Double checking

[miller]

Just wanting to know if my numbers seem close enough.

Recap...Crower #32241, into a 440. Almost convinced I've got this thing right, on degreeing the cam.

Cam card numbers-

Advertised (Hyd)Cam numbers..
Intake Duration: 267deg Lift: .477
Exhaust Duration: 271deg Lift: .486

This cam has 4 degrees advance ground into it.

Here's the recommended degreeing numbers- (@ .050" lift)

Intake - Opens: 2.0 BTDC (4)
- Closes: 38.0 ABDC (34)
Exhaust - Opens: 47.0 BBDC (49)
- Closes: -5.0 BTDC (-6)

Lobe Separation 112deg (113deg)

Numbers in () are what I actually came up with on this cam. Using a Mopar performance double-row roller chain and gears, that have the three key slots, including for retarded or advanced 4 degrees.
I had to use the 4 degree retarded timing mark, to get the cam to degree at my numbers. Does that sound right?
First installed all straight up, tried 4 degrees advanced, finally 4 retarded.

Am I looking at reasonable numbers, for the cam?
Thanks!!

 

[69Bee]

People seem to confuse their selves degreeing a cam. What you have essentially done is installed it straight up, removing the ground in advance, instead of how the manufacturer designed it to be installed. Unless you are concerned with piston to valve clearance, or dialing in a racing cam, you don't need to degree a cam. A number of you will post to disagree, but it doesn't matter. If you are putting together a stock/street motor, just line up the dots, and you will be good. One tooth either way on the cam/crank alignment will be grossly obvious, so you can't miss.

Cams are ground for the best operation on the street, but racing cams can be dialed in for the best operation for the conditions at the track. The difference you see in your numbers is you removing the 4 degrees of advance, and the 2 to 3 degree difference would be the tolerance when ground. As far as trying to get your numbers as close to the card numbers, install it straight up, with the 4 degrees of ground in advance, and you will match the card numbers within the tolerance of the grind. By changing the crank/cam adv/ret position, those numbers will change accordingly. Again, you do not degree a cam to achieve the card numbers, install it straight up, and you will do just that.

About the only benefit I see from degreeing a stock/street motor, would be to verify the manufacturers numbers matched the cam, or to identify where the timing events are when you adv/ret the cam timing. Other than that, degreeing a cam is unnecessary for a stock/street motor.

Flame on fellas...

 

[IQ52]

Did you check the ICL? For a 112 degree LSA cam with 4 degrees advance ground into it, the ICL would be 108. Now if your numbers are accurate, just going by the .050 numbers I think you are about another 2 degrees advanced for around 106 and that should be fine.

 

[miller]

Thanks, guys! The engines I've done before, years ago, I've always installed the cams dot to dot, never any issues.

Guess I'm looking at completely starting over on my cam bit, if even with the 4 degrees ground into it, 'should' be mounted straight up. For my overall build, I'm looking at, and kinda counting on, the intake closing point at 38 ABDC, to achieve the dynamic compression I need.
I understand what your telling me about how the cam is designed to be installed, dot to dot.

Mounting the cam dot to dot (for example), on the intake lobe, my readings were open 12 degrees, close 47 degrees.

Numbers are way off from what they are on the cam card, as shown in my first post. Note on the card also says 'If using
'lobe center' method of degreeing, cam should be installed on an intake centerline of: 108.

Throwing me off, why the degreeing is so off, mounted as it should be.

btw...checked ICL, getting 113, using the 300 lift method. Assuming I performed it right, by reading the degree wheel, at .300 lift at each lobe. Is that the correct way?

 

[benno440]

I just degreed my cam, and I still have no idea about it haha and your comment makes no sense to me. but I do know mine is right now

 

[miller]

Yeah, I read you.

Suppose mounting a cam up, you must assume straight up. Be kinda helpful if the damn cam card said so. But, after trying to look up a few things on degreeing one in, a real toss in the air. Bad marks on timing chain gears? Seems the bad gas is enough to deal with, making cam timing so critical, these days.

Numbers on the cam card 'should' mean something. I'll probably call Crower today, just to get their thoughts on how things 'should' be, and go from there. Just can't see from dot to dot, if a simple check shows things aren't as they 'should' be. Fun and games.

 

[miller]

btw...checked ICL, getting 113, using the 300 lift method. Assuming I performed it right, by reading the degree wheel, at .300 lift at each lobe. Is that the correct way?

NO. Thinking it was lift to lift, on each lobe. Supposed to be .300 'lift', from peak of intake lobe only, both sides, right?

 

[miller]

Did you check the ICL? For a 112 degree LSA cam with 4 degrees advance ground into it, the ICL would be 108. Now if your numbers are accurate, just going by the .050 numbers I think you are about another 2 degrees advanced for around 106 and that should be fine.

