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Boooo..spun rod bearing

Boooo..spun rod bearing

Old May 25th, 2018, 10:33 PM
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Boooo..spun rod bearing

The weather along the Colorado front range has been awesome the past few days so I decided to drive my car to work which is about a 30 mile trip. I got about half way there and noticed my oil pressure was pretty low at hot idle..~5-8 psi. But would climb to about 30psi under load. I made a mental note that it seemed low, and that I would get on the forum to do a little research. Well, about a minute later I got a noticeable pop and loud knocking. I immediately pulled over and called for the tow truck. I haven't done any diagnosis beyond listening, but I'm 99% sure it's rod knock. I hope not.


The engine has less than 100 miles on it since I put it in the car. I bought it 2nd hand rebuilt from a guy last year when I lived in TN. The engine was never revved above 4000, though it does see 3500 continuous on the highway since it has 4.10 gears. Obviously, I won't know the extent of the damage until I inspect it.

Hopefully it's not too bad..I'll keep this thread alive with updates as I get this thing fixed.


Here she is getting loaded on to the tow truck:
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Last edited by stampsicle; May 26th, 2018 at 02:25 AM.
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Old May 25th, 2018, 10:59 PM
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Beautiful car! I hope you are back on the road soon.
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Old May 26th, 2018, 02:22 AM
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I read a lot of the threads on the forum with some useful information. I'm going to go down the list of possible causes before I start tearing this thing apart.


-cut open the filter first thing to look for metal debris
-check the flex plate for loose bolts and cracks
-run the engine and remove one plug at a time and listen for continued knock
-remove the accessory belts and listen


Anything else I am missing?
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Old May 26th, 2018, 05:17 AM
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What was the oil pressure before? When I spun the mains on my 403, I dropped maybe 5 psi, just enough to notice. Big mains need everything need everything right to live. Plus heavy parts and soft factory rods are also issues that add up to bad things happening.
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Old May 26th, 2018, 05:36 AM
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I drove it about 40 miles 2 days before and it was right about 10 at hot idle. 30 at cruise. I didn’t think much of it. But I did just pull the oil filter and I don’t even have to cut it open to find metal. It’s definitely a swirly metallic mixture. Looks like I’ll be pulling this motor out.
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Old May 27th, 2018, 07:53 PM
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Dood, that sucks! I remember in my '82 Trans Am I had a long night of driving stoopud and I never turned the stereo down. When I finally made it home I turned the tunes down and popped the throttle, and heard the death knock! It only knocked above 2200 RPM so I drove it that way for weeks because I didn't have the money to do repairs. When I finally took the engine apart the rod bearing was still in place but it ate the crank pretty bad. I hope your repairs are minimal.
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Old May 28th, 2018, 03:05 AM
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I hope they are too! I'm going to try and pull it this week if I can get the time.
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Old May 28th, 2018, 04:58 AM
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If you find a spun bearing have your crank checked for straightness. Had a crank machined once and installed. After about a 800 miles a slight knock occurred. A rod bearing was starting to spin. I took the crank back to the machine shop and they said it was bent.... but did not know the reason. And it was not checked the 1st time so i guess it was bent when I installed it. They straightened it and it has been fine.
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Old May 30th, 2018, 07:09 PM
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Originally Posted by Oldsmaniac View Post
If you find a spun bearing have your crank checked for straightness. Had a crank machined once and installed. After about a 800 miles a slight knock occurred. A rod bearing was starting to spin. I took the crank back to the machine shop and they said it was bent.... but did not know the reason. And it was not checked the 1st time so i guess it was bent when I installed it. They straightened it and it has been fine.

Thanks for the input. I talked with the machine shop I am taking it to and they have experience with Olds motors and the shop manager was confident he would get me squared away. I should have the motor out on Friday and off to the shop.
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Old May 31st, 2018, 05:46 AM
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At least you found a good shop to take the engine too. Hope the repair goes smoothly.
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Old May 31st, 2018, 10:36 PM
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Sorry for your troubles on the engine, that is a beautiful car!

I assume the engine is a 455, is that correct?

I live in Lakewood, Colorado , very near the Bandimere Drag strip, and I have a lot of experience with Olds engines...... I have never seen a performance Olds engine stay alive with less than ~10psi per 1,000 rpm with good quality oil. And I like to see 25+ at idle and watch it climb quickly as RPM’s increase.

