This ^%$#(& engine is driving me crazy!!!

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Marshall V. Daut
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This ^%$#(& engine is driving me crazy!!!

Post by Marshall V. Daut » Mon Mar 23, 2020 8:37 pm

I posted last year about helping a friend get his 1924 Model T Coupe engine running better and stronger. It ran smoothly, but it always felt a bit doggy, unpowered even for a stock T. So, we decided to put on a "Z" head. Well, the best laid plans of mice and men...New rings, new pistons, new adjustable lifters, freshly cut new valve seats the Nuway way and re-faced valves later, the engine refuses to start or even give decent compression readings. After multiple trips to the "farm" 60 miles away where it was stored to find out what was wrong, we finally pulled the &*$#%*() thing out of the car and brought it to my garage for a post-mortem. There had been a great deal of poor workmanship encountered while trying to get the engine started after all our work and new parts. I have NEVER had this much trouble getting a reassembled Model A or T engine started.
After adjusting the valves every which way from Sunday, I am STILL experiencing a major problem getting them right. I originally set them the way I have been doing for the past few decades, namely using the Rule of 9. Always worked great before. Well, not on this engine! I would get all the lifters set according to this tried-and-true method and then double check them by following Glen Chaffin's heel adjustment method. The feeler gauges now wouldn't fit when the lobes were pointing directly down and the valve stems were resting on the heels. So, I set all the lifters according to Glen's method and checked them using the Rule of 9. Once again, not even close with the feeler gauges. I then set them where each piston was at TDC, another accepted method. The feeler gauges would only fit that way, not by camshaft lobe heel or Rule of 9. I did each type of adjustment multiple times with the same FRUSTRATING variations!!! Shouldn't adjusting the lifters give the same result in all three methods, namely attaining the recommended gap? Why the variations?
Tonight I decided to compare this engine's camshaft and fiber timing gear to a rebuilt T engine I have in my garage with a metal gear. I am wondering if the FIBER timing gear that came with this engine had been installed on the camshaft 180 degrees from correct and had been set one tooth off, namely by placing the timing mark 180 degrees to compensate for an incorrectly installed gear and miscounting the teeth by one, which would explain he engine's lack of zip. You can't install a Model A timing gear on the camshaft incorrectly because of the locating holes' offset. I don't see that offset on these Model T timing gears from what I can see around the large nut. Is there an offset? I had re-installed the camshaft so that the two timing marks lined up, as I have done 1000 times before. But when I study the first four camshaft lobes between the two engines when the timing gear marks mesh, the lobes are pointing in radically different directions, even after turning the crankshaft 180 and 360 degrees. Assuming the timing marks on both gears always put the camshaft lobes in the same position every time the marks meet, why would there be such a difference in which way the lobes are pointing? I think I smell a rat somewhere. Could the fiber gear be 180 degrees off from the correct orientation and/or the gear mismarked? That would explain all the problems I have encountered trying to perform a basically simply job of valve lash adjustment for the millionth time.
Jeez, this is frustrating. Am I missing something really obvious here???
Marshall

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Re: This ^%$#(& engine is driving me crazy!!!

Post by Charlie B in N.J. » Mon Mar 23, 2020 9:16 pm

The gear can be installed 180 deg. out. Actually it's the cam shaft that's 180 deg. out. The gear can be installed 2 ways. No "locator". This results in the companion cylinders swapping places. Lets say if correctly installed #1 is on compression and #4 is on exhaust. With the gear on a cam that's 180 out and the timing marks correct #1 is now on exhaust and #4 is on compression. Same for #'s 2 and 3. Swapped. The exact opposite of the factory setting. Going to get my keester kicked on this I'm sure. But it explains why the valves are in wacko positions.
Last edited by Charlie B in N.J. on Tue Mar 24, 2020 7:51 am, edited 1 time in total.
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Re: This ^%$#(& engine is driving me crazy!!!

Post by Henry K. Lee » Mon Mar 23, 2020 9:17 pm

Marshall I believe you have narrowed it down. Had a similar situation.., A reground cam shaft which was not centered when done and a missed marked cam gear! Yes two devils in one! Throw them away if both are screwed up and replace under normal rules should work well. I thought I was the only one to go though this!

By the way.., shave the dog for a hair transplant!

Hank


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Re: This ^%$#(& engine is driving me crazy!!!

