Why did the formula come into play to get valve lift if you were measuring at the valve?Originally Posted by turbo2point2
Why did the formula come into play to get valve lift if you were measuring at the valve?
Nice work Brian. Did you happen to check the actual seat duration? Just curious. And by chance did you record the @.050 crank degrees without the 1.75 multiplier?
Those specs come out looking similar to the ones Todd posted for the F4
best 1/8 ET-6.16 sec. best 1/8 speed-119.70 Best 1/4 MPH 145.5, Best 1/4 ET 9.65 sec. 8 valve NO NITROUS!!
k just did a little experiment to see how the follower ratio varies with lift
all of this on the stock turbo 2.5 roller cam, exhaust
first I measured the duration of the valve lift from 0.050", on the valve: 102.5 degrees
and the peak valve lift: 0.424"
then I measured the peak lobe lift at 0.242"
giving a follower ratio at peak valve lift of: 1.752
therefore the equivalent duration at the lobe would be 0.050" / 1.752 = 0.029"
I then measured the duration of the lobe lift from 0.029", on the lobe: 100 degrees
My measurement setup probably has at least 1 degree of overall error in it the way I did it this time. But I think this proves that the follower ratio doesn't vary significantly over a range of valve lift from 0.050" to 0.424".
Similar lift to the F4, but with a lot less duration If I'm reading right?Those specs come out looking similar to the ones Todd posted for the F4
Robert Mclellan
http://www.youtube.com/watch?v=wambNdfnu5M
10.04 @ 143.28mph (144.82 highest mph)
Worlds fastest 8v MTX Shelby Charger
Manitoba's Fastest 4cyl!
8 valve, No Nitrous!
New clutch combo is the SH!T!
Looks like roughly 10 degrees, but I still would rather the same person with the same equipment do the testing on both the F4 and R5 for a more direct comparison. It seems like it's never the same when another person tests.
I would agree with this.
And also say that when making cam measurements for purposes of comparing one cam to another, the rest of the engine should not be involved. All that does is introduce error into the measurements. The cam should be measured using as few tools and additional components as possible, and those components should remain the same between cams. Certain things make sense to measure in-engine like ring gaps, bearing clearances, and cams when you are synchronizing them to the engine, because those parameters only exist relative to the engine as a whole. But cam-to-cam comparison measurements exist without the engine and so including the engine in the measurements only adds error.
I think the best measurements we can get to compare cams are lobe measurements without the follower. Its pretty solid now that the follower ratio is 1.75 and it doesnt change much from 0.050" to 0.424" valve lift so we can use that to get real valve lift if desired. But the point here is comparing cams by how they differ, so all we need are lobe measurements for that. That will tell us how cams compare as far as duration, lift, overlap, LSA, etc..
All you need to measure a cam lobe is a degree wheel on the cam (print one out and make one that bolts under the cam bolt). A dial indicator, and a head that lets you bolt the cam in so you can spin it. I'm using a worm drive rotary table because I wanted to measure the actual valve lift which requires spring pressure and so a way to prevent the cam from snapping around was required. But if you take the follower out, then the cam just spins, and you can just use a degree wheel and a pointer.
The tricky part of doing this with such a minimal setup is syncing the measurements from intake to exhaust lobes, since you have to move the dial indicator and once you do that the relationship between the dial indicator and degree wheel is destroyed. If we put our thinking caps on though I'm sure we can come up with a clever and easy way around that. A little fixture would probably be nicest..something that bolts to two bearing caps and has holes which are perfectly square to the cam axis and centered over each lobe. Then you just drop the indicator in and you dont have to worry about anything as far as syncing, assuming the cam tower bearing cap surfaces are in the same plane.
I should have some installed #'s of R5 #'s in the next day or so. Been out of town, and came back into town extremely fatigued and sicker than a dog. I disagree about cam measurements out of engine being the best measurements. Maybe for comparing one camshaft to another, but for me the whole purpose of degreeing in a camshaft is so I know when and where the events are happening in relation to crank degrees. IMO, if all you want is something to compare from one camshaft to another you might as well throw them on a Cam Pro, as it takes 2 minutes or less.
Rob, making any headway on F4 cam measurements?
Todd
We dont disagree, I said "when making cam measurements for purposes of comparing one cam to another." Although if there is some reason to suspect that two cams wont proportionally behave in a engine relative to their out-of-engine specs then comparing them in-engine might be best. For instance if somehow the valvetrain linkage between lobe and valve changes significantly depending on lift. Other than that I can't see how an in-engine comparison would offer anything except more error and less significance to the world at large.
