The Alfa Romeo GTV6 engine sports an aluminum alloy cylinder block and heads. Pretty much all the external components of the engine are aluminum, with some magnesium alloy thrown in. While many lightweight alloys are used in the engine, the Busso V6 is not lightweight, coming in at about 397 lbs*. This is due to robust internals like a forged steel nitrided crank, forged rods, cast iron cylinder liners, and case-hardened steel camshafts, among other stout components.
The Alfa GTV6's all-alloy engine is rugged and imposing. The upper and lower oil sump and bell housing are lightweight magnesium alloy. The Alfa GTV6 set a record in the amount of magnesium used (about 99lbs.) in a road-going high production (over 10.000 units) automobile.**
The large two-piece magnesium oil sump holds nearly 8 quarts of oil.
Massive cam covers are a prominent feature of the Alfa GTV6 hemi-headed engine. This is my engine in 1997, just before installing it after a rebuild.
And what the engine looks like now after being parked for the past 23 years. Don't worry, we'll be taking care of that...
Cleaning the Alfa alloy engine presents some challenges. One is aluminum can be easily damaged using the wrong chemical. Even a handful of seconds in the wrong solution (like Purple Power / Alkaline chemicals) can discolor or even damage aluminum. Always read the instructions on these chemicals, and if it says dilute it, dilute it! Be careful.
Another is what kind of finish do you want? Do you like the natural aluminum finish or the painted, blasted, plated, or coated look? It's your car, so do your research and enjoy whatever you choose.
Alfa GTV6 Intake Tubes Clean Up
I like my engine's natural aluminum finish look, as long as it looks fresh and not old. My intake tubes looked dingy even after cleaning (WD40 and brake clean). I didn't want to paint them, so I thought of having them and other parts vapor-blasted / honed, but there were no facilities near me. Just as well, as I'm not working with an unlimited budget.
I've heard positive things about NAPA Aluminum Brightener and decided to try it.
I taped off a section of an intake tube and tried it out. You can see the results after about 30 seconds. The aluminum intake tube was noticeably brighter. Wow, something that works!
One note I'll make is to go slow with this product. If you do multiple applications, limit the applying time to 30 seconds or so for each pass and then check the finish carefully. Repeated applications can damage your part. It is also a combination of phosphoric and sulfuric acid, so don't even think about not wearing skin and eye protection. Don't take a chance.
Alfa GTV6 Intake Plenum Clean Up and Paint
My intake plenum was next. I cleaned it in a diluted Castrol Super Clean solution, leaving the surface discolored, grey, and dull. I wouldn't recommend using Super Clean.
The intake plenum on a GTV6, being on top of the engine, is very noticeable, so I wanted it to look good but not be gaudy. I was torn about what finish to go with, but I figured I would start with the natural aluminum finish and see how it looked. Wondering how the NAPA Aluminum Brightener would deal with the discoloration. I applied three applications with the above results. Not bad...
I then did the whole plenum to even out the finish. I did multiple applications using a stiff plastic chemical brush. Above is how it turned out. There were still some patchy discolorations, but the surface was clean and as close to new-looking as I could get.
While the plenum looked a lot better after the brightener treatments, I wasn't happy with the discoloration so I decided to see if I could match the factory color with an aluminum-colored engine paint. I tapped off the manifold to test how it looked, and it was an absolute surprise.
I found it was identical to the natural color of the intake plenum. The mounting boss at the top was also painted and it is nearly impossible to tell where the paint starts or ends.
I then gave the intake plenum a few light mist coats to blend in the discolored patches. Looking at the plenum in person, it is hard to tell it was painted.
Note that the roundish stain in the middle of the lower part of the plenum was from a yellow paint mark that has been there since I bought the car in 1986. I think the factory may put it there as a quality check mark. I wanted to save the outline so I could re-paint it when I was done. It gives you an idea of how light the mist coats were.
VHT SP955 Cast Coat Aluminum Engine Enamel paint (Amazon Affiliate Link)***
Alfa GTV6 Valve Cover Painting
The years were not kind to my GTV6's cam covers. These were originally painted with Kyrlon Dull Aluminum spray paint back in 1997.
Washed up with a mild degreaser. Whatever you use, check the warnings to ensure they don't mention Do Not Use on Aluminum. Many common degreasers at auto parts or hardware stores are incompatible with aluminum.
Degreased, cleaned, and sanded. Ready for paint.
Seymour Alumni-Blast Automotive Aluminum Spray Paint (Amazon Affiliate Link)***
I painted the valve covers with Seymour Alumni-Blast Automotive Aluminum Spray Paint.
I used a red permanent paint marker to paint the Alfa Romeo script.
Take your time doing this. It's good to practice on something to get the feel of how the paint flows.
Done and ready to install.
I'm not 100% with the look, but the Alumni-Blast is a popular paint, and the covers look much better. I may revisit them at a later date.
Painting the Alfa GTV6 Intake Plenum, Painting the Alfa GTV6 Valve Covers
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* Road&Track 1982 Alfa Romeo GTV6 Road Test. Alfa V6 engine weights have been reported between approximately 330 lbs to 400 lbs and up. The 397lbs. listed in the post above ia from a period Road Test and from a credible source.
**Source: Proceedings of the 39th World Magnesium Conference and Exhibition, 13-15 June 1982, Detroit, MI, USA, pp. 57-60
*** I spend hours doing research trying to find products I can use for my car. To save you time and the aggravation finding something that works for your car, I participant in the Amazon Services LLC Associates Program. The links posted are the products I've used, plus as an Amazon Associate I can possibly earn something from readers making qualifying purchases. Links to products may earn this site a tiny commission if purchased.
