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Cam Testing


TurboRaider
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I got my cam tester setup and was able to run a few tests.

 

I tested duration at .006" and .050" lift.

 

The AU roller is ground on a 110.5º center when used with the roller arms it was designed for. I got about .412 lift intake and exhaust.

 

.050 duration intake and exhaust = 208º crank degrees

.006 duration, intake and exhaust = 240, 254º respectively.

 

If you put in a set of V6 rollers on a AU cam it has a 114º center, .442" lift intake and exhaust.

 

.050 duration intake and exhaust 210º crank degrees

.006 duration, intake and exhaust 242.4, 256.8º respectively.

 

If you run a stock slipper cam with the AU rollers you get a 121º lobe center.

Lift is .444, intake and exhaust.

.050 duration intake and exhaust 210º, 204º respectively crank degrees

.006 duration, intake and exhaust 278, 247º respectively.

 

 

I will test the V6 rockers on the slipper cam later, the lobe center on those will be even wider, probably 129º.

 

I need to re- run all my tests just to be sure. Like any new setup I am learning how to use it and take good data.

 

Right now I just pulled the info into a spread sheet and crunched the numbers. I took a valve lift reading every .032º or 10,000 reading per revolution. The encoders I used to measure valve lift have a .0005" resolution.

 

Lots of data... Lots of learning.

 

Conclusion so far:

 

AU roller cam looks just like our stock cam when its used with the parts its supposed to have.

 

If you use V6 rollers with the AU cam It gains some lift and 4º of lobe separation. However you will need to add some clearance so the valves don’t hang open, the lash adjusters will bottom out. The profile looks good, I need to look at it some more. So far it looks like a good street turbo cam.

 

Rollers on a stock slipper cam gives you a very wide cam angle, slower valve opening at initial lift and is seems to fast over the nose of the cam.

 

The base circle of the roller is larger.

 

I need to get slipper rockers to run a baseline with.

 

Now that I have done this a few times it should go faster.

 

More work next weekend...

 

Kevin

Edited by TurboRaider
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Very nice.

The lifters are quite forgiving. Unless they would bottom out on the base, it should be fine. Maybe I'm missing something? I have the lifters preloaded .065 on my Schnieder roller. That is how far they are into their range of travel on the base of the cam. They have about .115 distance of full travel depending on what lifter it is (manufacturer, date of manufacture, etc..).

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Very nice.

The lifters are quite forgiving. Unless they would bottom out on the base, it should be fine. Maybe I'm missing something? I have the lifters preloaded .065 on my Schnieder roller. That is how far they are into their range of travel on the base of the cam. They have about .115 distance of full travel depending on what lifter it is (manufacturer, date of manufacture, etc..).

 

 

Time the base diameter of the AU roller cam is 1.50" the factory starion cam I have has a base diameter of 1.38.

 

On my test bench the combo of 4 cyl factory roller cam and V6 roller rockers had the valves hang open even with lash adjuster bottomed out.

 

The AU rockers for the roller cam have the lash adjuster set a bit deeper.

 

BTW... For each cam I had 30,000 data points per revolution! Three cam test =, 90,000 readings. This is why a data aquisition systems and computers to crunch numbers is a life saver. Way better than when I used to do this by hand.

 

Not ready to post my data as gospel.... So far just a guide. I did want to make sure that people knew I was working on it and progress is being made.

 

Kevin

Edited by TurboRaider
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Ahhh, yes. Bottomed out on the base will certainly hold the valves open.

 

1.50 - 1.38 = .120 Average full travel of lifters from my hand measuring was .115. I did not notice that aspect when I did measurements by hand. However, I got nearly the exact same measurements that I posted a while back.

 

That is definitely enough to hang the valves open with most lifters. I have seen lifters with different heights/lengths. The 3.0L roller rocker, lifter bore depth is the same as the OEM USA slip rockers last I checked. I have noticed on several occasions varying depths in the same exact set of rockers before too. I concluded the lifters are compacting the aluminum bore hole in the rocker because new rockers all had shallower bores than old rockers across the board. However, it could just be due to the manufacturing process, etc... There are too many factors out of our control to simply bolt it on and hope it works. Like you said, some clearancing is required. The problem is how to get that clearance. As valve seats are reground, that problem gets worse. Shaving length off the valve also takes away the tip hardening. Maybe a new Marnal head with old V6 roller rockers would work with the AU roller cam because the seats hold the valve further from the lifter for less preload.

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what valves were use'd in these tests , short or long stem valves

if you are useing long stem valves the preload problem will go away with shorter stem valves ,and get worse with long stem valves if your useing the short valves in the testing

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Rollers on a stock slipper cam gives you a very wide cam angle, slower valve opening at initial lift and is seems to fast over the nose of the cam.

 

The base circle of the roller is larger.

