Who says stock Yank motors don't make power...
Discussion
AER said:
LT1 makes 460hp in the US-homologated C7 Corvette. If 530hp was street legal and reliable, do you think they might have sold it as such?
Yup. 450ish BHP and the same in torque. That works out at about 75/litre for both.
This is a very similar number for the DOHC units from Ford and JLR as well as others. The last Merc NA unit was actually quite a bit lower. These units all manage competitive economy figures as well as performance.
It shows that at this level of the market the advantages of the DOHC design just aren't really manifest and that as the pushrod is so much cheaper to achieve comparable results then there is a strong argument that one is no better than the other.
I think that what is also clear is that when you look at the segment where DOHC systems were really derived, smaller displacement engines you can very clearly see the advantages and superiority over pushrod designs and as we all know that legislation is pushing us towards smaller and smaller engines then it's probably safe to say that pushrods for the road are probably very much in their twilight years.
It can only really be GM building pushrods in any meaningful numbers these days? And once they have to stop and use smaller capacity, FI engines then I would suspect that'll be the end of pushrod tech in normal road cars.
DonkeyApple said:
I think that what is also clear is that when you look at the segment where DOHC systems were really derived, smaller displacement engines you can very clearly see the advantages and superiority over pushrod designs and as we all know that legislation is pushing us towards smaller and smaller engines then it's probably safe to say that pushrods for the road are probably very much in their twilight years.
It can only really be GM building pushrods in any meaningful numbers these days? And once they have to stop and use smaller capacity, FI engines then I would suspect that'll be the end of pushrod tech in normal road cars.
I doubt the pushrod will be going anywhere anytime soon.It can only really be GM building pushrods in any meaningful numbers these days? And once they have to stop and use smaller capacity, FI engines then I would suspect that'll be the end of pushrod tech in normal road cars.
GM seems willing to invest in it's small block platform and as we can see, the results are fine. They sell more pushrod V8's than the entire UK car market combined.
skyrover said:
DonkeyApple said:
I think that what is also clear is that when you look at the segment where DOHC systems were really derived, smaller displacement engines you can very clearly see the advantages and superiority over pushrod designs and as we all know that legislation is pushing us towards smaller and smaller engines then it's probably safe to say that pushrods for the road are probably very much in their twilight years.
It can only really be GM building pushrods in any meaningful numbers these days? And once they have to stop and use smaller capacity, FI engines then I would suspect that'll be the end of pushrod tech in normal road cars.
I doubt the pushrod will be going anywhere anytime soon.It can only really be GM building pushrods in any meaningful numbers these days? And once they have to stop and use smaller capacity, FI engines then I would suspect that'll be the end of pushrod tech in normal road cars.
GM seems willing to invest in it's small block platform and as we can see, the results are fine. They sell more pushrod V8's than the entire UK car market combined.
My guess is that the bulk of GM unit sales are made up by blue collar, commercial vehicle sales like pickups and SUVs where the true advantage of the pushrod unit lies in it being cheaper to buy and then to run.
At some point legislative taxes on those vehicles will reach the point that the savings on the simpler tech are removed and GM will have no choice but to follow everyone else in downsizing and turboing.
GM are up to Gen 5 on the LS but if I had to bet I would say that the next big change when it comes to completely replacing the LS series is going to be smaller FI engines like everyone else has or is doing.
I assume GM is already using DOHC in its smaller engines and this is surely the clue as to where they will eventually be forced to go with the 'truck' engines?
Max_Torque said:
buggalugs said:
Anyone who wants to argue for pushrod engines from a bhp/litre angle is on to a looser. The question should be more, which ~500bhp engine would you buy with your own money to take to 100k miles - the ones that cost two/three times more with worse reliability, or this one?
I'm struggling to think of a modern 500bhp engine that won't do 100k miles?(the days of TVRs going bang every 10kmiles are long gone!)
DonkeyApple said:
Maybe not soon but I can't see it surviving in the face of ever increasing legislation.
My guess is that the bulk of GM unit sales are made up by blue collar, commercial vehicle sales like pickups and SUVs where the true advantage of the pushrod unit lies in it being cheaper to buy and then to run.
At some point legislative taxes on those vehicles will reach the point that the savings on the simpler tech are removed and GM will have no choice but to follow everyone else in downsizing and turboing.
GM are up to Gen 5 on the LS but if I had to bet I would say that the next big change when it comes to completely replacing the LS series is going to be smaller FI engines like everyone else has or is doing.
I assume GM is already using DOHC in its smaller engines and this is surely the clue as to where they will eventually be forced to go with the 'truck' engines?
The legislation just isn't there at the momentMy guess is that the bulk of GM unit sales are made up by blue collar, commercial vehicle sales like pickups and SUVs where the true advantage of the pushrod unit lies in it being cheaper to buy and then to run.
