New GenV 5.5 v8
07-20-2012, 12:06 PM
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New GenV 5.5 v8
I was digging last night and I just wanted to post what I had found. This is all theoretical for the mean time but I think it's very interesting, definitely a new approach in engine building.
I was trying to get info on the new GM trucks and their potential engines for 2013 or 2014 whenever they'd come out. There's been rumors out for the last 3 years of a 5.5 V8 for the new corvette that would trickle into the trucks but no specs. I found a couple of interesting things in the links posted below.
Chevrolet Corvette C7 to feature 5.5L V8
"According to one of Motor Trend’s inside sources, the Corvette C7 will come equipped with GM’s new 5.5L small block V8. The new mill will feature a number of technical advancements — including direct-injection and a new combustion system – but will retain its old school overhead valve design to cut costs and keep the engine compact."
I read somewhere else that the compression could be as high as 12:1 which is crazy to me unless the vehicles come with a lifetime supply of torco. (sorry I don't have this link, I did this at 2:00 AM and I was tired)
then I found this:
2012 Corvette ZR1 and Corvette C6.R Specifications - Corvette Racing
which is very cool. Bore, stroke, 336 cubes and almost 500HP's!
As soon as I read the bore and stroke figures it all clicked together. Back to the first article I ever printed off the internet, about 8 years ago, for my "library" of engine builds I've been keeping. "The 350 GM should have built." Back in 1997 they argue that they should have kept the short stroke, and increased the bore vs the opposite, which is what they did going from 327ci to 350ci They go into detail about the great benefits a long rod to stroke ratio's add to an engine. They then go on to prove it. 11.1 compression ration on 87 octane, just look at how FLAT the TQ is! Great results with good heads and a cam that I think could be spec'd out a lot better. Here:
412 HP 350 ci AFR 190 Cylinder Heads, P1
It all makes sense if you look at how much more timing a 4.8 can hold. It too has the high 1.94 (or so) rod to stroke ratio, but is limited in bore diameter. Plus how incredible it held together under the 1200HP twin turbo dyno session. I really think the 5.3 would have a hard time doing what the 4.8 did. Un-shroud the valves a little by increasing the bore a little and you've got a monster.
12.1 compression,direct injection, vvt, some great L92 heads, all aluminum block, titanium valves....that sounds like a PARTY!!! I cant wait, the next year should be fun to watch.
Let me know what you guys think!
I was trying to get info on the new GM trucks and their potential engines for 2013 or 2014 whenever they'd come out. There's been rumors out for the last 3 years of a 5.5 V8 for the new corvette that would trickle into the trucks but no specs. I found a couple of interesting things in the links posted below.
Chevrolet Corvette C7 to feature 5.5L V8
"According to one of Motor Trend’s inside sources, the Corvette C7 will come equipped with GM’s new 5.5L small block V8. The new mill will feature a number of technical advancements — including direct-injection and a new combustion system – but will retain its old school overhead valve design to cut costs and keep the engine compact."
I read somewhere else that the compression could be as high as 12:1 which is crazy to me unless the vehicles come with a lifetime supply of torco. (sorry I don't have this link, I did this at 2:00 AM and I was tired)
then I found this:
2012 Corvette ZR1 and Corvette C6.R Specifications - Corvette Racing
which is very cool. Bore, stroke, 336 cubes and almost 500HP's!
As soon as I read the bore and stroke figures it all clicked together. Back to the first article I ever printed off the internet, about 8 years ago, for my "library" of engine builds I've been keeping. "The 350 GM should have built." Back in 1997 they argue that they should have kept the short stroke, and increased the bore vs the opposite, which is what they did going from 327ci to 350ci They go into detail about the great benefits a long rod to stroke ratio's add to an engine. They then go on to prove it. 11.1 compression ration on 87 octane, just look at how FLAT the TQ is! Great results with good heads and a cam that I think could be spec'd out a lot better. Here:
412 HP 350 ci AFR 190 Cylinder Heads, P1
It all makes sense if you look at how much more timing a 4.8 can hold. It too has the high 1.94 (or so) rod to stroke ratio, but is limited in bore diameter. Plus how incredible it held together under the 1200HP twin turbo dyno session. I really think the 5.3 would have a hard time doing what the 4.8 did. Un-shroud the valves a little by increasing the bore a little and you've got a monster.
