Degree an installed/unknown camshaft

[beanhead]

Keep in mind that even with the dial gauge directly on the lobe, the very slightest angular difference on the dial indicator probe can throw the measurement off quite a bit. So for instance, if your dial is mounted to the deck surface, with the heads off, you would still have to have a pretty long extension on your dial gauge..it has to be perfectly straight and perpendicular to the lobe at all times or your numbers will be wrong

 

[Wietse]

Did you use s lifter? If not, the readings are not correct.

It was mentioned to go direct on the camshaft and not on the lifter, just to get the duration, lift and LSA.
DO NOT look at the degrees given, they do not match with the crankshaft position.

The only accurate (as possible) readings to consider:
Intake:
Duration @ 0.050" lift: 202 Deg
Total lift: 0.3645"

Exhaust:
Duration @ 0.050" lift: 206 Deg
Total lift: 0.3580



For the LSA i counted 200 deg, so half the number comes down to 100.
Intake center line was found at 95*, the exhaust center line was found at 255* when looking at a 360* point of view.
So there is a degree of 200, going from 255 to 95. (255*=>360/0*=105* + 95*=200/2=100*
Again, these degree's could be anywhere, they are not reflecting true crankshaft position.
To come to the exact degree of the LCA i found it to be constant for a few degree's so i went for the middle of those degree's found, it would not surprise me the real LSA is 105-106*

Yes the dial gauge was set straight and inline with the camshaft, obviously i am measuring from real top through the gap of the block.
It was not located at the lifter position, and i had not verified TDC to get the degree wheel lined up.
I just installed the degree wheel at random position and counted degrees what happens where.

 

[Wietse]

Just to clear things up here, with the current rough idea of what camshaft is in there i know that this is not the type of camshaft i want to keep.
I want a street car, decent idle & vacuum and i don't see the point of going beyond 5800-ish rpm for power.
I rather aim for a good low and mid range torque and let the hp take the last rpm's to do.
So i want to select a new camshaft for my needs, i also need new lifters obviously but there rises the question if i should check the valve spring pressure for selecting lifters? I want to stay with the hydraulic flat tappet lifters and reuse the push rods and the 1.6 ratio rocker arms.
Could i reuse the camshaft bearings if nothing obvious is found or are new bearings required?

Going from what my knowledge is able, i came to this camshaft:
https://www.summitracing.com/int/parts/cca-23-223-4/overview/
I could get the same camshaft local, but with a 1-bolt option, does it matter in my case?
Would there be a real gain in getting a 3-bolt? I will add a new camshaft drive kit to match whatever fits the cam.
Valve lift of .477/.480 is with standard rocker ratio, which is 1.5 right?
So with a 1.6 ratio i would end up with .509/.512"
Guess these lifters supposed to go with that camshaft:
https://www.summitracing.com/int/parts/cca-822-16/overview/

Torque converter i will need to select to match the camshaft, no idea what is in there at the moment so don't want to screw around with it.
The camshaft operating range is 1600-5800 rpm, so a converter with a stall speed of 2000 - 2200 would work well with this cam right?
I've seen the Hughes Performance convertors mention the stall speed approximate rating is for a BB.
This is a 2000 stall converter:
https://www.summitracing.com/int/parts/hup-24-20/overview/
Because most long runs will be driven at 50mph minimum where, as per transmission ratio chart, the engine would run at approx.. 2300 rpm@50mph with a 3.55 ratio gear.
Keeping in mind my current final drive is 4.10 with limited slip but i will change to a 3.55 ratio.
The car is a '69 Coronet R/T, what is the weight? 3500lbs?

Any suggestions?

 

[BSB67]

You can only measure lift directly on the lobe. The point of the dial indicator does not follow the lobe the same way as the lifter, so all the other data will be incorrect, by a lot. Just draw it on a piece of paper if you don't believe me.

 

[Wietse]

You can only measure lift directly on the lobe. The point of the dial indicator does not follow the lobe the same way as the lifter, so all the other data will be incorrect, by a lot. Just draw it on a piece of paper if you don't believe me.

I understand what you mean by the small tip of the dial indicator vs bigger diameter of the lifter.
But i am quite sure you can assume the reading at 0.050" before and after is a true reading.
Also the tip of the lobe can be measured, nothing changes there it is the highest point at a certain degree.

