What causes a spun bearing?

[Chuck Leeper]

I would think that..

"How does one dispute such a claim. Detonation is a gray area, it lies in between a good tune and a bad one, or between a good engine and a spun bearing, or between a busted engine being the customers fault vs the ability and knowhow of the engine builder. I am not a tunning master, but I can read a scanmaster and an EGT probe. I chase fuel with boost, not the other way around."

A. Disputing such a claim starts with some diagnosis as to what the problem REALLY is/are, and what the possible causes are. [Be there when the builder does his inspection.]
B. Detonation is not, IMO, a gray area. There are many indicators, from plug readings, brg condition, piston condition, etc. Again, refer to "part A".
C. Relying on a "Scanbastard", and an EGT meter, is too little, too late, when attempting to prevent a failure. Both these devices are waay behind the time curve when reporting a possible problem.....
Maybe a WB with some recording channels?? Like you suggested, sneak up on the max power. I'd suggest doing it with a more reliable data stream.

Just my $.02.
Back under my rock....

 

[Clark6]

My last Buick GN Engine was hauled about 450 miles to a great shop that builds a good Buick Engine. Why did I chose this route or place? This shop had a reputation of building a great engine. My only complaint was the time table to get the completed block back. It ran strong, good oil pressure and other than a few minor details no problems over 3 years of hard use. Counting the cost of removing an engine and doing it over several times way out prices sending to a good known shop and doing the work once. Several people have gone through this same experience in the past only to save a buck, myself included. A sore subject to talk about and for sure we all feel your pain. I don't know the reason why your bottom end failed and just gave some possible causes as did others. Take Care. GB

what shop did you use? i wish cal hartline would go ahead & open his performance shop but i dont know if he'd do short blocks if i understood correctly in the gmhightech mag. i may contact him to be sure....

 

[1991syclone]

Bearing fail from heat; caused by clearance, foreign matter, ect. If you want to find the cause you may want to contact the bearing company. My first job out of school was with TRW (the CL77 bearings). When we lost a motor we could send in the bearings and get an engineering report. They could tell us bearing clearances, outside matter in the bearing and the temp they failed at. Which made it easy to place blame. (about 4 pages of material) Start with the store you bought the bearings, then to their wholesaler to the Company Rep. (or just try the Company, they will be less helpful to outsiders) Hopefully they still have the service. Since you had a main fail I don't think it will relate to knock, that will usually take out the rod bearing first, once the oil is contaminated then anything can go. Hope that helps.

 

[Clark6]

Bearing fail from heat; caused by clearance, foreign matter, ect. If you want to find the cause you may want to contact the bearing company. My first job out of school was with TRW (the CL77 bearings). When we lost a motor we could send in the bearings and get an engineering report. They could tell us bearing clearances, outside matter in the bearing and the temp they failed at. Which made it easy to place blame. (about 4 pages of material) Start with the store you bought the bearings, then to their wholesaler to the Company Rep. (or just try the Company, they will be less helpful to outsiders) Hopefully they still have the service. Since you had a main fail I don't think it will relate to knock, that will usually take out the rod bearing first, once the oil is contaminated then anything can go. Hope that helps.

ahhhh a summed up simple answer yes it did help.thanks again to every one.
well lets see i dont think i had any contamination as i changed the oil before every track visit good filter & oil except for the final stage of the copper material flooding the oil pick up screen & i dont think it ran too hot-- engine never ran hot so now i guess it leaves what every one else was saying: Clearance issue::frown:

 

[GNDriven]

Can the main or rod bearing clearances be check if the engine is already together? Meaning can one pull the oil pan and check the clearances once the engine is assembled? Thanks.

 

[1991syclone]

Sorry, I was not clear enough. Heat refers to the bearing temp not oil or water. Contamination comes from the causal part (the first part to fail) not from changing the oil.

 

[need boost]

Clark6 did he line bore the block for sure? I know that block was straight and he used the caps that was one it already. I wonder if he didn't screw it up when he got the crankshaft for you. Hate to hear it man, after yours and dougs now I want to drop the bottom of mine to check it out again before it messes up!! Daniel Ray

 

[scottk]

shop

wild cat performance is the **** machine shop they know what they are doing!