Post by Scott_Conger » Mon Mar 23, 2020 9:19 pm

Gear goes on either way. The gears certainly don't care. Put the front cover on and stop worrying about "0" or "180 out". Set cam manufacturer's clearance for valve lash with pushrod on the heel of the cam. Crank engine over to #1 compression and 12-15 degrees ATDC and set the timer. Be done with it. Have a beer.

BTW, since you're used to using "Rule of Nine" I really suspect that you have a hot cam or a Chaffin's cam with some advance built into it along with lots of lap, which may lead to a valve at the top of the lobe not leading to a valve count to "9" that ends up with that corresponding pushrod actually on the lowest point of ITS cam, and CERTAINLY would not be where you thought it was based on piston position (which is probably more likely than aformentioned lead). Simply doing it directly, as I mentioned above rules out any duration, lap, or lead issues with a special cam. Modern cam geometry along with valve lap can achieve lifts that were unthought of years ago in that old methods would lead to the cam really spanking the lifter, where todays cams don't. Again, I think this is why a pure gap at perfect heel position and a gap set "9 minus valve count" can lead to that cam not being truely and fully "down" when you gap it and then you get a really big gap when measured a different way. I would also think that Rule of 9 could cause havoc with a worn cam or a reground cam with slightly imperfectly "clocked" lobes.

Given your trouble, and knowing that a manufacturer means "gap" when they say "gap" and you are getting 3 different gaps with 3 different methods, the ONLY method that achieves what the manufacturer says should be set is the direct, physical gap of a specific pushrod to a specific lobe at total heel.

I read Hank's response that snuck in before mine. I can't disagree with him that it's possible, other than wonder what the odds of two very freak things happening simultaneously on the same engine. I believe that would be very, very low. On the other hand, his scenario matches very well with either a worn or imperfect cam that has built-in advance.

I once ran into a car which after speaking with Glen years ago finally came to the conclusion that it was a Laurel-Roof special put into a standard stock engine. Nothing was where it belonged when trying to gap those valves other than pulling the pan and watching lobes and setting gap directly. Setting gaps based on piston position resulted in totally crazy gaps.
Last edited by Scott_Conger on Mon Mar 23, 2020 10:26 pm, edited 7 times in total.
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Re: This ^%$#(& engine is driving me crazy!!!

Post by Norman Kling » Mon Mar 23, 2020 9:20 pm

If your timing gear pin holes are built in the correct position, it wouldn't make any difference if it were installed 180 degrees off because the crankshaft turns two complete turns for every one torn of the cam shaft. If you are using adjustable lifters and you adjust them on the heel of the cam, the gauge should fit. Did this engine ever run with this cam shaft? Maybe there is something wrong with the shaft?
Norm

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Re: This ^%$#(& engine is driving me crazy!!!

Post by Steve Jelf » Mon Mar 23, 2020 11:01 pm

These other guys know a lot more about the subject than I do, but experience tells me you should ditch that fiber gear, especially in a 1924 which presumably has a generator.
The inevitable often happens.
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Re: This ^%$#(& engine is driving me crazy!!!

Post by Scott_Conger » Mon Mar 23, 2020 11:09 pm

Steve, you are absolutely right about that! Excellent point and advice.
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Re: This ^%$#(& engine is driving me crazy!!!

Post by Dan McEachern » Tue Mar 24, 2020 12:04 am

If all you are doing is setting valve lash, it should not matter a bit where you do it as long as the follower is on the base circle of the cam. If you are getting variation in your lash settings, the only thing that will cause that is base circle run out. You don't state how much variation you are seeing, but anything more than a few thousandths and you either have a bent cam, a worn out cam, a very poorly ground cam or terribly worn out cam bearings. Unless you know for sure its a Ford stock cam, with stock cast iron pistons, do not even think of using piston position to set the lash- you're wasting your time. As others have stated, the cam gear being out 180 degrees has no effect on cam timing due to the 2:1 ratio of the cam and crank.


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Re: This ^%$#(& engine is driving me crazy!!!

Post by Erik Barrett » Tue Mar 24, 2020 3:06 am

What Dan said. Piston travel adjustment works well with all original Ford parts. Any new parts and you will do better with the cam grinders’s recommendation. Cam gear can go on either way, makes no difference.


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Re: This ^%$#(& engine is driving me crazy!!!

Post by TBill » Tue Mar 24, 2020 7:03 am

Hi Marshall. We haven’t communicated in awhile, but I am slowly restoring the 1926 Fordor I bought from you. The engine will be like new with oversized aluminum pistons, new mains, new rods, new camshaft, new timing gears, etc.

I used an aluminum cam gear. I was afraid of fiber, especially when running a generator.

