Cam Degreeing/Checking Important

[GOSFAST]

This is another "tip" with respect to degreeing, or at least checking, the cam position BEFORE the final assembly!

It is an item I know few really pay attention to during most rebuilds. I would assume most professional builders would check and correct? We do this on EVERY build that leaves here, regardless of make/model or street/strip!

It isn't that easy to "move" a Flathead cam, just takes a bit of "outside-the-box" thinking!

The two photos below (on the left) show one member's build ready to be be corrected, I have another member's to do today also! The one in the photo below is 4* advanced with the "dots" lined up, the other (we've already checked it a few days ago) is 3* advanced also with the "dots" aligned.

Thanks, Gary in N.Y.

P.S. Here's a shot of one I'm working on at this moment, this is for an 8BA "blown" build. It will be moved to the correct spot later today. There's two ways to accomplish this, one is by a "quick-pin" method, the other uses a timing "pill" (pictured also) the same as a SBC and can be "moved" (advanced/retarded) easily at any later time if necessary.

[cadillac512]

That's a very important tip,Gary. I've seen cams ground as far off as 11 degrees and if not checked would have run like....you know what!

By the way, how far "out of the hole" are the pistons in that block? I like the way you think.


Terry

[A bones]

Thank you for taking the time for us,,, and them. I've had experience with off timed cams. Several in fact. It is the entire ball game.

[Bored&Stroked]

One thing to note is that it is really common to install a cam with it advanced 2 - 4 degrees. Some cam grinders will put the advance in the profile, while many others will ask that you install it advanced (given an adjustable timing chain, etc). It would not surprise me that given that it is not easy to change the advance on a flathead (and most do not have the skills/tools to do so), that the advance is pre-ground into the profile.

[Ronnieroadster]

Cam degreeing nothing to it! So far every aftermarket Flathead cam I have installed for initial checking has been consistent per the cam timing card all of them have been way off. Any Flathead being built with any brand cam needs to be checked. Not a simple task for most.
Also on every engine I build when correcting the cam timing all four bolts holes in the cam gear transfer the torque each one is the correct 5/16 diameter. Ford and all replacement cam gears have only two 5/16 holes the other two are oversize. Beware of limited ways to transfer torque on your cam gear mounting.
Ronnieroadster

[GOSFAST]

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Originally Posted by Ronnieroadster

Cam degreeing nothing to it! So far every aftermarket Flathead cam I have installed for initial checking has been consistent per the cam timing card all of them have been way off. Any Flathead being built with any brand cam needs to be checked. Not a simple task for most.
Also on every engine I build when correcting the cam timing all four bolts holes in the cam gear transfer the torque each one is the correct 5/16 diameter. Ford and all replacement cam gears have only two 5/16 holes the other two are oversize. Beware of limited ways to transfer torque on your cam gear mounting.
Ronnieroadster

Hi Ronnie, no different than decreeing a Chev, or any other brand.

On these Flatheads we start by slotting (elongating) all 4 cam gear holes, when we get the cam where we want it installed we tighten the bolts (we never use the OEM bolts).

We then slide the cam out of the block with the gear still attached and set it up in a fixture I made to install a SBC type pin (1/4"). The pin ends up getting pressed into in the cam and being a "slip-fit" fit for the gear.

Once the cam is in the fixture it's a 10 minute pinning job! I'll have a shot of this maybe sometime tomorrow! It takes about another extra 5 minutes if we want the "timing-pill" in the program. In this case the pin hole (only) in the cam gear gets drilled to accept the "pill" diameter after removing it from the cam. The other 4 now slotted bolt holes allow for the movement needed to locate the cam depending on the "pill" offset, 2*, 4*, 6*, or 8*.

We check every single build we do, always have. We drill the Chevy cam gears even before we start working with them, all 4 holes.

Thanks, Gary in N.Y.

P.S. Dale, these cams need to be moved, there is no "recommendations" on any of the cam cards where they want the cams, we wouldn't care anyway, we always put them where we know they'll work best, depending on the application!

[RalphM]

I’ve built plenty of engines, and as you say, I have never degreed a cam. So for us cam dummies, does the dial indicator on #1 cyl check for TDC? And how do you set your front needle point?

[frnkeore]

The general way of finding TDC, is to rotate the crank, only clockwise, while picking up locations.

Set the dial indicator on the piston and find the approx top of the stroke. Rotate again, set the degree wheel at 0, when the indicator gets to .100 BTDC, then rotate until it's at .100 ATDC. Divide the number of degrees by 2 and that is TDC. Next rev, stop the crank at that number and reset the degree wheel to 0.

You can use any number on the dial indicator but, .100 is covenant.