 

[Clark6]

Clark6 did he line bore the block for sure? I know that block was straight and he used the caps that was one it already. I wonder if he didn't screw it up when he got the crankshaft for you. Hate to hear it man, after yours and dougs now I want to drop the bottom of mine to check it out again before it messes up!! Daniel Ray

lets see he charged me...
1 238-2 main caps 177.00
1 arp main studs 58.00
rear seal 12.35
oil pump 41.72
1 3-35950 temp set?29.60
1 412530 rings 77.47
6 rocker arms 34.84
6 rocker arms 34.84
1 hs9941pt head set 72.08
1 main bearings 37.20
6 rod bearings 29.55
1 cam bearing 18.08
1 bottom gaskets 36.60
intake gasket 21.60
oil filter 5.95
5 something i cant makeout 11.95

1 used ground 10. 10 crank 110.00
1 used 3.8 block with pistons 400.00
machine block & heads 680.00 labor
698.83
total sublet???? 510.00
tax 48.92
total $1937.00
i thought i came out ok dont see any thing about honing or line boring just machine block. you mean to tell me you had the steel caps already on the block danny ,, oh well i think i came out pretty good any way ,it lasted a yr & about 40 track passes & about 25 get on it back road runs including a the race with the nova. any where from 20 to 26psi of boost i guess i got that alky kit about 2 months ago and got greedy with it thats what took it on out i guess. im gonna let mike do it at wild cat since dls is over stocked with builds...im just gonna check on every thing with mike & hope he does it himself instead of you know who or at least make him check behind him . i may just take the standard bore block to him & just sit on this .030 doug say i could do a line bore on that one & itd be ok i guess ill just start fresh & go .010 on my std. one.

 

[HP Man]

Again I reiterate machining needs to be completed by a shop that knows Buick Engines. Critical check to be made to make sure the lower end lives. Buicks like very tight bearing clearances, both rods and mains, the main cap needs to be aligned exactly 90* to the crank centerline or the thrust bearing will fail, all clearances need checking with both a dial bore mic and crank journal mic, don't plasti-gage anything on this engine, do it right. If these methods aren't followed then the bottom end will eventually fail. I've been there and it cost me thousands of dollars to do it right, AGAIN. GL GB

 

[ITSAV6]

????????????

He did not align hone the caps! He just threw it together I think. That's why he had my center caps in the wrong positions and had the wrong size thrust bearing in! I know the caps were in the right position when the align hone was done cause I was there. My block was there before he started ur motor and was there after yours was in and running!
DO NOT TAKE IT BACK TO TIM. I don't care if he works at Wildcat Perf now or not. You will need to replace all the rod bearings,poss the cam bearings,flush the block,the bearing material might get the turbo bearings too.
Tim said he checked endplay on my crank but it had .014 but I caught it in the first 50 miles. Then the excuses came.....the neoprene rear seal makes it hard to check endplay,his assistant must have reversed the caps,the shop that ground the crank didn't tell him they ground the thrust surface .010(which would have been caught when checking endplay). I let him install the crank in the block so he could check endplay and make sure it was right.
If ur scared to tackle it urself let Fred assemble it,he'll make sure it is all good and the machine work was done correctly!

 

[Clark6]

im talkin to mike himself at wild cat dont wanna hurt tims feelings come on doug, LESSON LEARNED. gonna take this slow dont wanna rush it freds a plus too when i get my finances in order i'll make my descision then but i think i AM gonna pass on tim this time. at least he did get the new flat tappet in right so i didnt wipe a lobe. or was that on my part???? its ok bite me once shame on you bite me twice shame on me........

 

[GNDriven]

After reading this I am even more frightened that my engine was not done right, because of the inexperienced buick engine builder I used.

Can someone please provide a list of all the clearances and endplay measurements that must be setup and done properly in a 231 ci turbo engine. I.E. Rod, Main, crankshaft, cam shaft, etc. I am going to contact my engine builder and ask him how exactly he set up the engine that I have now. If any of these are not suitable, what do you recommend I do? Thank you for any info.

 

[ITSAV6]

................

im talkin to mike himself at wild cat dont wanna hurt tims feelings come on doug, LESSON LEARNED. gonna take this slow dont wanna rush it freds a plus too when i get my finances in order i'll make my descision then but i think i AM gonna pass on tim this time. at least he did get the new flat tappet in right so i didnt wipe a lobe. or was that on my part???? its ok bite me once shame on you bite me twice shame on me........

Mike just works there I think,belongs to belongs to Richard Lasseter.
That's a motto I like,I will not get bitten twice either:biggrin:

GN T Type.org has all the clearances.

 

[need boost]

clark, yes it already had the billet caps on 2 and 3. He kept them on the block for you because he knew it was right. I know it was because my bearings looked perfect when I pulled the motor out except for some scatches from the metal that went thur from my cam whipping out. He ordered me new caps for mine since my block was new and put them in and did a line hone for me on my new block. Thats why I said you should check that crankshaft. I bet it isn't right somewhere. If the block was wrong it would have messed up my crank that was in it before. Tim did a good job on mine, so far anyway lol. Just took forever! I think if I ever have to get machine work done again I will take mine down to flordia to the poncho shop there. I have met the guy there and he has a great rep for excellent work. He builds mainly pontiacs but also is into buicks and oldsmobile motors also some. Later man Daniel Ray