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#16
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re: engine too tight
Chamferred bearings are beveled on one edge to allow clearance for radiused journals. I used a Scat crank with radius and clevite std. "P" series bearings and no further chamferring was required to make it all fit. The eagle rods and caps are serialized and are easy to match up as you said. Another thing to check is make sure your rod big ends are installed with the beveled side towards the counter-weights again allowing clearance for the radius.
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#17
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re: engine too tight
lol im not looking for a magic potion... im not new to newsgroups and i know how newbies are.... i just figured maybe there was a part number for the main caps like there were for the rod and cap.... we've spent 2 days building/and tearing the engine back down. and pretty much the only thing it can be is the main caps.. i just wanted to know how to tell what order they go.. also i might get my *** handed to me (again?) for this question but what is the torque setting for eagle i beams with arp rod caps if anyone knows off hand... i could pretty much get the flywheel to spin a little by hand up until the last few rods were tightned... and no the crank is NOT from a 400.... its a stroker crank made FOR a 350 that has the same (3.75"?) stroke as a 400 crank.. so again.. why would i have to use diferent or altered bearings?
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#18
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re: engine too tight
Some folks pee against the wind alot, lol, but I think your on the right track 383PoweredZ. You might be able to match up the caps with the main saddles by trying them in each position and feeling for a misalignment at the parting lines???
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#19
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re: engine too tight
i consider pissing against the wind as something like trying to get 800 hp out of an engine that starts out at 160 hp.. lol.. anyway... i checked a few of the rods and so far all of them i've checked have had the chamfered edge toward the counterweights... i also have a scat crank. the bearings are not chamfered.. ill play with it some more and when i get it right ill post what the problem was incase someone else has the same problem.. thanks for all the help guys.
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#20
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re: engine too tight
If the block and main caps have not been blasted, look closely to the cap and block mating surfaces. Usually, there will be some shadows or marks that are unique to each cap and corresponding block mating surface. Matching these up will help you determine the proper location for each cap.
tom
__________________
Ya cain't fix stoopid, but ya kin TAX it! |
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#21
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re: engine too tight
Stroker cranks made for a 350 typically have radius journals that are not on stock cranks.
Here is a "copy and paste" from summit racing from a description on an eagle stroker crank. ""Cranks you can rely on and afford. If you need a crankshaft that's dependable, but don't want to empty your bank account, Eagle Specialty Products has the solution. These cast steel crankshafts for Chevy feature .092 radii on rod, main journals, rear seal, and snout for increased strength. Crankshafts for Ford have .125 radii on all rod and main journals. Each crank is inspected for dimension, size, and stroke accuracy, has a journal finish of 6 R.A. or less, and has a target bobweight of +/- 2-percent for reduced balancing time."" So, you need a chamfered bearing and it has a direction. Point the bearing chamfer towards the radius. |
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#22
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re: engine too tight
Cranks with .092" radii do NOT need chamfered bearings. Cranks with .125" radii DO need chamfered bearins.
tom
__________________
Ya cain't fix stoopid, but ya kin TAX it! |
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#23
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re: engine too tight
did you measure bearing clearances? i've had a few eagle cranks that would have resulted in excessively tight bearing clearance... i mic everything before i ever send it to be balanced... crank, rods, pistons, etc... just one more thing to check...
you should EASILY be able to spin an assembled sbc (w/ plugs installed) with a 12 to 18 inch ratchet or breaker bar on the balancer bolt... measure measure measure... long gone are the days of bolt it together and if she spins she's good... stuff is too expensive to take chances with... least on my wallet... JR |
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#24
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re: engine too tight
Quote:
Good point to bring up. We mike all the cranks we get in to be balanced or are doing other work on. We also dial indicate all the cranks we touch to make sur e they are ok. And yes, Eagle (as well as others) can be all over the spec map. tom
__________________
Ya cain't fix stoopid, but ya kin TAX it! |
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#25
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re: engine too tight
Any radius needs some kind of chamfer. A stock crank will typically have a undercut radius to clear the bearing. With only 0.0150" side clearance on the rods, even a little a 0.092" radius can effect the bearing and therefore the bearings should be chamfered towards the radius. In this case, if the bearing is recessed more than 0.046" under the rod face then a chamfer isn't needed. However, this must be checked and verified.
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#26
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re: engine too tight
I had the very same experience once, I learned what it was soon after I
started it up. I had two rod caps switched and it ate the crank up very quickly. It's amazing how different the fit can be if you get them out of order. I now like the plastgage and use it. Make sure every journal is free moving. If it's that tight something is probably wrong somewhere. I learned the hard way (as always) ![]() |
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#27
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re: engine too tight
Quote:
Most cranks, stock or otherwise, do not have an undercut or filet radius. The cranks with .092" radii are designed to be a bit sronger than a crank with a stock radius but yet are compatible with stock-type bearings. You are correct, these things should be checked. The biggest problems that I see with some of these cranks is that the journal is sometimes too big just before the chamfer, causing too little clearance problem in that area. tom
__________________
Ya cain't fix stoopid, but ya kin TAX it! |
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#28
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re: engine too tight
so.. just say i check all the clearances with plastigauge... and one of them is too tight... what to do then? are there bearings made thinner than the STD bearing? or do i get the crank addressed by a machine shop?.. now im thinking maybe i should just take it all apart and take it to the guy that did all my block work and pay to have the bottom end professionally done... i know there are ALOT of variables but u'd think with all the high tech CNC machines etc we have today everything would be blot and go.. well so much for it being EASY.. ill have to check everything then if i still cant get it its going to the shop. thanks for all of the help... ill post what i find.
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#29
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re: engine too tight
Theroredically, its a balancing act between them. The loose one's go on the tight one's and the tight one's go on the loose one's. Gm engine plants used to have about six different ones for the same engine with different characteristics, ie, tighter, looser, offset, off-center, left and right, etc. It's not a perfect world! As i said before you are better off having an experienced person go through the engine and assemble it correctly then to throw it together and have the crank and bearings spill themselves over the pavement. Good luck.
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