If you use a bump stop, you'll be close but, you won't be at TDC, because of the back lash, between the crank gear and the cam gear and that's why you only turn the crank CW.

You don't have to turn only CW but, if you don't, you have to go well past your locations and start turning CW again, to be sure you've taken the back lash out.

[Ol' Ron]

hen running the stock car,I would put star washers under the bolts on the cam.I found thet they never slipped. I often wondered how much of a difference, 3 or 4 degrees would make in any engine stock, street or race. Checked a few L-100's Most ee\were close enough to pass on, lazy I guess.

[Ronnieroadster]

Originally Posted by GOSFAST

Hi Ronnie, no different than decreeing a Chev, or any other brand.

On these Flatheads we start by slotting (elongating) all 4 cam gear holes, when we get the cam where we want it installed we tighten the bolts (we never use the OEM bolts).

We then slide the cam out of the block with the gear still attached and set it up in a fixture I made to install a SBC type pin (1/4"). The pin ends up getting pressed into in the cam and being a "slip-fit" fit for the gear.

Once the cam is in the fixture it's a 10 minute pinning job! I'll have a shot of this maybe sometime tomorrow! It takes about another extra 5 minutes if we want the "timing-pill" in the program. In this case the pin hole (only) in the cam gear gets drilled to accept the "pill" diameter after removing it from the cam. The other 4 now slotted bolt holes allow for the movement needed to locate the cam depending on the "pill" offset, 2*, 4*, 6*, or 8*.

We check every single build we do, always have. We drill the Chevy cam gears even before we start working with them, all 4 holes.

Thanks, Gary in N.Y.

P.S. Dale, these cams need to be moved, there is no "recommendations" on any of the cam cards where they want the cams, we wouldn't care anyway, we always put them where we know they'll work best, depending on the application!

Gary I stay focused and specialized i never do Chevy engines or as I call them agent orange engines. My specialty is and always has been Ford Flathead's. But i have and will do any HEMI type engines of course including ARDUN's daily driving a 426 HEMI is also fun.
Ronnieroadster

[Pete]

Here is how I do the cam timing adjust thing on a Ford flathead engine.
I use an early press on timing gear core, usually steel.
I put the crank gear on ONLY far enough to match the cam gear which I only press on about 1/16 inch at the factory marks.
I degree the cam per standard procedure.
If I need to move the gear, I pry it off, move it and knock it back on at the new location, then recheck it. It only has to be on far enough to not slip. 1/16 or LESS.

As far as knowing how far to move it requires some math.
The drive hub is 2.624 dia. so is 8.23 circumference. Moving the gear one way or the other 1/16 inch from the factory mark will give you 3 degrees. (Eyeball resolution)

After I determine the final location I drill and tap for a 1/4-20 set screw on the parting line of
the gear/cam.

[frnkeore]

I like the buttons and make my own.

Here are some of my spares. I keep them on a 1/4" dowel and use both 3/8 and 1/2" sizes. The black one is store bought.

If the 3/8 hole is not a press fit or, I need more advance/retard than the 3/8 bushing will yield, I ream the timing gear or sprocket, to .499 and drill and ream a new .500 dia bushing to position. In this way I can get any degree movement I want and not just +- 2*.

[frnkeore]

For the actual valve timing, you do it the same way. Put the indicator on the valve, as in GosFast picture.

Rotate until you get .100 (or what ever you want it to be), mark the degree wheel, rotate until your on the down side, at the same indicator number. 1/2 that is your center line, for that lobe, same on the other one. Then you count the number of degrees, between those CL's and you have the lobe center.

You count the degrees between piston TDC and valve TDC and that gives you the installed lobe center.

You can then, get your valve timing. Reset you indicator at 0 on the valve, rotate to .006 lift and then to .050, mark those and do the same on valve closing and you have your cam timing.

A lot of time and effort but, you will KNOW what you have and if the cam is what it is suppose to be and set as it should be.

You don't put the degree wheel on the cam, because the timing is all in crank degrees.

[frnkeore]

I know that it's a lot of info to take in, in one shot. It's the same for everyone!

Do it a few times and you'll always remember it. My first time at doing this was with a twin cam engine, in 1974, you have to set one cam, decreed properly, then set the other cam, to that cam.

Very, very frustrating for someone that had never done it and I think that's why I've remembered it, all these years.

[Pete]

Originally Posted by frnkeore

I know that it's a lot of info to take in, in one shot. It's the same for everyone!

Do it a few times and you'll always remember it. My first time at doing this was with a twin cam engine, in 1974, you have to set one cam, decreed properly, then set the other cam, to that cam.

Very, very frustrating for someone that had never done it and I think that's why I've remembered it, all these years.

Was the first time an Offy or a NOVI?

