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C8 tease video - what is the cross section of?

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C8 tease video - what is the cross section of?

 
Old 05-23-2019, 05:49 PM
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stevestig
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Default C8 tease video - what is the cross section of?

Hi, sorry if this was asked before. I know this video has been talked about before https://www.chevrolet.com/upcoming-v...2#teaser-video . I grabbed a copy and looked thru each frame, and there are some cool pictures in there. This one, I am not sure what it is... anyone know?


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Old 05-23-2019, 05:54 PM
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engine. crank, conn rod, cam, timing chain
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Old 05-23-2019, 06:36 PM
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captain vette
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Originally Posted by wdwinder View Post
engine. crank, conn rod, cam, timing chain
Yes absolutely
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Old 05-23-2019, 09:53 PM
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A massive 2 gerotor oil pump that we've never seen and a 2nd timing chain that possibly leads to a 2nd cam making the LT2 twin cam in block.
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Old 05-23-2019, 10:10 PM
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Originally Posted by Tool Hoarder View Post
A massive 2 gerotor oil pump that we've never seen and a 2nd timing chain that possibly leads to a 2nd cam making the LT2 twin cam in block.
But there are enough lobes on the one cam shown not to need a second cam.
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Old 05-23-2019, 10:53 PM
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No room for error on these engines, warranty is your friend.

Has a chain tensioner there also, man this is no Model T but the Model T will out last that puppy any day of the week if you like an antique.

Last edited by ojm; 05-23-2019 at 10:57 PM.
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Old 05-23-2019, 11:01 PM
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Old 05-24-2019, 12:16 AM
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So what I don’t get is with all of the supposed advantages of 2 cams in block(?) why would Cadillac announce quite recently
the Blackwing DOHC engine platform which is also being built in BG?
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Old 05-24-2019, 02:48 AM
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Originally Posted by MitchAlsup View Post
But there are enough lobes on the one cam shown not to need a second cam.
Not necessarily. Variable valve timing, has an additional set of lobes on the same cam.
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Old 05-24-2019, 05:37 AM
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2nd chain may turn a counter balancer to help stop excessive vibration
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Old 05-24-2019, 06:52 AM
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Originally Posted by Dominic Sorresso View Post
So what I don’t get is with all of the supposed advantages of 2 cams in block(?) why would Cadillac announce quite recently
the Blackwing DOHC engine platform which is also being built in BG?
Just like the Northstar, image mostly. But supposedly its the "quiestest" V8 on the market which is good for a luxury brand.


https://www.caranddriver.com/feature...-gets-its-due/

"So if the pushrod design makes such a good V-8, why does GM make a DOHC V-8 Northstar? "I'm not going to touch that one," laughs Winegarden. GM's party line is that some customers want what it calls "high-feature engines."
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Old 05-24-2019, 07:53 AM
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Originally Posted by foot 1 View Post
2nd chain may turn a counter balancer to help stop excessive vibration
Or a chain driven supercharger

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Old 05-25-2019, 11:53 PM
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Originally Posted by MikeG37 View Post
Or a chain driven supercharger

Could be....
The cam is centered over the crank so the chain is not driving another cam.
The question is what other sprocket is that chain attached to and what is it spinning?
It has to be spinning something and needing a chain for reliability.
Interesting picture.

Last edited by speedmon; 05-26-2019 at 12:15 AM.
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Old 05-26-2019, 07:29 PM
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it would save space instead of a wide belt. But I dont think that will be the answer to the riddle.
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Old 05-28-2019, 07:33 PM
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I'm probably wrong but from the location of the rods on the crank it looks like a flat plane crankshaft. The ones in view look to be 180 deg apart.
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Old 05-28-2019, 10:56 PM
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Looks like 90° to me
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Old 05-28-2019, 11:05 PM
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Default FPC and Secondary Chain

It’s not a FPC- you can see second throw (no rods) at 90 degrees to front throw. If not a FPC, shouldn’t need balance shaft, but secondary chain is smaller in cross section so wouldn’t think it would be a second cam or even extra set of sohc cams. Could be chain driven balance shaft but 90 degree v8 is relatively a balanced setup.
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Old 05-28-2019, 11:21 PM
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Originally Posted by Extreme Engineering View Post
but secondary chain is smaller in cross section so wouldn’t think it would be a second cam or even extra set of sohc cams. Could be chain driven balance shaft but 90 degree v8 is relatively a balanced setup.

I'm not sure that your logic is correct on the chains...

The first chain has the load of both cams. The second chain only has the load of the top cam (and any others attached to it)

Thus, the first chain (the bottom chain) has the load of the top cam plus the load of the bottom cam... so, of course, the bottom chain would need to be thicker than the top thinner chain. The top thinner chain absolutely has less load than the bottom chain.

The fact that they are different thicknesses is what a 2 or more cam motor would have. The bottom will always be the thickest, and as you go up, they would become thinner and thinner.

There could be 2 more chains attached to the next cam up, and those would have even thinner chains yet, going over to the OHC's on each head.

Last edited by bbbvettes.com; 05-28-2019 at 11:26 PM.
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Old 05-28-2019, 11:48 PM
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Originally Posted by Extreme Engineering View Post
It’s not a FPC- you can see second throw (no rods) at 90 degrees to front throw. If not a FPC, shouldn’t need balance shaft, but secondary chain is smaller in cross section so wouldn’t think it would be a second cam or even extra set of sohc cams. Could be chain driven balance shaft but 90 degree v8 is relatively a balanced setup.
Are u saying there is an in block cam PLUS OHCs?
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Old 05-29-2019, 01:00 AM
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Originally Posted by Dominic Sorresso View Post
Are u saying there is an in-block cam PLUS OHCs?
No, his post says he believes there are no other cams other than the cam in the bottom which is in the picture. He made this deduction from the top chain being smaller, assuming that a top cam would require an identical chain thickness to the bottom chain's thickness.

Then I explained to him that whether there is one more cam up top, or 20 more cams up top, the 2nd top chain is always going to be thinner than the bottom chain, because the bottom chain is spinning the bottom cam plus whatever is up top, so it will always have a higher load than the top chain.

Last edited by bbbvettes.com; 05-29-2019 at 01:01 AM.
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