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FE Power Forums => FE Technical Forum => Topic started by: Qikbbstang on February 04, 2016, 10:16:45 AM

Title: How come most modern FE alum castings have the Extra Texture Finish?
Post by: Qikbbstang on February 04, 2016, 10:16:45 AM
   First Question: Got my Roush Timing Cover and it looks very impressive,  it has almost like very course sandblasted surfaces where it's not machined, both inside/oil wetted area and outside . There's a similar finish on modern Edelbrock heads and intakes. You compare these "new" parts to original FoMoCo intakes, timing covers, oil filter adaptors etc and they were cast very smooth not to mention they often sported typewriter sized print part numbers.. I don't know if FoMoCo used "finer" molds, different types of molding techniques for their castings, if it is from some form of agressively shot-peening the as cast surfaces?...............................
   

  Second Question: there is almost a rainbow color reflection from bright light on the machined sections - is this just from very fine machining of aluminum or some sort of clear coat/sealer applied to the entire part before/after machining?
   

 It all looks cool (modern but cool - it will stick out like a sore thumb if you used it on an all Ford FE motor). The modern castings textured finishes look to be road dust and grime magnets.  You can wipe grime off a FoMoCo timing cover with a Kleenex, you'd tear a Kleenex to shreds whipping it on a Roush cover.
Pardon my borrowing someone elses photobucket pic but his photo shows the surface perfectly and saved me the pic ordeal. 


(http://i12.photobucket.com/albums/a232/jaredaebly/Mobile%20Uploads/s-l1600-1_zpsoxdwltqy.jpeg) (http://s12.photobucket.com/user/jaredaebly/media/Mobile%20Uploads/s-l1600-1_zpsoxdwltqy.jpeg.html)
Title: Re: How come most modern FE alum castings have the Extra Texture Finish?
Post by: Lenz on February 04, 2016, 11:26:19 AM
Can't speak to all of the issues, but I am in the metal finishing business.  Not only does the "rough" finish look decent (but hard to clean), it will and does hide a multitude of defects that might otherwise might cause extra finish work at the end of the line.  In more extreme cases otherwise perfectly serviceable parts could end up in the scrap bin.

I would think that other manufacturers like Edelbrock would also do this for the same reason to some degree, as little to no mechanical finishing work needed is needed on those surfaces.
Title: Re: How come most modern FE alum castings have the Extra Texture Finish?
Post by: jayb on February 04, 2016, 11:30:35 AM
I think it depends on the foundry and the sand type that they use.  My first foundry for the intake adapters used a very fine sand, and the first 70 or so castings had a much smoother finish than the castings from my current foundry, that uses a coarser sand.  Probably back in the day Ford used a finer sand for the castings.  Everybody's got a process that they like to use, and the casting finish will depend on what sand is optimized for that particular foundry's process.
Title: Re: How come most modern FE alum castings have the Extra Texture Finish?
Post by: Drew Pojedinec on February 04, 2016, 11:59:11 AM
Look on the bright side BB, don't rough surfaces shed heater faster?
Title: Re: How come most modern FE alum castings have the Extra Texture Finish?
Post by: Qikbbstang on February 04, 2016, 12:28:10 PM
Drew I laughed so hard at your "bright side" I got tears in my eyes...Don't dimpled finishes also make the car go faster to because the course finish cuts through the air like a golf ball. (even under the hood).

 Wow I sure thought that was some crazy-ass top-secret type of shot-peening that couldn't be duplicated on all those new aluminum parts (you could make a fortune IF you could make old intakes look just like brand new intakes).
Title: Re: How come most modern FE alum castings have the Extra Texture Finish?
Post by: Qikbbstang on February 04, 2016, 12:32:22 PM
Hey you missed

Second Question: there is almost a rainbow color reflection from bright light on the machined sections - is this just from very fine machining of aluminum or some sort of clear coat/sealer applied to the entire part before/after machining?
Title: Re: How come most modern FE alum castings have the Extra Texture Finish?
Post by: Barry_R on February 04, 2016, 12:45:12 PM
The factory Ford timing covers are die castings - no sand involved
Title: Re: How come most modern FE alum castings have the Extra Texture Finish?
Post by: jayb on February 04, 2016, 12:54:12 PM
Hey you missed

Second Question: there is almost a rainbow color reflection from bright light on the machined sections - is this just from very fine machining of aluminum or some sort of clear coat/sealer applied to the entire part before/after machining?

That's just the machined surface.  A very finely machined surface will reflect colors like that.
Title: Re: How come most modern FE alum castings have the Extra Texture Finish?
Post by: fekbmax on February 04, 2016, 01:46:15 PM
What Barry said..
 ::)
Title: Re: How come most modern FE alum castings have the Extra Texture Finish?
Post by: Drew Pojedinec on February 04, 2016, 01:49:31 PM
Drew I laughed so hard at your "bright side" I got tears in my eyes...Don't dimpled finishes also make the car go faster to because the course finish cuts through the air like a golf ball. (even under the hood).

Now you are catching on..... that darn Roush fella is a genius.  Dang, now I have to send my whole car off to the powdercoaters.
Title: Re: How come most modern FE alum castings have the Extra Texture Finish?
Post by: Barry_R on February 04, 2016, 02:16:45 PM
On many of the castings you'll see the pebbled finish is the result of a post preparation media blast with stainless steel shot.  They will take the raw casting and hand deburr, remove all the foundry sprues and parting lines with a grinder, and then shot blast the part before finish machining.
Title: Re: How come most modern FE alum castings have the Extra Texture Finish?
Post by: ScotiaFE on February 04, 2016, 03:15:07 PM
My learning how to do it casting.
We used what is called green sand.
It was very fine almost like a powder.

(http://i135.photobucket.com/albums/q128/ScotiaFE/DSCN0590_zpszl5jcndp.jpg) (http://s135.photobucket.com/user/ScotiaFE/media/DSCN0590_zpszl5jcndp.jpg.html)
Title: Re: How come most modern FE alum castings have the Extra Texture Finish?
Post by: bn69stang on February 04, 2016, 07:57:49 PM
You guys are killing me , lol - figure out how much hp they make and then get with Jay , he may have to re do all his dyno figures
Title: Re: How come most modern FE alum castings have the Extra Texture Finish?
Post by: Heo on February 04, 2016, 09:13:41 PM
Nice Howie im impressed 8)
Title: Re: How come most modern FE alum castings have the Extra Texture Finish?
Post by: Drew Pojedinec on February 04, 2016, 09:47:57 PM
Howie was that off Dave Gingery's plans?
Title: Re: How come most modern FE alum castings have the Extra Texture Finish?
Post by: ScotiaFE on February 04, 2016, 10:10:25 PM
Nice Howie im impressed 8)

Thanks.
Title: Re: How come most modern FE alum castings have the Extra Texture Finish?
Post by: ScotiaFE on February 04, 2016, 10:17:48 PM
Howie was that off Dave Gingery's plans?

Not from his plan, but he did make some really kool stuff.
I started a double pipe lathe a long time ago.
It's pretty close to actually working. I should finish it before I'm gone.  :P
Dust collectors.
Title: Re: How come most modern FE alum castings have the Extra Texture Finish?
Post by: falcongeorge on February 09, 2016, 06:17:26 PM
...Don't dimpled finishes also make the car go faster to because the course finish cuts through the air like a golf ball. (even under the hood).


;)