Ceramic Coating 7M Crank

[Van]

So, here is the latest... The crank is getting lightened, checked for balance and that's it. My household budget got hit with a 40% reduction. So, it's time to shift the money from the build, rightfully to the family.
(SupraRich, that cam shaft set will have to wait).
Man, what a difference a day made! :nono: Van

 

[Adjuster]

Van, here's my .02 for what it's worth.

I've coated a crank with molydisulfied, and it was a great deal, right up to where I found out that washing out the crank WITHOUT pulling the plugs is a really, really really really bad idea. (There is quite a bit of crap hanging out in those oil passeges...)

That engine died a horrible death due to trapped hidden sand blasting media that then destroyed the bearings and crank along with them.

OK, round two! Stroker motor number 1) Crank was knife edged, and the stroke was changed by welding up the rod journals and then machineing them to a 2" size that uses 327 SBC bearings. This was fine untill a mechanic thought he would take a ride in my car.. Did not have the fuel pressure regulator or boost controller hooked up, and you guessed, it engine #1 was a bust. (Actually twisted the crank slightly... )

Stroker motor #2. Sent the crank back to Crankshaft Specialist in Tenn. (The guys who did it the first time.)
They hard chromed the journals, and then machined them all to the right specs, true as can be again. These guys did the original knife edges too. The hard chrome journals really did not look that special, but they are dang hard! We basicly just checked the size, and for true, and it was already polished. The only thing I had to clean up was they left a cross hatch on the thrust bearing surface, and I think that can strip away oil where you want it to stay, so I polished it, but that's it.

If you want to coat something, coat your bearings. The crank is not touching the bearings when the engine is running. But it does when the motor is shut off, and it is started. (My setup pre-lubes the engine before I crank it over, so there is very little wear.) But, as noted, there is some contact when it's shut down, and started. At those times, the coatings do a great job of keeping oil between the parts as much as possible, and since molydisulfied is a great high pressure lubricant, it does the job when the metal forces the oil out of the gaps.

I coated my bearings, and it seems to have worked very well, and it was much less work than trying to coat the crank. (I pulled the plugs on even this "clean" crank, and found more crap in there! Pull the plugs, use pipe cleaners, and rifle bore brushes on your crank! I can't say enough how much dirt, carbon and crap is waiting in there for oil flow to push it into your bearings.) When you put new plugs in, use loctite, and stake them back down, so they can't come out. I used easy out's to remove them. The allen heads will just strip, so I just go straight to the easy out for this.

Good luck.

 

[Enraged]

I just heard back from these guys regarding WPC: http://www.wpctreatment.com

Prices:
2 camshafts: $120.00/piece x2 = $240.00
6 rod bearings: $4.00/half shell x12 = $48.00
7 main bearings: $4.00/half shell x14 = $56.00
Crank: $280.00/piece (friction reduction) or $420.00/piece(friction
reduction + improving durability)
6 rods: $40.00/piece x6 = $240.00

seems like getting the bearings done would be the cheapest insurance.

and here is an article about shot peening and wpc treatment: http://www.turbomagazine.com/tech/turp_0902_shot_peening_wpc_treatment/index.html

 

[mecevans]

what parts would be best shot peened and what parts be done by WPC?

 

[Enraged]

from the turbomagazine link:

Another big advantage that WPC has is a big reduction in friction. WPC's micro-dimpled surface helps reduce friction in three ways. First, the dimpling helps maintain an oil film, which reduces metal-to-metal contact. Second, the dimpled surface helps reduce contact area in general to reduce friction. Third, the hard surface with anti-friction and extreme pressure materials embedded into it is a slippery and longwearing surface in its own.

and

WPC treatment of bearings has also shown to be very beneficial. Even though bearings are made of soft metals like aluminum, lead, tin, and zinc, they can be WPC treated with no change in dimension. The treated bearing shows a reduction in friction and an improvement in fatigue strength to where their load bearing capacity has improved from 20 to 50 percent.

From this, I would imagine bearing would benefit the most for the cost.

 

[suprarich]

please post if you get a price estimate on the salt bath nitride.

About 250.00 for a single crank. Less per crank if more are done at the same time. We can fit about 4 cranks in at a time. Send me your crank if you want it done. I have pics all over SM of cranks that have been salt bath nitrided.

Once a crank is hard chromed, there is no salt bath nitriding in its future. The two do not play well together.