Having trouble degreeing cam

[Dino]

Ron's been a ton of help as always but I figure I'd throw this on here to relieve the poor man of my troubles. 

I bought a Crower HDP271 for my 440, along with a Comp Cams Magnum double roller timing gear set. #2104.

The gear can be set straight up, or 4 degrees advanced or retarded. The cam has 4 degrees advance ground in so I want to set it straight up to get 108 degrees centerline. Problem is, I can't get there.

Dot to dot gives me 103 degrees, retarded (square to dot) gives me 112 degrees, and advanced (triangle to dot) gets me 94 degrees. So there's 9 degrees difference between each consecutive step.

So how do I get this thing to be 108 degrees centerline?

[cdr]

double check  TDC and the pointer & what does the cam card say to set the ICL at ?

[Dino]

LSA is 112 and the cam has 4 degrees advance ground in. ICL should be 108.

I have a stop on top of cylinder #1 and have reset TDC and the pointer every time I changed the setup. I also check it again from time to time while I'm working on degreeing just to be safe. I had the stop be a little loose early on which threw everything off.  My bad...
That said, I'm going to add another pointer tomorrow so I can take readings off two. That gives me something extra to check.

I have been using a short rod between the lifter and the dial indicator, and I have the rod in the center of the lifter, so tomorrow I'm going to set it up differently. I'm going to try to set the dial indicator pin on the edge of the lifter. My readings have been consistent, I've repeated each measurement several times and it is always within a degree but it doesn't hurt to try.

ICL is supposed to be 108 and intake is supposed to open at 3 degrees BTDC and close at 39 ABDC. With the cam installed straight up I get an ICL of 103-104., and intake opens at 7 degrees and closes at 34.

Tomorrow I'll start by mounting the dial indicator differently and reinstall the cam straight up. I have a feeling it won't change anything but I'm running out of ideas.

Maybe the problem lies with the two components and the cam and timing gears just don't match at all. But even if none of the marks put the cam where I need it, should I not be able to dial it in just right by moving one or two teeth on the top gear? There's eight teeth between two neighboring marks on the lower gear.

It's frustrating to do this and without a degree wheel socket it's a bit of a hassle to lock the wheel down where I want it but once locked it stays put. I will put one positive spin on all this: it's my first cam install and I'm not bored!   

[BLK 68 R/T]

No expert here, but I have read lots of info and many say that not all timing gear sets are created equal. It could be that your timing gear set is not correct, meaning the lower gear has keyways that are not exactly where they should be. I ended up getting a set from pro gear after much research.

[Dino]

I thought about that. Hence my thought of sort of ignoring the marks and going by the teeth. If you can move the top gear in relation to the bottom gear by each tooth then should I not be able to get the 108 degrees ICL? Regardless of where the timing gear marks line up? Or am I seeing this wrong?

Since the straight up install gave me 104 and the retarded gave me 112 I figured lining up the dot exactly in the middle of the two marks would give me 108, but that again is in relation to the key itself so that didn't work out! I got a really low ICL. I had a bone graft done on one side of my lower jaw yesterday and an implant placed on the other side so the drugs are making me a bit unable to figure this one out at the moment!   

I sure hope I didn't waste more money on this and am stuck with a timing gear set I can't use.

[BLK 68 R/T]

Wow! Sounds like you had fun recently.....maybe you need to take a break until the drugs wear off and give it another go with a clear head when you can focus, starting from the beginning again 
That's what I would do 

[Dino]

The drugs are not too bad, but I shouldn't do any work for a few days really.

Still, ther's a lot left to do and I didn't count on this being such a pita. Maybe I can figure it out tomorrow.

[Dino]

Woke up with some serious swelling this morning; I look like an oversized chipmunk!   

Time for me to be a patient instead of a caregiver and take it easy.   

I emailed Summit tech support to see what they can do. If they take the timing gear set it back I'll go for that option. They probably won't though since it's been oiled and installed. If they do then I'll get their house brand double roller chain which has lots of keyways.

