Cam timing issue

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B RON CO
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Cam timing issue

Post #1 by B RON CO » Sat Aug 11, 2018 4:28 pm

[image][/image]Hi, so I've been trying to dial in the cam on the replacement engine.
It is a Comp Cams 252H. 106 center line.
I have a 5/8 bolt 4" long stuck in the lifters pushing on the dial indicater.
I am checking exactly like the Echo video, with one difference, which will be my question, at the end.
I can precisely repeat the measurements.
When the crank to cam gear is dot to dot my center line is 96.5 #. (52 + 141=193, ÷ 2 = 96.5)
If I wind the cam counter clockwise 1 link I get
117#. 73 + 161 = 234, ÷ 2 = 117
If I go one more link counterclockwise I get
135# 91 + 180 = 271 ÷ 2 = 135.
I believe I am advancing the cam, as now you can really see the intake valve open before TDC.
If I go the other way, one link clockwise I get
82.5#. 39 + 126 = 165 ÷ 2= 82.5. and the valve is opening after TDC.
So my question is, unless you can tell me what is happening, am I getting these results because I am checking direct lift, and not lift at the valve, with the 1.5 rocker ratio.
I feel I am adjusting the cam timing as good as changing to a multi slotted gear. Maybe I'm wrong about that.
Thanks for reading. I hope to get this figured out before calling Comp Cams.
B RON CO. Still workin' on it!

1933 Ford Pickup - 59A Flathead V8
1966 Ford Bronco - U14 - 170/200 Straight 6
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pmuller9
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Re: Cam timing issue

Post #2 by pmuller9 » Sun Aug 12, 2018 12:46 am

The cam card specs the intake lobe center at 106* ATDC so 96.5* is almost 10 degrees advanced from where it should be.
117* ATDC is 11 degrees retarded.

You also need to verify the timing using .050" lift from the bottom of the lobe and also check the exhaust lobe timing for further verification of timing and LSA.
The exhaust lobe center should be 114* BTDC

The centerline method only works if the cam lobes are symmetrical.
The .050" duration method is more accurate and is the recommended method to degree the cam.

If it is still 10 degrees advanced after verifying, then a new keyway needs to be cut on the crank gear 85 degrees to the left (counterclockwise) from the present keyway and use the gear tooth that is five teeth to the left of the tooth that has the alignment dot.

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Re: Cam timing issue

Post #3 by chad » Sun Aug 12, 2018 9:41 am

not enuff in an "offset key" to come to where he needs?
Less hoops 2 jump thru...
How much can U get w/1 of those?
Thanx !
"Big thing is only make one change at a time. Change 2 or more things at a time it becomes difficult to figure which change helped or hurt" turbo2256b » 1/16/2017
Chad - '70 LUEB on '77 frame (i.e. PS, D44, trapezoidal BB 9", 4.11), 250, NV 3550 & DSII to B transplanted, "T" D20/PTO, 2" SL, 1" BL, 4 discs, 33"X15", etc. Seeking: Hydraulic gear motor for Koenig pto. chrlsful@aol.com (413) 259-1749

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Re: Cam timing issue

Post #4 by pmuller9 » Sun Aug 12, 2018 9:52 am

chad wrote:not enuff in an "offset key" to come to where he needs?
Less hoops 2 jump thru...
How much can U get w/1 of those?
Thanx !


The cam gear uses a pin instead of a key.

A crank gear offset key is only good for 4 degrees.

If it is still available, the nine keyway gear set from VintageInlines for $99 might get you close enough

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Re: Cam timing issue

Post #5 by wsa111 » Sun Aug 12, 2018 10:12 am

A Comp. Cam calls for 106" Intake lobe center. He got 106,5 which is 3.5" advanced. Thats what they say on the cam card.
Yes its a good idea to also check the events @ .050" that is also spelled out on the timing card.
That way you double check the settings.
67 mustang,C-4, with mod. 80 hd, custom 500 cfm carb with annular boosters, hooker headers, dual exh.-X pipe, flowmaster mufflers, HEI dist. Engine 205" .030" over with offset ground crank & 1.65 roller rockers. 9.5 comp., Isky 262 cam.
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Re: Cam timing issue