 

I need to get slipper rockers to run a baseline with.

 

Now that I have done this a few times it should go faster.

 

More work next weekend...

 

Kevin

 

Yes, this will be very useful info for the record, because of the misinformation that is out there (IE rollers rockers on the stock cam are a bolt on upgrade..as people who are selling them claim) Hard numbers about how it changes the timing/duration would be a good for the FAQ.

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asumeing theres .080" diff in the valve stems from short to long,, huge diff, guys will need to know befor hand what to expect acording to what valves their head has

where you are saying the lifter has bottom'd out (long stem)valves the lifter will have

.020" to .035" preload with the short valves (hyd)

 

but if the lifters are bottom'd out and you still get .06" clearance and your valves are the short stem,no way to preload the hyd lifter ,,any way huge diff in the set up,, easy to tell short and long valve stems at a glance

 

http://www.26liter.us/gallery/albums/userpics/10009/the_diff_in_retainers_install_d.jpg

Edited by Shelby
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Since mitsu only used the long valves in the early heads... I doubt they would have reverted back to them for the aussie roller heads. But I dont know.

 

Cant he also tell by the retainers?? round grooves for the long valves and square grooves in the short valves??

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Since mitsu only used the long valves in the early heads... I doubt they would have reverted back to them for the aussie roller heads. But I dont know.

 

Cant he also tell by the retainers?? round grooves for the long valves and square grooves in the short valves??

 

Yeah, maybe he can see where the top of the valve is compared to Shelby's pic? I think he might want to pull a valve to measure the length.

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in the pic by PQ the valve on the right has a flat piece of metal on top of the retainer,, showing that the short valves are very short,, they do not even protrude above the retainer,,makeing them super easy to ID

 

not trying to make a huge deal out of this ,just need to know which valves your useing in your test set up , and how you came about geting lash of .006"

a runing engine with hyd lifters would basicely have (0) lash

Edited by Shelby
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and how you came about geting lash of .006"

 

Yeah, a bit curious about that myself as the roller profile has a lot more degrees between 0.000 and 0.006 than the slipper profile so you'll report a lot less duration.

 

Scott

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Yeah, a bit curious about that myself as the roller profile has a lot more degrees between 0.000 and 0.006 than the slipper profile so you'll report a lot less duration.

 

Scott

 

Lash VS lift..... I had zero lash to test the cam.

 

 

I gave the DURATION at .006" ( Per SAE J604 standard lift VS duration. Lift is measured at the valve).

 

 

I used .006" because any lift below that is not signifigant when it comes to figuring effective duration. A better indication of effective cam duration is to measure the duration at .050" lift

 

.006 and .050 are two common lift figures used to when providing duration numbers. I will also provide total duration , but this is not as important since there is no signifigant flow.

 

SAE specs duration at .006", most hipo cams are rated at .006 and .050.

 

My work week is over and back to testing tommorow. I will post a link to a spread sheet with all the valve readings and graphs of each profile this weekend.

 

This link may help...

 

http://www.4secondsflat.com/Cam_Design.html

 

Kevin

Edited by TurboRaider
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http://kevincar1.home.comcast.net/rollertest2v.xls

 

The link is to a spread sheet of my cams tests.

 

I will update it as time goes on as well as add more notes for clarity.

 

I will go back and take another look at my work tonight just to be sure I did not miss anything.

 

Kevin

Edited by TurboRaider
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any way to view that with out haveing excell

 

http://www.microsoft.com/downloads/details...;displaylang=EN

 

Free viewer

 

When you do look at it make the graph really large and zoom in on the opening and closing points.

 

Kevin

 

 

Edited by TurboRaider
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Kevin i'm a little confuse'd here,,why is the exh cam lobe ahead of the intake lobe,, or is the box id'ing the line wrong ,it's saying the first ramp is the exh and the valve open point is where the intake should be ??

 

the 3.0 rollers sure add some thing to the oem stock aussie roller profile for sure ,i was suprise'd to see the max open peak as wide as it was i'd have thought it'd would have been much narrower with the sliper cam

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Kevin i'm a little confuse'd here,,why is the exh cam lobe ahead of the intake lobe,, or is the box id'ing the line wrong ,it's saying the first ramp is the exh and the valve open point is where the intake should be ??

 

the 3.0 rollers sure add some thing to the oem stock aussie roller profile for sure ,i was suprise'd to see the max open peak as wide as it was i'd have thought it'd would have been much narrower with the sliper cam

 

Shelby,

 

This is why people need editors... A fresh set of eyes alwyas helps.

 

The exhaust lobes are on the left side of the chart.

 

The zero degree position is with the cam's dowel hole straight up.

 

Since I did not have a crank to referance this is all in cam degrees. TDC would be at around 180º and of course the crank rotates two turns for on rotation of the cam.