Also what is a bit unnerving is that I need to slide the cam out until the first journal almost clears the bearing just so I can get the sprocket on. With the cam all the way pushed back I cannot get the sprocket onto the cam because the chain is too tight. That doesn't seem normal to me but then again this is my first cam install so what do I know?

I hope the issue does not lie with the cam itself.

[firefighter3931]

I hope the issue does not lie with the cam itself.

I don't think that is the case Dirk. There is a consistent 9* spread between each position when there should only be 4* so the issue lies with the timing set index markings. 

This is a first for me....


Ron

[Dino]

That's certainly a positive sign, I wouldn't want the cam to be bad.

Once I feel up to it I'll get back out there and set everything up again. I'll take pics so you guys can see if I'm doing something wrong.

[BSB67]

Woke up with some serious swelling this morning; I look like an oversized chipmunk!  Time for me to be a patient instead of a caregiver and take it easy. 

I emailed Summit tech support to see what they can do.

For your swelling, or for being a caregiver?   

I recommend that you double and triple check your work.  Precision is important.  Pictures will be good.

Hope you feel better.

[Dino]

For the swelling!   

Yeah I think it's best to start over with the setup and take pics of what I do.   

I'm feeling alright but the opioids make it impossible to do fine work right now so I'm going to remain horizontal for a while.

[firefighter3931]

Hi Dirk,

I spoke with a buddy and he made a suggestion. 

Start be installing the lower crank gear in the 4* advanced position. On the upper gear make a new mark one tooth left (counterclockwise) of the current mark and use that as your new marker. Go ahead and re-measure and see what you get. If it comes in at 108 give or take a degree we'll be good to go.

If this works i'll provide an explanation for the results. 


Ron

[b5blue]

  Sorry to hear this Dirk! Doing this critical step on pain meds is a no no! Let your head clear or you'll never even know if you got it right! If something acts up later like chasing ping or poor performance you need to have this aspect nailed down to adjust other things. Have you called the cam's help line? They most likely know what gear set works best with their cam. 

[Dino]

Hi Dirk,

I spoke with a buddy and he made a suggestion. 

Start be installing the lower crank gear in the 4* advanced position. On the upper gear make a new mark one tooth left (counterclockwise) of the current mark and use that as your new marker. Go ahead and re-measure and see what you get. If it comes in at 108 give or take a degree we'll be good to go.

If this works i'll provide an explanation for the results. 


Ron

Hey Ron, thanks for that!   
I'll give it a shot tomorrow and report back. I got curious when I read this so I went out and counted the teeth on the sprocket and I think I see how this works. I should come in at around 109...

Here's hoping!

  Sorry to hear this Dirk! Doing this critical step on pain meds is a no no! Let your head clear or you'll never even know if you got it right! If something acts up later like chasing ping or poor performance you need to have this aspect nailed down to adjust other things. Have you called the cam's help line? They most likely know what gear set works best with their cam. 

pool

True I need to get this right.   

I emailed Crower but haven't heard back. I had some difficulty with speech yesterday so I didn't call.   

[birdsandbees]

I haven't done anything like this, car wise, in decades. But is there a gear with an uneven tooth count that can be installed either way (180 degrees different)??

Had this issue on an airplane mag with a gear that had odd number of teeth. Could not time it on installation. Realizing it had uneven tooth count and could be mounted 180 degrees different on the shaft, the 1/2 tooth difference was the degrees I needed. Taking the gear off and putting it back on turned 180* was what it needed.

[Dino]

SUCCESS!!!

Ron I did what you said and made a mark one tooth to the left of the dot mark on the top gear and lined it up with the advance mark. I first made sure the dial indicator was secure and spun the crank several times. Numbers were consistent so I set TDC, zeroed the dial indicator at maximum lift and took my reading at 0.050 before max lift: 66 degrees. Next reading at 0.050 after max lift gave me 151 degrees. 66 + 151 = 217. Divided by 2 = 108.5 degrees!  YEAH!!

