Saving a S54 From Parting Out.

[Anri]

Gents,

Thought of sharing what I am rebuilding currently for a customer.
(I am almost sure he is a member here)

The history of this S54 is unknown. Purchased from a junk yard "as is"
Before the engine was going get installed I decided to do a leak down test and
get information on the health/condition. Started at cyl#1 and ones I push
air I heard the air crossing the block deck to cyl#2 and that was the
beginning...

When removed the cyl head the gasket was burned at the typical place
on 4 cylinders. Now the big trouble is that the heat combined with flames were
crossing back and forth and it torched the block surface and it led to surface
pitting/damage.

Before I proceed further up with this engine the first thing I wanted to find out is
if the block can be cleaned in reasonable measurement.

I set the cutter directly at 0.005"/0.12mm as my first cut, after 1 pass it did clean
a bit but far away from disappearing... then another 5 and another 5 and
one few....so I ended with 0.021"/0.53mm.

The last 2 cuts the blade speed was extremely slow in order to get the surface
as smooth as possible to work with multi layer gasket. At 0.53mm the factory
reference stamp "0" on the block ear is long gone..

Now the deck heigh is 0.53mm shorter, this means the timing chain will change
its length but no by much (its not a big deal since the sprockets are slotted), the
pistons will show 0.53mm more above deck height etc..in single word, trouble.

Cylinder 2 the piston went thru hard detonation resulting broken ring land.

Here is a video with the head removed and the gasket damage can be seen.

https://www.instagram.com/p/Cr3sL6SpXQd/

https://www.instagram.com/p/Cqws_XPgrp7/


Regards,
Anri.

[Anri]

Attention to detail. After the block deck was cut,
every single hole had to be de-burred. The top edge of
the cylinder bore was slightly chamfered in order
to make the piston ring installation easy and free
of potential damage/s.


Regards,
Anri

[cobra]

Nice work!

[Anri]

In the picture bellow one can see the very last deep pitting in-between the
bores. It was painful to make another pass and another one...removing
material from the entire deck height just for that little pin-hole. But in this
critical area were the cyl pressure is so close that can establish a potential
growing issue is something I don't want to see.

When the block was decked the profilometer showed in the ~35-45RA range
this covers the needed RA for the multi layer gasket surface finish.

Ones this was done I decided to "play" a bit with finish to see if I
can bring even better finish. I have the deck blocking tool and gave the surface
further finish towards even smoother results. I had very good success knocking
off the "Haze" and bringing shine, should I say similar to REM finish. So what its
in the picture is after I played with the surface finish. One would never be
able to bring it to absolute glass finish because the nature of the cast iron material.

Note- The entire decking surface area were it ends at the side of the block the
edge was also filed all around.

Moving forward.


Regards,
Anri

[Kcalhoun27]

Very cool, thanks for sharing your journey

[Anri]

Moving towards cleaning the block from nasty unwanted foregin objects...

The first thing I noticed inside the block/water area is 3 composite
broken pieces from the OEM pump impeller were floating all over the
place.

Under operation the water is being pushed up toward the head so
do these pieces and absolutely they would get stuck and "block"
some of the water flow. That is certainly not desirable.

I had actually pretty hard time to removed them. The size of the broken
pieces was slightly larger and twisted shape and was very tricky to
remove from top/deck water jacket oval shape holes.

This proves that the water pump was driven till completely failed and
caused the engine to overheat ! This is nothing New to me since I have
seen this happen many years ago on 3 customers of mine...

Indeed the owner was hard on the principle "If aaaaaiiiin't broken don't fix it"....

When the impeller brakes in this way some of the water flow gets by
passed in and that is causing slowly the engine to run very hot toward the
back because the water flow is lost no longer pushed hard.

This gives me the indication and strong reason of this massive head
gasket failure. I have seen gasket fail in-between the bores but its more
from age and its on 1 may be on 2 cylinders, this particular one was damaged
on almost all 6

Regards,
Anri

[tlow98]

Wow, that engine was abused. My HG failure and subsequent block pitting was far less. .005” and it cleared up.

question, will you have to remove material from the timing cover as it will be sticking up a bit proud of the block now?

I though about that with mine, but .005” didn’t seem to make much of a difference.

love this rebuild! Thanks for posting.

are the bores in good shape?

[Anri]

Wow, that engine was abused. My HG failure and subsequent block pitting was far less. .005” and it cleared up.

question, will you have to remove material from the timing cover as it will be sticking up a bit proud of the block now?

