it is good to know what sort of cams are out there

Depends on what you want to acheive. There are cams out there to suit all different factors such as streetability, fuel consumption, idle quality, fuel type and also compatability with the factory ECU.

a cam with a rough idle, lots of power yet still be streetable but be reliable, its alot to ask but there is no point having a car that can do 13 sec 1/4's and die in the a** on the way to work

Haha nicely put

most regrinds arnt welded. there is a little more to OHC cams than is first realised. The Ford 4ltr is whats know as a raduis (becuase the rockers follows an arc) roller (because of the roller that follows the cam lobe) profile, which is one of the rarest cam profiles ever produced. If only you could swap the profiles with other roller profiles life would be bliss. Most OHC profiles are called a slide rocker profile where a flat pad runs directly on the cam lobe, which is similar to that found in a flat tappet (whether solid or hydrolic) profile found in most engines prior to the mid 80's. The main differences with slide rockers to flat tappets is that you need to keep in mind that a slide rocker also follows an arc which means that the opening and closing ramps on slide rocker profiles can vary quite dramatically