TurboRaider

If you take a close look at the cam chart I posted there are two slipper cams tests. One data set is titled "Slipper Slipper New" That is a graph of a mechanical cam. You can see that up to about .008" or so it has a slow ramp. Thats the take up ramp for the lash on a mechanical rocker. IF you look at "slipper sliper old" That is the graph for a hydralic cam. Basicly if you use a hydralic cam with mechanical rockers it will have a harsh lash takeup. Thats can casue some float and its hard on the valve train. If you use a mechanical cam with hydralics the initial opening of the valve will be lazy. So you lose cylinder pressure at low speeds but dont gain flow at high speeds. Better to get the right cam for the job. Kevin C

Exactly... So far I'm very happy with the roller. For my motor this cam seems to be a perfect match, the stock cam had too much overlap for a turbo. The stock cam was designed to get max power from a small four with a passenger car RPM range and no turbo. On vacation next week... the next test will be the 1.6 rollers. Kevin

My swap and tests showed that the stock air can was restricting even the stock MAS.... As Shelby points out it only gets worse with the longer 1G sensor. A really simple upgrade is putting the original sensor in the 1G housing. Stock wiring, no mixture change and you get faster spooling with more power. Kevin C

Good point.... also you can go the other way. On my Wiesco pistons when I had the rods bushed I had them offset slightly to move the piston up in the bore. Since I needed the rods bushed it did not add any exta cost. I got a bit better squish and the bushing were a bit better centered in the rod. Kevin

Over the years I have modified the piston tops on a lot of motors to fine tune CR and combustion chamber fit. In general I would leave the outer edge alone if you have the same deck height. There is not a lot of squish... But that tiny bit does help. Not a deal breaker... Most pistons have enough deck to take a small cut. Measure a few and you will find that some brands leave you more to work with. I did this on a small block Dodge to allow me to run a stroker crank with off the shelf pistons and convert the motor to a closed chamber design. Starting out with low CR parts I ended up with a positive deck height and machined the cyl head chambers to match, converting the motor from an open chamber to a closed chamber. I put a .025 dish in the pistons to fine tune the CR. 10.5 to 1 without breaking the bank, one of the better motors I have built. On my current ACL's in my 2.6 Turbo I cut a .020" dish to get a 7.7 to 1 CR. I started out with the 8 to 1 pistons. A lot of the times the piston manf does this to offer a lower CR version of the same part. Most machine shops are set up do do this and its pretty simple to do on a 4 cyl. Also a number of the after market replacment pistons are "decked". If you measure the real deck heigh ( or look it up) you will find that they drop the CR by 1/4 to 1/2 point assuming that a rebuilt motor will have the block or the head milled. Its safer to have to low a CR and not detonate. BTW one theory on spoolup is a lower CR puts more energy into the exhaust with higher EGT's.... The idea is the motor spools up faster since there is more energy in the exhaust to spin the turbo. Depending on the piston manf if you build a motor using certain replacment pistons and a new head you probably ended up with a 6.8 tp 6.5 to CR and never knew it. There are a number of sub 7 CR Starion motors out there already! Kevin C

I put the stock MAS in the 1G air box and got a nice gain. The 1G air box seems to flow a lot better. Kevin

I would not expect an aftermarket cam company to carry a OE stock replacment cam. What I was curious about is that still a good part # from the dealer and / or is it availible from aftermarket shops that specalize in standard repair parts. Basicly the AU equivilant of NAPA and Autozone in the US. Any idea what the factory PN is? Thanks, Kevin C

Can that camshaft still be bought new? I would like to be able to set a few people up with them that run 4WD's So far I'm really happy with mine, its a perfect match for my Turbo Raider. My rockers were in decent shape.... The noise was my fault. Also if you look at the cam data is shows that the roller has as good an opeing rate as the slipper at the seat. I should be able to run the V6 rockers in a few weeks. I'm getting ready for a well deserved vacation. Kevin C

http://kevincar1.home.comcast.net/rollertestv3.xls I added two tests. Slipper / slipper new is the same cam I tested the roller lifters with but with the slipper rockes it was designed for. This is a mechanical cam... Slipper / slipper old is the cam I was running in the car. Its a hydralic cam. Both show a lot more overlap. For my Turbo Raider the roller feels like a much better match. In a few weeks I will try the AU roller with the V6 rockers. I will neaten up the data next weekend and provide overlap figures. This is pretty much just raw cam profile data. Kevin

I put the roller cam into the Raider this afternoon. One lifter is noisy... I will have to take a look at that tomorrow. I did take a short test drive and the roller has better low end power. In OD at 50 mph and 2000 RPM the motor pulls smoother with more torque. Off idle is better as well. At idle you can hear a tiny bit of chain slap as the rollers cause the drive to load and un load depending what side of the cam flank they are on. Nothing really noticeable, just slightly different. No question there is less friction. At 3000 RPM the pull seems pretty good, once I get the valve lash adjuster fixed I will take it up a few more RPM's. Kevin

I got the cam cleaned up and ready to go.... Long story but I ended up mixing concrete instead. Something about a cracked footing in the basement where the cast iron sewer pipe exits the house. Some home repairs need to get done sooner than later. Back on it this Friday. BTW I did find during the cam cleanup that it is an inverse radius profile, AKA it has a pear shape , not an egg shape. Kevin

Thanks, I hope to be able to test the slipper cam with slipper rockers next weekend. Way too many projects.... Kevin

Try this: http://kevincar1.home.comcast.net/big_cam_pic.JPG Kevin

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

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

http://kevincar1.home.comcast.net/cams1.JPG

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

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

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

It is a stock AU M7 head, I'm assuming its a long valve head. Kevin

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

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

Tim, Sorry to hear that. To update the cam testing work. I machined up one of the adaptors I need and will make the other two on Thursday. I spent a bunch of time getting my basement hobby shop set up so I have a nice warm place to work. Lights wired, cat 5e drop for my computer, new monitor for the computer, microscope, oscilloscope, soldering iron and a few other things. I still have to paint the walls and get my wifes craft shop done.... I should be able to take data and post results this weekend. Kevin

Considering that there is a breather at the back of the valve cover both the PCV and the back of the valve cover would have to be plugged up. Kevin

The balance shafts wont affect the loads that the main and rod bearings see. The forces generated by the spinning of the crank and firing of the pistons is huge compared to what the shafts do to keep the entire block from vibrating. The purpose of the balance shafts is to increase passenger comfort levels. If you could safely rev to 6000 RPM before removing them you can still rev to 6000 RPM. Removing them will affect how the motor as a a whole vibrates. Things bolted to the outside may shake loose and or vibrate a bit and make noise. There is a effective HP gain from reducing how much in mass needs to be accelerated but in my experience its not huge, in the range of 2-4 HP. This is from my own testing and calculations. For my daily driver I built my new engine with balance shafts. I did cut the OD down slightly to account for my lighter pistons. I have driven the same vehicle both with and without the shafts and there is an obvious difference in the sound level of the motor. With the shafts the motor is a lot quieter. Some people may not notice or care, I do. A quite vehicle reduces fatigue on long, I’m ok with a nice exhaust rumble. If you have a sporty type car that’s more about fun and are willing to compromise on some aspects to improve others getting rid of them may be a good choice. My Raider was never about all out performance, it is a fun vehicle that I can take a long drive in with my wife and dog and get no complaints about it. At the same time it still goes pretty well with the turbo. Kevin