Cam degree drama
 

I'm a virgin cam degree'er so be kind.

I'm swapping my heads/cam/intake over to a different block. My local machine shop put my previous setup together years ago.

I wanted to verify the cam was installed correctly, so a few youtubes later I'm an expert right? Cam is a the stump puller on a 114LSA. ICL at 109.

Here is my post on FB for some picture.
https://www.facebook.com/groups/1612...omment_mention

My local shop wrote their numbers down on the cam card when they degreed the cam. 150 and 70 = 220 / 110 deg.

I had the heads on and was using a piston stop. I cam up with the same 150 but 73 for my other, thus my number came up to 111.5 deg. Using the intake centerline method taking measurement in the clockwise rotation. The timing chain does have a small amount of slack.

On the cam card the local shop wrote "crank 4deg Ret". That is correct that was how it came off the old motor and went back on the new to me motor.

So 2 questions and this is really bothering me.

1. On the cam card the engine builder also wrote "Cam key 11+ Advanced" What the heck does this mean? How is it relevant to degreeing the cam? Is it maybe referring to an offset key on the cam? I didn't see one, but wasn't looking either. Maybe referring to ground in advance? That would be 109-114 that would 5 deg. IDK.

2.. I'm tempted to tear back into it and change the crank sprocket to strait up and remeasure. IS the +4/-4 on the crank sprocket equal to what I should see at the lifter? Meaning if I was at 111.5 and move to the strait up mark should I be at 107.5? That too much?


I found this in the Archives. Not sure where my 114 LSA falls into this discussion.
https://forums.maxperformanceinc.com...ght=degree+cam

Thanks for any help.

I have found that variations in measurements when degreeing a camshaft is primarily caused by the dial indicator not being "square" or " parallel " with the valve, or not having a flat surface to place the dial indicator stem tip on the valve retainer. Those two items can cause issues trying to get an accurate, repeatable measurement. Regarding the +4. Most cam manufacturers are adding 4 degrees advance in when grinding the cam. It will generally say that on the cam card by stating the cam grind number followed by +4. Lastly, if you use the +4 keyway and marks on the timing gear, it should advance the cam 4 degrees. Naturally, it needs to be verified by degreeing the camshaft in.

I use a lifter that comes with a degree kit set up which helps a bunch.
As noted in the above the dial indicator must be set up perpendicular in both planes.

The lifter needs to be lubed with a very light oil, such that almost no pressure from the dial indicator is needed to have it follow the cam lobe with total accuracy on the closing side .

I think I did ok on that. I had my lifter in place with a pushrod. I used the CC degree kit. I had the setup screwed into the rocker stud with the the guide plate installed. There was no movement of the plunger.

Did the FB link work? There is a picture of the cam card there. I see that there is a Part# and a Serial# The serial number: v 9054-11. Maybe that -11 is where they got the 11 deg Advanced? Regardless do I even car about that number? I'm still trying to hit the 109 ICL correct? And advance or retard is from that reference.

I feel pretty confident I got this part right. I did hit same closing 150 number as the machine shop just not the same opening number 70.

I'm concerned I'm leaving a fair amount of lower RPM power on the table at the 4 deg ret crank sprocket setting. I never felt it had the low end grunt to live up to the stump puller name. Above 3500 it pulls hard though.

Reading that other post I linked seems to make sense to change the crank sprocket to strait up.

Great tool. Eliminates some potential variables which is always a good thing.

https://www.summitracing.com/parts/p...38?seid=srese2

To just reinforce what’s mentioned in post 2 here, many cams are made with 4 degrees of advance ground in to cover for normal and eventual chain stretch.

Most likely the timing chain has stretched that reason for the 111 if you put in a new timing chain, most likely it will come in at 109. Most likely cam is designed to end up with timing chain stretch at 111 or 112 which should still be 2-4 degrees advance.

PS: no worries you did a good job on degree it in.

Even so what do I do with that information? The cam card says install at 109 ICL. Is that so when you install the timing set strait up it will install at 105 and then chain stretch would get it closer to 109?


Thanks for that although it may be undeserved.

I would tend to agree with ya, however I got the same number as the machine shop with 150 closing.

The question still remains should I re-set the crank sprocket to 0? The cam is current a few deg ret as measured. Seems like I would be better off a few deg advanced.

Where are you measuring 150 at?

The cam has a 114 LSA and the cam card wants a 109 ICL

Using intake 6 BTDC and 44 ABDC will have you at 109 ICL

Stan

Personally I would leave it, right were it is. Usually advancing the Cam picks up bottom end, seat of the pants and a chance of picking up ET, maybe, but top end usually suffers. Show it’s a trial and error thing. But if it’s a nice street cruiser I doubt your going to notice much of a difference. I mean you can try it at zero and see what you end up with.

