TU and F4 Camshaft Follow-on Discussion

[acannell]

No offense intended, but if you don't KNOW the exact procedure, then you really shouldn't post up your opinion on how it is done. Much of what you posted is far from the real procedure, and only leads to confuse the issue. Please stop.

BTW, first wrong thing, the degree wheel goes on the crank, not the cam sprocket.

I just found the procedure in the MP book, but it covers quite a bit of space, far too much to type in. I will try to get it scanned and posted tomorrow sometime.

Barry

Well first of all, anyone trying to degree their cam blind without understanding whats going on, and just following a procedure, probably should learn more about what they are doing and why, instead of just going all robot on the thing. And I added a disclaimer so its really not needed to suggest censoring things, I'll post up my opinion and my wrong theories whenever I feel like it, thanks. If anything, why dont you explain why the procedure I laid out wouldn't work? Its a teachable moment and we'd all learn something, versus the RTFM route. And BTW, "because the procedure says so" is not an explanation.

And I dont think this kind of thing has or needs an exact procedure. There are a million ways to skin this cat. Why cant you set the crank to TDC and then adjust your cam position as needed? 6 of one....

[knownenemy]

Degreeing is a method to find the EXACT center of the cam lobe.
Sounds simple, but is a very specific science.
On every lobe, there is a "Flat" spot atop for a few degrees.
What degreeing enables one to do is center the cam precisely.

The "Flat spot" is also true of crankshafts, and should be considered when building.
TDC is a "time" in the engine cycle, while the rod "switches" from going up to going down.
On a perfectly timed crank, 0° is marked at the exact center of the "switch".

Both of the correct centers require special tools, but are somewhat simple to perform.
Check YouTube, for "Degreeing a cam", and click on links from reputable people.
(In other words, machine shops, performance shops, etc. NOT "First time degreeing a cam" lol)

[wheming]

Thanks Mr. Barry. I was hoping if there was a good MP procedure someone would have it.
I had learned something like this way back in college 20 years ago on diesels, but can't remember. And I just have never had the time to rebuild one of my own engines.

[chilort]

I've degreed one cam ever and it was a Voodoo 60303 cam in a '68 440. And it was dead nuts on. I had the good fortune of having a good teacher. I couldn't do it again on my own without help. But, yes, it is a specific process. While there are often a number of ways to skin a cat, I'm not sure there are that many ways to degree a cam.

I was reading the gospel the other day and I'm now no longer sure where the idea that cams don't help these engines came from. The gospel clearly points out that different cam profiles that make different levels of power. But when I got started into this, and coming from big block Mopars, I asked about cams. And I was told a cam doesn't do anything for these engines because the the forced induction makes up for it all. What a load of BS.

[4 l-bodies]

Okay here is some elusive specs on the F4 that I asked for and received early this past summer. Please note I did not degree this camshaft in, but have degreed many others in. FWD lists intake centerline at 116° ATDC along with LSA at 116°. This camshaft was installed at 109° ATDC. So that means it is installed 7° advanced from what FWD catalog lists. 6 degrees advanced from where Rob (Shadow) lists his F4 is installed at. I corrected exhaust duration 1 degree based on open and closed #'s. I also listed overlap which wasn't listed, based on #'s provided. I felt this is an important spec. to list. The rest of the numbers came straight from vendor. Hope this helps.
Todd



Intake: Exhaust:

- Duration @ .050 213 204

- Duration Advertised 282 276

- Valve Lift .470 .467

- Open @ .050 4 ATDC 45 BBDC

- Close @ .050 37 ABDC 21 BTDC

- Overlap @ .050 negative 25°

- LSA 116

- Centerline 109* 123
*advanced 7° based on FWD catalog.

[turbovanman²]

Great job Todd.

Acannell, as said, you don't put the degree wheel on the cam and there is only one way to degree a cam. Newbies read this site and might take your info with a grain of salt. If your want to install it correctly, you have to degree it correctly. It might not seem like much but 1 deg can make a huge difference.

[Oggie Fisher]

Is there a current source for the solid adjustable lifter?

[turbovanman²]

Is there a current source for the solid adjustable lifter?