12.1 compression,direct injection, vvt, some great L92 heads, all aluminum block, titanium valves....that sounds like a PARTY!!! I cant wait, the next year should be fun to watch.
Let me know what you guys think!
07-20-2012, 12:45 PM
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Gotta remember with DI you can get the compression up a good bit and still run 87 oct.. look at the v6 camaros. i think they are 11.5ish cr?
Fuel is compressed alot higher PSI and its injecting at a finer mist and it doesnt have to flow around the valves to get into the Cyls.
Its hard to beat the cost vs power and reliablilty of the LS engines, not sure what the newer designs are gonna hold.
Fuel is compressed alot higher PSI and its injecting at a finer mist and it doesnt have to flow around the valves to get into the Cyls.
Its hard to beat the cost vs power and reliablilty of the LS engines, not sure what the newer designs are gonna hold.
07-20-2012, 01:46 PM
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Gotta remember with DI you can get the compression up a good bit and still run 87 oct.. look at the v6 camaros. i think they are 11.5ish cr?
Fuel is compressed alot higher PSI and its injecting at a finer mist and it doesnt have to flow around the valves to get into the Cyls.
Its hard to beat the cost vs power and reliablilty of the LS engines, not sure what the newer designs are gonna hold.
Fuel is compressed alot higher PSI and its injecting at a finer mist and it doesnt have to flow around the valves to get into the Cyls.
Its hard to beat the cost vs power and reliablilty of the LS engines, not sure what the newer designs are gonna hold.
But what I was trying to show, in the 412HP 350 article, was the improved combustion benefits of a higher rod to stroke ratio; along with greater cylinder filling from a larger bore. This is a 4.155" bore x 3.2" stroke motor (very close to the new 5.5) that ran 11.1 CR. It produced 99.5% of the peak HP/TQ on 87 octane as it did on 92 octane with 36 degrees of total timing. (they said the timing stayed the same on 89 as 92, but didn't say that for the 87 test. I suspect they lost a degree or two from the loss in 1 hp and 5ftlbs) on a simple carburated engine. No fancy DI, VVT, no PCM to monitor knock and pull timing. You can't run 87 octane on 11.1 CR on any LS engine with 34* - 36* total timing even today. (maybe the 4.8)
The engine made 412HP and 435TQ and had 394TQ @ 2400 rpm. It's hard to get todays 5.3 to those TQ levels. It becomes almost impossible when you factor in making almost 400TQ below 2500 rpm, I've never seen it in any NA dyno. Lastly, you add better cam, better heads, FI and great tuning like the LS engines have, 500 HP/TQ seems like just the beginning.
No matter what happens it's still great to see what auto manufacturers throw at you for technology. It's great when someone goes outside of "conventional wisdom" and creates something special. Time will tell, I'm hopeful.
Last edited by yurs78; 07-20-2012 at 01:56 PM.
07-20-2012, 01:47 PM
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Gotta remember with DI you can get the compression up a good bit and still run 87 oct.. look at the v6 camaros. i think they are 11.5ish cr?
Fuel is compressed alot higher PSI and its injecting at a finer mist and it doesnt have to flow around the valves to get into the Cyls.
Its hard to beat the cost vs power and reliablilty of the LS engines, not sure what the newer designs are gonna hold.
Fuel is compressed alot higher PSI and its injecting at a finer mist and it doesnt have to flow around the valves to get into the Cyls.
Its hard to beat the cost vs power and reliablilty of the LS engines, not sure what the newer designs are gonna hold.