Most of the factory cams were on a 114 , so cam company’s knew advancing them along with a little more intake and exhaust duration would definitely make more hp. They also knew the heads was the restriction.

So basically even though they say 109, they Knew with Timeing chain stretch, it’ll end up at 111-112. What their banking on is the opening and closing…change that to much and it’s going to effect cylinder filling.

Measured at .050 down from both side of the max lift of the intake lobe.

Basically followed the same method Fast Monte used as instructed by Buttler.
https://www.youtube.com/watch?v=jKpk64KWqag&t=992s



Well I know how it drives as is and it does lack bottom end torq. I had to put in a 10 Continental converter to unlock the power. So advancing seems preferable to me given its a street car. It want to pull well past 5500 and it still has stock rods:(

Well you know your car better then anyone else put in at Zero and see what you come up with, see how much it advances. I’d be interested to see how much.

The only thing those 3 keyway roller chain sets are good for is to practice my hook shot to the trash can over by the shop door. If you are going to run a bicycle chain on the front of your engine at least get one with billet sprockets and 9 keyways so you can accurately move the cam timing around........FWIW.......

Why not try using the 0.050" lift numbers on the cam card which Comp Cams said to use?

Stan

I think the Intake Opening event is subjective when going by Degree-wheel readings:
ILC from IO to IC gives a Measured result BUT, i think there needs to be a bias on the number so you know the ILC might effectively be an effectively advanced value above the measured value.
I always assume non-symmetric lobes.

While in there; Try for 2 types of ILCs based on "onset of Opening/closing, and 0.005" lift for ILC. Oh sure 0.050" values could be an3rd basis but not as defining the Idle result as 0.005".

Same goes for Exhaust ELC from EO to EC, but sooo less critical.

My last Cam Degree activity was fraught with looseness from every possible non-fixturing frustration. And the 14" dia degree wheel in 1* toothed increments magnified my lack of accuracy. I gave up and sold the ( Spare ) engine with explanation of the degree activity.
Was easier 40 to 30 years ago, when i was not sweating the precision details.

me too


What do you recommend? I thought those 9 key crank sprockets were terribly unreliable. I don't know what timing set this is, but I have been pretty impress with how tight it still is.

Because I have no idea how they got those numbers, LOL. The intake centerline method seems to be the preferred way of doing it from what I have found.


The only part of this activity that I questioned was finding TDC with the piston stop with the heads on. I don't know if piston rock would amount to much.

The other thing I followed was keeping all measurements in Clockwise rotation.

I found this cam timing test of interest to me. They went pretty extreme from -2 to +10. For me my concern would be possible detonation (Ping) issues if I were to go to advanced.
https://youtu.be/wimUgFd0Qkg

"What do you recommend? I thought those 9 key crank sprockets were terribly unreliable."

The Rollmaster 9 keyway set is DEAD NUTS on the money for moving the cam and on the upper end for quality with roller type timing sets. Those 3 keyway sets not so much. They are usually pretty close dot to dot at the "zero" keyway, but after that they can be all over the map for where you end up at from what I've seen here.

I've installed a number of Rollmaster sets in customers engines, they seem to be at the top of the pile and marketed by all the big Pontiac shops and used my most Pontiac engine "builders" from what I've seen.

For my engines I use the factory 3/4" wide stock Morse timing sets and offset cam keys if I need to move the cam.......

Those numbers come from Comp Cams and are your installation instructions.

230 / 2 = 115 - 6 = 109 ICL

Once the ICL is set so is the ECL so why check it?

236 / 2 = 118 - (-1) = 119 ECL

How else can you see what the LSA of your cam is and that it is correct?


109 + 119 = 228 / 2 = 114 LSA

Stan

Here I ALWAYS back up the ICL checking by also turning the engine is the same direction and taking a look at the intake open point @ .050". The cam card will also tell you when the intake opens in crankshaft degrees.

So if the cam card (for example) says that the ICL should be 109 and that the intake opens @ .050" at 8 degrees BTDC then it should be very close to that number if you have the ICL in the correct place.

I actually prefer to to use the intake open point vs ICL since a LOT less movement of the dial indicator is required. With the ICL method you are going clear up to full lift and recording numbers on both sides of the lobe. It sounds easy when folks talk about it but it can be a real PITA to get your dial indicator set up so it has the correct geometry to record the lobe movements without any errors from slipping or moving on the magnetic base, etc......