[frnkeore]

No, even though my dad worked for the owner of the Novi, I was a little young, at that time

My first time was with a Cosworth Twin Cam.

[Pete]

Originally Posted by frnkeore

No, even though my dad worked for the owner of the Novi, I was a little young, at that time

My first time was with a Cosworth Twin Cam.

A fine go fast engine.

[Tim Ayers]

As I've mentioned before, I have learned quite a bit having Ronnie build my engine. I was quite surprised to hear that the Potvin cam, as marked, would have been at 119 degrees v. 110.

Just stabbing a cam in and leaving it at 119 would created a horrible performing engine.

Being meticulous with what he does, Ronnie got it timed to be exactly 110 degree. He plugged and re-drilled the timing gear so it is dead nuts right.

The reason I mention this is I was left wondering how many cams are actually installed without being degreed and then a owner is disappointed and blames the cam.

Sometimes it is a poor cam choice, but I've wondered how many times it was just an incorrectly timed school that performed poorly.

[Pete]

Originally Posted by Tim Ayers

As I've mentioned before, I have learned quite a bit having Ronnie build my engine. I was quite surprised to hear that the Potvin cam, as marked, would have been at 119 degrees v. 110 as stated.

Just stabbing a cam in and leaving it at 119 would created a horrible performing engine.

Being meticulous with what he does, Ronnie got it timed to exactly 110 degrees and plugged and re-drilled the timing gear so it is dead nuts right.

The reason I mention this is I was left wondering how many cams are actually installed without being degreed and then a owner is disappointed and blames the cam.

Sometimes it is a poor cam choice, but I've wondered how many times it was just an incorrectly timed school that performed poorly.

I presume you are talking about lobe centerline. This can be diddled around.
The lobe separation angle can NOT be moved after the cam is rough ground.
The tag will indicate lobe separation angle MOST of the time.
The lobe center line is usually determined by the application of the engine.

A Potvin 425 has a lobe separation angle of 110.

[GOSFAST]

I brought this back (maybe for the last time?) to show the finished products.

You can see in the photo below the (.247") pin pressed into the cam and the corresponding hole in the cam gear (.248"/.249") to line it all up. If you look (very) closely you can also see the cam bolt holes are now "slotted" slightly to move the gear where it's needed. These particular pieces are for the "blown" unit, cam is now "in" where we want it when installed as seen.

At this point for this build we are done.

(Add) Not trying to say this entire procedure a "must-do" in order for the unit to run, if all is installed correctly (timing marks aligned) it will run, but when chasing HP (especially on the Flatheads) it's really the only way! And ALL builds should at least be "cam-degree" checked, this is "mandatory" here. It isn't all that difficult to just check where the cam's at.

Thanks, Gary in N.Y.

P.S. I'm adding this to show that when we've reached this stage it is really simple to go a step further and still move the cam more by simply drilling ALL 5 cam gear holes 13/32" and installing a "pill" (photo below also), same ones (most times) we use for the Chevy's we build, simple! No nonsense deal!

[40 Deluxe]

Originally Posted by frnkeore

The general way of finding TDC, is to rotate the crank, only clockwise, while picking up locations.

Set the dial indicator on the piston and find the approx top of the stroke. Rotate again, set the degree wheel at 0, when the indicator gets to .100 BTDC, then rotate until it's at .100 ATDC. Divide the number of degrees by 2 and that is TDC. Next rev, stop the crank at that number and reset the degree wheel to 0.

You can use any number on the dial indicator but, .100 is covenant.

If you use a bump stop, you'll be close but, you won't be at TDC, because of the back lash, between the crank gear and the cam gear and that's why you only turn the crank CW.

You don't have to turn only CW but, if you don't, you have to go well past your locations and start turning CW again, to be sure you've taken the back lash out.

Backlash? The only backlash involved in finding actual TDC with the positive stop method would be the oil clearance in the rod bearing! The timing gears are not involved in finding TDC. Since you're no doubt using very light checking springs, just hold the cam gear clockwise (against rotation) to take the backlash out when checking the cam timing.

[frnkeore]

As I was mauling this over last night, I remembered my first roller cam, that I installed in a Low Riser, 427, in 1969. It was a Chet Herbert cam (Father of the roller cam). At that time, I lived about 3 miles from his Anaheim shop so, I picked it up, in person and he told me how to set the cam timing. It didn't require anything but a indicator and a straight edge. At that time, he only made his cams to be installed "straight up" or "spit overlap", meaning that the cam lobe CL is at TDC.

He told me to find TDC, turn the cam, until the straight edge was level, across the lifters, on #1 and install the timing sprockets and chain.

Expanding on this way of setting cam timing, if you first find TDC as described, you can put a dial indicators on both in & ex valves (if the lift is the same) and turn the crank, until the valves are at the same reading and check the degree wheel to see if the cam is installed as it should be. Most FH cams are 0 advanced but, if not, the degree wheel will show you the amount of advance, to check against the cam card or factory spec.

