Question on Cam Gear Marks - UPDATE

[Russ/40]

The current status of my miserable running V8.

I decided to start from scratch on this motor. I pulled every piston rod assembly, and inspected for any broken rings. No broken rings. I had a set, so I replaced them anyway.

I pulled all valve assemblies and replaced all valves and springs. This corrected the fact it did have the wrong springs, they were the 52/53 springs. I used flathead valves. I touched up all seats to correct any non-concentricity. An lastly replaced my lifters with adjustables, correcting any lash errors. Lash set to 12 intake and 14 exhaust.

After comparing the cam gear with another, matching bolt patterns and matching marks. I left the cam and crank gears in place. The cam itself has been run in another motor so I was convinced the cam itself is a good 77B.

I disassembled the distributor checking and resetting points to .015". Used new plugs.

The test run on the stand gave a very nice idle, and throttle response did not create any loud exhaust pops, ran a rebuilt 97 for carburetion that gave some adjustability at idle.

Net result I cannot get timing correct. With the distributor at typical settings HELMIT DISTRIBUTOR TYPE it idles slow at 25 degrees advance. When setting up a timeing marker, i used a dial indicator for TDC number one, and included a degree scale for testing.

Side distributor timing set for 1/2 increment advance, like every other flathead I've had which was correct. Net is again 25 degrees advance at idle. Vacuum brake is screwed all the way in, but will still advance to about 35 degrees with RPM.

What the heck am I missing here. It's hard to start and not running as it should.

[cadillac512]

Congrats on fixing the mechanical problems, Russ. My money's on the shorter valve springs having been the trouble.
Now...is there any way this thing's trying to run on just the passenger side points? Like the driver side isn't making good contact or not closing for some reason?
If I'm thinking right, the pass side opens first, and then driver side later to fire the coil.


Terry

[JSeery]

Did you double check the TDC mark on the pulley when you had the engine apart?

[Russ/40]

There was no TDC mark except the one I created with heads off and a dial indicator. This is a 41 block with the factory correct pulley and crank mounted fan. I did use an 8BA crank.

Terry, would that cause so much advance? I can check it. I even used a different distributor this time. There was too much advance on the other distributor before. I'll have to look up which set is responsible for timeing as well as dwell.

[cadillac512]

I believe LH set is timing of the spark. RH side provides longer dwell time. Since RH side opens earlier it seems (in my mind anyway ) that if the LH side were not making contact for any reason, then the RH side would be doing the switching of the coil and it would happen earlier.
Now, I have not studied enough to say how much earlier but it would sure be earlier.



Terry

[JSeery]

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Originally Posted by Russ/40

There was no TDC mark except the one I created with heads off and a dial indicator. This is a 41 block with the factory correct pulley and crank mounted fan. I did use an 8BA crank.

Yes, I am well aware that there are no original timing marks, but you say you are checking the timing, so must be checking them against some added mark. The question was, was the added mark checked when you dissembled the engine this last time? It is easy to get the mark off using a dial indicator IMO. I would start by rechecking the mark. It about has to be mismarked or a distributor problem. Two distributors both having the points not functioning seems odd, but anything is possible.

[Russ/40]

Yes, the timeing marks were developed before I put the heads back on. I first located the location I wanted my marks for easy viewing. I then found TDC using a dial indicator. I then made my pully notch where it could be seen. I then mounted my degree scale with ZERO as my TDC mark on the block, matching the pully. Photos attached, but the engine was not at TDC for the photo.

[Step-down]

So you found TDC turning motor both ways and using your math split in two for the dwell .
Great
You also dialed in the cam with your wheel checking timing .

[JSeery]

Originally Posted by Step-down

So you found TDC turning motor both ways and using your math split in two for the dwell .
Great
You also dialed in the cam with your wheel checking timing .

That's my question as well, using a dial indicator can be a bit tricky unless you check it several times from both directions and split the difference. I much prefer a dead stop, but you can do it with a dial indicator. It would be fairly easy to double check it now with a stop placed through the sparkplug hole and turning the engine back and forth.

