The materials less traveled 1

[Savorra]

I was wondering what were some alternative materials used in engine block construction other than the typical Iron and Aluminum. In particular I was doing research into the TVR Speed Twelve Engine. I am sure TVR utilized Aluminum heads and while the heads would suffer from Galvanization corrosion if they came into contact. I was wondering if the microscopic flakes of steel floating in coolant passages will negatively affect the aluminum heads in the long run. I would also like to know if anyone had tried something similar in developing a Steel alloy engine block like the Speed 12 and if their are anymore information on the engine construction process.

 

[MikeHalloran]

The first thing that came to mind was the Crosley CoBra, which was copper- brazed from steel sheet. ... and had corrosion problems, probably not because of the presence of aluminum.

http://en.wikipedia.org/wiki/Crosley

I recall reading about someone who intended to use the same technology, brazed steel sheet, to make a much larger engine for boat racing. ... but I haven't seen reference to it anywhere in the decades since.

Note that steel is basically just iron with less carbon than cast iron, so it should behave similarly. ... except at the piston bores, where I'd expect a steel block to have severe wear problems absent iron liners or exotic coatings. I didn't find much detail on the TVR engine; I'm guessing it's simply cast steel, not sheet.

Iron blocks with aluminum heads have been used commercially for many years. Most of the problems encountered had to do with head gasket leaks, not corrosion, so if TVR is not too proud to copy technology from Chevrolet, they should be okay on that front.





Mike Halloran
Pembroke Pines, FL, USA

 

[pontiacjack]

Aren't the NASCAR 'cup' series engines all using composite-something-or-other blocks for a few years now? I know nothing about their cylinder liners.

 

[Tmoose]

I was surprised I could not access the rule book on the Nascar web site.

As of 2009 it looks like "iron" blocks were still required

http://www.hotrod.com/techarticles/hrdp_0803_chevy_nascar_engine/

http://www.hotrod.com/techarticles/hrdp_0803_chevy_nascar_engine/photo_02.html

 

[BigClive]

Similar to the Crosley engine the Mercedes Benz M196 engine (from the famous W196 car) had a built up/welded cylinder block and heads on a aluminium crankcase. I think MB changed to a conventional cast block engine later on.

 

[pontiacjack]

I guess I was remembering wrong.
Doing a 'net search, the most recent item I found (2011) was an announcement by Composite Castings LLC of Florida, regarding a carbon-fiber block for an inline four cylinder (Ford?) that's apparently used much in racing. Not finding more-recent posts about the block doesn't lend encouragement for learning that it was successful.

 

[Tmoose]

I was thinking, trying to remember articles in Car Craft or Hot Rod about plastic engines, maybe back in the '80s, and managed to dredge up Polimotor. Plenty of Google hits for that.

Here is a link to the 1982 Popular Science in which it is said Ford was backing Matty Holtzberg's first venture, Polimotor

http://books.google.com/books/about/Popular_Science.html?id=FzCnbu4xM0YC

In This Autoweek article Matty says Ford "actually contributed nothing."

http://www.automobilemag.com/green/news/0911_plastic_car_engine_matty_holtzberg/

On page 140 of that issue of Pop Sci the late great Smokey Yunick has an interesting comment about the status of US emission controlled engines, among other things.

 

[Savorra]

Thanks for the reply guys, I have been looking into alternative materials for engine production particular Steel. However TVR doesn't seem willing to release any information on their V12 engine besides what seems to be the mythical Steel alloy EN14T. I've looked around and can't seem to find any material that matches that besides EN14a.

On a side note the plastic engine is very interesting but I'm skeptical of it's durability in the long run. On Average many car owners don't take as good care of their vehicles as they should. I know I'm guilty of that sometimes. And I'm skeptical of plastic begin durable enough to withstand the type of temperatures needed to live in the automotive combustion zone. In example, if the engine starts to run low on oil, the reinforced plastic conrods are going to have to be able to withstand those temps for possibly 20-40 miles. That's a lot to ask for. However, for such things like oil pans and heads with the metal valve tunnels and such might be doable.