If the lift is different between in & ex, you'll have to use lobe centers as described before.

[cmbrucew]

Frank
That is as simple as you could make it, and easy to remember.


Bruce

[frnkeore]

Originally Posted by 40 Deluxe

Backlash? The only backlash involved in finding actual TDC with the positive stop method would be the oil clearance in the rod bearing! The timing gears are not involved in finding TDC. Since you're no doubt using very light checking springs, just hold the cam gear clockwise (against rotation) to take the backlash out when checking the cam timing.

I did misstate that a little, regarding TDC but, my point was back lash and unless your working with a roller bearing crank, you do have back lash.

Since your going to have to use a dial indicator anyway, to get accurate readings, why not use it to set TDC?

[Pete]

Even a cave man can do it.

[frnkeore]

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Originally Posted by Pete

Even a cave man can do it.

Yes, I can

[bobH]

Bottom line of this discussion... I can no longer build engines. (After 65 years of not attending to these details.)
Great read, by the way.

[Tim Ayers]

Originally Posted by bobH

Bottom line of this discussion... I can no longer build engines. (After 65 years of not attending to these details.)
Great read, by the way.

Haha. It is pretty crazy all the details that go into doing a engine dead nuts correct.

[JSeery]

Originally Posted by bobH

Bottom line of this discussion... I can no longer build engines. (After 65 years of not attending to these details.)
Great read, by the way.

It's not that they can't be built without checking things, it's just that it might not (and that is more like most probably) run as well as it would with everything dialed in.

[Ol' Ron]

I love it, someone that understands the simple way to check a cam. "Split overlap". Learned that in a shop cals in school. Some old engines didn't have any marks. However, I do like to advance the 400jr on a short track. Comes off the corners like a rocket. A good friend taught me that. That might be a good thing to do with the L-100. Never thought of that 8* would be enough

[Bored&Stroked]

RE: Since your going to have to use a dial indicator anyway, to get accurate readings, why not use it to set TDC?

The reason that many advocate for the positive stop method of finding TDC is due to the amount of piston dwell (in crankshaft degrees) at TDC. In other words, there are a few degrees of rotation where the dial indicator doesn't show movement. One could think they are at TDC with the crank actually being in a slightly different position than the dial indicator shows. So, this causes your TDC "pointer" to be off just a bit.

You can always use BOTH methods - so that your cross-validate one against the other . . . to achieve your final pointer setting.

When I use a dial indicator only, I have to visually pay attention to the "before/after" movement of the crank to figure out where TDC is. Hopefully I'm making some sense . . .

[Bored&Stroked]

Another Setup Method: One of the best ways to initially install a cam is very simple (assuming you have adjustable timing gears and a dial indicator):

1) Setup your TDC and pointer (this is needed for all timing tag related work)
2) Read the timing tag, at what degrees of crank rotation does it show the .050 profile intake lift to be at? (On the intake it is usually a BTDC degree value)
3) Rotate the crankshaft so it is at exactly the degree value shown for the .050 lift on the timing tag.
4) Install the camshaft/gears and one lifter for the corresponding cylinder - such that you are at .050 lift for the specified intake lobe. (Using the dial indicator to directly read the cam profile off of the lifter).
5) Lock the cam down at .050 lift.


If the timing tag says here is where the crank should be at .050 intake lobe lift, then you do exactly that and given the above approach, the rest of the numbers should match.

Now that you've installed the cam to match the .050 lift and crank degrees . . . check to see that it is at the correct place on both opening/closing events (both lobes).

I've used a lot of adjustable cam drive systems on various engines (flatheads and OHVs) - the above method is the easiest way to consistently setup the cam . . . and it should match the tag for both lobes on both the opening and closing ramps. If it doesn't match the tag - then I know the cam is incorrectly ground and I cannot "fix it".

Also, if you want to 'advance/retard' the timing, then once again you can use the above method - just move the initial crank degrees to do what you need/want.

There yah have it . . . another man's method . . .

B&S

[Frank Miller]

I've been aware of this but have never done it as it is not in the factory manuals. B&S made it sound easy as you just need to get one number and either it all lines up or the cam is incorrectly ground. Now I have the question, have any of you ever gone through every lobe in the cam checking for specs? Amazing seeing how much some of these are off.

[frnkeore]

Originally Posted by Bored&Stroked

RE: Since your going to have to use a dial indicator anyway, to get accurate readings, why not use it to set TDC?

