[Martinjlm]

Originally Posted by KMPrenger

Mercury Marine (owned by GM from what I understand) has a smaller/lighter (than a typical DOHC like the Mustang 5.0) DOHC V8 engine and so based on that, it IS certainly possible to make a DOHC engine that can fit into a short engine bay and make big N/A horsepower.

But will GM put an engine like that in their future products? Who knows.

Mercury Marine was not owned by GM. They were contracted by GM to assemble and test the LT5 DOHC (much of which was designed / developed by Lotus during that half hour when GM owned Lotus).

One of my most interesting jobs at GM was to take the LT5 out of production and arrange for service parts availability when the ZR-1 went bye-bye. Spent a lot of time in Oklahoma with the MM folks.

[DGthe3]

Originally Posted by crankaholic

Please no DOHC... GM should spend some money on an even lighter, higher-revving, short stroke LT1

That doesn't make any sense.

Lets say this new engine gets de-stroked by 0.6 inches, taking it down to 5.3L. To make the same power as the LT1, its going to need to turn at 7500+ rpm -something which will be very difficult with production pushrod engine. Not impossible, but that is only to get things back to LT1 levels of power.

And for what, exactly? What is the performance benefit?

Meanwhile, for everything that you'd need to do to the valvetrain to allow it to hit those speeds you could probably make a 6.2L engine go about as fast & easily exceed 500 hp.

There is a reason why people say 'No replacement for displacement'

[Bhobbs]

Originally Posted by DGthe3

That doesn't make any sense.

Lets say this new engine gets de-stroked by 0.6 inches, taking it down to 5.3L. To make the same power as the LT1, its going to need to turn at 7500+ rpm -something which will be very difficult with production pushrod engine. Not impossible, but that is only to get things back to LT1 levels of power.

And for what, exactly? What is the performance benefit?

Meanwhile, for everything that you'd need to do to the valvetrain to allow it to hit those speeds you could probably make a 6.2L engine go about as fast & easily exceed 500 hp.

There is a reason why people say 'No replacement for displacement'

I think the idea of a high revving engine is so appealing because so many super cars use small displacement, high revving engine but people forget the maintenance required for those cars. Also, iconic engines like the DZ302 from the first gen Z/28 but I'm sure GM would have gone with a bigger engine, had the rules allowed for one.

Unless rules or laws prevent you from getting more displacement for the same size and weight, I don't really see any downside.

[16silverSS]

Id be happy with a working LT1 lol. Still waiting for my new replacement motor and transmission for my 16 Camaro ss to arrive.

[crankaholic]

Originally Posted by DGthe3

That doesn't make any sense.

Lets say this new engine gets de-stroked by 0.6 inches, taking it down to 5.3L. To make the same power as the LT1, its going to need to turn at 7500+ rpm -something which will be very difficult with production pushrod engine. Not impossible, but that is only to get things back to LT1 levels of power.

And for what, exactly? What is the performance benefit?

Meanwhile, for everything that you'd need to do to the valvetrain to allow it to hit those speeds you could probably make a 6.2L engine go about as fast & easily exceed 500 hp.

There is a reason why people say 'No replacement for displacement'

Honestly, I just like the way high-revving engines feel... I do love the LT1 and know my pipe-dream won't happen for the reasons you stated. But there's more to driving than power; I'd love a free-er and higher revving LT1 just because it'll be more rewarding to take to redline; I also didn't really mean a modified LT1, what I'd love would probably be a re-design and the block could be enlarged so that GM could give it a larger bore and shorter stroke, retaining the roughly 6L displacement. That would keep low-end torque more than adequate while increasing power at higher RPM. I mean I know it won't happen, but that would be my dream engine.

Technically one could have something like that custom built... but that would be about as expensive as a Ferrari engine :(

[soloknight6]

My guess is an iteration of this for the mid engine C8, and Camaro z/28 if it stays natural.

http://www.chevrolet.com/performance...ines/lt376-535

[Mountain]

I can't wait to see a GM DOHC V8.

Why? GM hasn't come out with a DOHC V8 because they were able to continuously improve the OHV ("cam-in-block") V8's to a point where it didn't make a good business case to actually produce a DOHC. Now, GM is finally coming to the book-end for the OHV. The way GM does their performance vehicles and knowing how they continuously improved the OHV says this to me: When a DOHC V8 comes out of GM in one of their performance vehicles, it's going to be one bad mamma-jamma!

[Fraxum]

Originally Posted by Martinjlm

Mercury Marine was not owned by GM. They were contracted by GM to assemble and test the LT5 DOHC (much of which was designed / developed by Lotus during that half hour when GM owned Lotus).