Post #6 by B RON CO » Sun Aug 12, 2018 10:40 am

Hi, I think Bill is correct. The lifter is starting to come up just before TDC when it is dot to dot, reading 96.5* intake center line. 52+141=193÷2=96.5*
I know pmuller has a lot of experience, but to me it seems that when I wind the cam 1 tooth counterclockwise, and get an intake center line of 117*. 73+161=234÷2=117, the cam is advancing, as the intake valve is opening a little more than TDC. Pmuller says this is retarding the cam and that (respectfully) does not make sense to me.
The cam lobes are symmetrical, but I only checked the intake.
The cam card says the intake valve should open
@.006. 17* BTDC and close 54* ABDC.
It seems like it it doing this, but I will see if I can verify the numbers. Thank you all very much
B RON CO. Still workin' on it!

1933 Ford Pickup - 59A Flathead V8
1966 Ford Bronco - U14 - 170/200 Straight 6
1966 Ford Mustang - 289 V8

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Re: Cam timing issue

Post #7 by Econoline » Sun Aug 12, 2018 1:15 pm

You are doing this correctly, the lift is measured at the lifter. I was going to say more on this but I don't want to add any confusion to the discussion.

A 117 C/L would be retarded by 7 degrees. The cams spec is a 106 C/L with a 110 LSA, that is 4 degrees advanced. If you are reading 96.5 degree C/L you are 13.5 degrees advanced. The cam is indexed wrong and you are going to need an adjustable cam gear or a new keyway. Assuming you used a piston stop to precisely find TDC, you are using a solid lifter and the setup is right of course.
It ain't gonna fix itself

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Re: Cam timing issue

Post #8 by chad » Sun Aug 12, 2018 2:39 pm

sorry to bust in, email troubles.
U get any of my PMs Seth?
EDIT:
o0)PPps, OK...
:oops:
"Big thing is only make one change at a time. Change 2 or more things at a time it becomes difficult to figure which change helped or hurt" turbo2256b » 1/16/2017
Chad - '70 LUEB on '77 frame (i.e. PS, D44, trapezoidal BB 9", 4.11), 250, NV 3550 & DSII to B transplanted, "T" D20/PTO, 2" SL, 1" BL, 4 discs, 33"X15", etc. Seeking: Hydraulic gear motor for Koenig pto. chrlsful@aol.com (413) 259-1749

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Re: Cam timing issue

Post #9 by chad » Sun Aug 12, 2018 2:41 pm

chad wrote:sorry to bust in, email troubles.
U get any of my PMs Seth?
EDIT:
o0OPPps, OK...
:oops:
"Big thing is only make one change at a time. Change 2 or more things at a time it becomes difficult to figure which change helped or hurt" turbo2256b » 1/16/2017
Chad - '70 LUEB on '77 frame (i.e. PS, D44, trapezoidal BB 9", 4.11), 250, NV 3550 & DSII to B transplanted, "T" D20/PTO, 2" SL, 1" BL, 4 discs, 33"X15", etc. Seeking: Hydraulic gear motor for Koenig pto. chrlsful@aol.com (413) 259-1749

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Re: Cam timing issue

Post #10 by pmuller9 » Sun Aug 12, 2018 3:35 pm

My apologies for not giving you complete info on the cam specs for cam timing.

The advertised duration specs that you see for the intake (17 open, 54 closed) are not centered around the intake lobe center.
The opening ramp is shorter for quicker valve opening and the closing ramp is longer to let the valve close easier on the seat.

The .050" specs that are used to degree in the cam is the following:
Intake opens at 3 degrees After TDC and closes 29 degrees after BDC.
Exhaust opens 37 degrees before BDC and closes 11 degrees before TDC.

Zero the degree wheel. Are you using a piston stop?

Zero the dial indicator on the intake lifter when it is completely down on the heel of the cam.
Turning the crank clockwise only, take the reading on the degree wheel when the lifter comes up .050" and again when the lifter is .050" from returning to the bottom.

Do the same for the exhaust lifter.
Then please post the readings.

This is the only way to truely know where the Intake and exhaust lobe centers are at.

