Thought I would bring this up after seeing the previous "ACL Bearing Admin" post.

A year or 2 back when collecting the parts for my forge build I happen to check the main bearing fittment on the block and noticed a misalignment of the oil holes of the rear bearing/thrust shell to the oil groove in the block. This misalignment was approx 1-1.5mm out. The misalignment of the large hole also misaligns the crank journal hole hole.

The block oil groove was central in the block where as the oil holes in the bearing was off set. I emailed ACL in Tasmania asking them if I had a faulty batch and they were shocked at my statement. They replied back later to say that this was the first time they had heard this. After their investigation they agreed there was this off set and had sold many sets like this and never had a problem, they assured me that it would be fine to use the bearing but stated that I could dremel the bearing oil holes to correct the misalignment.

My correction of this was to dremel a radius in the block to align the bearing holes and dremel the large hole "oval" in the bearing for the crank hole alignment.

Below is a copy of his return mail to me.

Tony

 

 

 

Hi Tony,

Henry forwarded your email to me in relation to I believe our 5M2737 H main bearing set.

It is quite a coincidence that yesterday I was asked the same question by another customer here in Australia who also noticed the groove and oil holes were slightly offset on the OE bearing and the ACL one was central.

We obtained an OE bearing and find that the groove/oil holes were 1mm offset (except for the large central hole which was only 0.5 mm offset on the sample we obtained). We will be modifying our bearing to the OE design on the next production run. We have been manufacturing the Race Series bearing since 2004 and the regular aftermarket sets since 1998 for these engines, and yesterday was the first time someone had alerted us to this difference. Whilst you are quite correct that the oil holes may not line up 100% with the oil gallery in the block and the groove in the block behind the back of the bearing, to feed the 4 small oil holes, I think it would be safe to say that the oil path has not been substantially blocked, as there must have been adequate oil supply to both this main and the con rod bearing which is fed from the main bearing. The oil holes also have a chamfer on the OD and ID of the oil holes which will also assist with the oil flow, and on the bearings for the turbo engines there are 5 oil holes, but on the non-turbo engines there is only the large oil hole in the upper thrust bearing.

We believe you can use the bearings as supplied with confidence, however if you want more peace of mind you could enlarge the OD chamfer, before fitting the bearing. The feed gallery in the block is probably much larger than the large oil hole in the bearings, and you could check that there is adequate alignment when fitting the upper shell to the block.

We apologize for any concern this mistake has caused you, and hope that you are happy in general with the ACL product

 

Kind regards

Bruce Williams

Product Engineer

ACL Bearing Company

253-293 George Town Road

Rocherlea

Tasmania 7248

Australia[/i]

coincidence that yesterday I was asked the same question by another customer here in Australia who also noticed the groove and oil holes were slightly offset on the OE bearing and the ACL one was central.

We obtained an OE bearing and find that the groove/oil holes were 1mm offset

THAT surley should have rang alarm bells to say we will investigate and heres a full refund for your parts and if you are going to use then we surjest you do or try this. the word sorry should hace also been inthere and will will inform you of further testing and any developments. or is all my customer service skills out of date. 26 11 13

lol thats some coincidence too ... i'b had a set when building an engine that was like that .. i just got them replaced not by acl but the uk supplier