 

[BSB67]

I understand what you mean by the small tip of the dial indicator vs bigger diameter of the lifter.
But i am quite sure you can assume the reading at 0.050" before and after is a true reading.
Also the tip of the lobe can be measured, nothing changes there it is the highest point at a certain degree.

okay

 

[beanhead]

In regards to your bearing question...cam bearings are cheap! The problem is you don't know which cam is in there (base circle size) and the bearings that are in there were likely (should have been) fitted to match it...depends I guess on how 'properly' the engine was assembled. Me, I would just get new bearings and have them fitted to the new cam and then you know it's all good..

 

[Wietse]

okay

Look, one tells me this way, someone else tells me that way...i think i got it figured out and the next thing is all is wrong again.
Appreciate the help but this is going different directions on what to do with it.
I did what i could for now, i have to go from home for 2,5 weeks and after i will carry on with this.
Then i got the time to do this over and get a measurement with a lifter.
I will not reuse these anyway so i can go ahead and modify one to get a reading from that.
Not that the current cam really matter probably as i think i should change it, will see.

 

[miller]

Easy...and catch your breath.
If you don't like the cam, unknown or not, of course, research and pick one you would like. It's your engine!
Hydraulic lifters, push rods, rocker arms, you should understand they are not all built alike. Doesn't take much to screw up the works. Consider the cam, the 'brains' of your engine...choose as you will. Going with a new set of lifters, only checking pre-load will tell you if the push rods, and such, will work. Measure twice!
Those 1.6 rockers, should be asked if their needed. If you like 'em, keep 'em, but make sure everything fits.

Only way to know, on your cam bearings, is look once the cam is out...then decide.
You asked about the cam 'drive', or timing chain. Look at double-row roller timing chains. If it has one (it could), long as it's in good shape, you could probably re-use it. If it doesn't have one, get one.

Years ago, I helped a friend, with his 500,000 mile Toyota (ugh), thinking the timing 'belt' had slipped. Got the thing opened, and it had a 'still tight as a banjo string', double-row roller chain on it!

 

[Wietse]

After checking specs with a cam lifter i can decide what it needs, if it is a too radical cam i will change it.
Replacing it for something similar is no point because it is not worn or so.
And as you mentioned, things like timing chain, bearings, push rod and rockers could be getting involved as well which only boosts the costs.

 

[miller]

Yup...a package deal.

 

[Wietse]

Hey guys, my trip for work almost took me 4 weeks but i am home again.
In my time away i ordered some stuff to continue this task and got myself a solid tappet to do the measurements...never looked at them but did not know they are only $10-$15 a piece.
Anyhow, i went around 2x and had solid figures with a deviation of 0,5 degree...sometimes just how you look at it.
I found that the timing tape installed on the balancer is spot on actually which is good to know i can rely on it for timing etc.
I removed the rocker shaft on the driver side, popped the hydr. tappets and used the solid one.
I found some extension rods for the gauge and set it up to sit in place of the push rod, so measuring directly in line with the tappet.
To determine the centerlines i went up the ramp from both directions once i new maximum lift, and went for the middle of both readings found, guess that would be as close as possible. (as there is a certain amount of degrees it maintains max. lift)

Now, below numbers!!!

CAM CARD

EXHAUST
Valve Opens at _66_* BBDC
Centerline_124_* BTDC
Valve Closes at _1_* BTDC
Duration _245_* @ .050"
Lobe Lift _.3565_ "
Valve Lift _.570_ "

INTAKE
Valve Open at _27_* BTDC
Centerline_93_* ATDC
Valve Closes at _29_* ABDC
Duration _236_ @ .050"
Lobe Lift _.3530_ "
Valve Lift _.5650_ "

Lobe Seperation Angle _108.5_ *
Valve Overlap _26_ *
Cam Advance _15.5_*

The only "odd" things noticed is that the exhaust valve closes 1deg BTDC, while i guess most close ATDC?
Also cam advance is quite high i guess, i did not look at the crankshaft sprocket yet if there is any advance put in there but i will find out later when the engine is out and i remove the water pump and chain cover.

Now going to look for a camshaft with similar figures to see what type camshaft we are talking about here.
Guess duration is quite long, guess for better idle and driveability i should go with a more mild cam i guess.