It occurred to me when installing the timing gears that it would be possible to be 180 degrees out of time, so I made sure to set the exhaust valve on number one cylinder to open at the correct point in the piston stroke.

Wish I could work full time on this fun project but alas, too many other priorities. It will come. Meanwhile I still have a running TT, a 1942 Ford GPW Jeep and a 1946 Willy’s CJ2A.

Take care.


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Re: This ^%$#(& engine is driving me crazy!!!

Post by Jim Eubanks » Tue Mar 24, 2020 8:32 am

I'm with Steve and Scott, THROW that evil fiber timing gear out soonest. It will shred sooner than later.


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Re: This ^%$#(& engine is driving me crazy!!!

Post by fschrope » Tue Mar 24, 2020 9:21 am

What is the "Rule of 9"?


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Re: This ^%$#(& engine is driving me crazy!!!

Post by John kuehn » Tue Mar 24, 2020 10:20 am

Don’t know how much you want to spend but a good stock cam can probably be had from Lang’s or someone else along with a new aluminum timing gear. I have 3 T’s and rebuilt the engines in them using a good used cam with no issues. Some will frown about using used parts but I did use new cam bearings and the cars run fine.
At this point it might be a good idea to get another cam and gear. Just my opinion.

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Re: This ^%$#(& engine is driving me crazy!!!

Post by AndreFordT » Tue Mar 24, 2020 11:06 am

Rule of 9:

Valve 8 open valve 1 adjusted; valve 7 open valve 2 adjusted; valve 6 open valve 3 adjusted and so on.

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Re: This ^%$#(& engine is driving me crazy!!!

Post by dmdeaton » Tue Mar 24, 2020 12:06 pm

Don’t want to hi jack the thread, but good reading. What is the lash setting on these beasts? Stock cam or modified make a difference?


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Re: This ^%$#(& engine is driving me crazy!!!

Post by Marshall V. Daut » Tue Mar 24, 2020 12:45 pm

My thanks to everyone who has shared his advice and experience in trying to help me resolve this frustrating and confusing (at least, confusing to me!) problem with the camshaft gear and valve clearance setting variations. Great reading and very reassuring how nearly indestructible the Model T engine is and how it will run inspite of all-thumbs mechanics like myself.
Earlier this morning for the first time EVER I was able to get this website's search function operate without hanging up forever. I could only open threads from 2018, however, which provided more than enough information on this subject. I am apparently not the first Model T'er to have run into this problem! I don't feel so stupid now. The answers supplied back then pretty much parallel what you guys have supplied so far. I must admit, I am still having trouble wrapping my mind around the opinion that it's o.k. if the camshaft gear is installed 180 degrees off on the camshaft. This must be a holdover from my Model A days. I understand the two revolutions of the crankshaft vis-à-vis the single camshaft gear revolution 2:1 situation and that when the timing marks mesh, that is NOT #1 piston's TDC. But but I still can't quite grasp WHY it will work. Isn't 180 degrees off still 180 degrees off? What's the point in even having those timing marks if it doesn't matter whether the gear is installed on the camshaft correctly or not? Just for initial gear timing purposes, whose orientation to each other afterwards doesn't matter? Boy, is that a tough one for me to mentally picture and accept. I will, however, yield to the learned opinion of people on this website, whose experience I value and I won't lose any more sleep over the cam gear's orientation. You say it will work, so it WILL work.
Having said that, though, I intend to order a metal timing gear to replace the fiber gear. I was concerned when I first removed the timing gear cover last year to install new adjustable lifters and discovered that a fiber gear was in place in this engine with a generator. Trying to save my friend money, I didn't recommend replacing it with a metal gear. Now, however, given the group's consensus concern about stripping the fiber gear, I would like to install the new timing gear the CORRECT way right off the bat, which is NEVER shown or described in any literature I have seen. I am talking about where #1 camshaft lobe (exhaust) is pointing in relationship to the camshaft gear's timing mark's position. In order to do this properly and avoid some future mechanic cussing me out for installing the timing gear incorrectly, consider the timing gear as a clock face, looking directly at it from the front. Given that the camshaft timing mark is at the 12:00 position, where on the clock's face should #1 camshaft lobe be pointing? As I mentioned in my previous post, there are two camshafts here with that lobe facing different directions in regards to the timing mark on the camshaft gear. Obviously with a 50-50 chance, one gear has been installed correctly and one has not. Or, after reading the replies to my question, IS there even a correct and incorrect way of orienting the camshaft gear, as long as the two marks on the gears mesh upon installation?
So, the question of the hour now is: At what position on the clock face SHOULD #1 camshaft lobe be pointing when the cam's gear timing mark is at the 12:00 position? Whether it matters in actual operation or not, I'd prefer to get this camshaft/gear matter started out properly.
Thanks in advance.
Marshall


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Re: This ^%$#(& engine is driving me crazy!!!