MP used to make one, but its not that hard to make your own.

[moparzrule]

Probably the easiest thing to do would be get a PT lifter, weld it, and shim to where it needs to be. Not ideal, but a lot easier than making your own if you can't find one.

[Warren Stramer]

Okay here is some elusive specs on the F4 that I asked for and received early this past summer. Please note I did not degree this camshaft in, but have degreed many others in. FWD lists intake centerline at 116° ATDC along with LSA at 116°. This camshaft was installed at 109° ATDC. So that means it is installed 7° advanced from what FWD catalog lists. 6 degrees advanced from where Rob (Shadow) lists his F4 is installed at. I corrected exhaust duration 1 degree based on open and closed #'s. I also listed overlap which wasn't listed, based on #'s provided. I felt this is an important spec. to list. The rest of the numbers came straight from vendor. Hope this helps.
Todd



Intake: Exhaust:

- Duration @ .050 213 204

- Duration Advertised 282 276

- Valve Lift .470 .467

- Open @ .050 4 ATDC 45 BBDC

- Close @ .050 37 ABDC 21 BTDC

- Overlap @ .050 negative 25°

- LSA 116

- Centerline 109* 123
*advanced 7° based on FWD catalog.

Todd, Thanks for posting those specs, as it gives a chance for a perfect illustration as to why things can get so confusing with cam specifications for our 8V OHC engines. A large share of the confusion should be placed on the cam manufactures themselves for not being explicit when they list the opening and closing events, or what method should be used to check and measure them.
Take the posted F4 specs, the @.050 duration is given but one of the most important bits of information is left to the installer's best guess...does the cam grinder mean @.050lobe lift or valve lift?This would make a huge difference if you were checking the cam timing with a degree wheel and you did not know what the cam manufacturer was referencing. In this instance I believe they must be referencing Lobe lift, because that cam has way more than 213 deg. @ .050, BUT if you were measuring at the valve you have to remember to multiply the follower ratio (1.75)
Notice the cam card for the LRE cam posted previously. Probably because Lambros worked with our engines exclusively they were conscious of the fact that it was almost impossible to measure lobe lift in an assembled 8V because of the difficulty in getting a indicator under the follower, so they printed the duration at .050 at the valve They knew what they were dealing with, It is easy to set-up a dial indicator on the valve spring retainer.
Most cam grinders today think in terms of what they are used to dealing with, and that would be a V8, and by convention they express duration specs. by either the SAE method of @.006 seat duration (total seat-to-seat duration, also called "advertised") for most hydraulic cams, or the @.050 lifter rise method for solid lifter versions.
More on this later,(I have more cam grinder peeve's) as I have to get to work now.

[turbovanman²]

More on this later,(I have more cam grinder peeve's) as I have to get to work now.

You're awesome,

[sdac guy]

The installation centerline is defined as the relationship between the number one intake lobe and the TDC position of the number one cylinder. In less technical terms, it's the relationship between the cam and the crankshaft. This we can change, and do, on occasion (even through head milling or block decking). So relative to centerlines we not only have to consider performance improvements/special applications but we have to guard against mistakes. This error-free installation by centerline is very critical.

There are three ways of checking a camshaft for correct installation. A common method is to "line-up-the-dots." This is acceptable for standard cams, but is not recommended for performance camshafts. A second method, recommended by many shops and some camshaft grinders, is to check the intake and exhaust valve opening and closing events against TDC (top dead center). This is better than the "dots" system, but we don't feel that it's as accurate as the "centerline" method. The centerline method is also much easier to understand.

If you're going to swap camshafts, you've spent good money for a new camshaft and you want to improve on the stock one or whatever is currently in the engine. If you do not centerline, then you do not get the full value of your investment and you probably won't achieve the desired improvement. Once the engine is disassembled to the point of installing the camshaft, centerlining the camshaft costs very little and only takes a few minutes to do. If you have a problem with the engine's performance after assembly, you will ultimately need to centerline the camshaft. Centerlining may be a minor problem of a few degrees or a major problem of a tooth or two on the camshaft sprocket. Usually the problem isn't with the camshaft itself, except relating to installation; i.e., centerline.