The more people we can get to start making valvetrain measurements the better. Pretty much zero people here have access to a cam-pro so thats not a realistic option. Thats kind of why we are where we are right now still without basic solid data on 30+ year old camshafts, and new ones just released by vendors. Cam-pros are not helping us. That seems to be more of a convenience tool anyway since you can get the vast majority of the same data using the procedure I described above.
The problem with words like "degreeing" is that they have variable meanings which imply totally different things and then people get confused, and here we are. Thats the trouble with automotive jargon that doesnt have a real meaning. Do we mean "measuring a cams geometry" or do we mean "synchronizing the cam to another shaft", or do we mean doing both simultaneously?
Im pretty sure a huge majority of TD/TM'rs have old heads and cams sitting on a bench, and a cheap dial indicator. Theres nothing keep them from making measurements. And they have a good reason to. If they have not done something like that before then they need to in order to get up to speed on cams and reach the next level of performance. Its a great way to practice valvetrain measurements and learn about whats going on, to prepare for eventually syncing a cam to a crankshaft and/or measuring new cams. If we want to raise the bar as far as what cams come out with what kind of design theory behind them then we need alot more people who understand this stuff directly and "have done" instead of more passing the buck to someone else with more experience/better tools. This is well within the realm of even the cheapest TD/TM'rs toolset and skillset. But it seems pretty quiet in here, is anyone else experimenting with making cam measurements for the first time because so far not a peep.
Getting Very close to working on it. lol I Almost TDC'd the mtr and mounted the degree wheel the other day, but still other things getting in the way. Soooon though, Very Sooooooon!
Robert Mclellan
http://www.youtube.com/watch?v=wambNdfnu5M
10.04 @ 143.28mph (144.82 highest mph)
Worlds fastest 8v MTX Shelby Charger
Manitoba's Fastest 4cyl!
8 valve, No Nitrous!
New clutch combo is the SH!T!
Okay guys I had a chance to degree the R5 camshaft in earlier today. See attachment. Both attachments are the same, just different formats. NOTE These #'s are at the valve (retainer) not at the lobe. New follower. Zero lash as noted.
Todd
Great info 4-Lbodies, and heres turbo2point2's R5 data
now we just need to line em all up in a spreadsheet
So in trying to compare 4-Lbodies and turbo2point2's data, it would appear:
turbo2point2 data does not have a measurement point at 0.050" valve lift (all valve numbers are calculated based on lobe numbers and a follower ratio), and 4-Lbodies data is at the valve, so they cant be compared as far as duration or other measurements specified at lift locations that are not peak lift without interpolating.
there is a difference of 0.012" in peak exhaust valve lift
there is a difference of 0.011" in peak intake valve lift
turbo2point2: could these differences be due to adjusting solid lifters for a non zero gap since you were actually doing it for a customer?
4-Lbodies, why do you note that the follower ratio is 1.75 on the peak lift data? It was measured at the retainer right?
For the notes about cam being advanced 1.625 or 2.25 degrees, how is it determined that its the cam thats advanced and not the error in the cam key or cam pulley?
oops looks like 4Lbodies did some measurements at 0.0875" valve is .050" lobe, nice thinking! so that can be compared between the two
heres turbo2point2's and 4Lbodies data overlayed in a chart...future data (F4, stock, etc..) can be added and compared both as charts and tables
I cant seem to attach excel files oh well
Asa,
I'll try to answer your questions. Yes peak lift was recorded at the retainer. I noted the follower ratio simply for others looking at this in the future and as a check to determine that the dial indicator is set up correctly. Multiplying lobe lift times follower ratio should get you exactly the peak valve lift if you have your dial indictor set up properly. You listed a mathmatical formula in an earlier post relating to this, I found that very interesting. Axis not correct, not parallel, not perpendicular, and end of indicator skating all over the top of the retainer will get you erroneous readings as you know. It is very easy to lose .010-.015 lift that way. Obviously also effects other measurements too. Worn followers will also be a cause for losing peak lift, as will having lash not set to zero. Some people use about a .010 lash to simulate a hydraulic lash adjuster loss. I do not when degreeing camshafts in.
That is why that is my first step in degreeing a camshaft. I measure lobe base, lobe peak lift, then make sure I see that on dial indicator at valve retainer. If I don't get it correct, the peak lift will be an easy indication something isn't correct. In fact when setting up the dial indicator on the exhaust, I was initially getting about .020 short on peak lift at valve. I found out the bottom of retainer was making contact with the valve umbrella seal! This was because of replacement guides in head (concentric & had stop ring in them). The guides were not installed quite to the correct depth or they were made incorrectly. This is worth noting because when you start installing camshafts with a bunch more lift, this is but one of many things to check.
