ACL bearings

[Zans]

hello,
i'm looking for bearing options and found that ACL 0ffers them in regular size and +0.025mm oil clearance hole size (still standard size just a bigger oiling hole) and i'd like to know what's the difference between the 2 (except the obvious) and how would that make a difference on performance/longevity.
Thanks!

 

[<tuffty/>]

Where did yo get that info from?... typically (and according to the catalogue) the +0.025 relates to the bearing clearance to manage oil flow not hole size as the hole is largely irrelevant due to not all rods being rifle drilled...

If you look at the catalogue excerpt below you will see that the sizes column has the 0.025 size you refer too... if you look at the row for the VR6 bearings this also lists the same size ranges... VR6 rods are not drilled...

Also note the info from the same catalogue...

I am assuming this is where your info came from and this actually refers to bearing clearance in relation to oil flow rate past the bearing, not through a hole that feeds the small end on only a few rods in some engines...

Basically... stick to std size bearings... ACL are pretty good... I used them in my 20v and will be using them in my VR

<tuffty/>

 

[Zans]

Where did yo get that info from?... typically (and according to the catalogue) the +0.025 relates to the bearing clearance to manage oil flow not hole size as the hole is largely irrelevant due to not all rods being rifle drilled...

If you look at the catalogue excerpt below you will see that the sizes column has the 0.025 size you refer too... if you look at the row for the VR6 bearings this also lists the same size ranges... VR6 rods are not drilled...
View attachment 203265

Also note the info from the same catalogue...
View attachment 203266

I am assuming this is where your info came from and this actually refers to bearing clearance in relation to oil flow rate past the bearing, not through a hole that feeds the small end on only a few rods in some engines...

Basically... stick to std size bearings... ACL are pretty good... I used them in my 20v and will be using them in my VR

<tuffty/>

the part number of the bearings in question are 4B1606HX and 4B1606H, these bearings are the same except or the HX model being EXTRA OIL CLEARANCE SET (-0.025MM). i thought they were refering to the actual hole being bigger. Thanks!!

 

[Zans]

Where did yo get that info from?... typically (and according to the catalogue) the +0.025 relates to the bearing clearance to manage oil flow not hole size as the hole is largely irrelevant due to not all rods being rifle drilled...

If you look at the catalogue excerpt below you will see that the sizes column has the 0.025 size you refer too... if you look at the row for the VR6 bearings this also lists the same size ranges... VR6 rods are not drilled...
View attachment 203265

Also note the info from the same catalogue...
View attachment 203266

I am assuming this is where your info came from and this actually refers to bearing clearance in relation to oil flow rate past the bearing, not through a hole that feeds the small end on only a few rods in some engines...

Basically... stick to std size bearings... ACL are pretty good... I used them in my 20v and will be using them in my VR

<tuffty/>

for some reason the acl website can't give me any links so here are the 2 products in question:

regular bearing
https://fcp-engineering.com/en/audi-vw/77-vw-4b1606h-25-16-18-20-rod-bearing-set.html

and +0.025 oil extra clearance
https://fcp-engineering.com/en/audi-vw/71-audi-rod-bearing-set-4b1606h-std-.html

both are the same standard size

 

[<tuffty/>]

under sized bearings designed to give larger journal to bearing gap to allow higher oil flow...

<tuffty/>

 

[Zans]

under sized bearings designed to give larger journal to bearing gap to allow higher oil flow...

<tuffty/>

i see.. thanks!