IceY2K1Max

iTrader: (1)

http://www.swaintech.com/
http://www.swaintech.com/nissan.html

Anybody going this route? What about the valves or head?

Just trying to spend more of your guys money, while you've got your engines apart.

joenismo

I just picked up my pistons from having the tops, underside and skirts done. I had a local place do mine for me, Performance Coatings. I also had the greddy exhaust manifolds, turbo housings, and downpipes done. Everything looks great and all the parts were done inside and out. I am probably going to have the combustion chambers and valves done also. I just figured it couldn't hurt, and I got a killer deal on it $331 for everything.

IceY2K1Max

iTrader: (1)

Wow...that's a killer price.

Anybody else coating their new slugs?

G3po

iTrader: (8)

I'm considereing coating the pistons and APS cast iron TT exhaust manifolds. Still doing research ,talekd with swaitech and they recommend "TBC for the dishes and PC-9 for the skirts".
The "TBC-EX White" exhaust coating for the exhaust manifolds should help to reduce under hood temps and better transfer heat to the impellers.

Basic prices are : $38 per piston and $125 for the manifold pair. AnyTurbo manifold would benefit from this type of coating.

Anyone have any "negative" experience with Piston coatings?

Sharif@Forged

iTrader: (92)

Heat coatings are a sort of "black magic" industry. The companies that do the coatings tend to exagerate the benifits of heat coatings. I am also considering doing my pistons and manifolds, but I want to do more research. I wish there was a truely independent source of info. And since no two engines are the same, its impossible to determine if a heat treatment is actually effective, or if it was some other element that was providing the alleged benifit. There are just so many variables to work with.

That said, regardless of performance benifit, it is a GREAT idea to coat the manifolds, so the cast iron wont rust.

phunk

iTrader: (21)

prevention of rust on the manifolds is probably the greatest benefit of the coating.

i am not sure how much it actually helps undergood temps... but i had mine coated anyway just in case it helped... especially since the factory fuel lines are so close to the manifold.

as for coating the pistons... i wouldnt bother. people are making much much more power on uncoated pistons than any of our goals are... so whats the point.

my friend had his pistons coated once... had a problem with tuning and had to pull apart the motor a couple hundred miles and the skirt coating was pretty much gone. he didnt bother coating them again.

it also kinda screws with trying to get your piston/wall clearance correct.

-charles

G3po

iTrader: (8)

Maybe "black magic" but Nissan does Poly-Moly coat the skirt on the OEM? If it didn't serve a purpose , I doubt they would incur the extra cost. Now it may be just to insure a scuff free break in ?

IceY2K1Max

iTrader: (1)

I'd have to say most of the "horror" stories are related to some other coating company NOT SwainTech. I've read TONS of articles on them all glowing about how great their coatings are. I wouldn't consider anyone else, but that's me. Plus, Infiniti IRL motors use SwainTech, correct? As said above, the OEM pistons are even Moly coated. So, if OEMs are using these coatings, it can't all be mumbo jumbo.

A friend of a friend has a TT 502 Hemi engine in his boat that before coating would MELT the surrounding interior/engine cover once the turbines started heating up. Then he got them "Yitrium stabalized Zirconium Oxide" coated by Bolts Metal in Phoenix, AZ. It's supposedly a "plasma spray process developed for carbon fiber turbine blades.". I've seen it in person and it looks white/chalky. After that, he said you could "almost" touch the turbine housings and he never had a melting problem again. Coating the turbine housings alone would be worthwhile to prevent melting surrounding parts and reduce underhood temps IMO.

Yes, increased power may be marginal considering the cost, however the anti-detonation/anti-friction properties, and decreased wear justify the cost. Many...many people swear by these coatings, so it shouldn't be easily disregarded by a few horror stories from "Bob's Coatings R Us".

IceY2K1Max

iTrader: (1)

You can kind of see it in this pic...sorry it's crappy.

IceY2K1Max

iTrader: (1)

A couple more articles with pics:

http://www.nissanperformancemag.com/...ojectser.shtml
http://www.nissanperformancemag.com/march04/headwork/
http://www.sportcompactcarweb.com/pr...scc_proj300zx/
https://www.overboost.com/story.asp?id=129

Sharif@Forged

iTrader: (92)

That made me laugh.

Phunk brought up a really good point. coating the piston adds at least .020 and maybe more material to the piston. I wonder how that would effect the seating of the rings against the piston. Also, just make sure to treat them before boring your cylinder wall, becuase you are addiing to the overall diameter of the piston when you heat treat.

Swain has a much better reputation than Bob's Coatings R Us...which I had originally planned on using. Yes, I think almost every major racing team uses Swain coatings on just about everything. But that doesnt meant it should be used on street cars. There is a tendancy to "do-what-that-race-teams-do", which may or may not be the best applicatioin for street cars. Just something to keep in mind.

G3po

iTrader: (8)

THe skirt coatings either PM or PC-9 (Swain reccomends PC-9) for durability) adds far less than a fraction of .02" to the bore. Most of the "Moly" material is impregnated into the Aluminum surface. The main "benefit" appears to be that the Skirt to Bore clearances can be "reduced below nominal" to the min spec which helps reduce oil consumption and ring seating. The min clearance spec is ~0.0004-inch. In gneral if race technology doesn't make "dollars and sense" it won't find it's way into the mass OEM. Apparently this technolgy has proven itself enough for Nissan to find it worthwhile for OEM use.

IceY2K1Max

iTrader: (1)

I agree normally, but in this case it is good to be a groupie, plus they're used by OEMs.