[deuce_roadster]

I would have the distributor set up on a machine by someone in the know of how to set up a helmet.. Is the line to the vacuum brake hooked up with no leaks? Maybe try unscrewing the adjustment on the vacuum piston, if it always is pressing on the disk your advance is not working right.

[Russ/40]

I confirmed the TDC marks with the hard stop method, it was on. I was very carefull when I did it with the dial indicator before, going back and forth. Within a degree at least. I have no feel for how much dwell resides at TDC, but would expect that to depend on bearing wear.
Photo shows where it idles, about 25*.

Terry, I havent confirmed the drivers side points are closing all the way yet. Kinda hard getting in there, and I have to drain the radiator and pull it to do anything on my stand. I'd like it if your right about that. I have a Sun machine, and I took a quick look at it before using the distributor but I did not check the dwell, just the point gap and alignment.

[JSeery]

If you've confirmed the timing marks, cam gear, etc, it about has to be in the distributor.

[Russ/40]

Originally Posted by JSeery

If you've confirmed the timing marks, cam gear, etc, it about has to be in the distributor.

I agree. I have taken the distributor out and tightened up the advance springs, hoping that will retard the baseline timeing. Have yet to test. Not wanting to heat up the garage today. Expecting 105* today.

[JSeery]

Originally Posted by Russ/40

Not wanting to heat up the garage today. Expecting 105* today.

That doesn't sound like fun!

[Bored&Stroked]

It can also be where/how the t-slot was put into the cam core. I've seen many mistakes on a variety of aftermarket cams, so nothing would really surprise me at this point. Another option would be to put an "advance plate" on the distributor (like we do on Harman Collins mags), so you have a lot more adjustment in the timing. If it truly has 25 degrees at idle and 35 total, then it explains that hard to start as the starter is trying to overcome the heavy advance at crank speed. Your TOTAL advance should be around 23 - 24 degrees.

[Kurt in NJ]

Was the cam timing checked?, not just by gear marks, but by valve action compared to piston position--

[Russ/40]

Kurt, no that was not done. The reason being, the cam in question was run in my '40 for a period of time several years ago with no problems.

Bored&Stroked's comment as to starter struggling to overcome 25* advance sure rings true. I would never have considered that as I never have encountered this kind of problem. There is always more to learn.....

[Brian]

Have you run engine with a vacuum gauge connected?

[Russ/40]

No I have not. I only have the manifold single ports vacuum sources, not a central vacuum. The timeing is so off, I not sure that would be worthwhile. When I get the timeing issue resolved, I'll do a compression check. If that falls short, I'll do a leak down test. Timeing is the first issue of importance in my mind.

[cas3]

as Brian suggested, wouldn't a vacuum gauge show improper valve timing?

[Russ/40]

I no longer believe there is any valve timeing issue. Why would you suggest it in lieu of the overall story? Im open...

[cas3]

sorry russ, i follow the story, but its evolved over many days, and if i spoke of something irrelevant, its my memory, not the story thats the problem. just trying to help...best wishes

[Brian]

Russ, You say you haven't actually checked valve timing....the way I see it, if you're a tooth off, 44 teeth on the camgear divided by 360 degrees means each tooth gives just over 8 degrees. That equates to 16 degrees at crankshaft. being one tooth off would also advance the dissy by the same 16point whatever degrees. Then, depending on exactly where the points plate in distributor is located, could easily make up the rest of the ign advance you're seeing. As others have said, you need to degree in the camshaft first. And yes, a vac gauge will show if your valve timing is out, a very handy diagnostic tool I reckon. Good luck, Brian

[Kurt in NJ]

If you look in the plug hole watch the valve operation, as the exhaust just is about closed the intake will just start opening, when you have both valves equally just a little open the piston should be at tdc for most cams

[Brian]

Kurt is spot on with his advice.

[Mart]

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Further to Kurt's advice, if you observe through No6 plug hole, the valve overlap will occur as No1 is at TDC on the firing stroke.

