Line honing crank journals

[Bakerlite]

External manual adjustment. Bolt through timing case cover to back of pivoting tensioner.

 

[moper]

Sorry your incorrect. It's the resistance of the cam and valve train, that keep any slack being introduced into the drive side of the cam chain, in a SBC V8. If the cam was to keep more momentum than the crank at deceleration( try to spin faster than the crank) and effect cam timing then it would be a mute point because your not under power. Also who's to say that the spring in the tensioner would be able to resist that force anyway.....

No need to be sorry, I think you're wrong so we're even...lol. Suffice to say - I always run a tensioner on a small block because I believe it does provide a benefit.

 

[AJ/FormS]

Getting back to the line honing. Against my better judgement, I allowed a shop to align-hone my block. They said they had the right fixture for it. To my knowledge the alignment was fine, cuz the crank spun beautifully, and she hadn't spun a bearing in 2 years of wreckless abandonment driving. The block was only there to remachine the crooked decks gifted to me by a different shop. Since they were a well-established shop, I caved. Well, they mostly fixed the decks, so I put the engine back together, and the world was rosy-pink again. Until I found the rear mainseal leaking. Crap. So I put a new seal in and away I went. Well a short while later,crap, it was puking oil again. So it was getting late in the season anyway and it was time to freshen it up.So I yanked it out, and took a real good look at the seal.To my amazement, the seal was very worn on the one side and almost untouched on the other; 180* apart. Putting 2 +2 together, I went back to the well-established shop. After a long song and dance on their part, they offered free machining if I brought them another block. For them to also screw up?, I think not. So what to do? My block now had straight bores and straight decks, just leaked oil.Well after some research, I discovered that the 383 Mopar had come with a rope-seal back there. So I got one, made a tool to trim it to fit, and voila, problem solved. Right? Not so fast. Turns out, the cranks are finished differently between the two seals. So now it just leaks a little bit. I tried cranckcase evacuators, but they work really,really well. Too well. Even just one. So I decided to just add oil now and then and live with it, 'til it blows up. It will blow up won't it. Well, that was 11 or 12 years ,and over 100,000 miles, ago. Maybe next year she'll blow.....
-So, long story short,If your crank spins freely on new bearings,and the crush falls within limits, don't let anyone talk you into machine work.
Except maybe Rusty. No joke,He knows stuff.

 

[71beater]

Only since this already derailed, I'll add this.
Besides momentum or flywheel effect, a little more food for thought.
Let's look at a single cylinder.
With each individual power pulse the crank is accelerated, then slows. As the cam comes up on a lobe it wants to slow down, and then as it comes over center heading off the lobe it wants to accelerate. These forces are at their worst at low RPM. As speed (RPM) increases they tend to smooth out, but they are there. Obviously with a V-8 firing four times per revolution these fluctuations aren't as great, but now the frequency is X4. I'm pretty sure most cam drives are slightly less than perfect (although belt is a pretty good bet), so a tensioner is likely a good bet...

 

[Bakerlite]

Only since this already derailed, I'll add this.
Besides momentum or flywheel effect, a little more food for thought.
Let's look at a single cylinder.
With each individual power pulse the crank is accelerated, then slows. As the cam comes up on a lobe it wants to slow down, and then as it comes over center heading off the lobe it wants to accelerate. These forces are at their worst at low RPM. As speed (RPM) increases they tend to smooth out, but they are there. Obviously with a V-8 firing four times per revolution these fluctuations aren't as great, but now the frequency is X4. I'm pretty sure most cam drives are slightly less than perfect (although belt is a pretty good bet), so a tensioner is likely a good bet...

That's why motorcycles have manual or ratchet adjusters.. If you want to be sure to stop any sort of fluctuations, then you will need to get rid of the pissy spring and set it manually..

 

[AJ/FormS]

YABUT .....M/C chains are generally 3 to 4 or more,times longer, and a bazzilion times weaker. When an adjuster fails that chain starts whipping about pretty bad, doing all kinds of damage to the guide shoes and aluminum tunnels. Not to mention the awful racket that makes.
What I like about my Mopar tensioner, is how stable the timing marks are.No more guessing.Even after 100,000 miles.And I like the no-maintenance thing too.
But then at age 62, Ima getting lazier and lazier. I hate that about myself.I wish my oil would change itself.I guess I could sublet it out. But I'm an even bigger cheap-az then I am a lazy-az. Plus then I'd be worrying about the drainplug falling out, and so I'd be scooting under there to check it, and then I might as well just have done the whole thing myself already.....But now we're really,really, really,off-topic.

 

[69 Cuda 440]

There 'two' different methods for dealing with Mains in an Engine Block.

* Line Honing
* Line Boring

On the Automotive Engines, Line Honing is the 'typical' method to use.

On Diesel Engines, the only method to use is Line Boring.

Line Honing {ie; Sunnen Line Honing} the stone-mandrel will follow the
old hole.

So, if you clean up the bottom of the Main Cap {.002"}.

Then technically, you are removing more material from the 'Block Main' then
the 'Main Cap'.

The same theory can be used when Reconditioning Connecting Rods
on a Sunnen {LBB-1810} Rod Reconditioning Machine.

You are taking more material off the Connecting-Rod then the Cap.

 

[nm9stheham]

With each individual power pulse the crank is accelerated, then slows. As the cam comes up on a lobe it wants to slow down, and then as it comes over center heading off the lobe it wants to accelerate. These forces are at their worst at low RPM. As speed (RPM) increases they tend to smooth out, but they are there. Obviously with a V-8 firing four times per revolution these fluctuations aren't as great, but now the frequency is X4. I'm pretty sure most cam drives are slightly less than perfect (although belt is a pretty good bet), so a tensioner is likely a good bet...

This describes the variable chain loading well; turn a set up cam by hand and you will see this.