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Next piston treatment for my P400

Twisted Steel Performance

Anything worth doing is worth overdoing.
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Pauline, SC
I have my set of pistons prepped to send off and get a fairly new treatment process done. DiamonDyze is a treatment used by ALL top fuel teams and most big HP builders. This is a treatment not a coating, it provides much greater Thermal & wear protection than hard anodizing alone and treats the entire piston not just the top. I will have them leave the "sealing" process off and I will apply my coatings when they return, added coatings aren't necessary but will add another layer of protection. This will provide added benefits while making these pistons indestructible for life. No more worries about galling or scuffing.. This allows a bit tighter clearances without the worries mentioned and is very affordable considering the whole picture.

Here are before pics with the pistons prepped, all factory coatings half to be removed first. Once they get back I will post those pics.

001.JPG
002.JPG
 
Thats the one where the alumin pipe in the lathe takes the teeth off the file instead of the file damaging the coating or aluminum, right?
I didn’t think of that for this engine. Why are you messin with me? Dang it -that that is a great idea!
I think we need to talk about a set of your 18.5:1 done fully with that and their price. I just need to make sure my cylinders are all happy at stock bore still is my only hold up.
I am 2 hours from opening my engine btw. Got it out last night.
 
Thats the one where the alumin pipe in the lathe takes the teeth off the file instead of the file damaging the coating or aluminum, right?
I didn’t think of that for this engine. Why are you messin with me? Dang it -that that is a great idea!
I think we need to talk about a set of your 18.5:1 done fully with that and their price. I just need to make sure my cylinders are all happy at stock bore still is my only hold up.
I am 2 hours from opening my engine btw. Got it out last night.

Yes, that's the treatment.

It would be good to know in the next few days because 8 pistons doesn't meet the minimum charge.. would be more cost effective to send more sets.. You have a few days before I send mine..
 
A set of your 18.5:1 pistons diamondeyezed and fully coated.

This would be seperate from the other parts coatings we spoke about somewhere around a hundred years ago. Haha.
 
I have had many things done. Unfortunately the shop I used got some jpl/ nasa contracts and haven’t been open to the public for a few years now so I have no clue who to use now.

When it comes to something like the aluminum pistons, chryo doesn’t hurt, but can not compare to the wear abrasion resistance of the diamondeyze.

I am such a dork. I just spelled diamondeyze 2 different ways and went “oh he typed it above, I’ll scroll up to see how to spell it.” Then realized it was a hotlink to the video showing the hand file video I mentioned earlier.:facepalm:
Click the link in his first post if you haven’t seen it already.


There is no metal part the doing a chryo treatment hurts. Unless you have a metal wallet. There is still one 6.5 engine running around out there in a white 99 cclb srw 3500 that I chryo’d everything in the engine, including the block and heads. If I had the money, I would do the same to my optimizer, then ship it all to chris for 100% coatings, including block. Champagne taste and not even beer budget. Maybe messed that up but you get the point. Haha
 
Should be a tough piston. So you will apply diamondyzed all over then top coat areas (crown - thermal barrier, underneath - thermal dispersant) ? Can you still apply friction reducing to skirt and wrist pin bore?


What color are you going with? What is the most expensive metal, Platinum? At miniumum gold. Cause they are going to be some nice pistons worthy of the most expensive metal appearance.
 
I chose "Black" I could have gone with any color I wanted and could have made it a "engine builder's color" but black is less costly and after all they can't be seen when they are working :cool:

Yes, they will have all the other coatings applied when they get back.. and the entire piston gets the treatment making a tough piece of aluminum slug..

I don't apply anything to the pin bore, the pin doesn't move in the piston once the motor fires.
 
I didn't know that. I haven't touched a 6.5 piston rod assembly. The last one I had in hand was an interference rod type. You heated rod to expand hole inserted pin through piston into the heated rod and when it cooled the rod squeezed clamped onto the pin. In that type, the piston and pin would rotate relatively about approx a 25-30? degree arc.

I googled and saw a picture of a 6.5 and the pin is captured by clips. So I assume it slips in both the rod and piston? So you are saying with some sticktion of forces the pin pivots on the rod, not the piston.

Wasn't one downfall of the 5.7 diesel too small of a wristpin and it wore out then knocked?

Would some increased slickness between piston and pin free any rotation movement? Could it reduce a tiny bit of side loading on piston if it was freer to slip?
 
Our pins have a very close fit in the pistons, like .0003 or so, I can heat a piston & pin up to around 100* and the pin won't turn or come out.. thus I think the heat locks the pin.. I have never seen a piston that looks like the pin is moving around.. I can coat the pins but that is for the rod bushing, it's a brass kinda of stuff.. when I have rods I coat the bushing and not the pins, even tho the coating burnishes to a 0 clearance they are still hard to get back into the pistons, the clips are because the pins could move around before the pin gets locked I think. I don't know all this for sure I just know the used pistons don't appear to have wear in the pin holes...
 
Well, I don't know. It is just me talking.

I would think with the higher temperature of combustion and Aluminum having twice the thermal expansion rate of steel the bore clearance would increase while running. It would be hard to test at room temp cause the piston is so much bigger and might cool whereas the pin being steel and inside might hold the heat and get tighter in hand but be different in a heat soaking environment.

I damaged a boat engine running it hot then not letting it cool down slowly enough. I think damage went like this the blocked cooled faster than the piston which galled. Once the piston skirt galled the extreme piston drag then galled the wrist pin bore in the piston. The machinist said that is what caused the knock. This was an interference rod type assembly. Of course, the piston being galled and slapping also probably was some of the knocking noise.


The 6.5 low rpm, not extreme power wrist pins are not overstressed, under lubricated, or much of any mode of failure but I would say they do move in the piston and rod.

Food for thought.....

http://blog.diamondracing.net/when-to-upgrade-wrist-pins
 
imo the wrist pins are a non issue for these engines. The run tight on these engines because that very distinct rattle is how bad the side load is in the piston from the explosion/ burn traveling downward but in a very sideways direction. piston to wall clearances show a huge difference but most hear the difference in slight timing changes. that timing change isn't piston slap from up and down, it is sideways

Was your boat engine a 6.2/ 6.5? If so that would be the first 6.2/6.5 that any failure could be attributed to or even any sustained damage to pins. I doubt ot
 
It was a 3.0l merc. It was only an example of pin bore damage I’ve seen. And was secondary damage I believe not primary damage.

I agree no mention of pin damage in the 6.5 I’ve ever heard about just wanted to give my opinion that the pin probably does move in the piston after firing.
 
Well so much for this treatment.... our pistons can't be treated due to the top steel ring grove, the treatment would eat all the steel away in short time, this was disappointing, the shop doing it didn't say and I didn't know to inquire so 100$ in shipping and another bit of info gained..
 
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