Your on the mark, IQ52.

Clear as mud, now. ICL should be 108. Just wasn't sure from the wording on the card.
Going to be a day, or two, before I get a chance to get back on it. Priority BS, don't you know. Guess the goal would be getting the ICL in, within reason, to be good to go.

 

[Garys1969RR]

Miller, it seems that 2 degrees BTDC on an intake opening is a bit late, even at .050" lift. 12 degrees looks a lot more like it. I would install the cam straight up as some have suggested.

- - - Updated - - -

I had a 451 in my Belvedere that ran so so, but had no power. It had 220 PSI compression. Everything was right on until I checked cam timing. Previous builder had timed the cam with the keyway on the crank straight up! This put the cam at 20 degrees retarded! The keyway should be at around the 1 o clock position when the lower sprocket timing mark is straight up. These 3 position timing sets can be confusing to a new engine builder that isn't familiar with them. Follow the instructions and diagram carefully, install it neither advanced or retarded but straight up, and you should be ok. After I fixed the cam timing on the 451, it runs really strong! Good luck.

 

[nm9stheham]

One of the problems folks may be having with the posted valve event numbers in the original post is the meaning of '-5 BTDC' for the exhaust closure. Properly interpreted, this actually means 5 degrees AFTER TDC. But I have to use a number of 5 degrees BEFORE TDC to get the lobe separation work work out to 112. So is the exhaust close at .050" actually BEFORE TDC in your measurement? The cam card conventions seem kinda erratic at times......

If I interpet this number right then the cam timing per the published valve event numbers works out to be exactly 4 degrees advanced.

Going through your numbers in the same fashion, it looks like your cam is actually sligthly ADVANCED, by 2-2.5 degrees from where it is supposed to be; i.e., your cam is at 6-6.5 crank degrees advanced. I am wondering if you are misinterpeting the cam degreeing keyways in your gears, and mixing retarded and advanced?

I have the event timelines al laid out on paper, and if you like, I can post them. But, like you, work has to take priority for some time today!

And, BTW, when you are doing the measurements, are you always turning the crank in the forward direction as the final step of finding the numbers to keep the chain slack consistent?

BTW#2: 2 degrees BTDC in the intake opeing is entirely dependent on the cam profile, durations, and where it is measured. So be careful to dig into the details when making a comparative judgement like this.

 

[67 B-body]

Koffels (Flintstone flyer), Told me he has always installed camshafts Dot to Dot, ran #1 piston to true TDC, then placed a straight edge across the int and exh lifters. If they weren't even with each other, he would adjust the timing using offset keys....
Never tried it myself,,,, but I think I'm going to try it next time I have mine down....

 

[miller]

Much appreciated, guys!

Yeah,nm9stheham, gotta fully agree that exhaust close -5 BTDC seems kinda odd, that's on the card.

Busted the thing back down, starting fresh. Tried dot to dot again...got 4 ATDC!! Yes, have TDC set right, so on. Right now going to carefully check the ICL, which is listed as 108.
Talked to Crower tech, him saying the ICL would be the important number to fit in. Everything else is, let's say, relative.
Did some reading that timing chain gears markings have been found 'off'. Wonder.

On my close set at the retarted crank gear, came up with 105 ICL. But, all these parts and pieces are NOT made to the same standards. Gonna fool with it more.

 

[nm9stheham]

Well, my timing event timeline agrees with your 105 ICL with the original numbers. Just to make sure we are on the same page, that puts the cam at 3 degrees more advanced than it should be. (Total of 7 degrees crank advance.) Going dot-to-dot retarded that by 11 degrees?!? Not computing! Hmmmm, maybe the hydraulic lifters are doing something funny on you and throwing off the .050" lift readings. Are you measuring this at the valve? Is this lift spec'd at the valve?

And yeah, getting the ICL right makes it all fall out properly. (All assuming symmetrical cam profiles.)

 

[miller]

Repeat...recommended #s

Intake - Opens: 2.0 BTDC
- Closes: 38.0 ABDC
Exhaust - Opens: 47.0 BBDC
- Closes: -5.0 BTDC

Yes, sir, methods make a world of difference. Listed ICL on this cam is 108...but, there's a bit of madness to it, since finding the centerline of a lobe that has two different shaped ramps, kinda throws a kink into it. At least, depending on the method used. Checked it twice, and (after getting my other numbers in) just looked at the intake lobe 'peak', that's on top a range of 107-110.

What I've been using to check the lifts is, one of the old tappets, cleaned, gutted, making sure I had a good surface for the lobe. Added about 8" of brass 1/2" rod, that fit tight into the tappet body. That gave me the 'extension' wanted to reach my indicator. Worked nicely.

