Thread: bearing life

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Thanks, I wont bother you on this any more.

Aw, come on Joe, we've got a 3-pager goin' here. With any luck, we could stretch it to 6. Keep postin'.

Well if nobody has got anymore info than what can we talk about.
I would love to keep it going if you want. but I might have to think of some more questions.

I still havent had anybody tell me if they rebuild after so many races or hours. I dont know if anybody has a set time but that shure would be nice. Right!

AFTER ABOUT 40-45 NIGHTS IN A 383 TURNING 7,200 ON ONE TRACK AND 7,800 ON THE OTHER TRACK WE PULL THE ENGINE DOWN.WHEN WE INSPECT THE RODS THE FIRST THING WE LOOK AT IS THE (CROSS-HATCH)IF IT IS GONE OR YOU CAN'T HARD'LY SEE IT WE KNOW THE ROD IS WAY OUT OF ROUND.AFTER ABOUT TWO RE-SIZEING'S ON BOTH THE BIG END AND SMALL END OF THE ROD THEY GET THROWN AWAY.TO BE ON THE SAFE SIDE THE CAPSCREWS ARE ALSO REPLACED.THINK OF WHAT THE ROD IS DOING.WHEN IT PULLS AWAY FROM TDC TO GO TO BDC THINK OF THE ROD STRECTHING A LITTLE BIT AND WHEN IT GOES FROM BDC TO TDC IT IS TRYING TO BE COMPRESSED.WHEN IT COMES TO ROD LIFE IT IS A QUESTION OF CYLES.WE ALSO VIEW THEM AS A 8 SHOCK ABSORBORS TRYING TO SAVE THE CRANK.TO US THEY ARE ABOUT LIKE A DISPOSIBLE RAZOR AFTER SO MANY TIMES YOU JUST THROUGH THEM AWAY.

You mean cross hatch on the cylinders. And how many times is it run in a night.

after each weekend on my car, i would re-torque the heads and run the valves

if i burnt up something...motor came out and got a good cleaning along with every other part...i use GRP alum rods and they go a whole season easy...hone the cylinders and massage the pistons(new ones for the burnt up ones)...new rings, bearings, valve job & spring check along with setup, & sometimes gaskets...

no set schedule...i lean on it hard at the track...its built for it...thats the place to do it...i could easily go all season and not burn up pistons but i try things if you do the same ole, you'll get the same ole

Originally posted by joe bogger
You mean cross hatch on the cylinders. And how many times is it run in a night.

NO, I MEAN THE CROSS HATCH ON THE RODS.IT IS RUN 5 LAPS IN HOT LAPS, 10 IN THE HEAT AND 20 IN THE MAIN.ONE TIME A WEEK ON A 3/8'S MILE TRACK,THE OTHER TIME ON A 1/2 MILE TRACK.

bearings are made to take a lot .what you need to know is when is a good time to go thru the engine before something goes bad this is hard to say. my stuff see more miles that drag stuff and i look at 2 to3 times a year on springs and lash .and put new roller lifters in evey two years and go thur evey 3 years but this my stuff i run stuff on the street that a lot of guy drag. but i do not know what parts you have. and how good they are. here you have a blown drag car guy telling you what he dose this will not help you unless you have the same thing. a circle track guy and this will not help you unless you have the same engine and run a circle track to. and then you have me blown 548cid roller bow tie engine and 630 cid+ donovan roller engine. my big block s my stuff make about 850 hp and do not drive it much .the only thing you can take a way from this is they all have bearings in them. so if you are running some thing very hard for the first time. i would take it down and look at it after 2 or less weeks and check it out . but you need to know what to look at and what to look for and you need to know were is the running clearances on the engine so you have a way to check the stuff and you have to know how to read the bearings the piston the head gaskets etc you have to know what you are looking at.

Originally posted by erik erikson
NO, I MEAN THE CROSS HATCH ON THE RODS.IT IS RUN 5 LAPS IN HOT LAPS, 10 IN THE HEAT AND 20 IN THE MAIN.ONE TIME A WEEK ON A 3/8'S MILE TRACK,THE OTHER TIME ON A 1/2 MILE TRACK.

Joe, the big ends of the rods are honed to size with a stone just like the cylinder walls.

thank you techinspestor1 for explaining that a little, see that is something I did not know and maybe that is why the bearings failed. I got the block and rotating assembaly all assembled on a deal and was told it had a fresh rebuild and was ready for the top end then run it but when I tore the engine down to see for shure the crank and rod bearings had goudges in them so I put a new crank and bearings in it to be safe but did not know the rods need cross hatches in them also. Do the cross hatches in the rods serve the same purpose as the ones in the cylinders.

Originally posted by joe bogger
thank you techinspestor1 for explaining that a little, see that is something I did not know and maybe that is why the bearings failed. I got the block and rotating assembaly all assembled on a deal and was told it had a fresh rebuild and was ready for the top end then run it but when I tore the engine down to see for shure the crank and rod bearings had goudges in them so I put a new crank and bearings in it to be safe but did not know the rods need cross hatches in them also. Do the cross hatches in the rods serve the same purpose as the ones in the cylinders.

NO,THEY DON'T.THEY ARE JUST HONING,OR MACHING MARKS.

Well isnt cross hatches in a cylinder from a hone.

Originally posted by joe bogger
Well isnt cross hatches in a cylinder from a hone.

Yes, but the cross hatch marks in the cylinder are to roughen up the bore slightly so the rings can wear-in. They are also there to hold a little oil on the walls. As Erik said, the marks on the big ends of the rods do not serve the same purpose, they are just there because that's how the big ends are sized, with a stone.

Originally posted by techinspector1
Yes, but the cross hatch marks in the cylinder are to roughen up the bore slightly so the rings can wear-in. They are also there to hold a little oil on the walls. As Erik said, the marks on the big ends of the rods do not serve the same purpose, they are just there because that's how the big ends are sized, with a stone.

rod can be honed this is done and will have cross hatch marks or they can be bored with a rod boring machine .the machine i have is made by sunnen and i would say that 90% of the rods out there are done this way but not all.