BPG_Austin

Warning: this is a LONG POST

Hey gang, I’m looking for some perspective here. This might get a bit long, but hopefully provide some good info and stir up valuable conversation.

I’ve been researching the GTS intake and its coating for some time now. On and off for a number of years. Specifically how to effectively and efficiently completely remove its coating. Some interesting things have come up.
Blasting: I’m very interested to hear if anyone has successfully media blasted (or had a shop media blast) their GTS intake. Folks with S4/GT intakes, please don’t chime in. This is for GTS intakes ONLY. If you have, how successful were you or your shop in removing ALL, 100% of the coating? My experience with these has been that the coating is of uniform thickness throughout. This leads me to believe it was originally applied via a dip or a combination of dipping, then rotationally cured or baked. It was not sprayed on as the thickness behind the horns and deep inside the runners is of equal thickness to the more accessible locations. S4 intakes I believe were sprayed as they are easily blasted out 100%. Coating behind the horns and runners is much thinner.
I’m currently of the mindset that a GTS intake cannot be blasted out completely and successfully. And I personally would not install an intake with ‘chunks’ of stuck material behind the horns. If it did ever come dislodged its thick enough to cause serious damage to the engine. So, I think blasting is OUT. However, if you have had success, and I mean complete success please let me know the method. I just don’t see how blasting with any media will remove the inaccessible areas.

Next option: Chemical stripping. I’ve also been researching this for some time. I’ve been looking for a chemical to do the job. No home depot chemicals please.. This has to be on a much larger scale. (a side note, any box store chem. stripper won’t touch the GTS coating anyway). When I say a larger scale here I’m referring to a complete submersion in a dip tank. 100% coating removal.
The problem with nearly all the chemical strippers on the market is that they use water as a carrying agent for the active ingredient (usually Methelyne Chloride). Magnesium reacts with water and will destroy an intake. I’ve sampled nearly half a dozen industrial chem. agents over several years. I’m making a sweeping generalization by saying any stripper that uses water as a carrier will not work. By the time it reacts enough to remove the coating its eaten the mag. I have a few scrap parts in my shop from experimenting with this.
The solution, in my opinion, would be a non-water based chemical. I’ve recently been sampling such a chemical. Non caustic, non-toxic, Non-water based. I’ve had very good success, but not complete success as of yet. 90% of the way there!! The problem is the product is very expensive and requires a heated immersion tank. This gets to be very pricey for a limited number of GTS intakes to be stripped. Return on investment?? Not sure..

I’ve been in touch with a chemical engineer for this company and we’ve been discussing the GTS intake. We were trying to nail down what the original coating was. Based on my description to him he believes the coating may be a phenolic. Phenolics have excellent chemical resistant properties and can be applied very thick. They can be baked on or sprayed. In this case, I assume dipped and baked. I found this VERY interesting. Porsche comes out with the GTS engine which is burning a ton of oil. Oil residue is building up around the base of the intake runners… The solution? To coat the intake with a smooth, chemical resistant coating to help all than unburned oil to pass through the intake! Seems like a very poor band aid to me if this is indeed what happened. This is my sneaky suspicion. I don’t think it was to improve airflow, or even to keep engine temps down. These may have been added benefits, but I think they were trying to minimize a design flaw.. Mmm..

Sorry, this became terribly long. I’m interested to hear how people have removed this coating. Or if anyone has actually done it. If you’ve had your intake media blasted, please let me know what media and who did the work. Did they remove ALL of it? This is key for me. Did you send your intake out to be chemically stripped? I’ve never heard of this on RL before, but highly interested to talk to the shop doing it. I’d ship an intake across the country if a shop was able to safely chemically strip a GTS intake. So far, I haven’t found such a service. All the shops that are using the chemical I’m sampling are using it for in-house work only. So, if you RLers have any info/success stories please share them.

Thanks, Ben

SeanR

The ones I've done took me sitting at the bench with a small hammer and a narrow screw driver. Chipping away at it. Once you get a nice crack going you can typically get it done in pretty quick time. I've not found any chemical I was happy with although I used some industrial aircraft paint stripper and if it didn't eat the gloves I was using and try to kill me with vapors, I'd recommend it.

BPG_Austin

Thanks Sean. I agree with you on the vapors. The chem I'm testing has removed nearly all the coating. There's just a bit left deep inside the runners and around the backs of the horns. I'm pretty impressed with the product, it just isn't taking it ALL THE WAY.. stopped at 90% and the part is now soaking. It has minimal odor, not dangerous if you accidentally touch it and is OK to use in small spaces. Remarkable.. just crazy expensive.

I've gotten what I can with the chisel method.. There's just those few pesky spots left. You must be way faster than I am! I'll have to make some special tools to reach in those difficult areas. Would really like to avoid chiseling each individual GTS intake if I can.
I'll start with some more specialized chisels for this intake per your suggestion. Thanks for the feedback!

GregBBRD

I've had to rebuild probably 10 engines that "died" from the intake manifold being painted or powdercoated....one of which was a $50,000 Devek stroker engine, which smoked and used incredible amounts of oil, from the very first day. The customer "tried" to break the engine in for a few thousand miles....and finally gave up. When we took the engine apart, there was still "rivers" of media flowing down from some of the "nooks" above the intake bells.

After the first engine I saw destroyed, I vowed that this would never happen to one of my customers.....so I'm crazy **** about this process.

The process is so time consuming (it is impossible to charge enough money to make this a "profitable" process) that I only will do manifolds for customers whose engine are apart in my own shop.

Here's my process:

I've resorted to having them chemically stripped by a company that only does stripping....and they hate doing it. They leave it soaking, for days. (they are "cold stripping" them....they are afraid to put the magnesium into their heated tank.)

From this process, we immediately (while the remaining coating is still soft) take them to another company that media blasts them with a steel shot.

We then pick them up, bring them back here, and hand pick at the interior corners (around the bells) to make sure that all traces of the steel shot and now re-hardened traces of original coating are removed.

They then get pressure cleaned with hot water and soap.

From here they go to the powder coaters, who re-blast them with another steel media (to prepare the exterior surface for powder coating) and them powder coat them....outsides only.

We bring them back here and start the hand scraping and cleaning process, all over again. Two separate individuals hand clean each manifold....to make sure that no one over looks a single "corner". They then get pressure washed again....blown dry. Then they get a final "check scraping", pressure washed, and blown dry.

Then assembled.

Nothing to it.

BPG_Austin

I know Greg. Thank you for the valuable feedback. I'd be very interested in speaking with the shop that chemically strips those intakes. There just aren't that many chemicals that you are able to soak mag in without destroying it. I've been soaking my current intake for nearly a week. Although it does take a long time, there's no question its a superior process to initial blasting.
Our processes aren't much different btw.

GregBBRD

I chuckle at the people that get the entire job done for $150.00 and think that everything is good.

I took an engine apart, last month, that had the intake powder coated. They powder coated the entire flappy assembly spring assembly...in place.

I guess removing the vacuum actuator is all that one needs to do.

Silly me.

ROG100

I think that's my passion red GTS inlet manifold that Ben is suffering with so thanks for all the help Greg and your hard work Ben.

Rob Edwards

Don't forget the part about if the soapy water runs all the way down the gutter to the street, the city of Fullerton comes and staples your ******* to your chin and then fines you $5K.

As if this intake stripping wasn't hard enough.....

GregBBRD

That's just part of the price in doing business in North Orange County, California.

BPG_Austin

Roger, we're almost there, thank you for your patience. The GTS coating caught me a bit off guard unfortunately. I hate being late on a delivery.