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Re: Cam timing issue

Post #11 by B RON CO » Sun Aug 12, 2018 4:40 pm

Hi, thanks for the help. I started this process last weekend. This weekend I did it again. The numbers I get are from the method in the Echo video on this site. I will check out your method, and the method in the comp cam instructions. Everyone does it a little different and it is taking time for me to soak it all up.
The head is off the engine. I have not used a piston stop (yet). I can get a real good feel for TDC, and those 4 or 5 degrees where the piston is stationary, and my results are repeatable.
I see the latest Pmuller #s and here is where I got confused.
Dot to dot and the intake valve starts to open just before TDC. Isn't this what I want?
Pmuller shows the intake valve open 3* ATDC, and close 29* after BDC.
I will see if I can measure this.
This is also something I am not sure about. If I wind the cam counterclockwise 1 link, the intake valve opens earlier, before TDC. I thought this was advancing the cam, which is better for bottom end ( where I run with my Bronco, with 3:50-1 gears, I don't want too much advance I like the dot to dot).
If I wind the cam clockwise 1 link before dot to dot the intake valve opens later, after TDC, as the piston is going down, and the valve is closed a bit after the piston starts coming up. Is this retarding the cam, (better for high RPM, not my engine).
I know about multi keyed crank gears, but why isn't winding the cam gear just as good?
B RON CO. Still workin' on it!

1933 Ford Pickup - 59A Flathead V8
1966 Ford Bronco - U14 - 170/200 Straight 6
1966 Ford Mustang - 289 V8

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Re: Cam timing issue

Post #12 by wsa111 » Sun Aug 12, 2018 7:44 pm

My bad. If you got 96.5" for the #1 intake lobe center you are 10" advanced.
Lets start over. Since the camshaft has a 110 L/C 4" advance will be 106.
Do you have the dots on the crank gear lined up with the dot on the camshaft gear.
Sounds like you have the camshaft 1 tooth off.
Comp. Cams normally are very close when decreeing in. They index them for a 4 degree advance out of the box.
Clay Smith indexes theirs straight up.
I had a problem with a Schneider cam over a year ago that was 12 degrees advanced. I called Jerry & he checked his shaft mounting degree head on his grinder & it was 12 degrees off.
The problem was resolved over a year ago & he sent me a another camshaft & it decreed in within .5 degree.
Do not be afraid to order a Schneider Camshaft. Their profiles are up to date.
The Comp. Cam is an antiquated profile. I would not recommend the 256 or the 260 profile.
However you can special order a newer more aggressive profile from them.
My advice call Jerry at Schneider & he will advise what you need. He is very knowledgeable with our small six cylinder engines.
You need a camshaft that requires at least 100# spring set pressure to take advantage of the modern profiles.
Any camshaft that requires 50# of spring seat pressure is junk.
67 mustang,C-4, with mod. 80 hd, custom 500 cfm carb with annular boosters, hooker headers, dual exh.-X pipe, flowmaster mufflers, HEI dist. Engine 205" .030" over with offset ground crank & 1.65 roller rockers. 9.5 comp., Isky 262 cam.
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Re: Cam timing issue

Post #13 by pmuller9 » Sun Aug 12, 2018 10:54 pm

B RON CO wrote:I see the latest Pmuller #s and here is where I got confused.
Dot to dot and the intake valve starts to open just before TDC. Isn't this what I want?
Pmuller shows the intake valve open 3* ATDC, and close 29* after BDC.
I will see if I can measure this.


Good question.

As you turn the crank clockwise the lifter will begin to move up somewhere before 20 degrees BTDC and the dial indicator needle should begine to move off zero.
As you continue turning the crank the dial indicator should show the lifter up .006" around 17 degrees BTDC.
Again as the crank continues to rotate the dial indicator should read .050" at 3 degrees ATDC.

Continued crank rotation will bring the lifter over the top of the lobe and down the backside of the lobe.
When the lifter returns to .050" from the bottom of the lobe the degree wheel should read 29 degrees after BDC

This is the ".050" duration method".

The method in the Echo video is the "Centerline Method" and works provided the cam lobe is symmetrical which the Comp 252 is.
You can use both methods as a double check

B RON CO wrote: I know about multi keyed crank gears, but why isn't winding the cam gear just as good?


Each tooth on the crank timing gear is 18.9 degrees apart and is way too much of a change for cam timing.
A 7 or 9 keyway crank gear gives you 2 degrees between adjustments.

