Mrmerlin

So if you have an 85 or later 928 with 32 valves,
you may reach a point where you will need to refinish the intake as it will be peeling off the factory coating.

There are lots of ways to refinish these parts, the best way is to replace the factory powder coating with fresh PC.
Less desirable is to scrape off the coating and spray paint.

More to come....

I was in a hurry this morning and didnt have time to type this,
But I thought I should start it so I wont forget.

For anyone thats watched Top Gear UK ,
you would have seen a very cool engine block under the glass on the stage where they do the NEWS.

If you ever wanted to make a 928 coffee table with a real live 928 engine its quite possible to do,
here is how.

Install the intake that you have just spent good money getting powder coated to spruce up your 85 or newer 928 engine.
So you might ask how the heck could installing a freshly powder coated intake could this make me have a coffee table?

Well when a casting part that has been grit blasted is installed on the intake any loose debris will be be sucked into the cylinder and if there is enough of it the abrasive will score every cylinder to failure,
Thus you now have a perfect 928 coffee table.

Truth be told , there really isnt and protocol for the proper cleaning of intake parts after they are returned from the Powdercoater.

Mostly you will be very careful with the handling of these precious parts,
and thus might not see the potential for the damage that can ensue.

Anyway if you have ever done any work on restoring finishes using a grit blaster,
you will be very cognizant that the blasting media gets everywhere.
sometime even where you have plugged off or masked off.

So with this bit of info it is always a good idea to double even triple check the cleaning process after the parts have been grit blasted.
In most cases no one will have a chance to clean the parts after grit blasting except the person doing the blasting or the person putting on the powder coat.

So that leaves then next cleaning opportunity to be after the old parts come back looking like jewels.

It is a safe bet that any parts that are grit blasted will need to have any threaded holes chased,
the blast media will fill the threads and then make a fresh bolt bind when being installed.

So clean the bolt hole first, use a good bolt with 3 grinder slices added to the tip of the bolt and some grease turn the bolt gently in every threaded hole.
then rinse with your favorite spray lubricant PB blaster works well.

I know your working on jewelry but you need these parts to be spotless and free of all debris..

Next the casting cleaning,
there are more than a few ways to do this,
but this is how I do things and I know it works so I will share it .

You will need some water soluble spray detergent ,
I like simple green its strong and will cut the grease/oil/ carbon that can get into the intake parts.

You also need a hot water source and a compressed air source, and some small bore brushes .

With this you then proceed to clean the parts,
spray them down and scrub the nooks and crannies,
and wash the parts off in hot water,
then blow dry them with the compressed air.

NOTE each part should be subject to this cleaning process 3 times, from start to dry.
you may think that once is enough since the outside looks like jewelry but you will be sadly mistaken.

NOTE it is also advisable to take samples of the rinse water to verify that there isnt any grit being rinsed out, rinse the parts into a clean bucket.

Once you have done this to each piece then you can put them into a bag or wrap them with plastic till ready for use, just make sure the parts are dry.

This may seem like a waste of time to follow this suggestion but the payoff will be a grit free intake manifold.

THUS you will have cheated the 928 coffee table makers out of another potential 928 coffee table.

Oh one other tidbit involving cleaning,
IF you should ever have the crank polished,
please know that there are sludge traps in the counter weights.

These are areas at the ends of the oil pathways,
when the crank is in operation heavy parts of the oil flow are sent to these traps,
they eventually fill with sludge that is like tar, its very hard to remove.

Now when the crank is polished guess where the grinding compound goes?.
Doh, yep into the sludge traps,
when that happens you now have abrasive that is now stuck into the oil way of the crank,
you can try to bore brush and carb cleaner route this works pretty well so long as you follow the 3 step cleaning process as outlined above, or you could drill out the plugs at the ends of the oil bores. this requires tapping new threads for plugs and rebalancing the crank.

So dont be fooled by a polished crank,
the oil pathways must be spotless,
so the hot oil wont move the debris into the bearing surfaces.

skpyle

Such a brief teaser is cruel.
I am subscribed and waiting for the next installment...

Seth K. Pyle

KenRudd

OTR18WHEELER

Less worrisome option.....

M. Requin

From what I have read on this forum, the problem lies with the prep, i.e. blasting with abrasive media, not so much the paint or powder coat.

ltoolio

Too bad there's not an option here on RL to auto-follow any posts by Stan...

Randy V

Use the Subscribe function.

Bill51sdr

I assure you, you will not like where this thread is going.

Mongo

Oh God, please tell me this isn't a 'powdercoating destroyed my engine' thread. The bead blasting one was bad enough.

davek9

It does say how to make coffee table

Ed Scherer

Mark R.

You can to subscribe to a specific thread, but not a specific member...

Wisconsin Joe

I have a feeling this is going to be more of a compilation.

There have been 2 (one confirmed, one suspected) recently.

And it isn't the powdercoating that does it, it's the prep process (or more accurately failing to properly clean up after the prep).

As cool as an engine block coffee table would be, I definitely don't want one that way.

skpyle

Bill, I have no delusions that there will be a happy ending.
The 'coffee table' titled clued me into that.

However, if this happened to Stan, there will be carnage.

Seth K. Pyle

OTR18WHEELER

As most of us are aware, the original coating on the 85 _ 86 intake parts is degrading, it flakes of in large pieces with little effort, I spent several hours peeling, picking, and scraping the old coating off.
The advantage is that media blasting is not used, and it can be done in one day.
Compressed air will blow off the loose stuff, then a razor blade and a gasket scraper are used on the stubborn areas, also an assortment of dental picks will be needed for the small crevases.
Some small areas may still be bonded very well, in that case just feather the edges with sand paper.
Clean and degrease,
Do not prime the parts, the high temp bbq grill paint is formulated for bare metal, primers will not endure the heat.
This is just a quick DIY at home , looks good, and will last several years.
Of course it's not as nice as a custom powder coat job, but you eliminate the risk of blast media destroying your engine.
Sorry so long.