 

[wyrmrider]

good work
and interesting to help time your cam
but why?
how does it run?
what's your comprssion ratio and crankaing compredssion
problem is Harvey Crane's "Intensity"
how many degrees does it take to get from .004 to .050 on the opening and from .050 to .004 on the closing
Crane used .004
Comp and several others use .006
Engle Uses .008 and MP and MOPAR use close to .008
so your seat timing can be quite different between vendors
and quite different between masters ground for universal grinds- for the popular .842 dia chevy lifter
vs
grinds designed for the .904 MOPAR lifter
want to compare cams do your timing drill again at .004 and .006 lift and see what comes up
also at .100 and .200 will tell you a lot- just duration
could be you have a great cam
or not
so how does it run compared to how you would like to run
cheers

 

[Wietse]

Thx for the reply wyrmrider,

I only did a comparison on the exhaust valve and checked at 0.005" lift, where i found 301 deg duration.
I was not sure if there was anything to gain on taking them readings as well therefore i did not do it on both, but a guestimate would be 292/301 @ 0.005" lift.
My goal i am trying to get out of this is to know my camshaft, what type it is i.e. street/strip, performance street/strip, race/strip, etc.
What kind of power band does it have, what type converter should be in there and does all that work properly with my currently installed 4.10 ratio rear end.
Also planning to change the 4.10 to a 3.55 ratio and want to figure out if this is acceptable with this camshaft and maybe require another torque converter. (current converter stall speed is unknown)
It seems the car was set up by a PO to have fun with it on the drag strip, which is not my intention.
I want an agressive street car and get a bit better milage out of it (thats why the 3.55 gears) for the longer ends of cruising.
I already replaced my holley 750 double pumper with a 770 street avenger with vacuum secondary's which, after some f*cking around ended up doing well and giving better driveability and better AFR readings during cruising.

Cranking pressure is 200 psi, with not much deviation between cylinders.
Compression ratio is unknown.
Current ingnition timing is set at 18deg initial and 36deg total, all in @ 2500 rpm.
I tried vacuum advance as well but this engine does not like it at all, above settings are best i found.

It runs with a reasonable shitty idle, vacuum at best is 10Hg in idle and tranny in Park. (900-950 rpm)
I am aiming to get a better idle, which should lead to better drivability and an easier setup to get a good idling engine with more vacuum.

When looking at the figures compared to some other cams, mine seems to close the intake valve very early @ 29deg ABDC, which in result might explain the high cranking pressure, right?
Thinking about if this specific camshaft could be retarded 10deg, it would move more towards other cam figures i've came across, which makes me believe the crankshaft timing chain sprocket might be of the "adjustable" type. (if i get time i will open it up and confirm this)
But retarding this cam, what are the effects for idle and vacuum? Would it change?
My thinking is that when retarding this camshaft it should get less contamination of exhaust gasses as the exhaust valve closes later. (1deg BTDC vs. 9deg ATDC)
Retarding it will bring up the peak power in the higher end and i will lose some on the bottom, but if that is the price to pay i will take it.

 

[wyrmrider]

"292/301 @ 0.005" lift." almost the same as the 440 Magnum cam which is a little longer on the Exhaust and timing is quite different
magnum cam has a LCA of 113-115

cranking compression is 200
going to be tough running on 91
pm AJ/FormS on the Abody forum and have him run the dynamic compression numbers for you- point him at this thread
any idea where the intake closes at .005?
the .050 numbers can vary widely when you try and guess at actual timing as I tried to point out above
I'd suggest drive tests and check your times after the gear change
and do a stall test
you might want to check the timing chain and while you have the front end off see if it is an adjustable gear
did you check for intake lobe center with the dial indicator down .050 on each side of the lobe with your degree wheel?
gotta know where you are before making changes
Think about what a 10 degree change does to each of the four valve events
Intake Close
Intake Open
Exhaust Close
Exhaust Open
did you say headers?
one thing that helps your current combo and today's gas is the low gear...
cheers

 

[Wietse]

The 292/301 was just a rough guess from me.
Current fuel i am using would be 95-96 octane (being sold as 98 but guess it will be a bit lower)

I think for calculating dynamic compression he will need a lot more info, i have no idea what size pistons i have and other details as piston height, head gasket thickness, how much machining was done, etc. I did find out i have 906 heads installed.
I can make another run with the dial gauge and check the 0.005", 0.100" and 0.200" timings if that gives more info?

did you check for intake lobe center with the dial indicator down .050 on each side of the lobe with your degree wheel?