[Ol' Ron]

When I install the cam gear, I always check for "Split overlap". We were taught that in shop in high school. Some early engines, like water pumps, didn't have timing marks. You don't need a dial indicator to tell you , You have a problem.

[Zeke3]

Ol Ron, can you explain the term "split overlap"? I am not familiar with that term and how you check for it.

Thanks, Zeke

[JSeery]

Cam overlap is the time when both the intake valve and the exhaust valve are open around TDC. Split overlap is where both valve are at the same height above the valve seat and should be at TDC. I think the way Ron is using it is check TDC against both of the valves being in the same position.

As Kurt posted above: ...as the exhaust just is about closed the intake will just start opening, when you have both valves equally just a little open the piston should be at tdc for most cams

[Mart]

I might be wrong but overlap is something associated with performance engines. When I observe a flathead with a stock cam the exhaust closes then the inlet starts to open. They are not both open at a similar height at the same time.

But the bottom line is that the point at which the exhaust has just closed and the inlet is just about to start to open is the point at which the piston should be at TDC.

For reference, No.6 valves behaving as described above will coincide with No.1 at TDC having just fired. (On the firing stroke).

[JSeery]

Originally Posted by Mart

I might be wrong but overlap is something associated with performance engines. When I observe a flathead with a stock cam the exhaust closes then the inlet starts to open. They are not both open at a similar height at the same time.

But the bottom line is that the point at which the exhaust has just closed and the inlet is just about to start to open is the point at which the piston should be at TDC.

For reference, No.6 valves behaving as described above will coincide with No.1 at TDC having just fired. (On the firing stroke).

Yep, but that is what the term means. Guess you could call it "zero" overlap.

[Russ/40]

Originally Posted by cas3

sorry russ, i follow the story, but its evolved over many days, and if i spoke of something irrelevant, its my memory, not the story thats the problem. just trying to help...best wishes

I welcome any and all advice. With the new thread, I know it's gotten hard to follow.

I think I have eliminated any valve timeing concerns. I have a Sun machine, but the RPM and dwell functions are inop.

[Russ/40]

Mart, i think im seeing what you described as to the cam check. With number one at TDC both valves are closed. At that time, number 6 exhaust is almost closed. Any clockwise rotation closes the 6 exhaust and begins opening 6 intake. This puts to rest any concern about valve timeing, right?

Terry, I checked the points, both sets are closing, so it is running on both sets. When I get it running again, I'll try to measure the dwell. What should dwell be on a helmet type dizzy? Also will see if my tightening up the advance springs have retarded the timeing any.

Not going to be able to run it again today. Was 108* yesterday and supposed to be 105* today. Can't run it without heating up the garage.

[cadillac512]

Dwell in the 34-36 degree range will be about right.



It finally cooled off here...last couple weeks have been pretty nice in 70's and 80's. I do hate the summer weather, especially when our 95-105 temps combine with high humidity here.



Damn, this engine is being a pain in the butt!


Terry

[Mart]

Russ, Please clarify "almost closed".

From memory, with a stock cam in a flatty, as you reach TDC, The exhaust will have just closed and the inlet will be about to start opening. If the exhaust is closing after TDC then the timing may be out.

There are 44 teeth on the cam gear, one tooth is 8.18 degrees. So if you were one tooth out, the overlap (rocking) of the valves would occur 16 crank degrees after or before TDC, depending on which way you were off.

In other words, it should be obvious if it is wrong.

If it isn't obviously wrong, it is probably right.

Mart.

[Brian]

Russ, you said in your earlier thread that this is an Isky 77B grind.
The specs for this cam state inlet opens 19* BTDC and ex closes 19* ATDC.
So, at exactly TDC, both valves should be slightly open should they not?
OK, you've located TDC. So you know where the crank is....now you need to degree in the cam so you know where it is.
And then, when cam timing is correct....since the distributor is driven off of the front of the camshaft, if timed up correctly on a timing fixture, the ignition timing will be right!

I still reckon you're one tooth off on the camgear/crankgear, that advances everything 16 point something degrees [crankshaft degrees]. Then, I dunno how your distributor is set up, but it could quite conceivably be advanced, adding up to the 25* you're seeing at idle.

