There's a lot of shops that talk a LOT about balancing and how great they are at it. Yes..it's really cool to make every piece perfect...but reality is for 95% of the folks out there no way is anyone getting that close from their $200 balance job or do they need to.

My 555" has had several balance combinations over the years. The first..when it was a basic 540 used an Eagle crank, Scat Rods and 4032 SRP small dome pistons along with a fluid filled damper. That crank/balancer combo was not good for main bearing life...and eventually that balancer exited the end of the crank at about 7000 RPM. It was balanced by a very well known guy (who's now on TV and was engine builder for a multiple Pro Stock champion winner). Next it got a Callies crank with the center counterweights and an ATI balancer with same pistons and rods. Perfect forever..balanced by same guy. (BTW- that Eagle crank straightened (again) and was turned .010 and used with an ATI balancer and never had another issue in a blown 496) Then my engine got a heavier set of Oliver rods and a lighter set of Mahle pistons so the crank was rebalanced. This time we needed just a hair more weight....so we cheated and screwed two very short ARP 12 point bolts into some unused existing flywheel holes. THEN next it got a heavier set of Diamond Turbo pistons along with the heavy Oliver rods. We needed to add weight back to the crank..so one of the previously drilled holes had some weld added to it. Still used the two bolts. Perfect at 8000+ RPM for years. Later, I had a new aluminum flywheel made and it was made to accommodate the extra weight of the bolts so we didn't have to use them anymore! LOL

My latest project is an 8-71 blown 408" Ford Clevor engine for my Pinto. First time I've ever bought a "balanced" kit. This came from DSS and after talking to them and watching the videos of their processes...I was comfortable giving it a try. I haven't raced it yet (still building the car)...but I've had the engine running on the test stand and it's as smooth as can be,

And as far as piston weights....my experience is they are pretty darn close these days out of the box on the typical "good" forged pistons. Wouldn't surprise me to see them untouched on the average build..and most "good" rods are the same. The cranks have to be done because they have no way of knowing what combo you're assembling unless you buy a kit from them.

JIM

 

Well now that short term memory has temporarily diminished I went out of my way to build an internally balanced engine. I had a NOS Fluid Damper laying around i wanted to use and I had Ram make me an newtral balanced Flywheel. So no wonder I needed some heavy metal to make everything work.

 

That center counterweight solved a lot of problems in the 2000's......we made sure all of our Callies and Lunati cranks had them.

Jebby

 

"That center counterweight solved a lot of problems in the 2000's......"

I'm not going to state that he was the man that invented the idea, but he sure was one of the early big promoters of it, that in the attempt to aid in the proper balancing efforts of American V8's, this was 'Hank The Crank' in the late '60's thru the '70's, offering the option of the addition of a center counter-weight welded on to the O.E.M. steel crankshafts for racers.

Back then we had one of his modified O.E.M. cranks in a Ford 427 T.P. welded & stroked to a +.200", turned to the 392 Chry. Hemi journals, and with the added center counter weight.

Of the American push-rod V8's, the old '50's Ford Y-Block engine series (including the Mercury & Lincoln versions "Big" & "Small") was one of the better O.E.M. executions in counter-weight placements (just Google for an image, but not a chinese copy), as the difference is obvious, and these engines are known for their durability in this arena (of course they do suffer from some other engineering issues, though these being consistent for the period). And this execution is being revisited today (well, in the last couple of decades), not only in the after-market racing crankshafts (8-counter-weight option), but also in most of the newer O,E.M. production examples.

Just another case of: "that which is old, is new again"!

Scott.

.

 

Feel free to judge my bearings.
plastigage from the journals has front at .002
center three at .003
rear main at .003

 

What do the rod bearings look like?

Jebby

 

similar condition, some streaking, generally shiny, the dull babbitt has worn away.
I haven’t done any measurements on rods yet.

 

Well...it was getting oil but got dry on occasion......or someone spun the hell out of it......

Jebby

 

It would be better if one were holding the parts in hand to make a better observation but; I'll jump out there with thoughts of:

Bearing surface over-loaded
Bearing wear implies possible squareness & Bore-alignment issue, but mixed with perhaps poor crank-grinding and/or crank-whip makes for only the requirement for investigation.
Evidence of oil starvation.
Evidence of foreign particulate intrusion.
And perhaps it might explain a lot: yeah, maybe someone just "spun the hell out of it" too! At least too fast for the sum of the build.

Scott.

 

Agreed. Some questions are now popping into mind while we are talking motor builds and stuff like that. Are you loosing oil to the mains because it's slamming to the back of the pan when you race, or are you pumping it dry at high rpm? Take a look at your heads and lifter valley see what your oil drain back holes look like. It's possible it's pumping all the oil into the top end of the motor and then the pump sucks air etc. Remember the OE chevy block actually oils the cam and lifters before it oils the mains and rods. It's possible particularly if it's not draining back well due to windage and blowby that it's pumping the pan dry at high rpm.

It could also be sucking air because all the oil is climbing the back wall of the pan. If that's the case it would make sense to look at a Canton, Milodon, Moroso, etc pan IE something with a deeper sump and possibly a trap door. You might not be able to run the OE pan anyways given you're stroking the motor.

Food for thought.

