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Found my camshaft! - Pulling motor on 1948 Dodge.


Bryan

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Trying to learn about camshafts now. Some stuff I'm seeing (from others).  Not saying it is true.  -> Use special cam lube, not assembly lube. For cam break in, run at engine 2500 rpm or so for 20 minutes.  Keep seeing mentions of Zinc additive break in oil for cams.  Stiffer springs cause more wear.  Radically higher lift causes faster wear.  Seeing warnings not to use old lifters on a new camshaft, lifters/tappets probably would need to be resurfaced.   Seems like modern lifters are crowned, and cam lobes are tapered to make lifter rotate.  Older tappets are flat, but offset on lobes to spin the tappet.   Longer duration shifts power & torque to higher RPM point.  Too long of duration makes car idle rougher.  Increased lift doesn’t affect RPM point.

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I have deduced that to an extent, valve timing can be adjusted a little by setting tappet clearances. A tight valve opens earlier. A loose valve open later. Valve timing has a large impact on torque. I’ve experienced it when re-setting valves. 
 

As engine rpm’s increase incoming air/fuel mixture has less and less time to  get down into the cylinder. Spent gases hot to get out.  By changing valve timing and overlap you can change where the rpms make the most torque. 1/4 mile cars run wide open. I’d think they want torque higher up the tach.  An RV is a big heavy unit that doesn’t generally handle that great at speeds above 60. Makes more sense to have the most torque at a lower rpm. 
 

I suspect cam timing and changing the torque curve is sort of like playing with gearing. If you change the gear ratio for lower rpms at hi-way travel, then you lose torque at low rpms. The engine makes a max peak torque. What rpm would you like it at?

 

Someone moves the torque curve with a cam. Then they want to widen ithe curve out. So they try to make more engine power. Headers. Dual exhaust. Then they want quicker revving. Lighten the flywheel. Aluminum rods and pistons. Twin larger CFM carbs. Then change the gearing. Now the spark is too weak. New ignition. Shave the heads. Raise the compression. Now it runs too hot. Larger rad. Electric fans. Now the clutch keeps slipping and burning up. Bigger clutch. Later the tranny and drive lines start failing. Swap all that out. Then the diff blows up and axles twist. (yes very unlikely with a flathead 6)  On and on. You get my point.  Its a fun hobby. But boy can you ever go down a rabbit hole. 
 

The original engineers got it set up pretty well for what it was designed to do. Shuffle the average person or family around. I chose stock. Higher performance is fun too.  Just takes deep pockets. 

Edited by keithb7
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Lot's of monkey see, monkey do on the internet.  As in we don't know why we are saying/doing this but everyone else is saying/doing it so we will too.

 

Let's take the points one at a time with my opinions on those thoughts.  These thoughts are backed by research for the most part, observation in others and common sense.

 

Point one. Use special cam lube.  Never used it in the cams I have installed.  I have used moly grease on the lobes and pushrod tips.  I've used STP oil treatment poured on the lobes as well and just oil on the pushrod tips.  Looking at the FSM for the era, nothing is said about any special lube needed.  Looking at my 73 FSM, latest one I have available, it says this

 

Quote

Installation
(1) Lubricate camshaft lobes and camshaft bearing journals and insert the camshaft in cylinder block
(Fig. 30).
Whenever an engine has been rebuilt and/or a new camshaft and/or new tappets have been installed, add
one pint of Chrysler Crankcase Conditioner Part Number 3419130 or equivalent to engine oil to aid in
break in. The oil mixture should be left in engine for a minimum of 500 miles, and drained at the next normal oil change.
When replacing camshaft, all of the tappet faces must be inspected for crown with a straight edge. If
any negative crown (dishing) is observed, tappet must be replaced. The tappet must have a definite crown.

 

Point two.  Zinc additives.  No idea what is in the Chrysler Crankcase Conditioner Part Number 3419130 mentioned above, but that's from the era of "high zinc" oil.  Will it hurt?  Here's a link to get you started thinking.

 

https://www.onallcylinders.com/2018/08/10/ask-away-with-jeff-smith-can-i-mix-zinc-additive-with-off-the-shelf-motor-oil-to-save-money/

 

As for me, I just use modern 10w30 detergent oil.  It gets the job done with my stock engine.  No additives, no special high zinc oils.  But remember, if I am wrong it's my wallet that will pay for my oil choices in my engine.