One of my most interesting jobs at GM was to take the LT5 out of production and arrange for service parts availability when the ZR-1 went bye-bye. Spent a lot of time in Oklahoma with the MM folks.

And thanks for doing a great job. I was at Atco a few weeks ago and there was a C4 there keeping up with a couple of C7s and giving me a good run. The air was terrible and we were stuck in the 12s, but what was up with this C4?

Then I lined up with him and spotted the ZR1 on the fender. Cool! I asked him about parts and he said, yes you can get them. His ZR1 was worked a bit and said the car usually ran mid 11s, so something was not right. Wish I got a pic for you. The ZR1 package was a $31K option in the 1990s, gulp. Very cool, but give me a modern LT1.

This ZR1 is the original Chevy Exotic. There are different ways to make power but they all wind up at the same place. Physics and thermodynamics. After watching C6 Z06es run low 10s NA at Atco and tear up NJMP, the LS7 is my favorite Chevy engine of all time. And so affordable at $17,081.

http://www.chevrolet.com/performance/crate-engines/ls7

[Martinjlm]

Originally Posted by Fraxum

And thanks for doing a great job. I was at Atco a few weeks ago and there was a C4 there keeping up with a couple of C7s and giving me a good run. The air was terrible and we were stuck in the 12s, but what was up with this C4?

Then I lined up with him and spotted the ZR1 on the fender. Cool! I asked him about parts and he said, yes you can get them. His ZR1 was worked a bit and said the car usually ran mid 11s, so something was not right. Wish I got a pic for you. The ZR1 package was a $31K option in the 1990s, gulp. Very cool, but give me a modern LT1.

This ZR1 is the original Chevy Exotic. There are different ways to make power but they all wind up at the same place. Physics and thermodynamics. After watching C6 Z06es run low 10s NA at Atco and tear up NJMP, the LS7 is my favorite Chevy engine of all time. And so affordable at $17,081.

Glad you didn't ask him if they were reasonably priced....he might have cursed my name

[Fraxum]

Originally Posted by Martinjlm

Glad you didn't ask him if they were reasonably priced....he might have cursed my name

I did! But that is the price of owning an exotic. Sure you can afford to buy it, but can you afford to own it?

I know my LT1 parts will be somewhat affordable and probably with a little patience and a little help I can do just about anything on the LT1 as it gets older. And bolton SS LT1s have run 10s at the drag strip and kept up/embarrassed much pricier exotic cars on the track not to mention 1LEs. Also I can get over 30 mpg on the highway.

It is fun to talk about more exotic engines. But really we don't need anything more than an OHV. As in the software business simplicity is one of the keys to successful automotive long term enjoyment.

[Marty McFlew]

Originally Posted by Martinjlm

Camaro V6 are DOHC.

That's my point. Keep it as a V6 not a V8.

[Marty McFlew]

Originally Posted by crankaholic

Honestly, I just like the way high-revving engines feel... I do love the LT1 and know my pipe-dream won't happen for the reasons you stated. But there's more to driving than power; I'd love a free-er and higher revving LT1 just because it'll be more rewarding to take to redline; I also didn't really mean a modified LT1, what I'd love would probably be a re-design and the block could be enlarged so that GM could give it a larger bore and shorter stroke, retaining the roughly 6L displacement. That would keep low-end torque more than adequate while increasing power at higher RPM. I mean I know it won't happen, but that would be my dream engine.

Technically one could have something like that custom built... but that would be about as expensive as a Ferrari engine :(

A high revvng engine is good if you live in the dessert with space to wind it out. Our SS's with manual have tall gears and I don't even have the space to wind out 4th gear to redline. Many in my situation so we don't really need a high revving engine. Now what we have and can easily make use of is low end torque. I will take the torque any day over a high revving engine in a streetable car.

[Martinjlm]

Originally Posted by Martinjlm

Camaro V6 are DOHC.

Originally Posted by Marty McFlew

That's my point. Keep it as a V6 not a V8.

Got it. But then it can and likely will morph into Twin Turbo and/or electrified V6 DOHC that outperform large displacement V8. If the V6 DOHC becomes a high volume engine, boosting a few with turbos and/or electric motors will be a much less costly proposition than keeping an entire manufacturing facility open to make a low volume V8.

GM, Ford and Chrysler will be among the last with V8 because truck volume keeps the V8 plants running. But Ford, in particular, is seeing a shift. More than 60% of Ford trucks sold have V6.

[DenverTaco07]

well...

if LT6 is the new LT4 with more power (presumably)...

will 6th Gen ZL1 get a bump in a couple years?

and i suppose same could be said if LT2 is replacement for LT1.