 

[Greg5OH]

I believe cosworth had an engine made of UHMW plastic years back that did quite well?

 

[BigClive]

Ceramic engine block?

 

[MikeHalloran]

Plastics are creeping into engine design, maybe a few design wins per decade, including I think:
-water pump impellers
-timing sprockets
-valve covers
-valley covers
-vacuum tubing
-belt guards
-external accessory brackets
-radiator fans
-air filter housings
-acoustic covers
-accessory valves, e.g. EGR control valves
-radiator header tanks

Not all applications have been resounding successes, and some have been an embarrassment multiple times.

Indicators include combining parts to eliminate, snap fits for quick assembly, complex shapes as easy to produce as simple ones, chemical resistance.

Contraindicators include heat, cost of tooling and cost of resin.

About the cost of resin, ISTR that Torlon and similar high performance resins are obscenely expensive, but I've never quite understood why they remained so, while being available for decades. Is it that scaling up production is so capital-intensive that nobody will front the money, or is some basic resource limiting, or does the process also produce toxic waste or other costly and unmanageable byproduct, or is the yield of good product just pitiful, or what?



Mike Halloran
Pembroke Pines, FL, USA

 

[swall]

Plastic has also made it into intake manifolds.

 

[MikeHalloran]

Thank you.
Both of my current vehicles have plastic intake manifolds, as do many contemporary vehicles. I'd have to call that a successful application.


Mike Halloran
Pembroke Pines, FL, USA

 

[GregLocock]

...and they took 20 years to get right.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[MikeHalloran]

When today's cars are antiques, restoring them properly will be impossible because the plastic parts will have rotted away, so craftsmen will be faced with making sand molds for intake manifolds and then finishing the resulting aluminum casting to look like plastic.

... Okay, maybe additive manufacturing will be up to the task by then.


Mike Halloran
Pembroke Pines, FL, USA

 

[BrianGar]

@ Mike, some people are making good money at that already,,

Brian,

 

[IRstuff]

"When today's cars are antiques, restoring them properly will be impossible"

It may the exact opposite. Your kids' kids will probably be in a world where pretty much every home has a 3D printer; and the CAD files will be open sourced for downloading. Of course, IC cars may be banned completely by then, so restoration is moot ;-)

TTFN
faq731-376

Need help writing a question or understanding a reply? forum1529

 

[BrianGar]

As long as the kids dont turn into screen gazing/touch screen zombies then we will be ok. The movie ''Idiocracy'' seems possible though,

Brian,

 

[140Airpower]

Mike, can you visualize a rusted hulk of an antique car found in a barn somewhere with the metal parts all corroded away while the plastic parts are as good as new? I think most current plastics are damaged only by UV and chemicals. They have half lives in the 10s or 100ds of thousand years in a normal, but UV protected environment.

 

[MikeHalloran]

Really early plastics like Bakelite and celluloid are indeed durable.
Less ancient plastics like nylon and delrin are somewhat less so.
More modern formulations are much less so.

<limited data>
I watched my 1970 Mercedes turn into a rusted hulk in my carport while waiting for the engine to cure itself of a crack. ... never happened, and I never found the actual crack. ... but that's a metal problem. ... well, actually, it's a fluorescently stupid machine design, but that's another issue.

The nylon power brake vacuum tube fractured of its own accord when the car was only five years old. After 30 years, the heater control handles, which looked like molded black Delrin but were a little rubbery, had crumbled to dust, like polyurethane does, at least like it does in SoFla.
</limited data>

Basically, it appears to me that any plastic resin containing an elastomer alloy component, or a plastcizer, or an impact modifier, is going to have a limited useful life; it will get brittle and crack, even absent UV or solvents. Except for urethanes, it will still be identifiable in a landfill, but it will not be capable of performing its intended mission after a few decades.







Mike Halloran
Pembroke Pines, FL, USA