 

Point three.  Stiffer spring causing wear, true.  Especially when you consider that the spring pressure at the lifter/cam interface is multiplied by the rocker ratio on an OHV engine.  According to the 57 Dodge FSM the valve springs used in the flat head six have a rating of 110-120 pounds, open.  Hardly any pressure compared to today's stuff.  Remember even if an OHV engine using the same open rating the pressure felt at the lifter/cam interface is multiplied by the rocker ratio.  With our stock stuff that's not an issue.  The higher lift claim ties in here as they require stiffer springs to control the valve train.

 

Point four.  Reusing lifters.  See the quote from the 73 FSM, for stock applications but basically it says if it has a crown it's good to reuse.  So much for not using old lifters on new cams.  Lifters are offset from the cam lobes, that is what makes them spin and prevents wear in one spot.  Cam lobes are also tapered to encourage rotation. 

 

Point five.  Camshaft duration.  More duration increases over lap with the same lobe separation, this is what contributes to idle roughness.  If you widen the lobe separation you can mitigate that.  Modern OEM cams have as much as 114 degrees of lobe separation, whereas race cams have gotten down to 106 degrees.  We do not need high speed power for the most part, George Asche's rail aside.  I have no idea what the lobe separation is on our cams though.  Just remember, more lift will mean more duration, it's part of the geometry.  You can mitigate that by spreading the lobe separation, to a point and that is hard to do on a regrind.  Everything about cam design is a balancing act.

 

One final note on the subject in general.  I have talked with old time dealership mechanics that state they never used any special lubes or replaced used lifters that passed the crown test when doing warranty cam changes.  Nor did they do a break in period on the new cams and neither did the factory.  They never made a point of having the customer come back in at 500 miles for an oil change either.  Those guys are paid flat rate for warranty work and they don't get paid to redo their mistakes.  So they do what has to be done and none of what is not required.  Anecdotal but interesting. 

 

All of the above opinion applies to the OEM cams in our engines.  It does NOT apply to someone using a .600" lift cam with high ratio rockers in a race engine.  I would probably apply all of the above to anything under .500" lift at the valve even on my V8's.  As for the flat heads, you aren't going to see much above .400" lift, if that, even with the hot rod cams commonly found for them.

 

I believe most of the mantras involved in a cam change came from the racing world where those guys are using monster cams with monster springs and since the racers do it then it must be what a street cam needs too.  Nope.  Can you do it?  Yep, will it hurt, probably not, with the caveat about adding an additive and the hit to your wallet.  Cam manufacturers tell you these things as a no thinking required guide to all cam break ins.  You start giving people a "if this, then that" option and some rube will mess it up.

 

The flip side to that is if you don't do it and you wipe a cam it will cost a lot more than following the mantras.  That said, I don't do the mantra.  But I run real mild cams, well under .500" lift. 

 

 

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Los gets up on his soap box and shakes a fist at cheap Chinese steel  :D

 

I just feel that when Americans were running our own steel mills and making these cars, we did not have the same problems of modern day parts.

Seems almost everyone on youtube is complaining about wiping out new cams. I think Uncle Tony wiped out 2 of them on bottle rocket and now going to a more modern roller cam setup. No idea if that will be any better.

 

There is also talk about possibly the new cheaply made lifters may have failed. Thus wiping out the lobe on the cam.

 

Same time many people have not had any problems ..... Who knows ... 

 

I think many want to follow the guidelines with adding zinc, 20 min break in period, whatever the cam manufacturer says.

Hoping to be covered by a warranty if something goes wrong.

Same time the manufacturer has enough steps they can probably find a loop hole somewhere to claim you did not do it it proper order or skipped a step etc....

 

I think I would rather find another used lifter to use then replace with a new one, same with the cam. Have it reground if wanted, but still using the original steel.

But that only applies to these old flatheads .... A modern engine I am not sure what I would want to do.

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1 hour ago, keithb7 said:

The original engineers got it set up pretty well for what it was designed to do. Shuffle the average person or family around. I chose stock. Higher performance is fun too.  Just takes deep pockets. 

Yep, that's why if I change anything it will be close to stock. That's why I was looking for the specs of this "later cam".  If I send my cam off, it won't be to change the duration. Raise the lift to about what the last cam Dodge made for these, make sure the lifts are exact (think intake and exhaust are different) between lobes.  Got to chuckling over one think I read that was a Duh moment. You can't raise lift more than the difference between a fully compressed spring and fully open spring, and then you can have a lot of stress and problems (other than clearance issues).

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I am in agreement with almost all that has been said regarding the differences in valve train issues with flatheads, ours and all similar, versus OHVs. 