The reason that many advocate for the positive stop method of finding TDC is due to the amount of piston dwell (in crankshaft degrees) at TDC. In other words, there are a few degrees of rotation where the dial indicator doesn't show movement. One could think they are at TDC with the crank actually being in a slightly different position than the dial indicator shows. So, this causes your TDC "pointer" to be off just a bit.

You can always use BOTH methods - so that your cross-validate one against the other . . . to achieve your final pointer setting.

When I use a dial indicator only, I have to visually pay attention to the "before/after" movement of the crank to figure out where TDC is. Hopefully I'm making some sense . . .

It's true, that when you get very close to TDC, the indicator slows way down but, at .100, it's still moving at a rate that you can see. If your uncomfortable, at .100, you can use any distance, such as .300 or even .500. The number you pick, doesn't make any difference, it only has to be used on both sides of TDC. The slower the indicator moves, the easier it is to stop it at the distance that you want.

Also, you don't have to set up a stop, when using the above method but, you still do, have to set up a indicator to check the timing. One less tool and thing to do, plus a more accurate TDC setting.

Regarding checking all cylinders for timing, I haven't heard of anyone doing that. For the layman, by the time that you've done #1, your probably not interested in doing others but, for the ambitious, it would be good to check #4 in the firing order.

[Ol' Ron]

To Find TDC with a dial indicator, I run the piston up until the piston goes past TDC bt .1--". Mark it. now go back until the piston goes back down .100" mark it. TRU TDC is between the two marks. Just liker the tie wrap.

[Bored&Stroked]

My positive stop is a big-ass washer and a 7/16 coarse bolt . . . the crown of our domed pistons will hit the hard washer stop and you now have a "dead stop".

Two is Better Than One: I always double check TDC - with both a positive stop and the dial indicator . . . helps me sleep at night. Of course I also mark my front pulley in 5 degree increments - from 0 to 30 degrees BTDC (for future ignition timing settings).

Cam Gear Mesh, Thrust and Backlash: Depending on what year flathead you're building and what type of cam gears 32 - 48 versus 49-53 . . . the cam thrust will vary. On 32 - 48 engines the cam thrusts toward the block - on 49-53 it thrusts toward the timing cover. The reason this is important is that in order to get accurate cam timing events, you need to know that the cam is fully against the block - or fully against the cover. On 49-53 engines it tends to "walk" away from it. This screws all your calculations up if you don't have the cover on!

So, on a 49-53 engine it is really best to have the timing cover in place (with the correct backlash amount) before you do all the cam timing work. As the timing will change as the cam walks forward. You really want the cam to be touching the cover before you start doing all your timing checks. On earlier engines, I use a small rubber mallet to tap the cam gear - making sure it is flush with the block.

Timing Cover Gaskets: On a side note, make sure your timing cover gasket is the correct thickness! I've seen gasket sets from Speedway that have timing cover gaskets that were about .0245 thick - the correct/stock gasket is .0145 thick. By using the Speedway gasket, you've now increased the cam backlash by .010 - that is not good. This also effects your cam timing as the cam can now move forward an additional amount (more than it should) - and since the gear teeth are angled, the cam rotates as it comes forward and the timing changes.

In the end, the little stuff matters . . . . but Hey, I'm a tad bit of a perfectionist! LOL

Good luck,
B&S

[Lawrie]

On an 8ba it will also effect the ign timing.
Lawrie

[Frank Miller]

Originally Posted by Lawrie

On an 8ba it will also effect the ign timing.
Lawrie

Not an 8ba because the distributor is times to the crank with a light. The earlier motors it might be a problem because the distributor is timed on a machine and fitted to the cam. You've raised a good point thought about how changing the cam timing might change the engine timing.

[Bored&Stroked]

Originally Posted by Frank Miller

Not an 8ba because the distributor is times to the crank with a light. The earlier motors it might be a problem because the distributor is timed on a machine and fitted to the cam. You've raised a good point thought about how changing the cam timing might change the engine timing.

What he is probably talking about is that by having too much backlash, this allows the camshaft to move in/out by more than Ford intended (in the discussion, another .010 or so). The "normal" backlash is around .004 to .007, so by increasing the backlash, your allowing cam timing to change/move and the same with the final ignition timing.

To give you an idea about how this is important, on a recent 383 SBC build (high horsepower street engine), when we had it on the dyno, we noticed that the ignition timing was moving around by about 3 - 5 degrees - when it should have been at a steady state. It so happened to have an adjustable timing cover (nice Cloyes piece) - where you can externally set/control the backlash of the cam.

We tightened down the cam button just a bit and the timing then steadied as it should have. What started our checking was that we were getting inconsistent dyno pulls - HP was fluctuating about 15 - 20 HP . . . we needed to figure out why. The 'why' was the backlash. Now to bring this in context, this engine makes 520 HP . . . more than 5 times a stock 59AB.

