PTWA process?

[rhb1999]

I was reading, a May 2010 Popular Mechanics article about Ford patenting a "plasma transferred wire -arc spray process". That coats aluminum cylinder walls with a "tough form of iron oxide that reduces friction". Spray weld? And I was just wondering could a similar process be of any benefit to an vintage aluminum engine that does not use iron cylinder sleeves? Or do most or all aluminum blocks have sleeved cylinders?

Edited April 21, 2010 by rhb1999
adding information (see edit history)

[Larry Schramm]

The only aluminum block that I remember that did not have a sleeve was the Chevrolet Vega and that block was supposed to be silicone enriched to give it a good wear factor.

[john2dameron]

Larry, I think most people would rather forget the Vega aluminum blocks. LOL

[Larry Schramm]

Don't disagree, but it was out there.

[rhb1999]

Silicone enriched?, interesting. I also remember reading that certain coatings are used in the treating of the critical parts in racing engines at the time of assembly. Are these coatings any good? Yeah, the Vega engines were notoriously bad, that in the 70's, company's were starting to offer swap kits for Chevy small blocks. I understand Chevrolet was considering offering a V-8 for the Vega, but it never got off the ground. I remember seeing a Hot Rod magazine cover, from back then, showing something that looked like a prototype V-8 Vega. Was the Cosworth Vega any better?

[Rusty_OToole]

Porsche and Mercedes used the exact same Reynolds aluminum formula for their V8 blocks that Chev used for the Vega.

In the case of the Vega the oil burning was more a result of bad valve guide seals, or radiator failure than the blocks themselves. I know of Vegas that went over 100,000 miles on the original engine but the owners never ran them dry of oil or water.

For those not familiar with the Reynolds formula they made the blocks out of special aluminum alloy containing 17% quartz silica in other words sand. They etched the cylinders with acid to dissolve away the aluminum and leave the silica particles standing proud. The wear surface was actually the extremely hard silica or quartz particles.

The surface was very hard wearing and long lived. But if you managed to seize the engine the aluminum piston would weld itself to the aluminum block by friction, tearing away chunks of aluminum.

The cylinder could be rebored and washed with Easy Off oven cleaner to duplicate the original surface then new pistons installed. But most of them were just junked.

[Barry Wolk]

The V-12 in my '88 BMW used a similar technology only it used ceramic instead of silica alloy. They acid treated the bores, I believe, eating away the aluminum, leaving a ceramic wear surface. Well, that's how it was described to me.

I've had the car 22 years and have had no engine problems.

[rhb1999]

Thanks for clearing this up, Rusty O Toole, Barry Wolk. I never knew the real reason for the Vega's failure. Sounds like what happened with owners of the Buick 215 and lettting them overheat?, although it was a sleeved cylinder engine, right? This is what I seem to remember reading in an article in either Hemmings or AACA magazine. Easy Off oven cleaner, Hmm. I've read somwhere that this is what mechanics of old used to clean blocks and heads and other things with, but I didn't know it could duplicate the cylinder wall surface. 22 years?, I would say this is proven technology.

Edited April 22, 2010 by rhb1999
change wording (see edit history)

[Bhigdog]

I stupidly bought my son a nice looking Vega for his first car. It was without a doubt the WORST POS, ever built , by any maufacturer, for any purpose............Bob

[Rusty_OToole]

Vegas had some problems that should have been fixed before they reached production. But they weren't the worst car ever made. They weren't even the worst car GM ever made. That was the English made Pontiac Firenza, the only car ever to have an owner's club founded for the purpose of getting revenge on the company that made it.

I drove a Vega when they were new and was impressed with the quiet and smooth ride and economy. They had a lot to offer when compared with other small cars of the time.

[Bhigdog]

Yeah for maybe the first year. Then they rusted to dust, burned more oil than my furnace in January, and generally just fell apart right before your very eyes. Other than that they were a fine car. My Dad had a Pontiac Tempest of about the same vintage that gave it a run for it's money in the POS department.........Bob

[earl e rizer]

It's amazing how long the distaste or out and out hatred of Vega's has lasted. I had the 74 Pontiac Astre GT version in 76 and it truly was a POS never to be forgotten:D

[Larry Schramm]

One of the things that the Vega helped to make standard is the overflow bottles and radiator cap that made the cooling system closed. It purges to a point air from the system and draws coolant from the overflow tank back into the radiator. Standard on all cars now.