By centerlining the camshaft at installation, you can concentrate on fuel, ignition timing, and assembly problems (such as gasket leaks) to identify any problem. But if you didn't centerline the camshaft, you can't say for sure that it is a fuel, ignition, etc problem. To centerline the camshaft with the engine together requires partial disassembly. This is a lot of extra work. One added benefit of centerlining relates to advancing or retarding the camshaft for improved performance. You don't know which direction or the number of degrees to change if you don't know the original centerline first.

Note: When checking camshaft centerline, ALWAYS rotate the engine clockwise from the front. This is the normal direction of engine rotation. By rotating the engine in this manner, the clearances in the camshaft drive system (belt, sprockets, keys, etc.) will be taken up just as they are when the engine is firing, and your measured camshaft centerline will be what the engine sees when it is firing.

Barry

[sdac guy]

The procedure is as follows:

1. With the camshaft in place, insert the intake valve follower for the No.1 cylinder. It is suggested that this be the only follower installed, as that makes rotating the engine much easier and minimizes the chance of the valvetrain pulling the engine because of spring pressure (snapping to position).

2. Place a dial indicator on a retainer, parallel to the valve centerline. And have the dial measuring point resting on top of the follower or the valve spring.

3. Install a degree wheel so its pointer indicates TDC (0 degrees) when the No. 1 piston is at TDC. Install a dummy solid lifter (P4452014) set up with "zero" lash when it is against the base circle of the cam.

4. Turn the engine over (clockwise from the front) until the dial indicator is at maximum cam lift (max valve lift). Zero the dial indicator at this point.

5. Turm the engine over (clockwise) until the indicator reads .025" before reaching maximum lift. Stop. Read the degree wheel, write down the number of degrees. Continue rotating the engine in the same direction (clockwise) past maximum lift (zero indicator reading) until .025" is read again on the indicator. Stop. Read the degree wheel. Write it down. Add the two degree wheel readings together and divide by two. The answer is the cam centerline where it is installed.

Note: .025" was used for illustration. Any measurement above .020" is acceptable. However, on cams that have differing valve open and closing ramps (i.e. Super 60, for example has a much steeper closing ramp) then try to stay under .050" from max lift as differing ramp rates may play a part in where the center measurement appears.

Barry

[sdac guy]

Example: Use the numbers from the cam specification chart that comes with your camshaft. Let's assume that we are going to use a mechanical cam for the 2.2L engine. We'll install a 105° cam at a 105° centerline.

The cam and timing belt are installed. The lifter is installed on the number 1 intake lobe. The degree wheel is bolted to the crank and set to read TDC correctly with a pointer. The dial indicator is zeroed at the max. lift of the cam. Now, rotate the engine clockwise and approach the indicator reading of .020" carefully since you must not reverse the direction of rotation. At .020" the degree wheel reads 90°. Record the reading and continue to rotate the engine clockwise through zero until the indicator reads .020". The degree wheel now reads 134°. Add 90° plus 134° and divide by two. Answer = 112°. Thus, we must advance the cam 7° in order to have the centerline at 105°. A multi-keyed sprocket is used for this purpose. Insert the sprocket at the proper keyway so that the centerline of the cam is moved forward (advanced) in the direction of its rotation. Repeat the above steps with the advance cam position. Now we should read 86° at .020" before maximum lift on the indicator and 126° after maximum on the indicator. Add 86 to 126. Answer 212°. Divide this by two. Answer 106°. The cam is now installed correctly. (One degree isn't worth changing, and cannot be changed in less than 2° increments.) If .040" was selected instead of .020" for the indicator reading, the last step above would be as follows. We would read 70° at .040" before max. lift and 142° at .040" after max. lift. The two numbers added together yield 212 and this divided by two gives 106°.

In the example above, a multikeyed cam sprocket is used to adjust the cam timing, but an adjustable sprocket may also be used, as well as the MP Cam Timing Keys. While the keys are designated 1, 2, 3, 4, and 5 degrees, they actually change the cam timing by twice that amount since the crank rotates twice for every rotation of the cam.