But, as far as I think, it's now in. Here's the @.050 numbers I have, at the retarded mark on the crank gear...

Int - Open - 3 BTDC, Close - 38 ABDC
Exh - Open - 49 BBDC, Close - 5 BTDC (I'll leave the minus off, just for grins)

For the heck of it, again re-tried straight-up, and advanced, and got intake opens at 12 and 20 BTDC. Easy to see how far even dot to dot put things out on the numbers.

Really appreciate the help, guys!!

 

[nm9stheham]

OK, methods sound solid (as far I know...lol). From you latest numbers at .050", I am getting an LCA of 111.75 degrees, and an advance of 5-5.5 degrees. ICL computes to 106.5 (Again, assumes the lobe centers are symmetically located between the .050" lift points.)

Gotta wonder if the gear nothces are in 4 degrees of CAM position, which would be 8 crank degrees....??

And I won't pass any judgemnt on if this makes any difference...ain't goin' there! LOL

 

[miller]

OK, methods sound solid (as far I know...lol).

Yeah...me, too!

Devil's in the details. Just going by what recommended numbers are. What the heck do I know?
But, numbers finally came in, and going to assume (there's that dangerous word, again) that the cam will do what it's supposed to do.
It's one of the 'modernized' grinds, advertised as a good overall for the 440, without going over-board on lift. Will admit also looked at the intake closing point, via the compression(s) calculator for my set-up, and put it at the top end of the dynamic range, for the crummy gas.

Yes, agree the position numbers seemed off, but that degree wheel doesn't lie. Get what you get. Too easy to have variations in parts.

Be awhile before I find out. Retired, following orders from the 'boss', so 64 is low on the list. Still plenty to do.

I would be interested in seeing your numbers, nm9stheham!

 

[nm9stheham]

OK, I went through my numbers again and found an error and it looks like you are actually at 4.5 degrees advance on the cam. I did something I have been threatening to do for a whiel and put it in a Excel spreadsheet with a graphical event timeline. Here is a snapshot of your cam numbers; hope it posts readably....

 

[miller]

Thanks alot, nm9stheham!
Computerized layout...interesting that it shows 4.5 degrees advanced. Also see duration numbers at 221int/224exh...
listed durations are 220/223.

Flat odd, considering the gear set marks, and the cam ground 4 advanced. Or am I thinking wrong?

End of deal is, even at -4 on the crank gear, it's where it should be. That's what the Crower tech told me, get the ICL set and ignore the crank gear marks, and it will be right.

Other 'error' can be the lobe centerlines. since the computer assumes it is halfway. That's why I checked the 'dwell', for lack of a better word, on my intake ICL. It isn't halfway, depending on where/how the measurment is taken, since both ramp profiles are different. You get a shift, from the ICL, toward the slower ramp. The dwell I got 107-110, I looked at a few times, to be as accurate as possible, and 108 fell into the slot. Sure, I know some will totally dis-agree on the method, though if working with oddball stuff, like those ramps...any port in the storm.

 

[nm9stheham]

Sure, no problemo; kinda fun to do this. And, yes, I put the measured duration numbers in as a cross check; sounds like your measurements have been pretty accurate. Does not strike me as odd (off the top of my head) vs the advanced grind and the gear offset; duration is duration, no matter where it is in the cam cycle.

Here is something to chew on for you: If the ramps are asymmetrical, then it may or may not throw off computed ICL vs actual intake lobe peak. It all depends on the ramps shapes and what they do to the peak. I can see an opening or closing ramp being faster somehwere in the profile but then just slowing down at near the top and still leaving the peak halfway between the open at .050" & the close at .050". So, being asymmetrical does not automatically mean it will move the peak, but it may. It all is in the details of the profile.

I would think the Crower would spec ICL as halfway between the opening and closing .050" lift points, since that is pretty definitive to measure; finding the lobe peak is 'squishier'. Did they indicate that or anything else in the papers or in conversation? I just checked one of their cam's tags (grind number 271HDP) and put in their numbers and the ICL they spec is the same as the compted when worked out as halfway between .050" open and close. They call this the " 'lobe center' method of degreeing"

As far as the gear, I just think it is marked and/or made wrong!

 

[miller]

Ahh, yes, sir! I believe your absolutely right.

On the cam card, only thing shown on ICL was to put it at 108, if timing that way.

Timing chain/gears are Mopar performance, noting box had made in mexico on it. Of all the Chrysler engines I've glued together, all were timed 'dot to dot'. But, of course, that was many years ago.
Really glad I bothered degreeing this one (first time), since just slapping it in, would have gave me no telling. Especially if the marks on the crank gear are off, or wrong.
It will be a we'll see deal, on how it runs. Past the head-banging, been kinda fun going through it.

Many thanks!!