I had 80,000 miles on one performance 455 engine before a water pump locked up and flung the belts and I didn't catch it in time..... overheated to the max... ruined.

I took that engine to 6,000 rpm nearly every time I drove it, daily.


My list of minimum things to do to a street Olds to keep it alive are as follows:

Connecting Rod side clearance of .020 as well as oil relief notches

Buy a brand new eagle crank and have it checked out to make sure it is correct.

Have the assembly balanced

Oil galley restrictors (I can give you some brand new ones for free)

Perfect rod and main bearing clearances and high quality bearings only, not cheap junk rebuild kit bearings.

ported and polished #5 main cap oil journal holes and ported
High Pressure oil pump (if you are keeping the stock pan)

Use Excellent oil with high zinc (Gibbs)

Use American made hydraulic flat tappet lifters (Perfect Circle, Sealed Power, etc.) not junk Chinese lifters and a High Quality aftermarket camshaft from one of the major manufacturers
OR
buy a Hydraulic Roller cam and lifter setup and reduce one more worry..... (It is tough to keep from flattening cam lobes when breaking in an engine, and I decided that I would never own another flat tappet V8 after having to go through the trouble of valve spring swaps after breaking in the flat tappet cams with soft springs so they didn't push as hard on the cam lobes and lifters even with GM EOS and all kinds of break-in oils and lubes).

Buy a Canton 6 qt oil pan and pickup to install

TRW/Sealed power 4032 alloy forged pistons actually work very well for performance street/race engines and they are priced very well. Get the high compression ones because you live at an altitude that will reduce your effective compression ratio. They will last a long time in a street engine, over 150,000 miles (same type of piston used in all old factory forged piston engines). I do not recommend any cast pistons for performance engines, been there, done that, broke that junk

make sure the shop Removes and cleans the block oil galleys on both sides, as well as pulling the square plug near the distributor. Many shops do not pull this one and it fills up with crud and sludge and will get blocked and stop oiling your distributor gear and cam gear (ask me how I know...

Clean, Clean, and clean again.....

Let me know if I can help you in any way. We are slowly working on a Batten headed 67 Cutlass right now.....

Last edited by Battenrunner; May 31st, 2018 at 11:05 PM.
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Old June 2nd, 2018, 11:10 PM
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I got the engine out today and found the #3 piston rod bearing spun. The crank doesn’t look terrible but will need to be worked. All the rod bearings had considerable wear but with only 75 miles on the motor, I’m going to assume they all had too little clearance.





Last edited by stampsicle; June 2nd, 2018 at 11:12 PM.
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Old June 3rd, 2018, 07:14 PM
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Originally Posted by stampsicle View Post
I got the engine out today and found the #3 piston rod bearing spun. The crank doesn’t look terrible but will need to be worked. All the rod bearings had considerable wear but with only 75 miles on the motor, I’m going to assume they all had too little clearance.


That really sucks Dood! I don't know if Olds engines are like their other GM siblings but it doesn't look like the oil holes in that crank were champhered, should they be? Could there have been a few burrs around those holes that gouged the bearings and caused them to wear prematurely and spin? I have cleaned oil passages in other crankshafts and pushed some ungodly junk out of them. Could that be what killed your engine? The part of the oil passages that is visible looks clean enough but what about the rest of the holes, could there have been debris in them? What do the main bearings look like?

Last edited by cjsdad; June 3rd, 2018 at 07:20 PM. Reason: edited for typo's.
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Old June 3rd, 2018, 09:00 PM
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Is the crank standard/standard or has it already been turned .010/.010?

also, I know you don’t want to hear it, but I don’t trust local “good enough” shops to turn cranks.

I worked around a friend who had an excellent crank grinding setup, and we were both perfectionists about the finish of the cranks we ground.... it wasn’t hard to turn out mediocre work that was “good enough” to compare to other shops, but it was darn tough to dress the stone perfectly and make an awesome turned crank. The level of detail and labor to get to awesome would probably not be what a local shop will do.....

the original olds machine work was usually about as perfect as you could imagine, but local machine shops, not so much.... would make me look close at a new cast steel eagle crank for $150 more than a turned stock N crank goes for.

after seeing a few Moldex, Bryant, and Lunati cranks, you know what a good one looks like. Most of the eagle stuff is really pretty good also, especially for the price.

after spinning rod bearings, you now have another choice to make.... having your rods resized and rod bolts replaced, or upgrading to aftermarket rods. Once a bearing has spun in the connecting rod end, it loosens it up. You could also choose to replace just one rod.