Post by Scott_Conger » Tue Mar 24, 2020 1:29 pm

Marshall

you are still asking the correct way to do something that cannot be done wrong (so long as the timing dots/marks on cam and timing gear mesh).

If you had to walk around your house from the front door, is turning right or left the correct way to navigate around your house? It simply does not matter. Putting the cam gear on one way or another Is not being sloppy and "getting away with something"...it doesn't matter. End of story.

Chill dude! Move on! You have bigger fish to fry than this, with this project :)
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Re: This ^%$#(& engine is driving me crazy!!!

Post by Dan McEachern » Tue Mar 24, 2020 2:51 pm

AFAIK, general convention is that the #1 exhaust lobe should point toward the timing mark on the cam gear. This is just a convention, similar to the conrod pinch bolt being on the cam side of the engine. Both have no effect on how the engine runs. And no, I don't remember if this is in any Ford service manuals or???? In any case, yes, move on- this timing mark issue cannot cause engine performance issues!!!

If you feel you have other cam timing issues, the only real way to get to the bottom line is to put a degree wheel on the crank, locate TDC (correctly) and determine your opening and closing events for the intake and exhaust lobes and then make timing adjustments.


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Re: This ^%$#(& engine is driving me crazy!!!

Post by Roz » Tue Mar 24, 2020 3:06 pm

A Model A timing gear indexes only one way because of the way you time the ignition. Timing is set at #1 TDC. When you take the timing pin out, turn it over and put it back in the hole, there is only one spot on the gear that is #1 TDC. That’s where the pin drops into the dimple. I guess Ford thought this made it easier to time the distributor. If it wasn’t for that, the gear could go on either way. It doesn’t matter on a T engine. There is no 180 out. There could actually be two timing marks on the cam gear 180 apart and either one would work. Don’t worry about where the cam lobes are pointing. Just line up the timing marks and you’re good to go.


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Re: This ^%$#(& engine is driving me crazy!!!

Post by Scott_Conger » Tue Mar 24, 2020 3:18 pm

There could actually be two timing marks on the cam gear 180 apart and either one would work.
If all other things are equal, you might want to rethink that.
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Re: This ^%$#(& engine is driving me crazy!!!

Post by Roz » Tue Mar 24, 2020 3:46 pm

Scott_Conger wrote:
Tue Mar 24, 2020 3:18 pm
There could actually be two timing marks on the cam gear 180 apart and either one would work.
If all other things are equal, you might want to rethink that.
I don’t understand what you are saying. The gear could go on the cam two possible ways. One way is 180 out from the other. That means the cam could be in either one of the two possible positions when the timing marks are lined up and either one would be correct. If that’s the case, why couldn’t there be two timing marks on the CAM gear 180 apart, and both be correct?

I have redrilled a lot of cam gears to advance them 7.5 degrees. When I relocate the timing mark, I line up off the two new holes and count two valleys to the left and center drill. I could randomly have the gear turned 180 to do this and it wouldn’t matter, so why couldn’t I do both?


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Re: This ^%$#(& engine is driving me crazy!!!

Post by Scott_Conger » Tue Mar 24, 2020 6:34 pm

I think I get what you're saying but will not go further as while this sounds "on topic" for the OP it is not and can lead to much confusion for him and everyone else.
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Re: This ^%$#(& engine is driving me crazy!!!

Post by Roz » Tue Mar 24, 2020 8:48 pm

I’m sorry. I thought it was on topic. I was trying to explain why you can’t get the cam gear out 180 degrees, which was his question.


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Re: This ^%$#(& engine is driving me crazy!!!

Post by TBill » Wed Mar 25, 2020 7:11 am

It is possible to install the cam shaft 180 out of time when the timing marks on the crankshaft and camshaft line up correctly.

Put the gear on the camshaft with the timing marks aligned then rotate the engine by hand and watch when the exhaust valve opens on number one cylinder. It should start to open right before the piston starts to ascend on the exhaust stroke. If not you are 180 out of time. If this is the case rotate the engine back until the marks align then remove the gear and rotate the camshaft 180 before reinstalling. That’s what I did. The head was off so I could see what was going on.

