Valvetrain Tech: If Light Weight And Low Reciprocating Mass Matter So Much, Do Stiffer Valve Springs Cost Horsepower?


Valvetrain Tech: If Light Weight And Low Reciprocating Mass Matter So Much, Do Stiffer Valve Springs Cost Horsepower?

Roller rockers, roller lifters, beehive valve springs, lightweight valves, lightweight locks and retainers, and the list goes on. These are all things designed to aid in controlling valvetrain at high rpm and under extreme power levels, and they do this by reducing the load required to move and control these components. So it would make sense that lighter valve springs would also be good for that. After all, anyone that has built an engine before knows that spinning the engine over by hand is very easy when it is just a short block and gets harder as you add components. If you have an engine with no spark plugs in it, and no rocker arms, then it is still really easy to spin by hand. But when you also have to turn the valvetrain, it becomes much more difficult.

So if you had an engine that didn’t “require” heavier valve springs, because it wasn’t going to be run at high rpm or didn’t have a camshaft that needed the extra valve control that heavy springs provide, would it make more horsepower with lighter weight springs that the others? Logic says yes. Or at least it seems like it does. But what does the dyno say?

Luckily for us, Richard Holdener knows because he’s done this very test and here it is so you can see for yourself.

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Awesomely Weird: This 1970s Chevrolet Parts Film Stars Evel Knievel And Literally Makes No Sense


Awesomely Weird: This 1970s Chevrolet Parts Film Stars Evel Knievel And Literally Makes No Sense

We’re guessing someone lost their job for this one. You are going to watch this 1970s Chevrolet parts film which stars Evel Knivel and makes literally no sense at all. The theme of the film is “conflict” and it is illustrated by a series of scenes where animals eat other animals, black and white movies are shown, and Evel Knievel jumps stuff on his motorcycle, sometimes crashing, sometimes not. Throw in a dose of 1970s Anchoman-level hilarity with a bikini-clad woman, and you have yourself one of the most singular odd things we have ever seen.

Make no mistake, Knievel would never turn down a gig, especially one with Chevrolet that likely was a great payday for reading some cue-cards. The company definitely did not hire him for his suave acting ability because this dude is straight up stiff while narrating the action. By action, we mean the bizarre things we are shown on screen.

Oddly, while Chevrolet parts are mentioned a handful of times there’s barely (if ever) a Chevrolet car shown as a prop in the film. This whole thing is some weirdo theater of the mind that was likely schemed up by an executive’s kid. “Hey Johnson, get my son a job in the media department and let him run wild!”

Obviously, Knievel was majorly famous at this point and his star only grew bigger. Note that he mentions that someday, “I’ll jump a mile….” we all know how that quest ended.

You have to see this one to believe it.

Press play to see the weirdest Chevrolet Parts video ever made, starring Evel Knievel!

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Cleaning Up Your Act: The Hagerty Cadillac 365 Gets Washed Up Before Heading To The Machine Shop


Cleaning Up Your Act: The Hagerty Cadillac 365 Gets Washed Up Before Heading To The Machine Shop

If there is one way to make friends with your local machine shop it’s by bringing them clean stuff to work with. We know that not everyone has the awesome washer that the guys in the Hagerty shop do, but if you take some extra time and bring in parts that do not look like they have lived at the bottom of a lake of grease for 50 years, you’ll earn some bonus points.

In this video we see Davin doing just that. He takes the disassembled Cadillac 365 and scrubs it all up before taking it to the machinist to be worked on. The value here is pretty high. One, you can get accurate measurements of stuff, two you can see if there are any fatal flaws in terms of obvious cracks and stuff, and three, it saves you some money! If you paid the machine shop to remove the rusted and seized studs from the manifolds and block you’d be paying real money for it. Getting that done at the shop before it goes to the pros is a win.

This engine is going to be a 100% stock rebuild and that’s been stated before. Davin states it again when dropping the parts off, basically cautioning the machinist not to go crazy. Reuse the stock valves if they can be used, stuff some new seats in the heads, and let ‘er rip. This is a fun engine. Maybe we’ll see the Honda mill toyed with next week!

Press play below to see the next installment of the Hagerty Cadillac 365 rebuild –

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If You Aren’t Smiling After Watching These Citröen Dyanes Rally, Then You Are Probably Seasick From Watching The Suspension Work!


If You Aren’t Smiling After Watching These Citröen Dyanes Rally, Then You Are Probably Seasick From Watching The Suspension Work!

Think of the Citröen Dyane as an upgraded version of the 2CV: in top-performance Dyane 6 form, there’s a 602cc flat-two engine driving the front wheels, a very light body structure, and after watching them go all-out at a rally, suspension travel that requires Dramamine to tolerate. We love an inappropriate car doing what it shouldn’t do, and with bicycle-wide tires and 32 horsepower on tap, rally racing is the last possible thing we would do with one. Alberto Miera, on the other hand, has absolutely no issue whatsoever wringing out his Dyane 6 on rally courses. The YouTube video description refers to Miera as the “brave pilot”, and watching the Dyane move around reinforces that statement. It might not be powerful, but anything past cruising speed brings out the suspension travel, and Miera isn’t afraid of the car at all, going so far as to induce oversteer. Watching the front wheels lay over in the corners makes us wonder just how many tie rod ends he goes through per race!

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(Courtesy: Jalopnik)


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