I wonder what the clearances are at on the mains also, and I noticed a non-matching main bolt. I strongly suggest going to studs.

not knowing if there was trash in the oil passages of the crank or block galleys will make ya wonder what caused the problems... too tight or full of grit

Last edited by Battenrunner; June 3rd, 2018 at 09:03 PM.
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Old June 4th, 2018, 01:33 AM
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Good call on the crank CJSDAD, none of the oil holes look chamfered. Probably sharp as knives. The rod will probably have to be rehoned also. As sheriff Buford T. Justice said,
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Old June 4th, 2018, 05:26 AM
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Originally Posted by Battenrunner View Post

My list of minimum things to do to a street Olds to keep it alive are as follows:

Connecting Rod side clearance of .020 as well as oil relief notches Notches are a waste and throw more oil on the cyl walls.
Buy a brand new eagle crank and have it checked out to make sure it is correct. Yes
Have the assembly balanced Yes
Oil galley restrictors (I can give you some brand new ones for free) Not necessary and again a waste

Perfect rod and main bearing clearances and high quality bearings only, not cheap junk rebuild kit bearings. There really aren't any cheap junk bearings out there for Olds

ported and polished #5 main cap oil journal holes and ported Not necessary
High Pressure oil pump (if you are keeping the stock pan) Yes but again not necessary if the hp level doesn't warrant it.
Use Excellent oil with high zinc (Gibbs) Yes or equivelant
Use American made hydraulic flat tappet lifters (Perfect Circle, Sealed Power, etc.) not junk Chinese lifters and a High Quality aftermarket camshaft from one of the major manufacturers
OR
buy a Hydraulic Roller cam and lifter setup and reduce one more worry But that's really personal preference and budget
Buy a Canton 6 qt oil pan and pickup to install Yes

TRW/Sealed power 4032 alloy forged pistons actually work very well for performance street/race engines and they are priced very well. Get the high compression ones because you live at an altitude that will reduce your effective compression ratio. They will last a long time in a street engine, over 150,000 miles (same type of piston used in all old factory forged piston engines). I do not recommend any cast pistons for performance engines, been there, done that, broke that junk Probably the worst forged piston you can buy. Much better stuff out there now for the same money
make sure the shop Removes and cleans the block oil galleys on both sides, as well as pulling the square plug near the distributor. Many shops do not pull this one and it fills up with crud and sludge and will get blocked and stop oiling your distributor gear and cam gear (ask me how I know...Yes
Clean, Clean, and clean again.....Yes
Again there a lots of good parts out there now for an Olds 455. No need to run the stock rods anymore as well. They're junk too.
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Old June 4th, 2018, 12:30 PM
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Cutlassefi, not trying to start an argument, just trying to share a list of important things that I have done in the past that proved to work well since most folks who have never built an Olds engine wouldn’t be aware of.

The Speed Pro/TRW pistons aren’t junk, and although the Mahle pistons are much better, I wouldn’t say they are a requirement for a street engine for a user who was afraid to go over 4,000 rpm so far, and he is running 4.10 gears.... I doubt he will see the other side of 5,000 very often at that rate.

4032 alloy forged pistons have much better longevity than 2618 alloy, especially on the street, and 4032 is best if only using small amounts of Nitrous or boost. 2618 pistons tend to wear out the ring lands in less than 20,000 street miles, requiring replacement, but they will withstand detonation and high power very well. The 4032 Mahle Pistons are about the best street/strip pistons you can buy.

I have seen cheap 2nd tier bearings of multiple brand names for Olds and they are junk, maybe they don’t make them anymore.... I have only dealt with King, ACL, and Clevite for a long time.


I have had three cams go flat for no apparent reason after perfect break-in procedures and oils used. Never again have to worry about that nightmare of wiping out a bunch of bearings and trash in the engine everywhere if you go hydraulic roller cam....


