TheSamba.com :: View topic - Con rod bearings

Wed Apr 21, 2021 9:06 am

This topic comes up from time to time, but I thought I would share some experience with you. I'm currently rebuilding a 1776 using a Rimco crank reground to take 0.75 OS bearings. The regrind was perfect in every respect.

I normally fit Silverline mains and rod bearings and find the standard and 0.25 bearings pretty well spot on. I fitted Silverline mains to this engine and as usual they were a perfect fit. Then I trial fitted the rods with the 0.75 OS Silverline bearings. The rods were super tight on the journals with these bearings fitted. So I miked up the rods again - all to spec and perfectly round. Then I fitted the bearings and miked it again - big surprise! The bearings appeared to be over a thou too thick, making the bearing an interference fit on the journal! Weird or what?

So I ordered a set of 0.75 OS Kolbenschmit rod bearings and compared them. Firstly the KS bearings were, unlike the Silverlines, nicely chamfered at the edges and had better tangs. When I fitted them to the rods they were exactly correct, giving a 2 thou clearance on the journals. Now I've used STD and 0.25 Silverlines before with no problems, so it may be that only the larger sizes are too thick, but I would be interested if anyone else has found this problem recently.

Wed Apr 21, 2021 8:30 pm

Just tried 2 sets of Silverline rod bearings (std.) on a 2007 build and both have been tight, it seems that the tangs aren't correct.

Wed Apr 21, 2021 8:43 pm

I have heard nothing good about silverline rod bearings.
Still wondering where they come from. There does not seem to be any company of that name.
What type of bearing are they?

If you are looking for aluminum type, in addition to Mahle, there is also King & Moresa

KS is the only tri metal bearing left far as I know, besides old stock FM

Thu Apr 22, 2021 12:22 am

modok wrote: I have heard nothing good about silverline rod bearings.
Still wondering where they come from. There does not seem to be any company of that name.
What type of bearing are they?

If you are looking for aluminum type, in addition to Mahle, there is also King & Moresa

KS is the only tri metal bearing left far as I know, besides old stock FM

I think the Silverline rod bearings are steel backed and used to be made in Mexico. Whoever is producing them needs some feedback on quality control! Strange that they produce really good main bearings and some of their rod bearings are good.

Thu Apr 22, 2021 12:49 am

There is a Silverline factory in Mexico City. Ermita Iztapalapa 1999-2, Los Ángeles, Iztapalapa, 09830 Ciudad de México, CDMX, Mexico.

Can one of our Mexican members let them know that some of their rod bearings are oversized and need the sides chamfered to accommodate the radius on the crank journal?

Thu Apr 22, 2021 5:09 am

Sorry, I didnt take the time to read all the comments so mark this as irrelevant if it is.

But have you considered new mahle rod bearings? I know many builders use them and quality seems to be good from the 5 sets I've bough although I have measured all of them torqued down in the con rods.

Thu Apr 22, 2021 11:02 am

Chickensoup wrote: Sorry, I didnt take the time to read all the comments so mark this as irrelevant if it is.

But have you considered new mahle rod bearings? I know many builders use them and quality seems to be good from the 5 sets I've bough although I have measured all of them torqued down in the con rods.

Thanks - yes I have used Mahle in the past and they are good. Problem is that all suppliers in the UK have run out of stock! I bought what looks like the last .75 OS non-Silverline rod bearings in the UK. We are having problems with stocks of lots of parts here - combination of Brexit and the Suez canal blockage.

Thu Apr 22, 2021 1:46 pm

I ordered sliverline without knowing and they were too tight. I don't recall the clearance but I ended up getting mahle.

Off subject but I did the same with double thrust cam bearings. The mahle were way too tight but the silverline were much better. Just hear about how terrible the silverline is for everything but mains...

Thu Apr 22, 2021 1:57 pm

I typically run Clevite/Mahle rod bearings after having a problem with a set of Silverlines. They measured out fine, but the material delaminated in shortly after cam break in. I have also run Sealed Power rod bearings on stock or near stock engines with good luck. I did run into a situation where I had several sets of Clevite bearings, all manufactured the same date and all were too tight. That is the only issue I have had with them.

Thu Apr 22, 2021 5:14 pm

The silverline rod bearings have a purpose: when you have a slightly scored rod journal, and don't want to grind it to the next full oversize, polish it till you get the right clearance with the silverline bearings. I have done it once, and it worked well to get the oil clearance back to within stock specs.