Not sure what you mean by this, but to get an accurate figure for the centerline i went up the lobe from both rotating directions and noted the 2 readings when it hits maximum lift, which were 90 and 96deg so i aimed for the middle at 93deg as lobe centerline. So it actually maintains max lift over 6deg crankshaft rotation.

From my point of view, retarding this camshaft 10deg would put it as follows:

Exhaust open: 56 BBDC
Exhaust close: 9 ATDC
Centerline: 114deg BTDC

Intake open: 17 BTDC
Intake close: 39 ABDC
Centerline: 103 ATDC

As above, the intake valve will close 10 deg later, which in turn reduces cranking pressure right?
That should reduce the chance on knocking as well i guess.
I think this also give a bit more circulation of fresh air in the cylinder as the exhaust closes later after TDC.
Yes i got headers, one of them is cracked and i will go for a new set of TTI, 1-7/8" primary tubes, 3" collector. Also will get a full 2,5" exhaust system from TTI.

Edit: Something that worries me is the piston to valve clearance with this high lift, retarding the cam should give more clearance if i understood correct right?

 

[Wietse]

Ok, some more numbers...and a sore arm and back

Exhaust open @ 0.005": 89 ATDC
Exhaust open @ 0.050": 66 BBDC
Exhaust open @ 0.100": 50 BBDC
Exhaust open @ 0.200": 23 BBDC

Exhaust close @ 0.200": 45 BTDC
Exhaust close @ 0.100" 18 BTDC
Exhaust close @ 0.050": 1 BTDC
Exhaust close @ 0.005": 30 ATDC

Intake open @ 0.005": 54 BTDC
Intake open @ 0.050": 27 BTDC
Intake open @ 0.100: 12 BTDC
Intake open @ 0.200": 15 ATDC

Intake close @ 0.200": 14 BBDC
Intake close @ 0.100": 13 ABDC
Intake close @ 0.050": 29 ABDC
Intake close @ 0.005": 58 ABDC

So, duration at 0.005":
Exhaust: 301deg
Intake: 292deg

My guess was acurate

Measured lift remained same, centerline found some small differences. (actually on the intake i measured 89deg before, when double checking i found 93.
Now checking again and found 89deg again, probably lifter was sticky on previous session.
Anyway.....

Exhaust centerline: 123deg BTDC
Intake centerline: 89deg ATDC
LSA: 106deg
Cam advance: 17deg (on crankshaft)

 

[wyrmrider]

you may be on to something
for example Comp cams HE295XL is 295 307 @.006
but intake close is 74 ABDC
HE285XL is 69 ABDC
on measuring nose I was trying to say start on the tip of the nose and measure down on both sides .050 and read degree wheel
lobe center should be in the center of the two readings
not exact with an asymmetrical cam but close
of course measuring up .050 off the base circle can be way off with both asymmetrical lobes
your .005 numbers would be a few degrees larger than the .006 comps for the same grind but not much
not pushing comp but their seat Timing is easy to find

you might want to find our lurking Crower rep- he could be very helpful
at least he lurks on the Abody forum PM Dart19666

 

[Wietse]

Just went through a lot of Comp Cams but all have an LSA of 110, degrees is something quite easy to find similar as mine.
Guess i should not be too exited with an LSA of 106 and hoping to get a decent idle..
Tomorrow i will have some time to remove the chain cover and see what type of chain sprocket was used.
Would i benefit from retarding this cam? Is there any way to get this thing to run with better idle/vacuum?
Or am i really looking into getting a new camshaft to reach my goal?

 

[wyrmrider]

PM
PM Dart19666
pm AJ/FormS
ask them to look at your numbers
Crower also uses .005 AFIK
what did you find for a chain and install keyway if multi key gear?
do not worry about LCA yes 106 will be choppy
but then that is close to what the Thumper cams use to help hide a big intake lobe
keep focus on the intake close point as far as compression goes