Last edited by Battenrunner; June 4th, 2018 at 12:47 PM.
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Old June 4th, 2018, 04:05 PM
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That TRW Piston has a lot of silicone in it, making its material, 4032, questionable. They’re junk. For about $50-100 more you can buy the Wiseco which doesn’t require the extra clearance and has a better ring pack, not to mention it’s significantly lighter.
And although a 2618 piston is typically made for power adders, there are lots and lots of those on the street with no longevity issues whatsoever. Yes 4032 offers better scuff resistance but otherwise even a piston made of 2618 is still better than that TRW. Saying that a 2618 piston will only last 20,000 miles is total bs. If you look at the Keith black icon series, they’re virtually all 2618 and have no issues. Do you really think they would have a full line of off the shelf Pistons for multiple street applications, made from that material with such longevity issues? Just doesn’t make sense and is simply not true. I myself have install dozens of sets of those with no issues, they’re all still running today. Unfortunately I believe you’re the victim of some very bad information.
But yes imo roller cams are the only way to go.

Last edited by cutlassefi; June 4th, 2018 at 06:44 PM.
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Old June 4th, 2018, 07:41 PM
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I appreciate all the input. I’ll drop it off at the shop this week and as soon as I get the diagnosis, I’ll have some decisions to make. There are no markings on the crank that tell me it was ever turned. The bad journal is worse than I initially thought. I got a better look/feel of it and it’s very noticeably worn.

Last edited by stampsicle; June 4th, 2018 at 07:57 PM.
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Old June 4th, 2018, 08:20 PM
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Originally Posted by cutlassefi View Post
That TRW Piston has a lot of silicone in it, making its material, 4032, questionable. They’re junk. For about $50-100 more you can buy the Wiseco which doesn’t require the extra clearance and has a better ring pack, not to mention it’s significantly lighter.
And although a 2618 piston is typically made for power adders, there are lots and lots of those on the street with no longevity issues whatsoever. Yes 4032 offers better scuff resistance but otherwise even a piston made of 2618 is still better than that TRW. Saying that a 2618 piston will only last 20,000 miles is total bs. If you look at the Keith black icon series, they’re virtually all 2618 and have no issues. Do you really think they would have a full line of off the shelf Pistons for multiple street applications, made from that material with such longevity issues? Just doesn’t make sense and is simply not true. I myself have install dozens of sets of those with no issues, they’re all still running today. Unfortunately I believe you’re the victim of some very bad information.
But yes imo roller cams are the only way to go.


I worked at a hot rod shop selling parts and giving tech help for 8 years, on everything from small block chevy’s to 2jz-gte Supra builds.... I have also built more than 50 engines of all breeds, from mild to wild.

2618 pistons require more bore clearance ( loud when cold and wear the skirts more) and they do wear out the ring Land grooves faster as well. I used to have custom wiseco and Ross pistons made for several engines we built.

I know you are now the new resident Olds engine-builder expert and making money off of it ( nothing wrong with that, people who do a good job should get paid for their skills), but don’t just come out of the blue and call other people’s ideas wrong or say that something is junk, just because you don’t use or understand it. Different ways to get down the same path, that is all I am saying.

look up 440 six pack pistons, 5.0L HO engines up to 1993, factory Toyota Supra 93.5-1998, and lots more had factory forged 4032 pistons.....

Last edited by Battenrunner; June 4th, 2018 at 08:29 PM.
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Old June 5th, 2018, 04:53 AM
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Gotcha, but look up “sticking the L2323 piston if you don’t run about .004-.005 clearance on them”. I’ve had to replace those pistons BECAUSE they stuck. And with that much clearance they’re noisy too. That’s more clearance than an Icon 2618 requires. But don’t believe me, look it up.
I know for years it was the only aftermarket forged piston available. But today that TRW piston is junk as compared to what else is available now for not much more money.
For the record I use a custom 4032 Ractec in most of my builds. I agree a 4032 IS better for a street application, but there’s absolutely nothing wrong with using a 2618 for the same application. If you were really on top of the industry you’d know that most companies have now been able to reduce the amount of clearance that piston requires thru different skirt shapes and tolerances.
I used the Icon for years with 0 issues. I switched to my own 4032 piston mainly because I can dictate the dish style and size, as well as the ring pack. And I use different ring packs for different applications. I believe that results in added power and tq. My builds make as much or more hp/tq as other “Olds builders”.
I stand by my statements.