 

One thing not mentioned that I am really careful about is the importance of keeping lifters and cam lobes paired.  I never have nor will I ever put a used lifter on any cam lobe other than the one it has been running on.  When I remove them they go into a 2x4 with numbered holes so they can be returned to the same spot. 

 

If for some reason, I can't use a matched set cam and lifters, they go to a machine shop for regrind/resurface, or at least check and polish.  A local large scale rebuilder does that as a matter of course on all their products and did my last 230 cam and lifters for like 60 bucks.

 

I've only had one cam/lifter failure on an engine I assembled and that was back in the mid 60s when I didn't follow that rule on a 312 for Dad's wrecker.  OHV, but all stock, low tension lifters.  One of the old ones had a chipped edge, they are mushroom lifers, like our flatheads.  So I put in a used one.  Lasted less than a week.

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Your comment on Zinc reminded me of what I read in that blog I had listed before  MOTOR OIL ENGINEERING TEST DATA | 540 RAT - Tech Facts, NOT Myths (wordpress.com)

"This from the Brad Penn Oil Company:
There is such a thing as too much ZDDP. ZDDP is surface aggressive, and too much can be a detriment. ZDDP fights for the surface, blocking other additive performance. Acids generated due to excessive ZDDP contact will “tie-up” detergents thus encouraging corrosive wear. ZDDP effectiveness plateaus, more does NOT translate into more protection. Only so much is utilized. We don’t need to saturate our oil with ZDDP." 

 

And I think he had a section showing specific oils that did worse with a zinc additive.

 

On the flat surface tappet vs crowned ones, I had the impression that the modern lifters had the crown, and our flathead motors tappets were flat but offset on the cam lobes.  The FSM 73 I'm assuming is for modern engines?   I'm wanting to concentrate more on our flatheads.  When I first read the info I listed thought the crowned tappet was ours, but don't think so.

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5 hours ago, keithb7 said:

I have deduced that to an extent, valve timing can be adjusted a little by setting tappet clearances. A tight valve opens earlier. A loose valve open later. Valve timing has a large impact on torque. I’ve experienced it when re-setting valves. 
 

As engine rpm’s increase incoming air/fuel mixture has less and less time to  get down into the cylinder. Spent gases hot to get out.  By changing valve timing and overlap you can change where the rpms make the most torque. 1/4 mile cars run wide open. I’d think they want torque higher up the tach.  An RV is a big heavy unit that doesn’t generally handle that great at speeds above 60. Makes more sense to have the most torque at a lower rpm. 
 

I suspect cam timing and changing the torque curve is sort of like playing with gearing. If you change the gear ratio for lower rpms at hi-way travel, then you lose torque at low rpms. The engine makes a max peak torque. What rpm would you like it at?

 

Someone moves the torque curve with a cam. Then they want to widen ithe curve out. So they try to make more engine power. Headers. Dual exhaust. Then they want quicker revving. Lighten the flywheel. Aluminum rods and pistons. Twin larger CFM carbs. Then change the gearing. Now the spark is too weak. New ignition. Shave the heads. Raise the compression. Now it runs too hot. Larger rad. Electric fans. Now the clutch keeps slipping and burning up. Bigger clutch. Later the tranny and drive lines start failing. Swap all that out. Then the diff blows up and axles twist. (yes very unlikely with a flathead 6)  On and on. You get my point.  Its a fun hobby. But boy can you ever go down a rabbit hole. 
 

The original engineers got it set up pretty well for what it was designed to do. Shuffle the average person or family around. I chose stock. Higher performance is fun too.  Just takes deep pockets. 

 

Keith, I think that's why some of us are so eager to compare OEM parts. Yes, Mopar had a lot of great engineers when they were designing the flathead 6, with a lot of resources to find a good balance of performance, economy, durability, drivability. But they didn't get it perfect, and material science, oil tech, consumer habits, road conditions and average speeds changed dramatically from the '30s to the mid '50s. So they made incremental improvements every few years. 

 

As a hobbyist, I don't have these resources. The big aftermarket guys who do are 55% racing based, 40% profit driven and 5% total bull.

I wish magazines did 1/2 throttle Dyno pulls along with their full power ones to better show what improvement is made ALL the REST of the time you are driving.

 

I do want to drive my car fairly frequently, wherever I want to go, with my family inside, in the modern world. So what do I do? I look at Mopar's most modern versions with 8-1 Cr and improved cams. I look at their success with heavy trucks with highrise dual carbs and balanced dual exhaust. I look at the overdrives they offered as options, once highway driving became more common. Or the larger brakes they put on the heavier, more expensive cars. 