 

I appreciate everyone’s thoughts. I would like to make sure everything is right before dropping in a new assembly.
Im thinking it could be an oil starvation issue at high rpm. I do run a high volume pump, and it does see 6k rpm frequently. I wonder if it is draining the pan.
I also think the crank is not great. When I installed it 4 years ago I noticed the bearing clearances were not within .0011-.0023 but I figured .003 would be close enough. Which it might be.
I’m going to check for runout.
I would like to think there is nothing wrong with the block, and that a new assembly will fix these issues.
I will be giving the oil pump issue some thought though. Even tho I don’t think my hp level is enough to cause it, it’s not that fast(8.02 at 91 1/8mile)

 

The stock oil pan clears 3.750 stroke crank......I have a stock 70' LT-1 pan on my 406.
Get that HV pump out of there.......100% not needed in a street car up to 6500rpm.......
The stock oil pan also is a very good piece.....this is the "bathtub" long sump Vette pan...not the passenger car short rear sump. The stock pans pickup is centralized in a "bathtub".....it does a very good job of keeping oil in one spot...where the pickup is, and that is all that matters........the pickup should be 1/2-3/4" from the pan bottom, this is important. It also should be brazed all the way around where the pickup meets the pump body. This eliminates an aeration point.If you can find one the L-82 factory windage tray is a good piece that compliments the stock pan well.....it helps the bathtub even more by preventing slosh under heavy acceleration.......
You have to understand that although drainback is important......there is a tremendous amount of controlled leak flying around in a spray from the bearings and this goes right back in the pan.......this is why the whiz-bang pans with the scraper and the screen are so good at oil control.....it is damn near pushed through the screen and drains to the sump.......the diamond screens if you look close are tapered toward the top.......it goes through easier then it could come back.......
You do need a whiz-bang pan for sustained RPM's......like the Texas mile.......but you also should be massaging drain holes in the head and other things......

Jebby

 

When one thru observation of the bearings states that "oil starvation" is an issue, this doesn't always imply that oil wasn't being made available, as this popularly utilized term still lacks in specificity, beyond the application of the interaction between the two surfaces in observation, of the potential problem at hand. That is, oil very well may be present in the pan, quantities being shuffled by the pump, then successfully being forced thru the galleries and passages provided for distribution, nor does it even provide evidence that it wasn't being expelled into the void provided by the oil clearance volume between the bearing face and the crankshaft journal surface. But rather what is being stated is that there appears to have been instances where the sum of oil as required to provide for the dissociation of the two loaded surfaces (only a portion of the total area made available) was lacking, and this could also be due to oil film "displacement", this versus that with which many may perceive as simply "starvation".

Just food for thought.

Scott.

 

Yep...that's what I meant when I said someone spun the hell out of it......the oil is still getting there......but not enough.......

Jebby

 

Pristine near the parting lines yet grooved in the middles, I'd think about a line hone, too.

 

He mentions .003" clearance on a few mains...and .002" on another. It's a 2.45" journal.....so if it truly has .003" clearance...the HV pump might help outrun the leak at low speeds. Now I trust Plastigauge as far as I can throw it...so I'd get some real mic's and measure things to be sure as you go back together. If you're going to "spin the hell out of it" (LOL Jebby!), that .003" doesn't scare me at all, but .002" is too tight for me. As they say...a little loose...and you'll know it...a little tight and everyone will know it when it comes apart.

Those bearings aren't completely trashed,,,but do show some issues as discussed. If going all new stuff... a quick line hone would be nice to make sure. And double ck crank runout.

And PBF777...you have a definite knack for expounding in detail on things! That looks like something from a white paper. LOL. But it does describe what Jebby said well!

JIM

 

If I'm understanding the statement correctly: This lesser loaded surface demonstrating little to no surface damage inflicted at the parting-lines would be typical of what one would expect, assuming oil clearance values were reasonable and the bearings hadn't chosen to tighten-up on the crankshaft journal; and this as being attributed to the eccentricity built into the bearing profile providing additional clearance at the parting lines.

Though, if looking closer at this juncture of the loaded to unloaded surfaces, the positions #1 - #4 all display a marked loading incurred wear pattern that progresses closer to the bearings' parting line at the both left and right outer edges than that of the center of the bearing; the rear #5 demonstrates more of what one would want to witness as it is straighter in the separation, implying better parallelism of the two surfaces and a more equal distribution of the load being carried across the bearing face, and as being handed off from one shell section to the other.

There can be more than one cause for this, and yep, one participating cause maybe that "someone just spun the hell out of it", this causing the crankshaft to flex or "whip", but I'd probably look first at the crankshaft for having the journals ground and/or excessively polished to point of being what one would commonly identify as being "saddle" or "sway-backed", aka. low in the center.

But yes, there are other indications that might lead one to want to check the blocks' bearing bore alignment also.

Scott.

 

The uppers on the mains look much much better. Mostly dull babbitt flashing still present, minor streaking.
the cam bearings look decent, little shiny but no discoloration or copper. Better than the lower mains. Makes me further think that HV pump with stock 5 quart pan wasn’t helping.
now I can’t decide if I want to change the cam bearings out or not…..

 

It’s $30 for the bearings. I would.

 

Not the cost of the bearings,
the one tool I don’t have is a cam bearing installer lol
i know there are some workaround methods but one thing I’ve learned over the years is that jobs turn out better with the right tools