I though about that with mine, but .005” didn’t seem to make much of a difference.

love this rebuild! Thanks for posting.

are the bores in good shape?

Hi,

Thanks for your question. Answer in the picture.

The bores are absolute perfect and in spec.

[Anri]

The last stop on block work is the bore finish before it goes to washing.

I have tried many cross hatch patterns throughout the years and seems
like I am happy with single option which works wonderful for me.

A lot of Machine shops will roughen the bores with very heavy and
deep cross hatch valleys and the idea is "You need to sit the rings"
yes one needs the rings to sit no argue here but that is very general
statement...

Well, back in 1960s this was the ideology behind and seems like it
is still around now day....Very few shops are out of the 60's design..

In this case I do 2 stage cross hatch. One is to create deep valley but
not too deep were Compression/Blow will by-pass behind the rings !!!
Ones the rough pass is done, the bores are cleaned very well and
ready for the final finish.

Yes, the final finish is Plateau. One must knock off the rough edges
from the first cross hatch or otherwise the piston rings will receive
premature ware and we don't want that !

The S54 oil ring is paper thin and with combination of 1960s cross
hatch design it does not work at all !!!


Regards,
Anri

[Anri]

The bores in the pictures bellow are from S38.

The rough finish is what you get from most machine/shops. This is
a block I received from customer who wanted me to complete his un-finished
engine so I took the project but I had to go thru and correct things per my
liking.

Note: The sharp edges from the rough hone! (Left bore)

One can see how uneven the passes are(Left Bore). It can be done
better. The bore on the right has the Plateau finish. Again the idea is to
sit the rings with mild grit and also ones they sit the CR will not go behind the
rings and create Blow-By as it can be seen in another post here by
a member with freshly build S54.

I was lucky to have the ability to use Profilometer gauge to see the
roughens and experiment with my desired surface finish. After I reached
desired outcome I maintained the same exact finish every time.

Regards,
Anri

[tlow98]

Yeah that looks fantastic. Very similar to what I had done, I believe. Actually, after looking at my build pics your home looks to be finer than mine. Hard to tell via pictures, but really appreciate your advice and experience!

Inspiring. Makes me want to build another one of these.

and boy, you aren’t kidding about the oil control ring being paper thin. I was kind of shocked by them!

[Anri]

Yeah that looks fantastic. Very similar to what I had done, I believe. Actually, after looking at my build pics your home looks to be finer than mine. Hard to tell via pictures, but really appreciate your advice and experience!

Inspiring. Makes me want to build another one of these.

and boy, you aren’t kidding about the oil control ring being paper thin. I was kind of shocked by them!

Thanks for your reply.

Properly build and long lasting engine is what I offer to Customers.

The reason why your hone was slightly rougher is perhaps
your engine received New pistons ?

In this particular engine I am re-using the std '0' pistons.
dressed with New rings so the base hone "rough" has to be
very careful applied otherwise it may go to overbore....

My 1st base cut was with rough hone and then over is the
plateau pass.

If seen in person is a bit odd like a clear coat final finish but
with cross hatch to retain little oil just enough to lube the
bore. Bores don't need slosh of oil to maintain lubrication.

Regards,
Anri

[tlow98]

Makes complete sense Anri. I also re-used the standard size “0” pistons. They were in fantastic shape with next to no wear and no scuffs on the skirts. Motor had 212k miles on it.

I used standard sized NPR rings. They went in and fit BMW’s specs right out of the box. Didn’t have to file a single one.

About the bore. They removed .0005” for the hone. Told me it was two processes; once for rough hone and then second was plateau. Piston to cylinder clearance was still very tight. Well within bmw specs and still on the tighter side.

fwiw, I was the engjne builder and farmed out the machining of the block, head, etc.

I was thinking of using an abradable coating on the pistons like this https://www.line2linecoatings.com/ but since I couldn’t find any s54 successes with such a product I let it be. Have you ever used something like that with the piston to bore clearance gets too large?

[Slideways]

What about slightly thicker head gaskets for blocks that need extra mm removed? That combined with ARP head studs should make a block or head serviceable.

[Anri]

Makes complete sense AnriHave you ever used something like that with the piston to bore clearance gets too large?

I know very well line2line. It is pretty good stuff and no harm at all.

I work a lot on S38 engines as well and have seen those with nearly 300k miles
and beaten to death with poor oil etc..and the Pistons to wall clearance stays
pretty much the same....it reaches max permissible and freezes there and that
is it...I also have seen S54s with over 220k miles and the bores look totally in spec
just as this one.

I will post my coating when the time comes around.

Regards,
Anri