You can coat the tops and bottoms without any problems with clearance. For the sides of the piston according to the article, "Poly Moly also tightens the piston-to-wall clearance by about 0.0014 inches". I doubt that's enough to cause any issue, but your machinest will be able to compensate, if it is. For the seating of the rings concern, that part of the piston isn't coated. However you can have the rings antiwear coated, but that's typically done for high boost(20+psi?).

IMO, just do it. You can't go wrong. Do more research GQ if you're still unsure and need more convincing, but out of tons of articles I've read over the years, it's a warranted benefit for boosting.

I understand the cost seems steep for something you'll never see or feel in the seat of your pants, however the added protection while running on pump gas is worthwhile plus the added durability/antiwear advantages.

notnser

I used Swain coatings on the cylinder head on my 200sx. I used their TBC coatings on the valves, combustion chambers, and exhaust ports. I also coated my turbo manifold, exhaust housing and downpipe. Heat is the enemy in a turbo car and these coatings help keep the heat where it belongs... in the exhaust gas. You will actually gain turbo repsonse with coaings like this as hotter exhaust gas elps spool the turbo quicker. I make full boost a full 500 rpm's sooner than a similar car with Swain coaings and an extrude honed exhaust housing. I also see lower EGT's on long pulls over smiliar setups.

The benefits of Swain coatings are proven time and again especially their piston coatigns in turbo applications. Like at Mike Kojima's Twin Turbo 300ZX for a perfect example..........

phunk

iTrader: (21)

uncoated pistons have also proved themselves time and time again, probably more times in street cars than coated ones have.

I never use the coatings.

As for your turbo response and EGT comparison.. that doesnt work unless you do it on the same motor before/after. Lower EGTs dont make much sense to me... the coatings are keeping the heat in the exhaust so much better than the exhaust gets cooler?

0.0014" is a huge difference when talking about cylinder wall clearance. Cylinder wall clearance should always be machined precise to the 0.0001" , or one tenth of one thousandth of an inch.

This is one of my concerns with the coating. Cause if I have my bore/hone machined precise to my 0.0001.... what happened if that coating starts to wear? I have seen used coated pistons and there was definatly lots of wear on the skirt coating... I dont want that inconsistent value in my engine.

If nissan used it from the factory... thats cool... but I highly doubt they used the same coating you gonna buy from Swain???

I dunno... sounds nice and all, but I personally dont want to deal with the extra time out or the money when once its in the engine I will never ever know if its even doing anything or not. Whatever it is, its definatly not going to be noticable once that motor is in the car.

G3po

iTrader: (8)

The skirt coating offered by Swain which is comparable to the OEM is the PM version. The PC-9 is claimed to perform better than and last lonfer tham the PM (Ploy-Moly version.

WRT the "0.0014 inches" that is not the thickness of the coating but the minimum value recommended by Nismo for cold Skirt to bore tolerance (at least thats the claim of the articl)e. As one of the articlesl in this thread mentioned, the application of a TBC to the crown and a PM to the sleeve, allowed them to reduce the clearance tolerance to minimum as opposed to nominal.

I beleve this to be possible due to the more controlled rate of exapansion offered by the TBC on the crown and the reduce possiblity of bore scuffing during cold operation offered by the PM coating. During cold start there is very little oil film on the skirt or bore.

Regardless of the piston coating option, it is tough to argue with TBC coating (like the swain white lightenin" to the exhaust manifolds and possibly turbo impeller housings in a TT operation. Lower underhood temps is a good side effect and coupling more ehaust heat to the turbo adds efficiecny.

Personally , I'm definately doing the manifolds and am still researching the pistons. I'll leave the heads alone for now.

notnser

I agree ncaoted have been proven more often, you prove the reason why with your statement. MANY people do not take it to that level or spend the time and $$$ to do this. The reason more uncaoted pistons work in street apps. is because there are more uncoated motors than there are coated motors.

As for the comparison same motor, same setup, better ersponse in coupling the Extrude Hone and added efficency beacuse of the heat.

Over long pulls yes I do have lower EGT's than an uncoated motor. Again SAME SETUP for the comparison. Less heat soak in the cylinder head and the engine bay provides more consistent EGT's because heat is controlled over an uncoated motor.

IceY2K1Max

iTrader: (1)

That may be true, but coated pistons have been proven effective and allowed MANY many racers/engine builders to push the envelope even farther without meltdown. However, my interest is in protecting against detonation by forcing the heat out the exhaust vs. absorbing into the metal/oil and increasing durability by minimizing wear such as the manufacturers do to achieve 100K+ engines.

Manufacturer tolerance is 0.0004-0.0012. Your "precise .0001" will cause extra wear and even possible galling/seizing depending on piston material and heat treatment. Again, your precise machinest/engine builder should easily compensate to whatever thickness you want with the piston overbore+coating thickness end result to be.

I agree...not all coatings are created alike. However, I've *NEVER* seen nor heard a horror story with SwainTech coatings. If there has been, it's a small occurance.

All factory VQ pistons all the way back to AT LEAST '95 are poly coated.

That's the biggest catch 22 with building your own engine IMO. However, I'd rather spend the time/money upfront, then spend it later down the road rebuilding, if possible.

Ceramic coatings may not be noticeable or bragging worthy, but if it protects you from burning a hole in your piston just one time, it's a lot less hassle then the labor pulling the motor and rebuilding it again. If you're on a minimal downtime schedule, I understand the cost vs. benefits argument. It's a personal decision, I just wanted to make sure some of the guys/gals that may not have heard of SwainTech(probably only a few), at least have a chance to research/consider it while their engines are open.

Just my .02, which aint worth jack.