Thu Apr 22, 2021 5:21 pm

Without having a catalog there are no specifications to check, no instructions, no part numbers, and no complaint department.
it might be a .002" oversize bearing. I'd check the crush.
Most "parts sellers" don't even know the difference between undersize and oversize so the only way it works is with a catalog and order the right part number.
No catalog, no company IMO

Fri Apr 23, 2021 6:00 am

modok wrote: Without having a catalog there are no specifications to check, no instructions, no part numbers, and no complaint department.
it might be a .002" oversize bearing. I'd check the crush.
Most "parts sellers" don't even know the difference between undersize and oversize so the only way it works is with a catalog and order the right part number.
No catalog, no company IMO

The bearings were the correct part number. Silverline use VW part numbers on their boxes. These were 113 105 719T at 0.75 OS. Installing them with the rods torqued up would have locked up the engine. I've been looking again at why this happened and there are at least two issues with these

- the tangs are pushing the bearing outwards towards the journal. I am wondering if the tang tooling they used did not compensate for the increased thickness of the bearing.

- there is virtually no chamfer on the edges of the bearings. This means that the radius on the journal edges is touching the bearing.

As I said I have not had these problems with std and 0.25 Silverline rod bearings over the past 20 years of building engines. When I installed KS bearings on this engine they fitted perfectly giving 0.002 oil clearances and no interference with the edges. I've emailed Silverline in Mexico but I doubt if they will reply! You never know though.....................

Fri Apr 23, 2021 7:07 am

BJ1 wrote: modok wrote: Without having a catalog there are no specifications to check, no instructions, no part numbers, and no complaint department.
it might be a .002" oversize bearing. I'd check the crush.
Most "parts sellers" don't even know the difference between undersize and oversize so the only way it works is with a catalog and order the right part number.
No catalog, no company IMO

The bearings were the correct part number. Silverline use VW part numbers on their boxes. These were 113 105 719T at 0.75 OS. Installing them with the rods torqued up would have locked up the engine. I've been looking again at why this happened and there are at least two issues with these

- the tangs are pushing the bearing outwards towards the journal. I am wondering if the tang tooling they used did not compensate for the increased thickness of the bearing.

- there is virtually no chamfer on the edges of the bearings. This means that the radius on the journal edges is touching the bearing.

As I said I have not had these problems with std and 0.25 Silverline rod bearings over the past 20 years of building engines. When I installed KS bearings on this engine they fitted perfectly giving 0.002 oil clearances and no interference with the edges. I've emailed Silverline in Mexico but I doubt if they will reply! You never know though.....................

I work for UEM (Silvo-lite) and ironically got a call from someone the other day asking about Silverline bearings... I had to say sorry , we are a piston manufacturer and not a bearing manufacturer. I wanted to ask more but.... couldn't

Fri Apr 23, 2021 4:35 pm

the part number has a T at the end
What does the T stand for?

Fri Apr 23, 2021 4:42 pm

Tight😀

Fri Apr 23, 2021 4:51 pm

:lol:

Tue Nov 15, 2022 5:54 pm

I have had good results using Sliverline con rod bearings in the past. Until last night.

Installed a set and three of the rods move freely on the journal. But one rod has a sticky point that loosens up at two points when I rotate the rod all the way around the journal.
Measuring the rod bearings (with a dial bore gauge), I get a consistent .0025 bearing clearance.

I moved the rod from #1 to the #2 journal and the results were the same. A sticky point when rotating the rod around the journal, just not as sticky as #1.

I'm gonna switch the bearings from one rod to another and see if it's the rod, or the bearing. I suspect the bearing.
The rods are Scat Scat H beam, with ARP 3/8 bolts.

In the mean time, I placed an order for a set of Mahle rod bearings this morning.

Like I said above. I have had good results with Silverline bearings in the past.
This time, the mains measured all over the place and the rod bearings are giving me problems too.
I don't even bother with Silverline cam bearings.

Sorry for dragging up an old thread. But I thought it better to contribute to this, than start a new one on the same subject.

Tue Nov 15, 2022 9:36 pm

Well, Yeah. No matter what rod I placed the questionable bearing on.
The selected, rod was still a bit sticky in rotation.

Welcome new Mahle bearings! :wink:

Never again will accept Silverline bearings of any sort! :twisted:
Fn money down the drain.

Live and learn!

Wed Nov 16, 2022 9:11 pm

Tried using a set of Silverline std. rod bearings last week. They were very tight. I had a set of Mahles and they fit perfectly.

Wed Nov 16, 2022 9:11 pm

Tried using a set of Silverline std. rod bearings last week. They were very tight. I had a set of Mahles and they fit perfectly.