Looking for some ACL race bearings for my turbo gsr build. My block is bored to 81.5mm, I'm confused when ordering main bearings it says Standard, .025mm, .25mm, or Standard + 0.001. Which one do I chose? Also for rod bearings, I am using Eagle rods, are they just all the same? Looked in the Faq but didn't see a link to anything related. Google just gave me whole bunch of unaswered questions. Either I'm not searching the right thing or something.

Pointing me in the right direction would be great. Trying to get it the machine shop asap.

 

Did the machine shop size them up for you? You really want RACE bearings and not the standard bearings? I know you're going to the drag strip and all, but the RACE were for those that don't mind changing them once in a while.

Use the standard ACLs if you must. Or if they mic'd them appropriately, OEM is even better.

This was more of a question to ask as well as a suggestive idea, really.

 

I'm just wondering which would be best. I've heard my fair share of why you should use this or that. It's a drag/ daily driver in the summer. Machine shop did not mirco'd them. I'm just finishing gathering parts to take it to a machine shop.

But looks like I will be going with standard bearings. Thanks

 

yeah go with standard bearings. the goal is the clearance

 

You really have to mic the crank and journal to be sure. Even then they can be too tight. That's when you get the acl's hx line. They're the smallest bearing giving you a larger clearance.

I was told by mike laskey not to use the standard non race acl brand. He said they're being made else where now and the quality isn't there any more. if going acl always run the race series.

If you have your old bearing's toss them in and plastigauge them.

 

Give the Clevite race bearings a shot. The clearance on them were great for my motor

 

So you're suggesting I take in my crank to a machine shop to get it mic before buying new bearings? I bought everything seperately because the crank in my block as a damaged keyway for the crank pulley. The current black has acl bearings in it. Have not yet tore it apart either.

Everything is new besides the crank which I purchased from a member on here as well. Money isn't the issue. I just want to make sure everything is done right without cutting corners besides not sleeving the block.

Guess I'll have to pull the motor out sooner than expected. I wanted to do all the fab work with the motor still in the car and making sure everything fits fine before taking it out.

Thanks for the replies

 

If that's the case I would definitely get the crank mic'd before buying bearings.
Shouldn't cost much.

 

Sounds good. Will do!

 

oem blows ACL junk away when it comes to bearings

 

How would you even know which color bearings to order? lol

 

And why is that? Im not saying I know everything about bearings but since they never actually touch the crank (unless you have a crap tune) why are they so bad? Ive read post of people using them for up to 75000 miles with no problems.

That's when you get the crank and journals mic'd and you dial in you clearance's.

With the acl's, each journal will most likely be off one ten hundred of a thousandth (.0001)

 

in my experience ACL's are junk. but thats just what ive seen and heard from reputable people in my area. some people dont have problems with them, some have major problems. i always use oem bearings and havent had a problem yet.

 

OH.......Ok...

 

ive seen freshly built engines eat bearings(ACL's). they were replaced with OEM bearings and everything was fine once the crank and rod(s) were replaced or fixed. plus, what happens if you have a main or rod that needs a different size bearing to be within the tolerance you are shooting for? have fun with that with ACL's

 

Isn't that why you have to mic the crank before buying bearings?

 

He's talking about getting a certain clearance for each journal. (.0018 for main#3 and .0017 for main #5) with acls you don't have much of a variety.
Oem bearings you can mix and match bearings.
example: You want just a tiny bit more clearance and you're using oem green's, so you use one half green and the other yellow.

Here's the oem bearing chart.
Red being the thinnest bearing.(more clearance)
Blue being the thickest (less clearance )

Main Bearing thickness by color
Blue 2.013-2.010 mm 0.0793”- 0.0791”
Black 2.010-2.007 mm 0.0791”- 0.0790”
Brown 2.007-2.004 mm 0.0790”- 0.0789”
Green 2.004-2.001 mm 0.0789”- 0.0788”
Yellow 2.001-1.998 mm 0.0788”- 0.0787”
Pink 1.998-1.995 mm 0.0787”- 0.0785”
Red 1.995-1.992 mm 0.0785”- 0.0783”

Rod bearing thickness by color
Blue 1.510-1.507 mm 0.0594”- 0.0593”
Black 1.507-1.504 mm 0.0593”- 0.0592”
Brown 1.504-1.501 mm 0.0592”- 0.0591”
Green 1.501-1.498 mm 0.0591”- 0.0590”
Yellow 1.498-1.495 mm 0.0590”- 0.0589”
Pink 1.495-1.492 mm 0.0589”- 0.0587”
Red 1.492-1.489 mm 0.0587”- 0.0586”

 

My block/crank was stamped for greens across the board. I got everything mic'd and the specs were dead on for stock, so I ordered a pair of OEM yellows and a pair of OEM pinks for the mains. Plastigaged everything and the pinks gave me the clearances I wanted across the board, so that's what I went with.

On the rods, OEM reds were still too tight, and ACL HX promised .001" more clearance than the .0008" the original greens gave me. Ordered up a set of HX's for the rods, plastigaged them and came out spot on at ~.0018, so that's what I went with.

From what I've learned through my personal experience, it's all about finding the shoe that fits, not about running brand X or Y. Like turbohatch said, the crank should never touch the bearing when the motor is running, therefore I believe any issues some homeboy had with brand X vs Y was probably because they threw it in without any measuring and didn't have a clue what their clearances were.

 

Thanks for the input. You actually cleared it up alot for me.

 

There's more to bearings than clearances, a lot more. Engines don't just "eat bearings", tight clearances, poor oil supply, and dirty/contaminated oil is what kills bearings.

ACL's Race bearings are designed to be better than stock bearings, otherwise what's the point? Two big reasons I prefer ACL's (I use them in pretty much everything) is that they have a higher crush than OEM bearings and a higher eccentricity profile. Crush is what's responsible for keeping the bearings from spinning in the bores and the eccentricity profile is what forms the wedge of oil that keeps the journal from contacting the bearing.

Leave the stock bearings for the stock rebuilds.

 

To answer your question, the .001"/.025mm bearings are for when you need less clearance. Each shell is .0005" thicker, so together you will get .001" less clearance than the standard size bearing. The .25mm bearings are even thicker for when the crank has been turned down to a smaller diameter.

 

 

This thread is not a debate about OEM vs ACL bearings. That has been discussed ad nauseam.

The .25mm and .025mm sizes are undersized bearings for if you have your crank journals milled.
http://www.freeasestudyguides.com/cr...nspection.html

Standard is usually close to the OEM green size. And the HX is usually gives .001" extra oil clearance.

I keep a spare set of ACL Stds and various OEM bearings to plastigauge a baseline from. If you dont have that you can have your machine shop dial bore gauge the main bores and rod big ends and mic the crank journals. With a little math you can figure out what bearing sizes you need to order.

 

Acl takes the cake ;p

 

That's funny because my acl rodd bearings are dooing just fine is my 11 second car.

From my personal experience the hx with the xtra clearance came out to be right about oem reds for ls/b16 rd bearings.

The big issue is that people throw them in without actually measuring and wind up with tolerences that are way off