What's under the ZR1 hood?
09-27-2017, 08:41 PM
#21
Race Director
Because the genius that made the c8 section forgot that the c7zr1 is coming out sooner then the mid engine whatever the flock it will be that's been talked about for decades. Makes sense right..
Last edited by Chicago1; 09-27-2017 at 08:41 PM.
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sunsalem (09-28-2017)
09-28-2017, 12:03 PM
#22
The same can be asked about threads started in the C7 General section inquiring about something in their neighborhood (should be in Regional section). Or comments on their Prius parked in their garage in C7 General section (should be in Off Topic - Other Cars section).
Laziness? Probably. At least now we’re starting to see stuff like this in the C8 area. Maybe we can get some more relevant info back in the C7 General section.
And don’t get me started on forum users inability to do a decent search for about 99.9% of the questions asked. 98% can be answered with “It’s in the manual. Did you read it?”. And another 1.9% can be answered with “Search, it’s been discussed a thousand times before”.
Laziness? Probably. At least now we’re starting to see stuff like this in the C8 area. Maybe we can get some more relevant info back in the C7 General section.
And don’t get me started on forum users inability to do a decent search for about 99.9% of the questions asked. 98% can be answered with “It’s in the manual. Did you read it?”. And another 1.9% can be answered with “Search, it’s been discussed a thousand times before”.
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sunsalem (09-28-2017)
10-02-2017, 10:37 AM
#26
Team Owner
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St. Jude Donor '05
10-02-2017, 12:37 PM
#27
Would LOVE to see a DOHC in any upcoming Corvette.
10-02-2017, 04:23 PM
#28
What are the benefits of a Dual Cam versus a single camshaft like we have? Just more power?
10-02-2017, 05:06 PM
#29
Drifting
Nevertheless, I am in a minority. I like our cam-in-block. It is lighter overall (camshafts are heavy; 1 versus 4 is a huge weight savings). It also has a MUCH lower center-of-gravity (four heavy cams on the top of the engine, versus 1 near the center). The cam-in-block engines are generally smaller overall. Also, generally, a cam-in-block motor develops more torque (although turbos and modern technology are closing that gap). It does not rev as high, but even on a track, I don't care - I'll take lightweight and torque any day.
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Z06NJ (10-02-2017)
10-02-2017, 05:10 PM
#30
https://en.wikipedia.org/wiki/Overhe...shaft#Overview
https://en.wikipedia.org/wiki/Overhe...rhead_camshaft
Last edited by sunsalem; 10-02-2017 at 05:11 PM.
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Z06NJ (10-02-2017)
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SpeedyD (10-03-2017)
10-02-2017, 06:39 PM
#34
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St. Jude Donor '10
had GM designed people would be sucking it off the design as the greatest thing ever. But then again we are talking about the same GM that brought us the C6 ZR1 hood right?
Last edited by SurfnSun; 10-02-2017 at 06:43 PM.
10-02-2017, 06:39 PM
#35
Le Mans Master
What aspect of a cam-in-block motor do you believe gives it a torque advantage over DOHC?
Depends if what GM designed was ugly or not! They've done some nice hoods (SD shaker, L-88, etc) and some horrible things (plastic ZR window), so they can go either way. I don't think being an official GM hood makes it one or the other.
had GM designed people would be sucking off the design as the greatest thing ever. But then again we are talking about the same GM that brought us the C6 ZR1 hood right?
Last edited by davepl; 10-02-2017 at 06:40 PM.
10-02-2017, 09:19 PM
#37
Good read. Thanks for the links 
10-04-2017, 10:59 AM
#38
Melting Slicks
There isn't a technical limitation or benefit to either having more torque (other than maybe it takes a bit longer to get the extra cams, gears, chain spinning) but in practice OHC engines are tuned for high RPM HP which kills torque. OHV engines tend to be tuned for torque because it's the main thing that can overcome the lack of RPM
10-04-2017, 11:32 AM
#39
Team Owner
There isn't a technical limitation or benefit to either having more torque (other than maybe it takes a bit longer to get the extra cams, gears, chain spinning) but in practice OHC engines are tuned for high RPM HP which kills torque. OHV engines tend to be tuned for torque because it's the main thing that can overcome the lack of RPM
My Mercedes has a small 2.3 Liter DOHC supercharged engine with a 5,800 RPM redline.
My C6 Z06 has a huge 7 Liter OHV engine with a 7,000 RPM redline.
Which of those two examples are tuned for high RPM operation?
My Z06 is "tuned" for higher RPM operation than my Mercedes. What gives it more torque is it's larger piston top area(and twice the number of pistons) and it's longer stroke.
At 70 MPH, my Mercedes has to cruise at ~2,500 RPM to get 30 MPG. My "high torque" OHV engine cruises at 1,500 RPM at 70 MPH for the same 30 MPG. It has higher torque at 1,500 RPM than my Mercedes has at 2,500 RPM. Both weigh the same but my Z06 is not quite as aero efficient as my Mercedes.
What does help the DOHC engine develop more low end torque is the smaller two intake runners and individual cam intake/exhaust phasing. But, if the DOHC is designed for high RPM operation, those two intake valves and the two exhaust valves offer more area to flow greater amounts of air.
10-06-2017, 04:53 AM
#40
Le Mans Master
love to see a merc marine dohc engine back in the vette
more food for thought power is more a factor of cyl head flow
the ls7 will blow away most NA engines with dumb old pushrods
but I'm biased and appreciate the efficiency and potential of dohc
as the vette guys show, their old pushrod tech is pretty competitive, however, I'll take the cam phasing advantages and lighter valves, bigger flow area, ect. of dohc
8500+ takes lots of cam and cyl flow which typically doesn't do well for low end torq and the high rpm operation generates lots of friction and is hard on parts (ie expensive). If you really want exotic engines, they bear more exotic price tags
more food for thought power is more a factor of cyl head flow
the ls7 will blow away most NA engines with dumb old pushrods
but I'm biased and appreciate the efficiency and potential of dohc
as the vette guys show, their old pushrod tech is pretty competitive, however, I'll take the cam phasing advantages and lighter valves, bigger flow area, ect. of dohc
8500+ takes lots of cam and cyl flow which typically doesn't do well for low end torq and the high rpm operation generates lots of friction and is hard on parts (ie expensive). If you really want exotic engines, they bear more exotic price tags