Done carefully, these are all factory proven improvements that apply to "daily driver" cars. They can also be much more affordable than the Racing/street rod stuff, and often with better results for actually use. I am sure we all know that guy with the fastest car that never leaves the garage.

 

Frankly I am far less worried about the consequences of getting a 50 year old cam profile to match my dual carbs and "high" compression than I am with some of the homebrew disk brake and front suspension clip swaps guys act so nonchalant about....

 

We are also blessed to have a guy like George Asche, who has so much knowledge building these cars and engines. Everything from near stock, road racing and all out drag racing, he has years of experiments and experience, that he is pretty happy to share. 

 

 

Edited by FarmerJon
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21 hours ago, Sniper said:

I registered yesterday, still not able to access it.

Registration done, but from what I'm finding now you have to be a Subscriber and not just register to access archived content more than 3 years old. Pretty well a dead site, hardly any posts since 2018.

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  • Bryan changed the title to "Law of last one" - Pulling motor on 1948 Dodge.
44 minutes ago, Sniper said:

Looking at the remains, it appears it was cracked to begin with.  I have two the machine shop will have to deal with.

I've got a set of new left hand nobibdium (spelling) drill hog bits.  Might try that but not an extractor.

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That was as far as I wanted to go. Mostly drilled out. Next bit I had fit exactly in the other threaded holes. Didn't want to mess up the threads.  Tried an extractor but the one I have wasn't all that great. Couldn't get it to start. Last pic is my workshop.

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2 hours ago, Sniper said:

As thin as that is now you could probably run a cutting tap of the correct size in there and take the remainder out.

It looks weird but it's not paper thin. The remaining sleeve actually goes almost to the recessed area diameter. The dark color is from the drill bit. Probably 1/16 thick or more.

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Got the core plugs and water distribution tube out. The distribution tube pulled out very easy with vise grips.  The last three holes were stopped up.   On the core plugs kind of worried about the rear one. Had a lot of wet black dirt like material. Hope it isn't oil. The motor block sat upright on the rear side for a long time before I bought it.  The oil plugs front and rear have square holes and are not 1/2" or 3/8".  Time for another tool.  I'll dry the rear core plug area out some more with my Map torch, clean it out somewhat and see if I can fill the oil galley up with brake fluid or some thing thin to see if it gets in the rear core plug area.   Did manage to thread the manifold stud hole with a 5/16 tap. Threads look good, but need to use a 3/8" tap & die to make it the same as the others. The one I have is dull and couldn't get threads started. 

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  • Bryan changed the title to Pulled core plugs - Pulling motor on 1948 Dodge.
Just now, Bryan said:

 On the core plugs kind of worried about the rear one. Had a lot of wet black dirt like material.

I would say that everything I have read and me changing my own plugs.

 

There is a lot of left over casting sand left in the blocks. From when they were created new.

The sand always settles to the lowest point in the block.

 

I would venture to say all these old blocks needed to be ran a couple hundred miles, then the sand cleaned out of them.

 

Of course that never happened. A good indicator is if you open the petcock on the side of the engine block to drain the coolant ... it is plugged.

Most likely left over casting sand from when the engine was born.

All of it ends up on the left side of the motor at the lowest point. Pull the core plugs and flush it out and good to go.

 

I got a ton of casting sand out of my block when I flushed it and many others have shown same results.

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1 hour ago, Los_Control said:

I would say that everything I have read and me changing my own plugs.

I got a ton of casting sand out of my block when I flushed it and many others have shown same results.

Just worries me because it was wet and black like it had oil in it.  Maybe I should have got a handful and smelled it.

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2 minutes ago, Bryan said:

Maybe I should have got a handful and smelled it.

Possibly so. Just that the area on the lower left side of the block with the core plugs is coolant.

 

Would be natural for the leftover sand to be wet & dark.

 

I believe oil & sand you will be able to tell apart from water & sand. I can be wrong .

 

Thing is, casting sand from birth in the water jackets is a normal thing all these old engines suffer from.

 

I just would not get excited about it.

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39 minutes ago, Los_Control said:

I was going to add that with my sniffer, I cant smell the difference between oil & water anyways  :D

I'm hoping there's not a crack between the oil galley nearby and the coolant passages.  I might go a sniffing tomorrow. Or maybe see if it burns with my Map gas torch.  

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  • Bryan changed the title to Found my camshaft! - Pulling motor on 1948 Dodge.

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