[JSeery]

Originally Posted by Brian

Russ, you said in your earlier thread that this is an Isky 77B grind.
The specs for this cam state inlet opens 19* BTDC and ex closes 19* ATDC.
So, at exactly TDC, both valves should be slightly open should they not?
OK, you've located TDC. So you know where the crank is....now you need to degree in the cam so you know where it is.

Ya Brian, I only know one way to do these cam deals, so difficult to relate to just sticking them in. I know it is common practice, but I'm not a fan of tearing engines back apart chasing issues, LOL. Besides if your looking to maximize performance it's just about a requirement.

I'm sure Russ thinks I sound like a broken record (and I could be dead wrong), but I find it difficult to attempt to troubleshoot a problem like this without 100% nailing down all the basics.

[flatjack9]

Originally Posted by Russ/40

I welcome any and all advice. With the new thread, I know it's gotten hard to follow.

I think I have eliminated any valve timeing concerns. I have a Sun machine, but the RPM and dwell functions are inop.

The dwell on my Sun machine doesn't work so I hook up a separate dwell meter.

[flatjack9]

I agree with Brian.

[bbrocksr]

Originally Posted by Mart

I might be wrong but overlap is something associated with performance engines. When I observe a flathead with a stock cam the exhaust closes then the inlet starts to open. They are not both open at a similar height at the same time.

But the bottom line is that the point at which the exhaust has just closed and the inlet is just about to start to open is the point at which the piston should be at TDC.

For reference, No.6 valves behaving as described above will coincide with No.1 at TDC having just fired. (On the firing stroke).

Hey Mart, The intake opens just before the exhaust closes, so both valves are off their seats at the same time near TDC but only for a few degrees which is called overlap. The exhaust stroke is overlapping the intake stroke for a few degrees.
Good subject for a video on Mart's Garage.
Bill

[Russ/40]

Originally Posted by Mart

Russ, Please clarify "almost closed".

Mart.

Mart, after further scrutiny of number 6 with 1 at TDC, i think both valves are closed. if any valve is off the seat, I cant really see it. Rocking the crank back and forth opens and closes both valves in opposition.

Brian, I've had the heads off this thing three times. In the past I have never had to do that even once. It would be my very last ditch effort to do it again. Can the cam be degreed without removing the heads?

[bbrocksr]

Originally Posted by Russ/40

Mart, I don't know how else to state it. The exhaust valve on number 6 is barely perceptible to be off the seat, and the intake is closed when number one is at TDC. One thing puzzles me Mart. How is it we are talking about number 6 in this timeing discussion.

Brian, I've had the heads off this thing three times. In the past I have never had to do that even once. It would be my very last ditch effort to do it again. Can the cam be degreed without removing the heads?

When number 1 is at TDC firing, number 6 is at TDC overlap. The easy way to find TDC firing on number one is to put number 6 on TDC overlap.
Overlap is when the intake and exhaust valves are both off their seats at the same time for a few degrees at or near TDC number 6.
number 1 & 6 come to TDC at the same time, one is firing the other is
overlapping.
Intake valve opens 0 degrees BTDC on a stock 59a , so if the intake on number 6 just starts to open at TDC the valve timing is correct.
Bill

[KGS]

Just a shot in the dark here so don't laugh. Is the cam gear a press on? If so, could it have slipped to cause this problem? If it is a bolt on cam gear and possibly slotted, could it have moved?
Ken

[JSeery]

Originally Posted by bbrocksr

Intake valve opens 0 degrees BTDC on a stock 59a , so if the intake on number 6 just starts to open at TDC the valve timing is correct.
Bill

Keep in mind this is not a stock cam, so there is overlap. The intake on number 6 will not be just starting to open in this case. Needs to be in a positions such that the exhaust and intake are the same height above the valve seat.

If the cam spec posted is correct, it would be intake 19 deg BTDC and exhaust 19 deg ATDC. A problem is there is very little valve movement at these positions, that is why cam numbers are given at 20 or 50 degrees, so you can actually detect valve movement.