 

All tests are relative to the position of the dowel hole as best as I could set it. I put referacne marks to get it to repeat as best I could. And optimal cam timing assumes the cam is degreed in.

 

I got the intake valve start point pretty well lined up, IMHO this is one of the most critical timint events.

 

What we are seeing is the exhaust valve opens ( if we had a piston it would be comming up) . closing at the 180º point.

 

The intake opening at about the 160º point.

 

Converting to crank degrees is a good next step but there is a lot of information in the chart that I think es very usefull.

 

One of the most important aspects of a cam is once you start to open a valve the timing event has started. That duration and overlap you get from that opeening sets the motors basic RPM range.

 

SO if the valve opens slowly you get the effect of a high RPM cam but not a lot of flow.

 

The most important event is the opening of the intake valve (I know I said it twice)

 

Look at how lazy the slipper cam is at its initial opening (when used with rollers) !!!!!!

 

All the intakes open at just about the same time..... But look at the cam degrees at .1" lift . To get the same valve opening the slipper cam needs 10º more cam rotation or 20º more of crank rotation! This is one of the most important cam timing events and this combo falls on its face.

 

This clearly shows how much of a compromise putting rollers on a slipper cam is on the intake valve opening.

 

The other part is how late the slipper with the roller rockers closes the intake valve.

 

I will try and crank degress onto the chart.. but for now remember I started counting with the dowel pin straight up and its for one roation of the cam.

 

Again more to follow... This is my first time through for trying to publish cam data and make it understandable.

 

Kevin

Edited by TurboRaider
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Kevin i was in no way complaining just trying to get my thoughts all in alignment

with the dowel at 12:00 the intake has done it's thing (piston is on fireing stroke )and the exh is next to open

hence the exh lobe first

for the intake to be on the opening stroke the cam dowel is at 6:00 and the valve has already start'd opening

 

ok now i understand the number,,on you linar chart 180degrees is 0 or TDC

it's hard to pin point cause you use'd 50 degree markers

 

blowing it up and adding 5 degree markers it apears the valve opening point is very close @20btdc,, that is due to the .006 lift measureing point , that would make the point of valve open a few degree's late

Edited by Shelby
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Kevin i was in no way complaining just trying to get my thoughts all in alignment

with the dowel at 12:00 the intake has done it's thing (piston is on fireing stroke )and the exh is next to open

hence the exh lobe first

for the intake to be on the opening stroke the cam dowel is at 6:00 and the valve has already start'd opening

 

ok now i understand the number,,on you linar chart 180degrees is 0 or TDC

it's hard to pin point cause you use'd 50 degree markers

 

blowing it up and adding 5 degree markers it apears the valve opening point is very close @20btdc,, that is due to the .006 lift measureing point , that would make the point of valve open a few degree's late

 

 

Shelby,

 

Thanks for the input... It really helps.

 

I'm no expert at spread sheets so this is a learning experiance.

 

Also in Excel if you put the mouse pointer on any part of any line in the graph it tells you the degrees and the lift! I dont know if the reader version does that or not but I hope it does.

 

Kevin

Edited by TurboRaider
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kevin i know you have a lot of time and effort into this, beleave me no one appreates it more then i do,, i'm not as well verse'd in the english language as some but with the right referance points i can make out most things

 

those things i ask'd about i wasn't picking at your work , only trying to find a starting point so my poor brain could work it all out so i could understand what the numbers etc was telling me,,

 

that and maybe get a better idea of what i'l be going thru to install the aussie cam , will

i have to pull the head and swap valves or not , cause i honestly can't recall if the truck head has the short or long valves right off ,,been too many heads sence then :)

 

is it posible to change the chart numbers to reflect every 5 degrees or better yet every 2 degrees

 

any way GREAT work you've done thanks

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kevin i know you have a lot of time and effort into this, beleave me no one appreates it more then i do,, i'm not as well verse'd in the english language as some but with the right referance points i can make out most things

 

those things i ask'd about i wasn't picking at your work , only trying to find a starting point so my poor brain could work it all out so i could understand what the numbers etc was telling me,,

 

that and maybe get a better idea of what i'l be going thru to install the aussie cam , will

i have to pull the head and swap valves or not , cause i honestly can't recall if the truck head has the short or long valves right off ,,been too many heads sence then :)

 

is it posible to change the chart numbers to reflect every 5 degrees or better yet every 2 degrees

 

any way GREAT work you've done thanks

 

Try this:

 

http://kevincar1.home.comcast.net/big_cam_pic.JPG

 

Kevin

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yes that helps,,thanks,, now sence you've first hand testing of rolers vers slipers, tell us how much roll effort differance are in the two set ups

for those guys that have never turn'd a rollor cam set up by hand

 

oh and are you gona do a oem slip rocker cam with slip rockers and compair that to the aussie roller cam and roller arms

Edited by Shelby
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