[Mike51Merc]

I still find it hard to believe with all the emphasis on precision (especially in engine building) that a cam could be designed, cast, and machined that doesn't conform to spec in the most elementary way. What's worse is that obviously it happens enough that cam degreeing is a routine part of engine building. Is it really so hard to machine it in line with the spec?

Makes me wonder about other faults that are out there.

[GOSFAST]

Originally Posted by Mike51Merc

I still find it hard to believe with all the emphasis on precision (especially in engine building) that a cam could be designed, cast, and machined that doesn't conform to spec in the most elementary way. What's worse is that obviously it happens enough that cam degreeing is a routine part of engine building. Is it really so hard to machine it in line with the spec?

Makes me wonder about other faults that are out there.

Hi Mike, you would not believe what we see here EVERY day, day in and day out, not only on these Flatheads??

I'll have more to add about the original topic, with respect to "controlling" the overall end play, a bit later today! Absolutely no different when building a SB or BB Chevy with a roller cam in the older units, with a cam button, end play MUST be "controlled". We set these at .003".

Read the P.S. below, this issue discovered yesterday has totally stopped us from assembling a forum members build. Of 4 Flathead builds going on at the moment two had a number of issues beyond our control and the other two we haven't begun assembling yet!

Thanks, Gary in N.Y.

P.S. Went to install a Speedway/Offenhauser "custom" timing cover on a "blown" unit here and discovered there is no way it's going on w/o some very major "surgery", I can't even get it started to go! The other issue I mentioned above was with a 100% defective pressure plate from a respectable clutch builder (they had to replace it, more downtime for us), you just can't take anything for granted, ALL must be scrutinized closely.

[Bored&Stroked]

I hear yah Gary . . . one has to check everything and there are usually issues to solve. This is why you can rarely build an engine and everything just "bolts up" and has the correct clearances . . . just doesn't happen!

Great Example: Friend bought a re-pop Winfield SU-1A cam and I was going to help him install it (new engine build). In my initial look at it, the journals seemed a bit small - so I took out my 1" - 2" mic . . . yep, .010 undersize. I check everything - regardless of where it came from or what I want to believe . . .

Many folks/shops would not even have checked it . . . then wondered why the oil pressure was very low with STD cam bearings!

Tis the nature of the beast . . .

[Ronnieroadster]

Originally Posted by Bored&Stroked

I hear yah Gary . . . one has to check everything and there are usually issues to solve. This is why you can rarely build an engine and everything just "bolts up" and has the correct clearances . . . just doesn't happen!

Great Example: Friend bought a re-pop Winfield SU-1A cam and I was going to help him install it (new engine build). In my initial look at it, the journals seemed a bit small - so I took out my 1" - 2" mic . . . yep, .010 undersize. I check everything - regardless of where it came from or what I want to believe . . .

Many folks/shops would not even have checked it . . . then wondered why the oil pressure was very low with STD cam bearings!

Tis the nature of the beast . . .

Dale great example of why when someone wants a Flathead built they really need to go to the experts who know what to do. Not just the local machine shop that on occasion will build a Flathead in between a Chevy, Toyota or Honda builds especially when its a modified Flathead. Heck decades ago i ran into an Isky cam new out of the box with .010 under cam bearing journals of course discovered after the crank assembly was already installed! Ford dimension 1.7955 is etched into my memory for just this reason. Lesson learned measure cam before installing cam bearings. This talk about cam end play is interesting my solution is simple check end play without cover gasket prior to assembly most of my builds do not have cover gaskets to help on this movement issue just something I always do.
Ronnieroadster

[RalphM]

P.S. Went to install a Speedway/Offenhauser "custom" timing cover on a "blown" unit here and discovered there is no way it's going on w/o some very major "surgery", I can't even get it started to go!

I had one of those covers several years ago tried to put it on and never could get the damn thing to fit right.

[Ol' Ron]

I find that cam backlash is pretty bad on the 8BA cams, I've found as much as .022", The 59 covers , if not worn to bad can hold closer tolerance. I never use the cover gasket. On the 8ba cam you have to put a shim behind the dist drive gear. I always use the early timing gears, this puts the thrust against the block under all engine operations. I didn;t realize this untill we switched to an 8ba cam in the stock car..
Learn sumpin every day.

[GOSFAST]

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When you're ready to begin the actual (final) assembling of the build the very first item to begin with is the installation of the camshaft. If it's not going to go in and turn correctly you want to know this way before any other pieces are installed.

When we do cam brg installations here on any builds we check every one with a an older cam blank with the lobes taped up so as not to mark up the new brgs. we don't want any calls AFTER the fact!

Below here is a few shots of the cam end-play being checked and addressed, you can see the dial indicator (not really able to read it) showing the EXACT amount of movement, on this build it has .005" clearance, "dead-on".

