[HWYSTR455]

Been a while, but isn't the 1- or 2-piece seals for cranks with no hash marks?

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[78w72]

Originally Posted by HWYSTR455

Been a while, but isn't the 1- or 2-piece seals for cranks with no hash marks?

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From what I understand & was told, the serrations just need to be polished a bit or if higher miles they may already be smoothed out some. I have the 2 piece BOP in 2 engines, one is a 50k mile stock W72 crank that the serrations were pretty smooth, we didnt do anything to them & the BOP seal has been pretty much leak free for ~15 years. another car with a forged eagle stroker crank alos had pretty light serrations, didnt do anything special and its also close to leak free after ~9 years with lots of drag strip runs & harder street miles & no vac pump, it will seep just a tad but no drips... using full synthetic oil too.

[Verdoro 68]

From what I've read, the Eagle cranks from the last few years have less aggressive serrations than they used to so it's normally not an issue anymore. The ones on my crank don't look like they'd cause trouble, but with the way my luck has been maybe I shouldn't write them off. Stock crank serrations are way smoother and at a different angle.

[Gach]

Makes me wonder my Crower crank has no serrations, using rope seal.

[HWYSTR455]

I ran a couple cranks with no serrations and rope seals, think in the beginning there was an issue with the neoprene seals that was later corrected, but it's been a while, may not be recalling that clearly.

I think with the best seals, you don't need serrations, per se. Serrations were obviously there to hold a small amount of lube to help seal, so minor seepage is acceptable. I recall when a car would sit for a while, seal could shrink, and may leak a little. But with a little regular use, it would 'correct' itself. But don't believe that is the case with the best seals.

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[HWYSTR455]

Originally Posted by Verdoro 68

From what I've read, the Eagle cranks from the last few years have less aggressive serrations than they used to so it's normally not an issue anymore. The ones on my crank don't look like they'd cause trouble, but with the way my luck has been maybe I shouldn't write them off. Stock crank serrations are way smoother and at a different angle.

Those look pretty distinct, but still can't say if they would be ok. I know the factory cranks I've had in the past, the serrations were worn to a point where they were almost not even complete lines.

I say do another best seal, and when you roll it, the socket, or whatever you use, should make contact across the seats. As I recall, the edges of the seats where the seal rides is slightly higher/smaller than a main saddle with a bearing in it. The seat the seal rides in have a chamfer on each side, and the seal spreads out a little in that area.

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[HWYSTR455]

Turn the crank by hand without any rods on it once installed, if you get more than 5lbs or so of resistance it's probably too tight. I vaguely recall there is an actual spec for it, or a 'builder preference' for that, but it's in the 5-10lbs range.

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[Gach]

Looking at that picture the serrations seem to get longer (bigger ) from smaller to wider. I don’t know maybe just seems that way in the picture. Hope I am wrong but that could be taking out the seal.

[HWYSTR455]

I think that's just the camera lens/optical illusion.

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[Gach]

Thats My thoughts. Camera effect

[Verdoro 68]

Better pic of the serrations from today. You can see where the seal was.



Curious what you all think about the mains and rod bearings. I'm wondering if they're salvageable? The pics make them look bad, but they feel smooth and I can't catch much - if anything - with my fingernail. The thought of getting the crank polished and refitting new bearings doesn't make me thrilled, but if it's the right thing to do...







Here's a shot of the main caps. These have more wear than the upper portion of the shell. Wondering if there's anything that might indicate a crank or a block problem here. These were coated bearings, but much of the coating has worn off.

[Gach]

I hate to say it, but I would ditch those bearing and definitely get crank polish. Plus have it checked for straitness. Yeah better picture, look same size. Other thing The serrations look off set from were the seal sets. Like its riding on the back edge of the seal. Or is it just the picture.

[Gach]

Hopefully i’m not being paranoid.