According to Cam-Pro results, this cam has a single pattern centerline. 113.53 is noted for both intake and exhaust. So when I set the dial indicator up, my goal was to set it up straight up at 113.5 installed intake centerline, so that is what I did. Took my measurements on intake, then moved on to the exhaust. It was only then that I found the exhaust was at a 115.75 centerline. So in my case 1.25° advanced on intake vs. exhaust centerline. Yes I could have started over and moved centerline to 114.6 on intake and repeated all the measurements. Didn't feel it was necessary. Yes it could be errors anywhere in camshaft, keyways, keys, pulleys, deck on motor, deck of head, head gasket thickness, etc. For example, installing this camshaft using stock cam pulley my initial intake centerline was 119.75°. I know my deck and head have had about .006 shaved from them, I also know head gasket thinkness is a few thousands thinner. All this is stacking up in one direction to make it about 5 crank degrees retarded using stock pulley. That is exactly why I degree my camshafts in.
Todd
Last edited by 4 l-bodies; 01-16-2015 at 03:21 PM.
Yes I did that so we can compare Brian's and the F4 lobe duration at .050 which was determined to more than likely be .0875 at valve. I actually went back and re-took those measurements after Brian posted his so we had that to compare to. Although we really need the F4 measurements at the valve. No pressure though Rob!Hehe It's all good making progress...
So it definitely seems the F4 and R5 are the stars of the show these days but really we'd like to have measurements of as many cams as possible in "the database" right?Yes I did that so we can compare Brian's and the F4 lobe duration at .050 which was determined to more than likely be .0875 at valve. I actually went back and re-took those measurements after Brian posted his so we had that to compare to. Although we really need the F4 measurements at the valve. No pressure though Rob!
I think with two dial indicators, and a fixture that locates them square to the cam axis and in the same plane with each other, that we could just mail the fixture to folks who have odd cams and they can measure the cam on the bench with a cam degree wheel and pointer, and with no followers. A 30 minute job at most? Then they slip the whole "kit" back in the box and mail it off to the next person. Pretty soon we have tons of cams in the database and those people who wanted their weirdo cam measured basically get it done for free (they do the work, the kit is free).
The measurements would not be relative to the engine so the position of the lobes relative to the key would not be measured. Although if a clever cam degree wheel is made that can be synchronized to the key and/or the bearing cap split then we could get that data too.
In other words I'm trying to think of the easiest and fastest way to build this database HUGE, with lots of redundant data and coverage of as many cams as possible.
As initially promised, all R5 camshaft information has now been provided and the current sale will be ending shortly. Big THANK YOU goes out to Todd and Brian for taking the time to record the information.
We strongly agree with what Matt said above by using the example of Brian and Todds results. Unless someone offers up an F4 camshaft for testing it doesn't appear that true comparison information wil be available anytime soon.
Chris-TU
Chris Wright www.TurbosUnleashed.com Chris@TurbosUnleashed.com 602-76-BOOST Tech/Sales#: Monday-Saturday 9AM-7PM MST Proudly Serving the Turbo-Mopar Community since 1997 TU is a performance, not marketing company. We provide accurate performance data on all our performance products. Fabricating data to make us appear better is just not our style. Do the research before you buy. ROCK BOTTOM PRICES WITHOUT THE HIDDEN HANDLING FEES.... -----HOME OF THE 9 SECOND FWD T-M CLUTCH-----
Were you previous results at the valve also? Just not sure if we need to compare .050 specs or .087 specs. If we compare .087 than the R5 has 6 degrees less duration on intake and exhaust but if we compare .050 than the R5 has 14 degrees more. The first one seems more likely, but just want to make sure. Either way we know the R5 has .020 more lift.
What I'm finding sort of bizarre about this discussion is that there doesn't seem to be a focus on WHY the R5, F4, etc.. were designed the way they were. It doesnt cost more to make a cam with more lift, or more duration, or more anything except perhaps some enormous lobe that requires custom blanks. Theres no "accomplishment" that a vendor figured out how to add duration or lift, in the same way its not a victory or discovery to add or remove fuel from a cal. Its a DECISION. And we are still left in the dark as far as why that decision was made, regardless of how many specs come out. So the logic of this is really nonsense and appears to go like this:
-vendor wants to release a new cam
-vendor asks their cam designer to design a cam for them, presumably for a certain "ballpark" build
-cam designer uses their experience to come up with initial design, and then perhaps tries it on a vehicle, then adjusts it slightly if needed, and gives it to vendor
-vendor sells it so us
Notice that the two most important and most valuable pieces of information or nowhere to be seen. 1) What the vendor's goals with the new cam were. 2) What the cam designers goals and results were.
I do not count single sentence descriptions like "For street/strip with good exhausts" as filling the blank for #1.
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