If you look closely you can see the "nylon" cam button in the photos below fitted to the cover to keep it all in place.

Thanks, Gary in N.Y.

P.S. The first 2 shots show the dial indicator, the second 2 show the button separate from the cover and then installed sitting in place! This was all checked with the timing cover gasket in place and all 5 cover bolts tightened!

[Ronnieroadster]

Originally Posted by Ol' Ron

I find that cam backlash is pretty bad on the 8BA cams, I've found as much as .022", The 59 covers , if not worn to bad can hold closer tolerance. I never use the cover gasket. On the 8ba cam you have to put a shim behind the dist drive gear. I always use the early timing gears, this puts the thrust against the block under all engine operations. I didn;t realize this untill we switched to an 8ba cam in the stock car..
Learn sumpin every day.

Ron the idea the early cam/crank gears thrust towards the block being a good idea is not what it seems. Without anything else in the assembly thats exactly what happens thrust is rearward into the block. However when add in the oil pump idler gear and the oil pump you will find the cam is now trusting forward. Testing this was a surprise to me again I learned something new but that was a very long time ago now.
Ronnieroadster

[Ol' Ron]

Ron & Gray
Like I say learn sumpin every day. I like the method you use for the cam thrunt and never considered the oil pump drive. It's amazing how much there still is to learn about these engines. I wonder if my new port will work?

[Bored&Stroked]

Given my expeience with the Cloyes adjustable SBC timing cover, I think if/when I built another 8BA I will make an adustable "button" with a bearing in it - that way I can get exactly the end-play/backlash that I want and with the engine running (or on the dyno), I can actually adjust it if needed. I was VERY happy to have that timing cover on the SBC - it saved me from having to screw around with a cover that only allows pre-adjustment/setup of the backlash - not after it has actually ran a bit.

[V8COOPMAN]

Originally Posted by Frank Miller

…... or the cam is incorrectly ground. Now I have the question, have any of you ever gone through every lobe in the cam checking for specs? Amazing seeing how much some of these are off.

It can be EXTREMELY amazing! I bought a brand new "151" 350 HP Chevy cam across the local Chevy dealer's counter about 1968. I threw it in a little 283 I rebuilt for a friend's '61 Vette. Had hell trying to initially set some of the rocker arms. That thing wouldn't crank for nothin'. We even tried pulling it...notta! After much butt-scratching, I pulled the cam back out and laid it beside the stock cam. NINE lobes out of sixteen were ground nowhere near where they were supposed to be on that stick. Only after finally convincing the guys at the Chevy house to lay another cam beside this one did they believe that this cam came from the manufacturer ground this way. DD

[GOSFAST]

Originally Posted by Bored&Stroked

Given my expeience with the Cloyes adjustable SBC timing cover, I think if/when I built another 8BA I will make an adustable "button" with a bearing in it - that way I can get exactly the end-play/backlash that I want and with the engine running (or on the dyno), I can actually adjust it if needed. I was VERY happy to have that timing cover on the SBC - it saved me from having to screw around with a cover that only allows pre-adjustment/setup of the backlash - not after it has actually ran a bit.

Hi Dale, do yourself a great favor and get away from using cam buttons at all, all-in-all they are a "headache" to setup (time-consuming) and just more "moving" parts in the unit (this is assuming you use the roller buttons like we use to)!

P.S. If you have time here's a method we actually devised over here to eliminate the buttons in the early SBC's, we set them up like the later OEM roller units with the stepped-nose cams and the thrust plates. We've actually sold dozens of the installation kits so far, containing ALL the necessary tooling/components to set up the early blocks with the stepped-nose cams, mostly to other machine shops. No more "adjusting/measuring/shimming", put the cam in, bolt on the thrust plate, throw on the timing chain, and you've got your .003"/.004" end play! If you have time follow this link here, the entire story is over on the Chevelle site! Makes no difference anymore which timing cover you use!! We've built "dozens" already with our method.

https://www.chevelles.com/forums/18-...t=postusername (It's the second "sticky" down)

[Pete]

Originally Posted by V8COOPMAN

It can be EXTREMELY amazing! I bought a brand new "151" 350 HP Chevy cam across the local Chevy dealer's counter about 1968. I threw it in a little 283 I rebuilt for a friend's '61 Vette. Had hell trying to initially set some of the rocker arms. That thing wouldn't crank for nothin'. We even tried pulling it...notta! After much butt-scratching, I pulled the cam back out and laid it beside the stock cam. NINE lobes out of sixteen were ground nowhere near where they were supposed to be on that stick. Only after finally convincing the guys at the Chevy house to lay another cam beside this one did they believe that this cam came from the manufacturer ground this way. DD

You might have had a cam for a left hand marine engine. Some were gear drive, some were chain drive. In either case the lobes were in different locations from a standard right hand automotive one.

