Engine Porn

"BringBackTheCommodore" (bringbackthecommodore) 07/29/2016 at 07:12 • Filed to: Mustang, Shelby, GT350, Ford, Muscle

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Went to Autoblog, the first article that popped up did not disappoint.

Flat. Plane. Crank. Sounds delicious.

!!! UNKNOWN CONTENT TYPE !!!

Echo51 > BringBackTheCommodore 07/29/2016 at 07:20

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I somewhat hope that’s an unfinished crank, imagine the windage losses? Oh wait, this is america, just throw more displacement at any issue instead of optimizing? Riiiight.

Disclaimer: I’m no engine expert, but don’t they normally make the counterweights just slightly more smooth?

BringBackTheCommodore > Echo51 07/29/2016 at 07:31

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I would venture to say that it’s likely not a finished crankshaft, as you stated. There was once a day when racers would have the crankshaft knife-edged to reduce drag through the oil pan.

Likely, what’s on display in the photographs was not a finished product because it was intended to be on display rather than living under the hood.

Echo51 > BringBackTheCommodore 07/29/2016 at 07:34

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Maybe they want to show that they CNC/whatever out the counterweights, but then again the bearing surfaces look like they won’t need much if any work, and i’d keep that finishing for last untill all other processing is done... oh well, probably just a display model

XJDano > BringBackTheCommodore 07/29/2016 at 07:40

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I have this for my 84 VW Gti.

Sounded like a good investment at the time. It hasn’t been started for quite some time.

SidewaysOnDirt still misses Bowie > Echo51 07/29/2016 at 08:08

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Every crank I’ve ever seen has a pretty rough finish on the counterweight. Not on the inside of them like that, but most are cast and ground or forged, not full billet CNC’d. There’s already a crank on ebay and it looks like the one in the article.

http://www.ebay.com/itm/like/32220…

450X_FTW > Echo51 07/29/2016 at 08:24

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I’d say not finished. I don’t see any machining marks on the outer area of the counter weights indicating that it’s been balanced

450X_FTW > Echo51 07/29/2016 at 08:27

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Like this

Sweet Trav > Echo51 07/29/2016 at 08:51

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No, that’s a production crankshaft. The added cost of machining would outweigh the 1-2hp you’d gain from having a clearer surface.

And honestly if you’re complaining about “optimization” it makes 100HP/L there aren’t even many naturally aspirated European engines that make that kind of specific output.

And actually there was a lot of optimization done to this engine. The heads are revised to flow better than any previous Mod Motor head and they had to put special external mass dampers on the bell housing and transmission to keep it from shaking itself a part.

petebmwm > BringBackTheCommodore 07/29/2016 at 08:52

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it might be early, and i might be missing something, but isn’t that a 4 cyl. crank?

petebmwm > petebmwm 07/29/2016 at 08:53

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nevermind... it’s early....

BringBackTheCommodore > XJDano 07/29/2016 at 09:02

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Mmmm....engine internals. That crankshaft is a work of art!

BringBackTheCommodore > SidewaysOnDirt still misses Bowie 07/29/2016 at 09:04

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Interesting. Surprised it’s left unpolished, I’d think the unpolished surface of the counterweight would create some amount of drag as the crankshaft passes through the oil. Engineers designed it that way for a reason, though...

XJDano > BringBackTheCommodore 07/29/2016 at 09:04

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It's in the bottom of the 1.8 waiting to be situated in place. Long story short, bought with messed up title, blew up on day 3, had an engine rebuilt, lost interest, moved a couple times, but I still have it. It's waiting for me.

BringBackTheCommodore > petebmwm 07/29/2016 at 09:06

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I’m not being sarcastic at all when I say this, those would be some big-ass connecting rods. Interesting thought - I wonder what the displacement would be on a 4-cylinder with pistons that large.

BringBackTheCommodore > XJDano 07/29/2016 at 09:07

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Smart way to handle the vehicle, don’t give up on it, return to it when there’s time. I kick myself every day for not holding on to a 1981 Scirocco I used to own - I gave up on it because the fuel pump quit. Stupid, stupid idea.

petebmwm > BringBackTheCommodore 07/29/2016 at 09:09

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it’s early and it’s at an angle, didn’t realize at first glance... but figure a piston almost 8 inches across..