I did this about 4 times to make sure the numbers were consistent and they were.

I then zeroed the dial indicator at the heel of the lobe to see if the readings would match to the cam card intake closing and opening numbers and they are spot on! 3 degrees opening and 39 degrees closing.

Thank you very very much for solving this issue and thanks to everyone for pitching in.   

So, why did this work? 

[firefighter3931]

Good work Dino ! 

The problem lied with the timing set markings and that was obvious to me once the results were seen to be consistent between the three positions in the timing set. This bugged me because I knew you were doing things right and it still wasn't working out. I had to take some ownership in this because I convinced you to dial in the cam and recommended the timing set you purchased. 

So after reviewing your results I consulted with my buddy Dwayne @ Porter Racing Heads and he provided the explanation. He told me that the newer 3 way timing sets are basicly useless unless you want to do some modifications. At some point the specs they use changed. The lower end Comp Cams (and many others) advertise a 4* advance/retard adjustment. The 4* is actually 8 crankshaft degrees because the crank turns twice as fast as the cam. See where this is going ? 

Based on the readings you came up with using the 4* advanced position the cam timing was a 94* ICL. We needed to retard it 14* to get to the 108 ICL that the cam card called for. The easiest way to get there was to move the upper gear one tooth backwards ; one tooth = 14* so that's what we recommended.

The other option would have been to use the straight up position which yielded a 103 ICL which would have been 5* advanced. At that point you can purchase a bushing kit from someone (Comp/Crane etc...) and drill out the pin hole, insert the 5* retard bushing and reassemble. Sometimes this is the only option viable due to the original design of the timing set.

In your case, the math worked in our favor....the results were achievable with a combination of crank advance on the lower sprocket and cam retard on the upper to achieve the desired ICL. 

This is why we degree in a camshaft 



Ron

[b5blue]

  Hooray!

[BLK 68 R/T]

Great news! Glad you got it all figured out.
Maybe this one needs a sticky?

[Dino]

Ron I would never hold you responsible for a company's mistake and wrongly stamped markings. The timing gear set looks very well built and that's ultimately what counts. I'm sure there's many more brands that have mismatched markings on them.

When you told me to make this modification I made the same calculations and it did come out to 108-109 degrees so I couldn't wait to get out there and try it.  I did so first thing this morning without drugs on board so I wouldn't mess it up.   
I made a little happy dance when everything checked out. 

Big lesson learned here; never ever install a cam without degreeing it. I would have been running this cam at 103 degrees ICL if I did. Thank you very much for convincing me to degree it.

[firefighter3931]

Hi Dirk,

For sure the 103 ICL would have been a problem. You would have ended up with detonation issues and wondered why this was happening. 

I knew it could be fixed because it's just math and a matter of making some adjustments to make things line up where they are supposed to be. What had me concerned was ; why this was happening now ? Dwayne cleared the air on that issue with a viable explanation. He can't get the 3 way sets to line up either  PRH is a pro shop and builds lots of different stuff and this is an issue with all brands (Ford/Chevy/Chrysler) so he just uses the 9 keyway sets from the get-go to avoid these headaches. Lesson learned. 

It's been many years since I used a 3-way and I don't remember having this type of an issue. The last few builds have used Billet 9-way sets for solid flat tappet builds and Roller cam stuff with increased spring loads. The high end stuff all comes with 9 keyways by default. No problem with those either....they have been spot on from my experience. 

Time to button it up and shoot some paint on her. With your talents she'll shine up pretty nice.   



Ron

[71 SE3834V]

Dirk, I'll throw my   in here (which is worth about 1/2 cent) and say if you haven't already, write all this down or print this thread out and keep a copy with the car and your files. If you're like me and you have to go back in years later you'll be saying "what the heck was I doing back then. Was I on drugs?" w/o some notes to refer to.  

Man that was a lesson. Wish I was there to see it all come together.

[Dino]

That's a good idea because when I do look back the only thing I'll be able to say is "yes I was on drugs"...and that's not very helpful.