07-20-2012, 03:20 PM
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agreed, my old ecoboost was a DI, 10.1 CR, twin turbo, on 87 octane.
But what I was trying to show, in the 412HP 350 article, was the improved combustion benefits of a higher rod to stroke ratio; along with greater cylinder filling from a larger bore. This is a 4.155" bore x 3.2" stroke motor (very close to the new 5.5) that ran 11.1 CR. It produced 99.5% of the peak HP/TQ on 87 octane as it did on 92 octane with 36 degrees of total timing. (they said the timing stayed the same on 89 as 92, but didn't say that for the 87 test. I suspect they lost a degree or two from the loss in 1 hp and 5ftlbs) on a simple carburated engine. No fancy DI, VVT, no PCM to monitor knock and pull timing. You can't run 87 octane on 11.1 CR on any LS engine with 34* - 36* total timing even today. (maybe the 4.8)
The engine made 412HP and 435TQ and had 394TQ @ 2400 rpm. It's hard to get todays 5.3 to those TQ levels. It becomes almost impossible when you factor in making almost 400TQ below 2500 rpm, I've never seen it in any NA dyno. Lastly, you add better cam, better heads, FI and great tuning like the LS engines have, 500 HP/TQ seems like just the beginning.
No matter what happens it's still great to see what auto manufacturers throw at you for technology. It's great when someone goes outside of "conventional wisdom" and creates something special. Time will tell, I'm hopeful.
But what I was trying to show, in the 412HP 350 article, was the improved combustion benefits of a higher rod to stroke ratio; along with greater cylinder filling from a larger bore. This is a 4.155" bore x 3.2" stroke motor (very close to the new 5.5) that ran 11.1 CR. It produced 99.5% of the peak HP/TQ on 87 octane as it did on 92 octane with 36 degrees of total timing. (they said the timing stayed the same on 89 as 92, but didn't say that for the 87 test. I suspect they lost a degree or two from the loss in 1 hp and 5ftlbs) on a simple carburated engine. No fancy DI, VVT, no PCM to monitor knock and pull timing. You can't run 87 octane on 11.1 CR on any LS engine with 34* - 36* total timing even today. (maybe the 4.8)
The engine made 412HP and 435TQ and had 394TQ @ 2400 rpm. It's hard to get todays 5.3 to those TQ levels. It becomes almost impossible when you factor in making almost 400TQ below 2500 rpm, I've never seen it in any NA dyno. Lastly, you add better cam, better heads, FI and great tuning like the LS engines have, 500 HP/TQ seems like just the beginning.
No matter what happens it's still great to see what auto manufacturers throw at you for technology. It's great when someone goes outside of "conventional wisdom" and creates something special. Time will tell, I'm hopeful.
You do know Carbed setups run different timing curves and different total timing? So thats apples vs strawberrys.
They said they ran a knock sensor setup on the 87oct run and still ran the same timing they did on 92 or 93 oct.
Pretty cool article!!
Now get a 4.8 and get to work
07-20-2012, 03:22 PM
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Actually you would have to get a 6.0 block for that large of a bore.. not even sure you would wanna go that far on the 6.0 block tho.. Isnt the 427 a 4.125" bore?
wonder what a 4.030 bore and a 3.2 stroke would do with a good CR?
wonder what a 4.030 bore and a 3.2 stroke would do with a good CR?
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07-20-2012, 04:25 PM
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[QUOTE=nonnieselman;4959443]You do know Carbed setups run different timing curves and different total timing?
I did not, just a bench racer for the last 8 years. The deepest commitment I've ever made was a nelson tune! Oh and buying the ecoboost LOL. Too scared of being disapointed, still looking for the needle in the haystack.
I'll have to read up on the differences. Thanks.
I did not, just a bench racer for the last 8 years. The deepest commitment I've ever made was a nelson tune! Oh and buying the ecoboost LOL. Too scared of being disapointed, still looking for the needle in the haystack.
I'll have to read up on the differences. Thanks.