Technical Roller cam

When replacing a timing belt on a roller cam 2.3 ford I was surprised how much easer it was to turn the cam than the old non roller cams Got me to checking on how much Hp is gained by loss of friction. https://www.bing.com/search?q=how+m...+to+run+a+roller+cam+vs+flat+tappet&FORM=AWRE

 

all those little tricks add up. Some guys would say that you do not gain any you just loose less.

 

I'm going to do a roller cam retro fit in a 327 soon, with most oils not having zinc and the other good stuff, and the anxiety of cam break in with flat tappet, I'm going for it.

 

Rabbit holes. Sometimes you find rabbits, sometimes you find a hole.
Flat lifters Vs rollers. Spend cash for power not parts! - YouTube
Now it seems some will watch, some won't, nor care that they didn't, but I find doing so usually opens up points for further discussion fitting to many conversation in the forum.
Changing minds and opinions, that requires some typing.

Well, It seems money can't buy happiness, but it does buy a solution to the friction in your life. Down a different hole I'm reminded of the cam posts and the recent SBC no oil pressure troubles.

COMPARING SBC ROLLER CAM PROFILES TO FLAT TAPPET CAMS. - YouTube

And OT speaking of friction, our friend with the welding problem...his troubles could be the result of...that's right, friction.

 

I still cannot understand the line of thinking that produced the end-result that was that engine.

 

The nice thing about loss of friction is the increase in fuel milage https://www.bing.com/search?q=hp+to...ANNTH1&refig=bf2bcd1637e0495791af801d877403b9 So if it takes 10 to 20 hp to drive your car at 60 and at low rpn the roller cam gained 10 hp can see why new stuff uses a roller cam.

 

There are a lot of places where horsepower can be freed up. It's not that horsepower is gained, but is not lost. All tests I have seen on roller rocker arms focus on top end gains and valve train stability. A milder engine should gain some power across the lower rpms, however the gain may be from having a true ratio, 1.5 for sbc. The gen 2 lt1 had a factory windage tray which could easily be added to an early sbc. A clutch fan, where applicable, reduces drag. proper oil level and viscosity, all factors when thought out can bring in some lost horsepower. It wont change the characteristics of the engine per se, but could yeild a bit more power in the normal operating range. Is it worth the money spent, maybe, maybe not. The factory went to quite a bit of effort to make the later engines more efficient. Some of this can be applied to earlier engines, and remain invisible.

 

I was the lead dyno engine engineer on the Fox bodied Mustang GT program. In '85 the 5.0 V8 got a roller cam. As I recall the biggest gain was at idle speed - around 16 lb-ft of torque.
But...as RPMs increased the gains dropped off until at the red line RPM there was only one or two lb-ft of improvement. This actually makes sense since as speed increases the hydrodynamic oil film strength of the flat tappet cam will improve and there will be less of a difference in roller vs flat tappet friction. It made sense to go roller for improved fuel consumption and peppy drive, but as far as TV dynamometer drama shows go there would be little to be seen at WOT HP peak - move along people.

 

I think the big push to roller cams was regs requiring higher fuel mileage from new vehicles. Like was said, every bit of friction lost was less fuel used. I’m sure the factory engineers have ways to measure the gains or losses to the tiniest fraction. Multiply that fraction times x number of those engines sold and it makes a big difference in the overall fuel economy numbers, which is what they look for, the averages. We benefit with freed up horsepower that would normally be lost to friction plus any increased fuel mileage.

 

If I remember it right, A. Graham Bell mentions a clear drop in oil temperature when going to rollers. That implies a smaller power loss.

 

Not that most of us drive our hotrods for hundreds of thousands of miles. But once roller cams became standard for modern engines, we suddenly saw engines going twice as many miles before needing to be rebuilt, vs. the exact same engines that were previously flat tappets.
The friction that wears both cam lobes and lifters in flat tappet engines, also means metal that wears off gets pumped throughout the bearings, and speeds up wear on those parts also. So the roller cams have increased longevity by 100% or more on later engines.
And add roller rockers also to the mix, and you don't have wear on the end of the valve stems like typical stock rockers had.