At some point legislative taxes on those vehicles will reach the point that the savings on the simpler tech are removed and GM will have no choice but to follow everyone else in downsizing and turboing.
GM are up to Gen 5 on the LS but if I had to bet I would say that the next big change when it comes to completely replacing the LS series is going to be smaller FI engines like everyone else has or is doing.
I assume GM is already using DOHC in its smaller engines and this is surely the clue as to where they will eventually be forced to go with the 'truck' engines?
American's have no Co2 tax/incentives and the north american market is large enough to justify continued production.
When it comes to trucks the American's have been experimenting with forced induction V6 units, but still offering the V8's as an alternative.
buggalugs said:
Max_Torque said:
buggalugs said:
Anyone who wants to argue for pushrod engines from a bhp/litre angle is on to a looser. The question should be more, which ~500bhp engine would you buy with your own money to take to 100k miles - the ones that cost two/three times more with worse reliability, or this one?
I'm struggling to think of a modern 500bhp engine that won't do 100k miles?(the days of TVRs going bang every 10kmiles are long gone!)
It's nice to be able to argue which form of V8 is best, it will not be as exciting the future arguing about which battery gives the most juice....
RoverP6B said:
AER said:
LT1 makes 460hp in the US-homologated C7 Corvette. If 530hp was street legal and reliable, do you think they might have sold it as such?
That's what GM say. The truth is it's making 70 more bhp than estimated. GM aren't alone in sandbagging - it's well-known that BMW and Porsche BHP claims are often rather conservative.In the original article linked, the LS engine tested was done so WITHOUT any FEAD/ancillaries (alternator etc) , WITHOUT any aftertreatment (catalysts etc) WITHOUT any exhaust system (no backpressure), WITHOUT and intake system (no air box, just a socking great bellmount directly on the throttle), WITHOUT an OEM spec Engine control system with emissions compliance (ie, any fuelling / spark necessary for max performance can be dialled in)
Here is the picture again:
In THAT^^^ condition it made 525 bhp, or 84.7 bhp/litre (vs 430bhp / 69.4bhp/litre in production trim)
GM are not SANDBAGGING, any engine in the world, when freed up of the burden of ancillaries and boundary conditions (like intake / exhaust losses etc) will make significantly more power.
GM are required BY LAW to specific the performance of there engine in fully type approved trim, ie with all the emissions equipment in place, and with boundary conditions matching those of the vehicle (ie fully intake / exhaust system and production tune EMS system etc)
Typical Euro spec OHC 4v engines, like the AMG 6.2 V8, make well over 100bhp/litre similar trim. I'd expect something like 650bhp from the aforementioned AMG engine in a similar trim. (or over 20% more output per litre of swept capacity!)
Max_Torque said:
Troubleatmill said:
Max_Torque said:
DonkeyApple said:
It is definitely worth noting that an NA AMG 6.2 v a 6.2 LS built to the same standards don't differ in any meaningful terms in BHp, torgue or economy.
http://www.chevrolet.com/performance/crate-engines...
http://www.chevrolet.com/performance/crate-engines...
http://www.chevrolet.com/performance/crate-engines...
And... they are not expensive.
If we are allowing race engines, the (inlet/rev restricted) SLS AMG GT3 engine makes 552bhp, and the (downstroked) 5 litre M159 AMG race engine makes 650bhp even with the mandatory 7500rpm limiter necessary for sports cars!!
Why stick with NA when we can discuss the benefits of adding forced induction? AMG have a history of adding superchargers and turbos to their engines but I guess nobody wants to challenge LS motors under these circumstances?
Judging by some of the posts on this (increasingly ridiculous) forum, we should all be dropping AMG engines into Golf Rs to create the best performance car in the world ever.
Edited by anonymous-user on Monday 27th April 14:33
Max_Torque said:
RoverP6B said:
AER said:
LT1 makes 460hp in the US-homologated C7 Corvette. If 530hp was street legal and reliable, do you think they might have sold it as such?
That's what GM say. The truth is it's making 70 more bhp than estimated. GM aren't alone in sandbagging - it's well-known that BMW and Porsche BHP claims are often rather conservative.In the original article linked, the LS engine tested was done so WITHOUT any FEAD/ancillaries (alternator etc) , WITHOUT any aftertreatment (catalysts etc) WITHOUT any exhaust system (no backpressure), WITHOUT and intake system (no air box, just a socking great bellmount directly on the throttle), WITHOUT an OEM spec Engine control system with emissions compliance (ie, any fuelling / spark necessary for max performance can be dialled in)
Here is the picture again:
In THAT^^^ condition it made 525 bhp, or 84.7 bhp/litre (vs 430bhp / 69.4bhp/litre in production trim)
GM are not SANDBAGGING, any engine in the world, when freed up of the burden of ancillaries and boundary conditions (like intake / exhaust losses etc) will make significantly more power.