[V8COOPMAN]

Originally Posted by Pete

You might have had a cam for a left hand marine engine. Some were gear drive, some were chain drive. In either case the lobes were in different locations from a standard right hand automotive one.

Purchased from Knapp Chevrolet, Washington Ave., Houston.....they don't sell boat parts. Plus, it had the correct "3863151" part number on the tube. DD

[JSeery]

V8, the supplier/manufacture could have mixed them up?

[Pete]

Originally Posted by V8COOPMAN

Purchased from Knapp Chevrolet, Washington Ave., Houston.....they don't sell boat parts. Plus, it had the correct "3863151" part number on the tube. DD

My local Chev dealer sold a cam to my customer once. The box had been opened at some point and a new gear drive marine cam exchanged for the original one in the box. Who knows why but guess how I can relate to part of your story.

[Ol' Ron]

Monday morning cam

[Bored&Stroked]

Originally Posted by GOSFAST

Hi Dale, do yourself a great favor and get away from using cam buttons at all, all-in-all they are a "headache" to setup (time-consuming) and just more "moving" parts in the unit (this is assuming you use the roller buttons like we use to)!

Hey Gary - good idea! I used a similar technique on the FlatCad engine for Bonneville - using a Timken thrust bearing and my own thrust plate - then I put a BBC Chevy nose on the cam and ran a Donovan gear drive. I much prefer a thrust setup like this - over anything that uses the timing cover.

I'll checkout your link - seems like a good way to go on any SBC/BBC type engine. Thanks!

[Desoto291Hemi]

Gary I am glad to hear this now.
I have degreed every cam I have ever used,,,,but I have never owned a Flathead before.
I just assumed they were doweled already to the cam gear.

Didn’t Isky do this already?
I can’t believe no one has ever done a kit with a cam gear already drilled for a dowel to set the cam timing advance.
Man,,,I am glad I came here,,,already learned a few things,,,no longer than I have been here.

Tommy

[GOSFAST]

Originally Posted by Desoto291Hemi

Gary I am glad to hear this now.
I have degreed every cam I have ever used,,,,but I have never owned a Flathead before.
I just assumed they were doweled already to the cam gear.

Didn’t Isky do this already?
I can’t believe no one has ever done a kit with a cam gear already drilled for a dowel to set the cam timing advance.
Man,,,I am glad I came here,,,already learned a few things,,,no longer than I have been here.

Tommy

Hi Tom, many of the procedures we do no one else in the country is doing to the best of my knowledge anyway??

Here's a few:

We pin the heads/gaskets to the blocks, same as a SBC (we do this with the block plate that we use to finish-hone every block we build). This keeps the heads from "moving around"?

We set up the cam up with a "pin and (sometimes) a pill", also the same as the SBC, makes moving (degreeing) the cam a simple task.

We install bronze-lined guides/stainless valves in EVERY build we do here along with some "Viton" valve stem seals on the intakes!!

We use "Teflon" coated cam brgs (when needed to tighten up cam brg clearances some).

We do the oiling modification to the blocks to run a "real" remote oil filter. This is done by others.

More recently (in the last couple months) we began modifying the dipstick mounting brkts on the pans to be 100% removable from the outside without "dropping" the pan! I can all but guarantee the original gasket is about disintegrated? This is something you'll never know unless you remove the OEM rivets!

An oversea's member here just ordered a kit to modify his!

There's probably more but that's about all I can think of tonight!

Thanks, Gary in N.Y.

P.S. On a side note here I see you're into the early "Hemi's", just did a 341"/345 HP (I believe) from a '57 Desoto? Have also been talking to my friend at "Topline" (the original Johnson adj tappet mfr) about doing a hyd-lifter Flattie, not sure it will ever happen, but I've been kicking it around! We could pull it off here, I know it, I'm just running low on time!! I have another member's build here now with so many issues with some of the aftermarket parts (alum timing cover/Mallory distributor), these were supplied by customer, I'm not certain tonight we can even use them? These are for his "blown" unit.

[Desoto291Hemi]

I will be communicating with you soon.

Sorry,,,I don’t mean anything by this,,,,but your in Long Island,,,,,what n the world is a Flathead shop doing in Long Island,,,,Lol?
Man,,,I can’t believe it.
I remember reading some stories years ago about a lot of Mopar guys in New York and Jersey,,,and having a lot of Hemi stuff,,,they were really cool guys too!
But,,,Flatheads,,,,,man I am blown away,,,,Lol
You seem to really know your stuff too,,,,no BS artist.

I will definitely contact you for some help soon.

Tommy