SidewaysOnDirt still misses Bowie > BringBackTheCommodore 07/29/2016 at 09:15

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The crank doesn’t pass through the oil unless you overfill it, which is bad. You’re not going to gain anything by polishing it.

XJDano > BringBackTheCommodore 07/29/2016 at 09:16

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Yeah after it blew up and got transferred with a guy who was working on it as he switched jobs, then I took possession of it and the engine is wedged from the top, not bolted in. It’s a mess. But it’s paid off and when I get my garages in order I may get it running.

2- 84 Gti, 99 Cherokee with stuff, Yamaha R1 are the project cars,

Drivers are the metro, Equinox, wife’s van, and an 82 Honda silverwing motorcycle.

I have my hands full and the silver Gti is stored at my rental which I’ll have to make room for soon in my garage.

Sweet Trav > 450X_FTW 07/29/2016 at 09:27

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That’s Mallory Metal, used to add weight to a crankshaft. Typically production cranks are made a little heavy and then drilled to remove weight like this.

From a mass production standpoint, this is much easier than ADDING weight to crank through drilling and pressing in Mallory Metal.

BringBackTheCommodore > XJDano 07/29/2016 at 09:43

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Ah, nothing like a garage full of projects to keep life interesting. Any plans for the XJ?

BringBackTheCommodore > SidewaysOnDirt still misses Bowie 07/29/2016 at 09:45

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Mixed knowledge floating around in my head, then. In some applications utilizing a crankshaft, the counterweights pass through the oil, but generally that applies to splash lubrication which is widely used in reciprocating air/refrigeration compressors, not modern engines.

BringBackTheCommodore > petebmwm 07/29/2016 at 09:52

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I worked on an engine with pistons that diameter, it was a Fairbanks-Morse 38ND8-1/8 diesel engine. Needless to say, that engine took up quite a bit of space.

Not installed in the configuration I worked on, but that’s the same make/model of engine I worked on. BIG.

http://www.dieselduck.info/machine/01%20p…

Fuel consumption, unloaded, was measured at 64 gallons/hour burned. Loaded up, that diesel generator burned 69 gallons/hour.

450X_FTW > Sweet Trav 07/29/2016 at 09:57

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That’s the picture I was trying to find. Google image failed me.

AMGtech - now with more recalls! > Echo51 07/29/2016 at 10:35

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To add to what Travis and sidewaysondirt said; I bet the rough looking machined surfaces on that crank aren’t actually that rough. Machined surfaces often look like that but will in actually be super smooth. And the unmachined casting actually looks very tight and high quality. It would surprise me if there isn’t a windage tray below that crank when assembled as well.

Could they have optimized it more? Certainly. But the gains wouldn’t remotely justify the time and money invested. That’s already a very nice crankshaft by any standard.

XJDano > BringBackTheCommodore 07/29/2016 at 10:49

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That’s kind of done for now meaning stuff = 5.5 RE long arm lift, 33's, ford 9" rear with Currie hi9 & ARB, 4.56 gears, trussed D30. I put money into it before I got married.

A caliper froze up on me a few years ago, I had my wife trying to help me bleed brakes, got frustrated, sent her inside and haven’t touched it since. It’s like the VWs, paid for and ready for me to work on when I get a chance.

Since I parked it I had 2 kids, and they are about to get old enough to appreciate it (6&4 soon). So I keep saying next year I’ll get it driving again.

I have other family drama that involves a rental house & im about to kick them out, so I’m happy to have a car that drives. Soon I’ll be able to get everything drivable, just not too soon.

When I was a kid I always thought owning a bunch of cars means you’re rich. Well I’ve made it, I just don’t have time to work on anything.

BringBackTheCommodore > XJDano 07/29/2016 at 11:32

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Sounds like a pretty beastly build...unfortunately, life gets in the way of living sometimes. Hang in there - that sounds pretty insane to go through.

WiscoProud > petebmwm 07/29/2016 at 12:20

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each connecting rod journal holds two connecting rods. For a 4cy engine, the cranks look similar, but the journals are much narrower.

petebmwm > WiscoProud 07/29/2016 at 17:07

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i realized that after....