And it should be noted that not only is 1° of adjustment next to impossibe to do, 1° doesn't make any noticeable difference in how the engine runs.

Barry

[turbovanman²]

Barry, do you have a stutter?

[4 l-bodies]

A large share of the confusion should be placed on the cam manufactures themselves for not being explicit when they list the opening and closing events, or what method should be used to check and measure them.

Take the posted F4 specs, the @.050 duration is given but one of the most important bits of information is left to the installer's best guess...does the cam grinder mean @.050lobe lift or valve lift?This would make a huge difference if you were checking the cam timing with a degree wheel and you did not know what the cam manufacturer was referencing. In this instance I believe they must be referencing Lobe lift, because that cam has way more than 213 deg. @ .050, BUT if you were measuring at the valve you have to remember to multiply the follower ratio (1.75) which would mean .087 valve lift. At that point you would probably see more like 248 degrees. But we don't know because they don't specify @.050 lobe, or .050 valve???????

Notice the cam card for the LRE cam posted previously. Probably because Lambros worked with our engines exclusively they were conscious of the fact that it was almost impossible to measure lobe lift in an assembled 8V because of the difficulty in getting a indicator under the follower, so they printed the duration at .050 at the valve They knew what they were dealing with, It is easy to set-up a dial indicator on the valve spring retainer.

More on this later,(I have more cam grinder peeve's) as I have to get to work now.

Warren, I never gave it much thought that on the rare occasion we do receive some specs, that spec it isn't at the valve. As you stated, trying to get a dial indicator where the follower wants to ride is difficult to say the least. At the retainer, no sweat. I have always degreed the 2.2 cams in the way LRE did, which is at the valve @ .050. I have also seen results of other 2.2 SOHC camshafts degreed in by people from years past and they also appeared to use the same method (.006,.020, &.050 at the valve retainer). Having never degreed in the F4, I just assumed the duration #'s were at the valve @ .050. Can't even fathom why they would provide lobe lift figures for our application, when you couldn't verify them. I couldn't figure out why some thought the F4 was a big step up from stock. It didn't seem very big at all just looking at the #'s supplied to me. With that said, IMO, it still could have used a bunch more lift for people that have good flowing heads. If you're running a F4, chances are your top half of engine isn't stock. To compare apples to apples (at least for me), it would be nice to degree in the F4 like the other camshafts @ .050 at the valve retainer to get some real comparable #'s between the grinds available.

IMO, aside from knowing what the exact peak lift of #1 intake lobe is in relationship to TDC, the intake installed centerline is just a reference # to what the manufacturer meant to grind the cam to. The valve events opening and closing points (around TDC) are far more important to me in choosing the correct camshaft than an intake centerline # or LSA #. Other events like intake closing (for cylinder filling) and exhaust opening (for low RPM, mileage, off boost driveability), area under the curve, are good need to know info too. The more info the better!

I have many found aftermarket cams to be all over the place in regards to what the intended installed centerline is supposed to be. I eluded to this in a previous post about the last cam I degreed in for my friends 2.2. Had I ran the cam at the suggested centerline (105) and not known the actual opening and closing points around TDC, it would have been a terrible performer. Since I knew those points, I set my own intake centerline based on those #’s. I set it 10 crankshaft degrees retarded from what I was told centerline was supposed to be. Of course no cam card supplied, just a note scribbled on back of business card or invoice (can't remember). The cam worked great! 19HG idle, good off boost throttle response, and pulled great to 7K. The sad part is had the cam manufacturer bothered to publish or include a meaningful cam card they could have probably sold a lot more of these camshafts. Few were made and none sold to vendors that I am aware of. It would have been a win, win, win. Consumer gets what they want, remanufacturer and vendor sell product. And yet cam cards don't get posted (in our Mopar 2.2 world) because they regard it as proprietary info. How many people are there like me, that won't buy a camshaft without specs? I’d wager quite a few. Only reason we even tried it was because of default. Found nothing much else out there that would complement the application. F4 camshafts were months away from shipping. We also found that trying to buy new roller cam blanks in the US, was futile as well because of some proprietary Chrysler road block. Found the OEM manufacturer, they just couldn't or wouldn't sell to us. May also have been too small of fish in the big pond.