The exhaust valve is the first one in the valve train.


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Re: This ^%$#(& engine is driving me crazy!!!

Post by Roz » Wed Mar 25, 2020 8:15 am

TBill wrote:
Wed Mar 25, 2020 7:11 am
It is possible to install the cam shaft 180 out of time when the timing marks on the crankshaft and camshaft line up correctly.

Put the gear on the camshaft with the timing marks aligned then rotate the engine by hand and watch when the exhaust valve opens on number one cylinder. It should start to open right before the piston starts to ascend on the exhaust stroke. If not you are 180 out of time. If this is the case rotate the engine back until the marks align then remove the gear and rotate the camshaft 180 before reinstalling. That’s what I did. The head was off so I could see what was going on.

The exhaust valve is the first one in the valve train.
If you put the gear on with the marks aligned and see what you are saying above, that the exhaust valve is not opening just before BDC, just turn the crankshaft one full turn and you will see that it is correct the way it is. No need to remove the gear and change it.


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Re: This ^%$#(& engine is driving me crazy!!!

Post by Scott_Conger » Wed Mar 25, 2020 10:44 am

There is but one reference in the entire Ford Manual related to actually installing the large gear onto the cam shaft, and the reader is sent to this instruction a couple of times in the course of normal work regarding gear mesh, gear wear, cam straightness and cam bearing wear and gear installation. It is instruction (i) in paragraph 458:

Replace large time gear by driving it onto camshaft with a driver
as shown in Fig. 272 , making sure that the tooth marked
"FORD" on the small time gear meshes between the two teeth
on the large gear at the point marked zero (O). After gear has
been installed run down camshaft gear lock nut, drawing nut
down tightly.


Since the crank rotates two times for each cam revolution, there is no "180 degrees out" on the thing. There is no warning in the manual that you can do it "wrong", because you can't. Either way works so long as the marks line up between the cam gear and the crank gear when installed. The marks are the key to it.
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Re: This ^%$#(& engine is driving me crazy!!!

Post by Ruxstel24 » Wed Mar 25, 2020 10:55 am

I think the title of the OP is contagious :lol:
The only difference between proper cam gear alignment and 180 off is a compression stroke or exhaust stroke. Makes no difference and 360 degrees of the crank puts it back either way.
I don’t recall anything said about tappet wear, guide wear and valve guides possibly sticking.
Just a thought....don’t beat me up !! :lol:


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Re: This ^%$#(& engine is driving me crazy!!!

Post by Scott_Conger » Wed Mar 25, 2020 6:51 pm

Well, I like to do things right...whatever right is :?

I know that Marshall and others came up with the definition of "right" for cam lobes vs cam gear "o" mark SOMEWHERE and I wanted to find it's source.

Enter the trusty Dyke's Manual. Very clearly under the section of valve timeing and cam rotation, the information Marshall presented (and as I recall while typing this, others did too) is found. Additionally it is directed that the operator should observe the conventions mentioned when replacing the cam gear. Further, and this is key to the point, actually, it tells the operator that they NOW know where to place the wiper for the timer. This I think, is due to the potential for placing the timer wiper 180 degrees out on an early camshaft which is drilled all the way through and can obviously be put on wrong otherwise. I believe that this is the entire and ONLY reason for worrying about "right" and "wrong" gear installation. Those worries vanished when the later cams came out with a hole only partially drilled, thus forcing the wiper to ALWAYS be in the right place at the right time relative to the crankshaft, so long as timing marks were meshed adjacent to each other.

So there! The A-HAH! Moment. Source of info found! Now I can rest tonight. :lol:

Epilogue to this discovery of information:
Interestingly for the Model T, knowing the "right" way relative to "doing it wrong" has no effect on an engine made after (as I recall) around 1913, as after that period, the cam hole for the timer contact is drilled only 1/2 way through, eliminating the possibility of installing the timer wiper incorrectly (and even then, simply rotating the wiper 180 degrees would undo the error). Since the cam gear has twice the number of teeth as the crank gear, that if the gear is put on "wrong", the timing marks line up with exhaust just opening, but PRESTO, one complete revolution of the crank places the exhaust valve just closing and just like magic, the timer wiper is exactly where it belongs...the only heartburn being that the cam timing mark is now 180 degrees out. Fortunately, the engine doesn't know this, nor would it care if it could. Whether you get it "right" or wrong, you don't even have to sleep at a Holiday Inn to get it to work.
Scott Conger

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