I have never tried to degree a cam with the head on. I would think you could at least check the exhaust valve if you can get a dial indicator through the sparkplug hole and on the edge of the valve such that it can move without rubbings on anything. If alum head, need to figure out a way to mount the base. Looking for very slight movements during part of the cycle, so everything needs to be very secure.

[bbrocksr]

Originally Posted by JSeery

Keep in mind this is not a stock cam, so there is overlap. The intake on number 6 will not be just starting to open in this case. Needs to be in a positions such that the exhaust and intake are the same height above the valve seat.

If the cam spec posted is correct, it would be intake 19 deg BTDC and exhaust 19 deg ATDC. A problem is there is very little valve movement at these positions, that is why cam numbers are given at 20 or 50 degrees, so you can actually detect valve movement.

I have never tried to degree a cam with the head on. I would think you could at least check the exhaust valve if you can get a dial indicator through the sparkplug hole and on the edge of the valve such that it can move without rubbings on anything. If alum head, need to figure out a way to mount the base. Looking for very slight movements during part of the cycle, so everything needs to be very secure.

There is overlap on a stock cam as well, the point is if the overlap occurs at TDC the valve timing is right .

[Ronnie]

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Put a buzz box on the dizzy to confirm its operation. Rotor Wrench will chime in as it is used often on aircraft engines.I made mine 50 + years ago when I was involved in a C dragster. They work no problems in determining point action. I am sure Tub Man has used one as well. I guess a digital multi meter with continuity test could do it also.


R

[Russ/40]

In post 41 I revise my observations of cylinder 6, for which Mart asked me to clarify "almost closed." Both valves are closed as best as I can tell. This must be the overlap that I really cant see. When turning the crank by hand, it is really hard to make observations.

[Ol' Ron]

To be honest, I can't remember using a stock cam. I did use an EAB cam in the 289, but never checked it. I did however use the original alum timing gear. Runs great so far.

[flatjack9]

A 77B at TDC overlap will have both valves open about .030.

[Russ/40]

I don't think you could visibly tell through the plug hole whether both valves are open .030" or closed. Especially if they sit low in their seats. JMO

[Russ/40]

You guys are probably giving up on me, wouldn't blame you, but I still need some help.
I have set up a few different distributors, and I am sure my problem is not ignition. Engine runs and starts best at 20+* advance. And distributors are set correctly. Retard the timing and it runs like s##t. I even modified a distributor to increase the range of adjustment, and no improvement.

I wish I had, as you have suggested, degreed the cam. I have never done so, and wouldn't know where to start. I'm thinking the cam needs to be retarded, but the question would be "do I and how much". What would rotating the distributor do for the situation? I would have to create a mount to do so. If one of you true tech savvy guys could give me a recommended simple test where I could measure exhaust valve timing with a dial indicator to determine the number of degree correction of the cam, I can work out a cam timing adjustment.

I wanna screem! If I can't fine a solution soon, i will sell the dam thing for parts.

[Bored&Stroked]

Just to go over the timing once again: Are you still saying that it has 20 degrees of advance at startup . . . and about 35 when running at a decent RPM (say 2500)? If this is still the case, then my guess is either the CAM is off, or your TDC and timing marks are off. It should start just fine with low advance and the total should be in the 22 - 25 total degrees of advance range.

[Brian]

Try this; remove timing cover, line up your existing timing marks, undo the 4 bolts holding the camgear on. Remove cam gear. Replace gear after moving cam [edit]clockwise sufficient to be able to bolt gear back on with its timing mark one tooth to the [edit] LEFT of that on the crank gear. bolt everything back. You have just retarded the cam [and timing] by 16 odd degrees. See how it runs now. Good luck

[Brian]

You cannot get 35* advance out of a distributor, unless the slot it engages in is out.

[flatjack9]

With #1 spark plug out, you can get a dial indicator on the exhaust valve. Get a degree wheel, set up a pointer and degree the exhaust event.

