i need advice on rod bearing oil clearance, i have a stock 4g63 crank which spun a bearing.

now after polishing it and with new standard size ACL bearings the clearence is .003

is this fine or should it be tighter? can i run the car like this or do i need to cut the crank and get oversize bearings.

i really hope i can get away with this clearence, what do you guys think?

 

He bud, I just finished my build, so I know the feeling! Truth is you will get many answers. Even though it will be in the same ballpark of clearences, you need to determine that cars use and ultimately your ideal clearence.

few questions for ya, are you using an outside micrometer for the journals and a dial bore gauge for the rods with bearings installed? Or are you doing the plastigauge old school way?

On my setup, I ended up with 0.0022-0.0024" on my mains, and 0.0026" on all my rods, i used king xp series bearings and hd a brand new billet uncut crank. All my main journals measured out to 2.2437" and my rod journals about 1.7731" or so (off top of my head)

anyway I would personally say 0.003" is a little too loose. Depending on other factors you might be fighting oil pressure issues, that last thing you want is for the oil pump to not make enough flow at high rpm and have that loose bearing grap. This is just my personal opinion, This is given you ARE using correct measuring equipment.

-Roni

 

I would agree, out of spec and crank bearings do not go together.

If it was an old school chevy or daily driver stock civic. It would be ok no boost no high load.

Now on a evo i wouldnt risk it. Everytime you do a pull its gonna be in the back of your head.

 

You need a new crank, or you need to cut it .010 and get oversize bearings. Rod bearings should be in the 2-2.5 thou range.

You COULD resize the rods, but I would not recommend that.

 

^^^this ....what did the machine shop tell you? How much did they take off and what are the clearances? Sounds like you polished out the scuff marks and are trying to fit bearings---that's not going to work.

 

The journal will be out of round....they always are.
Needs a grind and undersize bearings.

 

thanks for the response pal! i used the plastigauge to check it, i dont have a micrometer.

i read other forums aswell and they also say .003 is loose, so now my other option is to cut the crank and get oversize bearings.

there's no point in running this loose of a gap only to have oil pressure issues or spiining a bearing again.

thanks again!

 

thanks! i'll cut the crank and get oversize bearings

 

Plastigauge is very inacurate, you may have 0.002" actual clearence or 0.004" no one knows until you mic it, either get the proper equipment and cry a little (like i did) or buy a new crank for peace of mind, regardless any builder will recommend you buy the proper tools. Hope that helps ya brother

 

Hi...im now in the middle of building 2.0LR spec...piston wiseco CR 9:1..rods 156 manley..kings bearing ...evo 8 crank..turbine gt35 ..my concern is on the bearing clearence for main and rods..finally what is the best for it ?..thinking of revving 9krpm with liqui moly 10w60 oil engine...and i will fit in the new oil pump..and coworth oil scrapper in oil pan...my worry is on bearing durability..need advise..

 

For high revving ud want to focus on the rods and rod bolts, I would do pro h rods with Carr bolts, will also be better on the bearings, your choice of crank is perfect stay stock.
Idk what your intentions are but I'm guessing a highway monster but not strip/drag because non aluminum rods, and CR?
I'd go with 10.5:1 w/ upgraded wrist pins and of course E85, I would also stay SLR. Just my opinion.
If your far into build upgrade your rod bolts 625+
​Good on scrapper but also focus on a mod that will keep your strainer in oil at high hp pulls, your rotating assembly will thank you.

 

thanks mate.
Noted with that...my aim is highway monster haha..
for piston...ive brought the wiseco LR set cr 9:1 which i can't change anymore...
only that now thinking, what is the best main crank and conrod bearing clearence for this spec to rev 9krpm ?..mind to advise me...tq

 

Bearing clearance and PTW are determined by the power you expect to make. The kind of use the engine will see also has a factor in the PTW.

 

any chance to those that has achieved the setup to share the spec ..especially on your bearing clearence?..
tq in advance.

 

I recently purchased a set of Manley Turbo Tuff Rods and inside the the box they had a sticker attached recommending ACL or Clevite bearings.

What do you guys think?