Last edited by cutlassefi; June 5th, 2018 at 06:46 AM.
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Old June 6th, 2018, 11:28 AM
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The motor is at the machine shop. It appears the crank is not worth salvaging anyway. It was already ground .030 on the rod journals, and with the amount of wear from the spun bearing, I’m just going to go with a new crank. The cylinder walls got pretty scored as well so it looks like I’ll be going .030 over on the cylinders.

Last edited by stampsicle; June 7th, 2018 at 07:26 AM.
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Old June 6th, 2018, 05:57 PM
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Get Quality pistons, aftermarket rods and crank. The most critical is proper machining and clearances, every Olds builder varies on clearances, follow who you trust. Extended 3500 RPM runs with a 455 needs quality parts to last long term, the lighter the better
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Old June 15th, 2018, 09:28 AM
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Originally Posted by olds 307 and 403 View Post
Get Quality pistons, aftermarket rods and crank. The most critical is proper machining and clearances, every Olds builder varies on clearances, follow who you trust. Extended 3500 RPM runs with a 455 needs quality parts to last long term, the lighter the better
I’m looking at just buying a complete rotating assembly from Eagle. Going this route, I’m considering just getting a stroker kit and set myself up better for future upgrades like aluminum heads.
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Old June 20th, 2018, 10:16 AM
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I have all the parts ordered and machine work scheduled. I’m going with a new Eagle crank, H beam connecting rods, and forged Icon pistons, ARP main bolts, plus rings and bearings. Cylinders will be bored .030 over, mains line honed, and the block decked. This should be a vast improvement from all stock internals. Thanks to everyone for the help and advice. I’ll post some pictures once I get it home for assembly.
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Old June 21st, 2018, 07:13 AM
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May I ask who you are having do your machine work? AND are the Speed Pro Pistons made by TRW or just the same material as TRW?
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Old June 23rd, 2018, 06:01 AM
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Originally Posted by Tom442 View Post
May I ask who you are having do your machine work? AND are the Speed Pro Pistons made by TRW or just the same material as TRW?
One in the same for Speedpro/TRW.
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Old June 23rd, 2018, 06:34 AM
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Originally Posted by Tom442 View Post
May I ask who you are having do your machine work? AND are the Speed Pro Pistons made by TRW or just the same material as TRW?

Geddes Auto Machine in Colorado Springs
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Old July 20th, 2018, 12:01 AM
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I got the engine back from the shop today and I’m ready to start assembling. New parts include an Eagle crank, Eagle H beam connecting rods, Icon forged pistons, ARP main bolts, and of course all new bearings. The block was align honed, bored, decked and rotating assembly balanced. Bearing clearances came back as follows:

Mains-
1) 0.0022
2) 0.0022
3) 0.0028
4) 0.0024
5) 0.0034

Rods-
0.0022-0.0026

I haven’t checked the rod side clearance yet as I have not assembled it.
My question is, are the main clearances suitable given the stronger new parts? My thought process is that the larger clearances usually recommended are to account for the “weak” connecting rods and heavier pistons, correct?...These clearances are within spec but I want to hear what the Olds experts have to say. Obviously I don’t want to do this again.

Additionally, I will be running a 7qt pan and a HV oil pump.

Last edited by stampsicle; July 20th, 2018 at 12:04 AM.
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Old July 20th, 2018, 04:17 AM
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In my opinion, the mains that are under .0028 are too tight and I would want all the rods to be .0025 minimum

I am going for .003-.00325 on my mains and .0025-.00275 on my rods with polydyne coated bearings

remember that tighter is not better on bearing clearances in olds engines

My crank is at mile high crank right now, getting ground to adjust to these new specs. Dave is great to work with and he is very affordable and has quick turnaround. He quoted us $150 to get the clearances ground correctly and $175 more for nitriding ( still on the fence for that).


On Normal stock or eagle stroker Olds cranks without center counter weights, anything short of a billet fully counterweighted crank, they still flex quite a bit, and even more so when left as externally balanced and spun higher than 5500rpm. This flex requires more bearing clearance to keep metal from touching.


