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While I got the motor out I thought I would pretty things up while my heads are getting decked. What's a good way to do this? I was thinking sandblast with some high temp black paint. Any thoughts?
While I got the motor out I thought I would pretty things up while my heads are getting decked. What's a good way to do this? I was thinking sandblast with some high temp black paint. Any thoughts?
Bead or slag blast and then hi temp etch primer and hi temp gloss black paint and then linish any figuring on the top with 120 or then 80 grade paper and finish with lacquer with hi temp clear lacquer. Saves polishing later
Originally Posted by The Deputy
Hate to be a kill joy, but there is a reason they don't paint aluminum engines (heads and block). Aluminum has a thermal conductivity three times greater than case iron. It's all about heat transfer. There is what is called a "boundary layer", which mates with the cooling fluid and ambient air under the hood. These two areas decide how the engine will be cooled. When you obstruct the outer boundary, by painting, you are in essences partially limiting the aluminums ability to transfer heat externally. Which in turn, causes the fluid side to do more work in that area.
Learned a lot about this in a three week course put on by Allison Transmission/Detroit Diesel. They talked extensively about "why" aluminum should never be painted. Allison transmission will reach temps close to 300F, so displacing heat is paramount.
Like I said...hate to be a Debby-downer...but this is just something I learned and thought l'd pass it along. Hate to see this practice become common place and folks start seeing even worse cooling issues.
Hope this isn't the case on your engine, but time will tell.
Brian.
Brian had also mentioned this in my build thread and kind of agree -- Decided to just clean my parts and leave them be. Used wire wheel, wire brush and lots of elbow grease along with the purple degreaser stuff i have. Took about 20 mins to do each one
Hi Saturnine, I disagree. TDi's run far hotter in many cases. However, low revving V8's never get very hot at the rocker covers. Many race engines are painted rocker covers as standard.
Cosworth Ford DFV engines were always finished in black rocker covers and BDA/BDX engines were always finished at the rocker covers in black or red as standard.
Last edited by OffroadFrance; 05-20-2018 at 01:23 AM.
I used a ton of carb cleaner spray, simple green degreaser, scotchbrite, hot water and a pressure washer.
I agree in not painting any engine parts, kind of a silly thing to do really
, but my valve covers looked like crap so I painted mine... aluminum color, haha. Leave the rest of the engine alone... plus bare aluminum is sexy
Don't forget to unscrew the baffle plates inside the covers and clean under there
I used this graphite spray stuff on the manifolds, as apparently it can withstand the heat, but it was a waste... 1 week after installing the engine they were orange again
I use the same dupli-color DE1650 on v covers, intake, etc.
That stuff holds up very well.
If you want to paint the exhaust manifolds use VHT Flameproof. It stinks like crap until it cures (about 2 heat cycles) but it works like a champ.
05-20-2018, 12:33 AM
