320SI owners

Jan E. · 04-08-2014, 01:39 PM

Anyone with the N45B20S engine that has a steel liner swap installed?
I'm thinking of the HT Howard job, or any other liner swap.

Have you experienced any problems?
Please give feedback on mileage after swap. Regardless problem or not.
And where was the work done?

I have my engine in for the liner swap (crack in old alu liner) now here in Norway. And they done one car earlier.
Now the first car has developed a high oil usage. They opened that engine, but found nothing wrong. So they suspekt that the steel liner maybe vibrates?

Jan E. · 05-15-2014, 10:17 AM

They had already installed some thicker liners in my block that on the oil-using-engine. And they were in contact with the liner factory to design and make even thicker to install instead.

But then the owner of the oil-using-engine decided to go for a new original block instead.

When the machine shop got the new engine they told that the new block have a new design. It comes now with steel liners instead of the old aluminum liners. And it looks like a much sturdier and better design.
The problem was that on the new block the crank only had 1/100mm (39/1000 inch?) clearance. And that was with the thinnest bearing shell

So they ordered another new block. And same on that one: 1/100mm clearance.

They say that they don’t install anything under 2/100mm. Couse they are reliable for the warranty. And 2/100 is still little. Especially here in Norway where there can be -35 dgr (-31F) some places during winter.

They got the papers from BMW claiming that the spec for the crank supposed to be 2-6/100mm after production.

That means that BMW gives out the new modified blocks outside there owne specifications

(Wasn’t there back in the days some 30 engines rejected after production? What was that rejection based on? And I guess that was old stile aluminum liner blocks?

So now the machine shop awaits answer from BMW that they take responsibility for the close tolerance, and that 1/100mm is enough. Or that they can machine up the clearance, but BMW still holds the warranty if something happens...

Hmmm. Concerning that BMW has redesigned the blocks to something that finely looks like the problem should be history, and introduces a new problem...
Anyone know when BMW began producing the block with steel liners?

Jan E. · 09-08-2014, 05:34 AM

The shop was given all clear from BMW to machine up the clearance.
Now I get a BMW factory produced steel liner block, and not an after marked liner insert job

The old block BMW wanted in return as a core refund charge.

andrey_gta · 09-08-2014, 06:14 PM

Wow, what a mess. Such a cool engine though and it has racing pedigree too

HristoKolev · 08-06-2018, 11:00 AM

What happened ? I am facing the same dilemma.

Jan E. · 08-13-2018, 06:28 PM

Cars up and running.
But I only put on 12000 miles on the engine so don't know in the long run.

If I was facing the same problem again I would trie to track down an N52, N54 or S65 engine instead.

04-08-2014, 01:39 PM	#1
Jan E. Enlisted Member 13 Rep 39 Posts Drives: 320si Join Date: Dec 2013 Location: Norway iTrader: (0)	320SI owners - anyone with a liner swap engine? Anyone with the N45B20S engine that has a steel liner swap installed? I'm thinking of the HT Howard job, or any other liner swap. Have you experienced any problems? Please give feedback on mileage after swap. Regardless problem or not. And where was the work done? I have my engine in for the liner swap (crack in old alu liner) now here in Norway. And they done one car earlier. Now the first car has developed a high oil usage. They opened that engine, but found nothing wrong. So they suspekt that the steel liner maybe vibrates?
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05-15-2014, 10:17 AM	#2
Jan E. Enlisted Member 13 Rep 39 Posts Drives: 320si Join Date: Dec 2013 Location: Norway iTrader: (0)	They had already installed some thicker liners in my block that on the oil-using-engine. And they were in contact with the liner factory to design and make even thicker to install instead. But then the owner of the oil-using-engine decided to go for a new original block instead. When the machine shop got the new engine they told that the new block have a new design. It comes now with steel liners instead of the old aluminum liners. And it looks like a much sturdier and better design. The problem was that on the new block the crank only had 1/100mm (39/1000 inch?) clearance. And that was with the thinnest bearing shell So they ordered another new block. And same on that one: 1/100mm clearance. They say that they don’t install anything under 2/100mm. Couse they are reliable for the warranty. And 2/100 is still little. Especially here in Norway where there can be -35 dgr (-31F) some places during winter. They got the papers from BMW claiming that the spec for the crank supposed to be 2-6/100mm after production. That means that BMW gives out the new modified blocks outside there owne specifications (Wasn’t there back in the days some 30 engines rejected after production? What was that rejection based on? And I guess that was old stile aluminum liner blocks? So now the machine shop awaits answer from BMW that they take responsibility for the close tolerance, and that 1/100mm is enough. Or that they can machine up the clearance, but BMW still holds the warranty if something happens... Hmmm. Concerning that BMW has redesigned the blocks to something that finely looks like the problem should be history, and introduces a new problem... Anyone know when BMW began producing the block with steel liners? Last edited by Jan E.; 05-15-2014 at 10:24 AM..
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09-08-2014, 05:34 AM	#3
Jan E. Enlisted Member 13 Rep 39 Posts Drives: 320si Join Date: Dec 2013 Location: Norway iTrader: (0)	The shop was given all clear from BMW to machine up the clearance. Now I get a BMW factory produced steel liner block, and not an after marked liner insert job The old block BMW wanted in return as a core refund charge. Last edited by Jan E.; 09-09-2014 at 05:45 AM..
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09-08-2014, 06:14 PM	#4
andrey_gta Brigadier General 298 Rep 4,040 Posts Drives: 130i coupé ;) Join Date: Nov 2011 Location: Bimmerpost iTrader: (1) Garage List 2008 BMW 128i [10.00]	Wow, what a mess. Such a cool engine though and it has racing pedigree too __________________ 128i Sport 6MT converted to Euro 130i spec, 3.73 diff, tuned by evolve ~220 whp 207 wtq(ft-lb) SAE In-progress: //M front arm, M3 rack, e36M lip Wishlist: Coils, n55 mnts, headers, LSD, e60 finn diff "The 1-series is the last car that BMW engineered before the Germans, as a car-making culture, fell out of love with driving." - R&T 2013 135is
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08-06-2018, 11:00 AM	#5
HristoKolev New Member 2 Rep 7 Posts Drives: BMW 320si Join Date: Aug 2018 Location: Bulgaria iTrader: (0)	What happened ? I am facing the same dilemma.
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08-13-2018, 06:28 PM	#6
Jan E. Enlisted Member 13 Rep 39 Posts Drives: 320si Join Date: Dec 2013 Location: Norway iTrader: (0)	Cars up and running. But I only put on 12000 miles on the engine so don't know in the long run. If I was facing the same problem again I would trie to track down an N52, N54 or S65 engine instead.
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