It is cheaper to get it ground/fixed now than mess it up and spin a bearing on a fresh build

Last edited by Battenrunner; July 20th, 2018 at 04:29 AM.
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Old July 20th, 2018, 04:44 AM
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The Eagle crank is markedly stiffer and lighter than a stocker so that helps but the block/caps still move around as well, especially without studs and/or straps etc.
I’m guessing you’re using Clevite mains. If so buy a set of Federal Mogul 108m bearings instead. They’ll give you a little extra clearance and don’t have a full groove, another plus.
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Old July 20th, 2018, 02:22 PM
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Originally Posted by cutlassefi View Post
The Eagle crank is markedly stiffer and lighter than a stocker so that helps but the block/caps still move around as well, especially without studs and/or straps etc.
I’m guessing you’re using Clevite mains. If so buy a set of Federal Mogul 108m bearings instead. They’ll give you a little extra clearance and don’t have a full groove, another plus.
They are Clevite. I read in some of the other threads that the FM’s will give me about a 0.0006-0.0008 clearance. If that’s the case I’ll be looking at 0.00028-30 on the low end. Just curious, What is the benefit of less groove? Thanks!
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Old July 20th, 2018, 02:26 PM
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Originally Posted by stampsicle View Post


They are Clevite. I read in some of the other threads that the FM’s will give me about a 0.0006-0.0008 clearance. If that’s the case I’ll be looking at 0.00028-30 on the low end. Just curious, What is the benefit of less groove? Thanks!

Simple, think of it in terms of a tire hydroplaning. A slick hydroplanes more than a treaded tire right? Same with bearings, less groove on the bottom half gives more oil support.
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Old July 20th, 2018, 02:29 PM
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Originally Posted by Battenrunner View Post
It is cheaper to get it ground/fixed now than mess it up and spin a bearing on a fresh build
You’re telling me..
I am kind of wondering though if my rod bearing spun due to an oil starvation issue caused by the sustained high highway rpm and the poor oil return to the stock pan. All the bearings looked like they were eventually going to go, after I inspected. One of the reasons I’m adding the 7qt pan that was on my 425 is for the added insurance..or peace of mind.
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Old July 21st, 2018, 06:24 AM
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The larger pan will help and follow Mark's(Cutlassefi) advice. Long trips at 3500 to 4000 rpm is rough on a BBO, not really designed for it. I say 4L80E.
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Old July 21st, 2018, 08:27 PM
  #36  
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There is a old machinist saying about bearing clearance, if the clearance is loose, only your machinist will know. If it’s too tight, EVERYONE will know.

Most at machine shops will set parts up with clearances that work well for chebby engines.
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Old July 21st, 2018, 09:29 PM
  #37  
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Originally Posted by matt69olds View Post
There is a old machinist saying about bearing clearance, if the clearance is loose, only your machinist will know. If it’s too tight, EVERYONE will know.

Most at machine shops will set parts up with clearances that work well for chebby engines.
That is exactly what happened with my 400 motor when I rebuilt it. The machinist was a chebby guy and was kind of caught off guard when I asked him to loosen it up (per Mark Remmel). Guess Mark was right, the thing runs like a scared antelope!
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Old July 22nd, 2018, 05:50 AM
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The problem is all your “chebby” guys are just stupid, or stubborn, or something.
My guy was in no way an “Olds” guy before I started going to him. BUT I could see that he was smart and open minded enough to know not everything is exactly the same. He’s the best imo.
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Old July 22nd, 2018, 06:18 PM
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Originally Posted by cutlassefi View Post
The problem is all your “chebby” guys are just stupid, or stubborn, or something.
My guy was in no way an “Olds” guy before I started going to him. BUT I could see that he was smart and open minded enough to know not everything is exactly the same. He’s the best imo.

i agree, the problem is unless the owner request the parts set up the way Olds engines prefer, or the machinist is familiar with the specifics of successfully Olds engine builds, chances are your going to get the tight clearances. I was lucky enough to have a old timer machinist that raced Olds back when these cars were new, he knew what he was doing and never had issues. He retired ( guess he figured working in his 80s was long enough!) and sold his business to a chebby guy, I’m not confident with him, he kinda questions some of the things I request. So far I have been lucky, the last engine I was involved in that he did work on is still going. I was pretty concerned, I understand everyone learns something new, I just didn’t want him to learn on my stuff!!
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Old July 29th, 2018, 09:20 AM
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I put a set of FM 108m bearings in and rechecked the clearances. I’m now at:
  1. 0.0029
  2. 0.0029
  3. 0.0030
  4. 0.0031
  5. 0.0045
Is there any concern with #5 being so loose? I still have the Clevite set and could just swap the #5 back in if less clearance is desirable. Thanks for the help guys.
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