My whole point of this is by not knowing the opening and closing points of the camshaft at a certain installed centerline, you're making a rather large assumption that the camshaft is ground correctly. For some, knowing those specs to crucial to making an informed decision on a proper camshaft selection for your application, and the ability to check the grinders work. I degree all four cylinders in, because I've seen a few camshafts ground incorrectly on a individual cylinder lobe. After degreeing some of these camshafts in, I think sometimes manufacturers throw a dart at a dartboard when they post installed intake centerline. Pick a # between 105 and 125. Just kidding, sort of…

Todd

[moparzrule]

That's why, instead of going through all that (only to possibly not have it correct since we don't know if specs are at the valve or lobe), I simply keep making passes while changing the cam timing 2 degrees. Once I have it narrowed down to the best passes within 4 degrees I'll make 1 degree increments and see what works best. Quite honestly, even if you degree in the cam, you're going to have to do this anyway. Just because you degreed in your cam doesn't mean that's where it's going to run the best. So who gives a crap if someone degreed in their cam or not. jeez

[4 l-bodies]

That's why, instead of going through all that (only to possibly not have it correct since we don't know if specs are at the valve or lobe), I simply keep making passes while changing the cam timing 2 degrees. Once I have it narrowed down to the best passes within 4 degrees I'll make 1 degree increments and see what works best. Quite honestly, even if you degree in the cam, you're going to have to do this anyway. Just because you degreed in your cam doesn't mean that's where it's going to run the best. So who gives a crap if someone degreed in their cam or not. jeez

Matt,
I'll take a stab at this. By knowing the opening and closing points, you have a far better understanding what exactly is happening at TDC and ultimately how to go about tuning for success. For example, I think you stated in your project log thread IIRC, that your vehicle was experiencing detonation even at relatively low boost pressure on pump fuel. Could this be because of the heat from exhaust pressure is backing up in the intake and overheating it because of incorrect valve timing around TDC? Maybe, and maybe not. Could very well be ignition timing related. It is true that diluting intake charge with some exhaust can lessen detonation (EGR theory), but it widely accepted that the heat put into the intake charge, promotes detonation more than the benefit of EGR reduces it in turbo applications. Chrysler figured that out in 87 on their intercooled cars. Making cam changes based solely on dyno peak HP results is definitely not the fast way down the track. If you look closer you may find that you've lost HP and torque under the power curve. Gained 5 HP up top at redline, but lost 8 HP where vehicle spends more time rowing through gears. Ultimately going slower going down the track.
We all have our ways of attaining goals, and I degree cams in so I'm not chasin my tail unnecessarily especially when breaking in a fresh motor. Good luck with your build. We won't be holding our breath looking for new TU cam #'s from you (lol).
Todd

[turbovanman²]

We won't be holding our breath looking for new TU cam #'s from you (lol).
Todd

This catiness and backstabbing shitt has got to stop. What are we? 3? Time for everyone to grow up, I've been here for 9 years and somethings never change, how sad. Why don't we pull the knives out of said backs and just concentrate on building fast cars/vans without the drama. Bad enough we have members slamming Gary D! TD is still taking shots at TM but I haven't seen any on here for awhile, at least that's a start.

[Warren Stramer]

Warren, I never gave it much thought that on the rare occasion we do receive some specs, that spec it isn't at the valve. As you stated, trying to get a dial indicator where the follower wants to ride is difficult to say the least. At the retainer, no sweat. I have always degreed the 2.2 cams in the way LRE did, which is at the valve @ .050. I have also seen results of other 2.2 SOHC camshafts degreed in by people from years past and they also appeared to use the same method (.006,.020, &.050 at the valve retainer). Having never degreed in the F4, I just assumed the duration #'s were at the valve @ .050. Can't even fathom why they would provide lobe lift figures for our application, when you couldn't verify them. I couldn't figure out why some thought the F4 was a big step up from stock. It didn't seem very big at all just looking at the #'s supplied to me. With that said, IMO, it still could have used a bunch more lift for people that have good flowing heads. If you're running a F4, chances are your top half of engine isn't stock. To compare apples to apples (at least for me), it would be nice to degree in the F4 like the other camshafts @ .050 at the valve retainer to get some real comparable #'s between the grinds available.