[Russ/40]

Originally Posted by Bored&Stroked

Just to go over the timing once again: Are you still saying that it has 20 degrees of advance at startup . . . and about 35 when running at a decent RPM (say 2500)? If this is still the case, then my guess is either the CAM is off, or your TDC and timing marks are off. It should start just fine with low advance and the total should be in the 22 - 25 total degrees of advance range.

Bored&Stroked, Yes, it has 25* static advance and with RPM will hit 35* with the vacuum brake full on, bolt fully in. Keep in mind, the distributor thinks it is zero* at TDC, so I'm only getting 10* advance from the distributor.

TDC was determined two ways, with a dial indicator when the heads were off. After heads on, I did the double stop method with a big zip tie. Both TDC's agree by a degree or so. What should the base (static) timing be for an Isky 77-B cam? I can't find that anywhere.

Flatjack9, I'll see what I can do with the exhaust event plot. That may take me awhile.

Thanks guys

[Brian]

Russ, you 'know' this cam is right because it's previously run very satisfactorily in an earlier engine. You 'know' where TDC is. BUT, you don't 'know' how the camshaft is timed to the crankshaft. Please, follow flatjacks or my advice. Your original question pertained to timing marks. Whatever 'marks' you have ultimately used, obviously are wrong. Until you have established actual cam timing events, anything else is pure conjecture. I'm not going to post anymore on this thread. I can only offer advice, if you choose not to follow it, so be it. Again, good luck!

[vincent]

You might try to put air pressure into #1 to find out the actual cam timing. Fit a degree disc to the crank. As soon as a valve opens you will hear a hissing sound in the carb or exhaust. That indicates that the valve is lifted off the seat. By turning crank slowly both directions and hearing the changing hiss you can get the timing almost as precise as with a dial gauge on the valve.
cheers, Harty

[flatjack9]

Originally Posted by Russ/40

Bored&Stroked, Yes, it has 25* static advance and with RPM will hit 35* with the vacuum brake full on, bolt fully in. Keep in mind, the distributor thinks it is zero* at TDC, so I'm only getting 10* advance from the distributor.

TDC was determined two ways, with a dial indicator when the heads were off. After heads on, I did the double stop method with a big zip tie. Both TDC's agree by a degree or so. What should the base (static) timing be for an Isky 77-B cam? I can't find that anywhere.

Flatjack9, I'll see what I can do with the exhaust event plot. That may take me awhile.

Thanks guys

Faulty timing light?

[Russ/40]

Flatjack9, My light has no advance detection ability, so it can only work correctly or not work at all.

Brian, thanks for your patience. I will take your advice and try to degree the number one exhaust valve to find where the cam is relative to the crank. When I have some data, maybe you can help me interpret it. Your idea of advancing the cam is interesting, and hopefully degreeing the exhaust valve will result in info confirming or nixing the wisdom of changing valve timing. It looks more all the time like the cam gear could be the culprit. I used a used gear with no known history that I have not used prior.

Vincent, thanks for the idea of pressurizing the cylinder to define opening and closing valve points great idea.

Again, thank you all for thinking it through.

[Brian]

No Russ, I've put you crook...you need to move the cam to retard it one tooth. That'll put your mark on the camgear to the LEFT of where it was....I previously said to the right. Sorry about the confusion.

Currently your cam is ADVANCED 16 odd degrees [crankshaft]. Which is why the #6 ex valve appears to be shut @ TDC, whereas it should shut later in the cycle @ 19* ATDC. Also why your ignition is firing so early.

[Mart]

Brian, Forgive me if I've misunderstood, but as the cam turns counterclockwise, turning it counterclockwise one tooth will advance it (? Won't it??).
I understand exactly what you are saying but believe it needs to go clockwise to have the effect you are saying.
That would mean the mark on the cam gear needs to be to the left (as viewed straight on) of the mark on the crank gear.

(Hope I've got this right)

Mart.

[Brian]

Yes Mart, I'm confusing the issue, you are correct; clockwise. I've edited my previous incorrect information. I need to read my 'motto' more often!! Lucky I only consider myself halfway there! lol

[Bored&Stroked]

Originally Posted by Brian

Lucky I only consider myself halfway there! lol

An old friend had a funny saying for team work . . . "All of us working together are dumber than any of us!"