[Verdoro 68]

Dropped the crank off today to get checked out. The machinist thinks it will clean up with a polish and said I can likely use the same size bearings. He's going to smooth over the serrations too. New rod and main bearings are on the way from Summit. I'll measure everything again when I get the parts and see where the clearances fall. Fingers crossed.

His assessment of the seal failure is similar to everyone else's - too much pressure and friction on the seal. He said the line bore on my block might have some issues given the way my main bearings are worn, but he doesn't think it had anything to do with the seal failing.

I spent most of the afternoon tediously fitting the BOP one piece seal. I had to sand quite a bit off the outer diameter to remove the pucker at the seam. I assume that's due to the line bore on the block. The spring steel is starting to show around the edges but Wade said that's ok - just be sure to use a film of sealer when it's installed. I think it's looking about a seamless as I can get it without taking too much off.

I'm measuring 3.16 at the ID of the seal across the middle with the cap torqued. The crank measured 3.188 which should put me within the overlap tolerance the seal calls for of .025 +/- .005 - provided too much doesn't get taken off the crank.

[Gach]

smooth over the serrations too

Smart move on his part. Great that it’ll Polish up. Smart move doing all this and going with new bearings. Thanks for the up date. Appreciate it

[Verdoro 68]

Got the crank back from polishing - it looks much, much better but there are still some shallow scars from the trash in the oil. The crank doesn't appear to be bent so we'll write the seal failure off to user error.

The new wrench in the works is that my main clearances are off with the replacement bearings. I was going nuts today trying to figure out why I was only seeing .020 with the mic/dial bore and double checking with plastigauge when I set the mains to .0024-.0025 last time. As a last resort, I checked the bearing thickness and sure enough the old bearings are .0976 and the new ones (same brand and part number) are .0978. So I guess there's my .0004. Put the old bearing back in and I'm back at .0024.

I ended up with these King bearings (.001 extra clearance) because Clevite and SpeedPro were tight. Not sure where to go now - maybe back to the machine shop to get some more taken off the crank.

[Gach]

It’s crazy.

[HWYSTR455]

King bearings are good.

.0978 - .0976 is actually .0002, so maybe there's a saddle issue too. The machinist should be able to give you the crank journal sizes and that might give you an idea. At those clearances, even shop & tool temps can vary measurements.


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[mgarblik]

.002" is a little tight, but not panic mode. Your crank is STD. Size? If it is, I think I have a set of American made FM 151 bearings. They tended to run a little larger than the current Mexican made bearings. PM me if interested. These are 3/4 groove race bearings. In general, it is NOT a good idea to try and polish a crankshaft to a dimension. Polishing is to polish. When over-polishing to achieve a dimension, taper and out of round is often introduced. Make absolutely sure your bore gauge is zeroed exactly. That's very difficult with a micrometer and not a setting fixture.

I see you have the King +.001 bearings now. That should do the trick. Let us know where they measure out. I am just fine with main clearance up to .0033"

[Verdoro 68]

Sometimes when things get frustrating I have to remind myself to put the tools down and walk away for a bit. I've been thrashing to get this engine sealed up and reliable for several months now and I think it finally got to me the other day.

After letting stuff sit in the garage for a couple days at the same temperature, I slowed down, took my time and remeasured everything. The clearances with the King bearings are all in the mid 20s as they were when I put it together the first time. I am noticing some of the journals look like they may be a smidge out of round which fattens up the clearance on some parts of the bearing diameter. If I had to do things over, I'd have had the machine shop check the previous shop's line hone work when they had the block because it looks like it may have some issues. At any rate, I think I'm back in business now.

In my frustration the other day, I hastily ordered some King HP series .001 bearings. They are softer and supposed to be easier on the crank than the XP series, so if the clearances measure the same, I'll likely use those. FWIW, the crank is a STD size Eagle stroker. It's crazy how hard it was to find main bearings that weren't too tight. Seems it would usually be the opposite. I've got quite a collection of main bearings now, but I don't have any FM 151s!

Thanks for all the help and support as I navigate this mess.