IMO, aside from knowing what the exact peak lift of #1 intake lobe is in relationship to TDC, the intake installed centerline is just a reference # to what the manufacturer meant to grind the cam to. The valve events opening and closing points (around TDC) are far more important to me in choosing the correct camshaft than an intake centerline # or LSA #. Other events like intake closing (for cylinder filling) and exhaust opening (for low RPM, mileage, off boost driveability), area under the curve, are good need to know info too. The more info the better!

I have many found aftermarket cams to be all over the place in regards to what the intended installed centerline is supposed to be. I eluded to this in a previous post about the last cam I degreed in for my friends 2.2. Had I ran the cam at the suggested centerline (105) and not known the actual opening and closing points around TDC, it would have been a terrible performer. Since I knew those points, I set my own intake centerline based on those #’s. I set it 10 crankshaft degrees retarded from what I was told centerline was supposed to be. Of course no cam card supplied, just a note scribbled on back of business card or invoice (can't remember). The cam worked great! 19HG idle, good off boost throttle response, and pulled great to 7K. The sad part is had the cam manufacturer bothered to publish or include a meaningful cam card they could have probably sold a lot more of these camshafts. Few were made and none sold to vendors that I am aware of. It would have been a win, win, win. Consumer gets what they want, remanufacturer and vendor sell product. And yet cam cards don't get posted (in our Mopar 2.2 world) because they regard it as proprietary info. How many people are there like me, that won't buy a camshaft without specs? I’d wager quite a few. Only reason we even tried it was because of default. Found nothing much else out there that would complement the application. F4 camshafts were months away from shipping. We also found that trying to buy new roller cam blanks in the US, was futile as well because of some proprietary Chrysler road block. Found the OEM manufacturer, they just couldn't or wouldn't sell to us. May also have been too small of fish in the big pond.

My whole point of this is by not knowing the opening and closing points of the camshaft at a certain installed centerline, you're making a rather large assumption that the camshaft is ground correctly. For some, knowing those specs to crucial to making an informed decision on a proper camshaft selection for your application, and the ability to check the grinders work. I degree all four cylinders in, because I've seen a few camshafts ground incorrectly on a individual cylinder lobe. After degreeing some of these camshafts in, I think sometimes manufacturers throw a dart at a dartboard when they post installed intake centerline. Pick a # between 105 and 125. Just kidding, sort of…

Todd

Todd, I believe you partially misunderstand what I was saying. I hope not to confuse anyone into thinking that you should not check cam centerline at the spring retainer, as this is really the only practical way to do it on these engines. I really wasn't addressing the issue of checking install centerline as that is a whole different can of worms as you alluded to.

What I was trying to make clear was that unless you are on the same sheet of music as the cam designer and how he expresses ALL timing events, then there is no accurate way to check the cam card against the actual cam (as you rightly stated) You end up with gibberish like the F4 specs you posted (which by the way, are the same specs I was quoted for that cam). That doesn't make it a bad cam, It just makes no sense on paper, and makes it hard to compare it to another cam. Maybe by intention.

You can check and set the designed install center line at just about any arbitrary valve lift figure, and you don't even need to know any of the more important specs.( I will have to qualify that statement later) BUT There are some important definitions that you and the cam maker must mutually understand if you want to check his work, or even know how to pick a cam.

A good example of the confusion that is caused by lack of accurate information can be found in the fact that cam cards (if you even get one) rarely say if the recommended install centerline should be measured at equal distances from highest lift point, or from equal distance off the base circle. On an asymmetric lobe such as is commonly used now days, it can make a difference of 4-8 degrees. The only time I feel sure of using the nose of the lobe as the measuring point is if the lobe profile is perfectly symmetric. And once again, the installer has no way of knowing if the lobe is symmetric or asymmetric unless the cam designer gives all the timing information in a concise form.

I think we are basically saying the same thing, with different words
More later, gotta go.