Bearing problems

Message

dadnova · #16 Post by **dadnova** » Wed Jan 10, 2007 10:38 pm

Well I found the problem. My SCAT crank was and is bent right out of the box. I have a freind who was a machinest and I asked him to bring over some dial indicators as oil was not the problem it had to be the crank or the block. I placed the crank in the block after checking the block and 1-4 journals were within 1/10 of a thousands of an inch, however the rear journal has 1 1/2 thousands of run out, more then needed to distroy the rear bearing. Hopefully SCAT will honer there crank and replace it with a good one.

#17 Post by **John_Heard** » Thu Jan 11, 2007 7:03 am

Ouch, well at least you found something wrong.

jones_performance · #18 Post by **jones_performance** » Thu Jan 11, 2007 11:27 pm

well that'll do it. guess you never should assume that new parts are right.

dadnova · #19 Post by **dadnova** » Fri Jan 12, 2007 9:12 pm

The builders should of check it. Thats what I paid them for. The engine was supposed to be blueprinted, that means perfection only. Well I know everyone in my car club will now never use eather of these builders for anything, their loss.

jones_performance · #20 Post by **jones_performance** » Sat Jan 13, 2007 1:25 am

yup they should have. they probably figured since the part was new that it was correct.

dadnova · #21 Post by **dadnova** » Tue Jan 16, 2007 8:43 am

Thanks Racer 704
I took your advise and looked for the problem myself, took me all of 15 minuets to find the problem myself after my friend show up with his instruments. Now Scat is telling me they dont make a bad crank, well I got news for them, THEY DO.

BigTiny540 · #22 Post by **BigTiny540** » Wed Jan 17, 2007 12:00 am

It does happen! I bought a crank 3 years ago from a reputable company and when I sent it out to be balanced the machinist phoned me to say they were having trouble getting the crank to balance. I told him to stop everything and I sent it back to the company and told them the run out journal to journal was outside the range stipulated on their spec sheet. They had me send the crank back to them and they checked it themselves and found the same run out issues. They gave me full credit and I moved to another manufacturer.

dadnova · #23 Post by **dadnova** » Wed Jan 17, 2007 7:13 pm

Here is my problem. The mechanic checked it and said it was OK. Now we sent it to the best crank shop in Anahiem and they said it was good as well. So I called them and told them to check it my way or the way I did, and it will be bad. The problem is everyone keeps checking it with the front and the rear placed in the blocks, what happens is its out about 3 tenths is all this way as the extra lenght is taking up the bad and spreading it out. As I told them today, check it with the blocks on #1 and #4 journal or # 1,2,3,and 4. for everytime its only the rear bearing at the very rear of it that goes out within 1/2 hour. If you put the crank in the block on
#1-#4 journals as those bearings are always in great shape then if you check the rear journal you will see its now out 1 1/2 thousands.
They said they would check it running it on #1 and #4 journals and call me right back. I think they found out what I was talking about for I never recieved the call back.

jones_performance · #24 Post by **jones_performance** » Thu Jan 18, 2007 10:42 pm

wow, thats an odd place for it to get bent, usually its out in the middle. wonder if it got dropped at one time?

dadnova · #25 Post by **dadnova** » Fri Jan 19, 2007 4:45 pm

Well that's it I give up. Now the crank shop is telling me its OK. I know what we seen and the dial indicator doesn't lie. I don't see how a crank can be good if it destroys bearings every 1/2 hour?

jones_performance · #26 Post by **jones_performance** » Fri Jan 19, 2007 11:43 pm

have the mains of the block checked maybe they are out.

got any pics of the bearings?

nj · #27 Post by nj » Sat Jan 20, 2007 2:41 am

Are all the main bearings bad or just the rear main? An is it just on the thrust surfaces or is in the bearing itself? Which thrust surface is bad? the balancer side or the transmission side. try to get us some pictures.

As for finding rag material in the filter, that is rather common on a fresh rebuild. After we rebuild a motor, we warm them up to 180 or 190 degrees and then we drain the oil and check the filter. It always has some lint in it. Now excess lint is due to using the wrong type of rag and should be addressed. By the second or third oil change most of that should be gone unless you adjust the valves alot or have the valve covers off and wipe them out with the wrong types of rags.

sunsation540 · #28 Post by **sunsation540** » Sat Jan 20, 2007 4:55 pm

it could be that the crank is not bent ,but ground out of round. on the eagle and scat stuff we have had to go through as many as 3 to get one that is on size and round without taper. take it to the best crank shop in the area or a deisel shop they have highley mantined stones have it cut to a 0.10 under on the mains this will remove any imperfections and don't grind out the radius. as many production shops will do... then go back and presure ck all the main galleys for proper lube flow you could have a pin hole in the casting .. then follow the other guys suggestion about priming the engine with the pan and intake off. cut a old pick up tube off and put a hose on it, put it in a drain pan with oil and spin- er up with a primer tool it works we had a lifter bore that was too big this is how we found it, as well slleved it down and never lost another cam it,s a lot of work but thats racing

dadnova · #29 Post by **dadnova** » Sat Feb 10, 2007 11:03 am

three times this has happened. No ware on the thrust sides.

sc racing · #30 Post by **sc racing** » Sat Feb 10, 2007 2:54 pm

Did you ever put the brg in,torque the caps and measure the inside dia of the brg?This will give you your oil clearence when you subtract the dia of the crank journal.Does the main cap have a hole all the way through where the oil pump bolts to it maybe the bolt (or stud)is hitting the bearing????Does the oil hole in the brg line up with the oil hole in the block?Just some things to check.

Bearing problems

Who is online