I didn't actually agree with it - if one had a decent team of folks!

[Russ/40]

About advancing the cam. The cam gear is a bolt on and will fit only one way. I would have to pull the cam and gear forward enough to clear the crank gear before I could retard the cam. All the lifters would drop off the cam lobes, and the engine would have to have the heads and valve assemblies pulled to reinsert the cam. So, would elongation of the cam gear mounting holes be a reliable option to eliminate the necessity of pulling the cam? Should one be comfortable with the holding power of the 4 bolts to hold the cam long term?

[FlatheadTed]

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Slot the holes on your cam when your happy drill and tap ,two additional holes between to lock it. I would , Get a distributor set up on a KR fixture ,accurately to find TDC ,bolt that to your motor and with a light set up in searys with the points re mark your pully,Your cam ran fine in another motor , Ted

[GOSFAST]

Here's a link (https://www.fordbarn.com/forum/showt...reeing+pinning) to some interesting reading I put up here a while back!

We degree check EVERY cam we install on EVERY build and move them when necessary!

Thanks, Gary in N.Y.

P.S. If you look closely to the photo you'll notice a "timing-pill" installed in the Flathead gear, this allows us to "move" the cam from "+6* to -6*" if ever needed, the other photo is how the cam is degree-checked before the assembly!

[FlatheadTed]

A Kr would give you a 4Deg built in advance ,You could pull the gear out fit longer bolts rotate it to were you want cam and all ,(use a large bar or the like between the bolts ) when the tooths lined up screw the bolts in ,replace them later .Sorry for butting in on this thread , Ted

[JSeery]

Originally Posted by Russ/40

About advancing the cam. The cam gear is a bolt on and will fit only one way. I would have to pull the cam and gear forward enough to clear the crank gear before I could retard the cam. All the lifters would drop off the cam lobes, and the engine would have to have the heads and valve assemblies pulled to reinsert the cam. So, would elongation of the cam gear mounting holes be a reliable option to eliminate the necessity of pulling the cam? Should one be comfortable with the holding power of the 4 bolts to hold the cam long term?

If you are wanting to move it one tooth on the cam gear, wouldn't you unbolt the cam gear, reinstall it one tooth over, align the camshaft with the cam gear and bolt it back up?

[FlatheadTed]

Sometimes a cam can move just move the crank around , a zip lock doesn't give you 4 Deg , I could be wrong though

[flatjack9]

Do as JSerry says. Have you degreed the can yet?

[Mart]

Originally Posted by Russ/40

About advancing the cam. The cam gear is a bolt on and will fit only one way. I would have to pull the cam and gear forward enough to clear the crank gear before I could retard the cam. All the lifters would drop off the cam lobes, and the engine would have to have the heads and valve assemblies pulled to reinsert the cam. So, would elongation of the cam gear mounting holes be a reliable option to eliminate the necessity of pulling the cam? Should one be comfortable with the holding power of the 4 bolts to hold the cam long term?

I thought the theory proposed is that you want to retard the cam by one tooth.

Undo the gear, rotate the cam a little clockwise and refit the gear one tooth clockwise from where it was previously.

You don't need to worry about the lifters and such.

[Ideucev8]

I would remove the cam gear & rotate the crankshaft the one tooth as it would be much easier to turn than turning the camshaft.
Phil

[Russ/40]

Originally Posted by Ideucev8

I would remove the cam gear & rotate the crankshaft the one tooth as it would be much easier to turn than turning the camshaft.
Phil

Your the winner! The simplest and most clearly articulated for my feeble mind, thanks.

I have not degreed the cam yet. Got a lot going right now and it may be awhile.

[flatjack9]

You will degree it before changing the gear location?

[Russ/40]

Originally Posted by flatjack9

You will degree it before changing the gear location?

I will do that flatjack9. I need to locate, or make, the degree wheel arrangement.
Thanks