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Re: Cam timing issue

Post #14 by B RON CO » Mon Aug 13, 2018 6:51 am

Thanks for getting me closer to what I need.
Now I am learning what I need to know.
I will try the method of .006 and see where the pointer is. I didn't grasp that. Now I can try it.
Just to clarify, I have been winding the cam one link at a time, which I guess is 1/2 of the crank, but it is still not getting me on the money.
So you think with a multi groove crank gears I can get this close.
I'll measure again before buying the gear set.
Thanks to you guys I'll get this done.
B RON CO. Still workin' on it!

1933 Ford Pickup - 59A Flathead V8
1966 Ford Bronco - U14 - 170/200 Straight 6
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Re: Cam timing issue

Post #15 by wsa111 » Mon Aug 13, 2018 8:43 am

You can't make up for a 12 degrees. Double check if you have the camshaft gear 1 tooth advanced??
67 mustang,C-4, with mod. 80 hd, custom 500 cfm carb with annular boosters, hooker headers, dual exh.-X pipe, flowmaster mufflers, HEI dist. Engine 205" .030" over with offset ground crank & 1.65 roller rockers. 9.5 comp., Isky 262 cam.
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Re: Cam timing issue

Post #16 by pmuller9 » Mon Aug 13, 2018 9:35 am

The .006" point is not as accurate as the .050" point because the lobe ramp is very shallow at that point.
The .050" point puts you on the steeper point of the ramp and is the more accurate.

That's why most cam manufacturers use the .050" duration method to degree the cam in.

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Re: Cam timing issue

Post #17 by fast64ranchero » Mon Aug 13, 2018 5:53 pm

I ran into this exact problem. 96.5 is where my cam was at on the stroked and turbo'd 250. What I found was I had the wrong timing chain set for the cam, the cam was cut for one set and I had the other set. Whatever timing chain set you have (early standard straight up or late retarded cam set) buy the other.
63 Ranchero,1965 Mercury Comet Convert V-8, 1978 Fairmont small six, mill'd off intake, 62-1 ET 12.332 @ 123.49 mph (gone)

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Re: Cam timing issue

Post #18 by B RON CO » Mon Aug 13, 2018 6:40 pm

Thanks, I have the new one from comp cams, and the old one which came off the engine. I'll try that next.
B RON CO. Still workin' on it!

1933 Ford Pickup - 59A Flathead V8
1966 Ford Bronco - U14 - 170/200 Straight 6
1966 Ford Mustang - 289 V8

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Re: Cam timing issue

Post #19 by B RON CO » Wed Aug 15, 2018 8:16 pm

Hi, so working with the info fast 64ranchero gave I compared the new Comp cam timing chain set to the set that came with the engine.
The gear sets are identical.

To remind everyone, I bought a 200 mustang engine from a member on this site, mainly to get the 2 barrel head, a 1hotvega head.

Now I want to freshen up the 200.

So I compared the new timing set to the one from the engine and they are identical.

So I put the cam that came with the the engine back in. First I measured a cam lobe and it is bigger. ( I know that may not mean too much, because of base circle, etc.) But the main thing is the intake center line is 96.5, just like my new cam.

So maybe the engine was under performing because of poor cam timing and the guy was not happy with the performance.

I ordered a timing chain set, which is 0 advanced, so let's see how that works out.
B RON CO. Still workin' on it!

1933 Ford Pickup - 59A Flathead V8
1966 Ford Bronco - U14 - 170/200 Straight 6
1966 Ford Mustang - 289 V8

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Re: Cam timing issue

Post #20 by wsa111 » Wed Aug 15, 2018 9:10 pm

I would get the JP timing full roller chain from Matt at vintageinlines.com
The lower gear has corrections from +8 to -8.
I would get a refund on this cam & get one from Jerry @ Schneider Cams 619-297-0227
Also get the correct valve springs & new retainers & keepers from him.
Get your wallet out & do the job right.
67 mustang,C-4, with mod. 80 hd, custom 500 cfm carb with annular boosters, hooker headers, dual exh.-X pipe, flowmaster mufflers, HEI dist. Engine 205" .030" over with offset ground crank & 1.65 roller rockers. 9.5 comp., Isky 262 cam.
2003 Ford Lightning daily driver. Recurving Distributors. billythedistributorman@live.com
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