guinness2

I spun a rod bearing and I have damage down to 2.086 on the journal.how much can these cranks be turned down to??

guinness2

well????????

Bryan@LME

iTrader: (4)

You can turn the crank .020 no problem. That will be enough to clean up the rod journals

Cal

iTrader: (1)

I believe NASCAR engines run a much smaller rod journal than LS1's. People also offset grind LS1 cranks to get a longer stroke. Do you have any idea what caused the bearing to spin?

guinness2

What bearings are used for that??

guinness2

Yeah, low oil. Do you have any specifics on this offset grinding and is it cost effective??

Cal

iTrader: (1)

Oh OK; yeah that's what just happened to my bro-in-laws Evo; you have to really watch that oil level. Especially with the way these LS1's like to drink oil.

Many people claim offset grinding is very cost effective, given the price of stroker cranks. Maybe for you especially since you have to grind one journal anyway. Do a search, there have been a lot of posts on this in the past.

Steve - Race Eng

iTrader: (1)

If that rod journal is discolored from heat the crank is most likely bent. It will also most likely not clean up at .020" under. Most of the wear will be on one side of the journal. You will probably have to go .040" under if the crank isn't bent or cracked.

Cup cars, drag cars etc. use small diameter bearings to cut friction. Rod bearings usually Honda 1.88" or Olds Aurora. Mains generally small journal (283") small block Chevy size.

You can have your crank ground to small block Chevy 283" rod journal size of 2", even offset ground a bit to increase the stroke. You will need a new custom set of rods and pistons (if offset ground) specially made for your combination. $$$$$

Steve

Ben R

Steve,

how many people have you seen use a BMW Rod Journal in a small-stroke application?

1QWIKZ

iTrader: (6)

i had my crank offset ground to a 3.72" stroke. you will need rods that have a 2.00" rod journal and custom pistons. scat sells those rods for about $450 and the piston/ring combo will run about $850(depending where you call). so its not as expensive as steve said since you will save money on the rods"(as compared to eagles or lunati rods).

guinness2

Thanks for the education. There seems to be no discoloration,this gives me some things to think about. Is the offset ground performance gain worth the cost over the stock parts??

guinness2

Can you give me the specifics of what you did with your combo and what it runs like??

1QWIKZ

iTrader: (6)

my nephew ended up with my engine combo since i converted to a 408. one thing i can say is that engine loves to rev. but what i had done was offset grind the crank to get a 3.72" stroke. i used scat 6.125"SBC rods with a 2.00" rod journal, custom diamond pistons, GTP S3 heads. never had the engine assembled but my nephew does. the only difference is he is using PRC s2.5 heads. that should be putting him in low 11 sec range. he will be taking his car out to the track by the end of this month, so i will get back to you with the #s. as far as cost, you will spend about $1350 for the forged offset setup(depending on who you call of course)

guinness2

Thanks

Steve - Race Eng

iTrader: (1)

If you can get the crank offset ground and nitrided for a reasonable price, go ahead and have it done. I believe the Scat rods are offset beam for a small block. They will work in the LS1 but the pin end of the rod will not be centered in the piston.

Steve

Steve - Race Eng

iTrader: (1)

I have not used the BMW bearing myself but I know some are using them. There are many other small journal combinations used but the most common ones are the Aurora and Honda B18C series bearings.

Steve

1QWIKZ

iTrader: (6)

are they expensive? from what i understand thats why people kept away from doing the offset stroke.