# Why interference engines? **URL:** \ **Category:** Factual Questions\ **Created:** [January 12, 2008, 7:28pm UTC](https://boards.straightdope.com/t/why-interference-engines/433320 "2008-01-12T19:28:56Z")\ **Posts on this page:** 5\ **Page:** 3
**Author:** ![Tuckerfan](https://avatars.discourse-cdn.com/v4/letter/t/eada6e/32.png) [@Tuckerfan](https://boards.straightdope.com/u/Tuckerfan)\ **Post date:** [January 14, 2008, 1:02am UTC](https://boards.straightdope.com/t/why-interference-engines/433320/41 "2008-01-14T01:02:26Z")
[QUOTE=Rick] Umm, cite? To the best of my knowledge the US government has never mandated the technology used to achieve a particular emission goal. Having worked in the industry during the formative years of emission controls, trust me when I tell you there were plenty of different approaches tried. Plenty. [/QUOTE] It was an interview with a Ford exec on a Hitler Channel program. IIRC, it was a show about the history of the Mustang. It was also _him_ saying that, not a recap by a host/narrator, so it’s not something that could be blamed on the producers screwing up. Nor was it something that could have been created out of editing different parts of an interview together. To be fair, I found it a bit hard to believe myself. After all, I would think that if they _had_ such technologies, the smart thing to do (of course, being “smart” hasn’t always been the Big 3s strong suit) would have been to put them on cars _before_ the emission mandates took effect and show that they’d lowered pollution without harming performance, then let folks scream at their Kongress Kritters when the mandated vehicles turned out to be pure crap. And I must admit that I’m not completely clear on how all the various emission laws worked, as I know that Chrysler and a few others went for technologies that lowered emissions _without_ using a catalytic converter, even though it was at a time when I thought that they were mandated to be on all vehicles. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [January 14, 2008, 1:05am UTC](https://boards.straightdope.com/t/why-interference-engines/433320/42 "2008-01-14T01:05:45Z")
> [@Rick](#): > > You are correct unless you are going to spin the engine at some insane RPM. Like Ducati does (scroll down click on engine details) I understand the point of desmo for uber-high RPM operations. But there’r otehr ways to achieve a similar result. If you want weird valving, try this: [Sleeve valve - Wikipedia](http://en.wikipedia.org/wiki/Sleeve_valve) They worked pretty well for producing large valve surface areas. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [January 14, 2008, 1:12am UTC](https://boards.straightdope.com/t/why-interference-engines/433320/43 "2008-01-14T01:12:19Z")
[QUOTE=Sunspace] I thought this was going to be about radiated electrical interference. [/QUOTE] I thought it was going to mention OPS5. ---
**Author:** ![Sockmunkey](https://avatars.discourse-cdn.com/v4/letter/s/f17d59/32.png) [@Sockmunkey](https://boards.straightdope.com/u/Sockmunkey)\ **Post date:** [January 14, 2008, 1:51am UTC](https://boards.straightdope.com/t/why-interference-engines/433320/44 "2008-01-14T01:51:12Z")
[QUOTE=Tuckerfan] [Chrysler was all set to introduce a mass production turbine car](http://www.allpar.com/mopar/turbine.html), but was blocked from doing so because of conditions placed on it in order to get the government bail out. That they haven’t revisited the idea probably has a lot to do with their shakey finances. [/QUOTE] Ah, the turbine car. I love that concept. IMHO it would probably work great if used in a series-hybrid. ---
**Author:** ![gazpacho](https://avatars.discourse-cdn.com/v4/letter/g/6f9a4e/32.png) [@gazpacho](https://boards.straightdope.com/u/gazpacho)\ **Post date:** [January 14, 2008, 2:31am UTC](https://boards.straightdope.com/t/why-interference-engines/433320/45 "2008-01-14T02:31:03Z")
I had a GPZ 550 motorcycle that had a bad oil leak. I replaced the head gasket and that helped things for about a year then the leak came back so I replaced it again. The second time I had a hard time getting everything aligned at top dead center. When I was tightening the bolts holding one camshaft in I head a loud crack. I thought I busted the bolt. I checked and the bolt seemed fine so I tightened the rest. I then went on to do the same with the other cam shaft I head the same crack and when I started the bike it did not run well so I took the head off to see what was wrong. Both cam shafts were broken. I sold the bike for $50 after that. [Previous page](https://boards.straightdope.com/t/why-interference-engines/433320.md?page=2)