Rocker arm ratio

[tryingbe]

Is our roller rocker arm ratio 1.75?

So far, I've seen 1.78 being used at Turbosunleashed and 1.75 used by Todd Nelson.

I can't imagine there are two ratio numbers out there.

Thanks.

[4 l-bodies]

Harry,
At least two different factory vendors supplied roller followers plus several aftermarket vendors thrown into the mix. 1.75:1 is very common, 1.77:1 is pretty hard to find. Add in wear, and you'll be lucky to be at 1.75:1. Never measured one beyond 1.77:1, but I don't doubt TU's findings. Don't compare any Cam Doctor or Cam Pro readings to actual degree reading of valve motion in the engine. I won't bore you with the details, but it has to do with using a translating follower (which all cam measuring stands use) measuring a camshaft designed for a pivoting follower. This had me scratching my head many years ago. If curious George bug has bitten you, Google, Audie Technology Valve Pro program.
Todd

[glhs875]

The rocker ratio is variable with it being greater at the valve opening point and dropping in ratio amount as the cam lobe travels away from the pivot point/valve lifter.

[tryingbe]

So, how do we compare "valve" lift on a different camshafts? If the rocker ratio changes?

[glhs875]

So, how do we compare "valve" lift on a different camshafts? If the rocker ratio changes?

I was physically measuring the actual valve lift at the valve. A person needs solid/mechanical followers/lifters to perform the measurement.

[tryingbe]

I was physically measuring the actual valve lift at the valve. A person needs solid/mechanical followers/lifters to perform the measurement.

I guess I will include the rocker ratio and cam lift in my database. Thanks.

[iTurbo]

Sorry for being off topic here...

But what if aftermarket rocker arms were available that had an increased lift ratio? I keep hoping that aftermarket TIII rocker arms will one day be available and a slight tweak would possibly negate any want for regrind cams. Going to 1.9 ratio rockers on the Regal GS was pretty awesome..

[glhs875]

Sorry for being off topic here...

But what if aftermarket rocker arms were available that had an increased lift ratio? I keep hoping that aftermarket TIII rocker arms will one day be available and a slight tweak would possibly negate any want for regrind cams. Going to 1.9 ratio rockers on the Regal GS was pretty awesome..

That would require that the roller on the rocker arm to be located closer to the lifter for an increase in ratio. I would like to have some of our rockers made with a roller from a 4.6 L Ford engine. They are larger in diameter, and could add both lift and duration to the same camshaft. I had some measurement increase data but it's been awhile. I made up a rocker with a larger roller to measure with. It was definitely a worthwhile increase on both lift and duration. If I remember correctly the lift on a .430 cam was increased to .495 and with 9 degrees added duration with the larger roller. But in order to get the increase in lift the larger roller needed to be installed closer to the lifter so that the valve closing point remained the same as stock.

[masterjr33]

got any more info on the 4.6 rockers? I have a small lead i could pursue with a friend that works/owns jesel rockers..
if it is something simple to get them to work i could see about having them made.

[glhs875]

got any more info on the 4.6 rockers? I have a small lead i could pursue with a friend that works/owns jesel rockers..
if it is something simple to get them to work i could see about having them made.

What are your questions? www.glhs875@yahoo.com

[glhs875]

got any more info on the 4.6 rockers? I have a small lead i could pursue with a friend that works/owns jesel rockers..
if it is something simple to get them to work i could see about having them made.

Basically for the larger diameter roller to be installed in a stock rocker arm all that needs to be done is a little clearancing for the larger diameter roller. If the larger diameter roller is installed using the stock pin location, the lift will remain the same with only a duration increase. If the pin location is moved towards the lifter enough to keep the same closing point as stock, both lift and duration will be increased. The latter is what I would shoot for. And then degree the cam in however is desired.

[Dr. Johny Dodge]

I'm in for 8 .. no 9 (spare)

how different was the ford rocker ?

I know the 4.6/5.4 top end looks a lot like a dodge 2.2 and I happen to have a new set of 5.4 rockers SOMEWHERE down stairs but I've yet to compare them side by side to a 2.2 rocker

guessing they're wider and probably longer (?)

[glhs875]

I'm in for 8 .. no 9 (spare)

how different was the ford rocker ?

I know the 4.6/5.4 top end looks a lot like a dodge 2.2 and I happen to have a new set of 5.4 rockers SOMEWHERE down stairs but I've yet to compare them side by side to a 2.2 rocker

guessing they're wider and probably longer (?)

The 4.6/5.4 rockers are close to the 2.2/2.5 rockers but are different enough not to work. The valves on the 4.6/5.4 are smaller in diameter and if I remember correctly the tip on a 4.6/5.4 lifter is smaller in diameter as well. And the overall length of the Ford rocker is a little shorter. Like I said it's been awhile since I compared the the two rockers to each other.

[DOHCRT]

If you look at the TIII rocker, there isn't much room to move the roller centerline toward the pivot point. What diameter are the 4.6 rollers? I have a 2.0 SOHC rocker arm disassembled and that roller is too large to move centerlines.
I'm working some custom stuff in the dark here and would be interested in thoughts for a custom rocker arm. I think a larger diameter roller will work, I don't think there is room to move it.

[glhs875]

If you look at the TIII rocker, there isn't much room to move the roller centerline toward the pivot point. What diameter are the 4.6 rollers? I have a 2.0 SOHC rocker arm disassembled and that roller is too large to move centerlines.
I'm working some custom stuff in the dark here and would be interested in thoughts for a custom rocker arm. I think a larger diameter roller will work, I don't think there is room to move it.
.901 is coming to mind for the 4.6 roller diameter. Need for someone to confirm that.

[glhs875]

Jessel is saying their 4.6 2V roller is .900 in diameter. The 4.6 3V is .700 in diameter. I can't remember what the roller diameter is for a 2.2/2.5 rocker arm.

[glhs875]

I could be wrong and would take a dyno to confirm my theory, but I think a rocker with a larger roller positioned to provide a higher ratio/more lift would be more beneficial being used on mainly the intake valves.

[4 l-bodies]

.700 is what the roller diameter is on our 8V applications.
Todd

[glhs875]

.700 is what the roller diameter is on our 8V applications.
Todd

Thanks for the Info.