GM are required BY LAW to specific the performance of there engine in fully type approved trim, ie with all the emissions equipment in place, and with boundary conditions matching those of the vehicle (ie fully intake / exhaust system and production tune EMS system etc)
Typical Euro spec OHC 4v engines, like the AMG 6.2 V8, make well over 100bhp/litre similar trim. I'd expect something like 650bhp from the aforementioned AMG engine in a similar trim. (or over 20% more output per litre of swept capacity!)
buggalugs said:
Max_Torque said:
buggalugs said:
Anyone who wants to argue for pushrod engines from a bhp/litre angle is on to a looser. The question should be more, which ~500bhp engine would you buy with your own money to take to 100k miles - the ones that cost two/three times more with worse reliability, or this one?
I'm struggling to think of a modern 500bhp engine that won't do 100k miles?(the days of TVRs going bang every 10kmiles are long gone!)
I was going to mention the TVR Speedsix S engine, normally aspirated 4lt 400bhp.
The post 2004 engines and Indi rebuilt engines are fantastic.
wormus said:
Judging by some of the posts on this (increasingly ridiculous) forum, we should all be dropping AMG engines into Golf Rs to create the best performance car in the world ever.
Well, it's not all madness. The SOHC M113 AMG 55 unit is a cracking little engine and seeing as it is no larger than a Rover V8 or LS3 it seemed silly not to fit it to a Range Rover Classic. Especially as the torque curve looks perfect on paper for the old ZF 4 speed unit.
I'm fitting an old 5.0 unit to start with to prove the concept and then in goes the 55
To me it seems like a really obvious way to get a solid, reliable wall of power for a fraction of the cost and hassle of building up a Rover engine. And just more interesting that using the same LS or SBC solution that everyone goes for.
DonkeyApple said:
Well, it's not all madness.
The SOHC M113 AMG 55 unit is a cracking little engine and seeing as it is no larger than a Rover V8 or LS3 it seemed silly not to fit it to a Range Rover Classic. Especially as the torque curve looks perfect on paper for the old ZF 4 speed unit.
I'm fitting an old 5.0 unit to start with to prove the concept and then in goes the 55
To me it seems like a really obvious way to get a solid, reliable wall of power for a fraction of the cost and hassle of building up a Rover engine. And just more interesting that using the same LS or SBC solution that everyone goes for.
Great work! The SOHC M113 AMG 55 unit is a cracking little engine and seeing as it is no larger than a Rover V8 or LS3 it seemed silly not to fit it to a Range Rover Classic. Especially as the torque curve looks perfect on paper for the old ZF 4 speed unit.
I'm fitting an old 5.0 unit to start with to prove the concept and then in goes the 55
To me it seems like a really obvious way to get a solid, reliable wall of power for a fraction of the cost and hassle of building up a Rover engine. And just more interesting that using the same LS or SBC solution that everyone goes for.
Are you having to use completely new engine management and a custom bellhousing to mate up to the gearbox?
The engine from the W210 E55 would be a superb donor given how cheap the cars are (and how trouble free the engines seem to be).
braddo said:
DonkeyApple said:
Well, it's not all madness.
The SOHC M113 AMG 55 unit is a cracking little engine and seeing as it is no larger than a Rover V8 or LS3 it seemed silly not to fit it to a Range Rover Classic. Especially as the torque curve looks perfect on paper for the old ZF 4 speed unit.
I'm fitting an old 5.0 unit to start with to prove the concept and then in goes the 55
To me it seems like a really obvious way to get a solid, reliable wall of power for a fraction of the cost and hassle of building up a Rover engine. And just more interesting that using the same LS or SBC solution that everyone goes for.
Great work! The SOHC M113 AMG 55 unit is a cracking little engine and seeing as it is no larger than a Rover V8 or LS3 it seemed silly not to fit it to a Range Rover Classic. Especially as the torque curve looks perfect on paper for the old ZF 4 speed unit.
I'm fitting an old 5.0 unit to start with to prove the concept and then in goes the 55
To me it seems like a really obvious way to get a solid, reliable wall of power for a fraction of the cost and hassle of building up a Rover engine. And just more interesting that using the same LS or SBC solution that everyone goes for.
Are you having to use completely new engine management and a custom bellhousing to mate up to the gearbox?
The engine from the W210 E55 would be a superb donor given how cheap the cars are (and how trouble free the engines seem to be).
The Merc block is actually a little shorter than the Rover so I am really hoping that I can get away with just fabricating an adaptor plate. If I'm lucky.
The AMG unit from the E55 gives about 360bhp but it has quite a restrictive exhaust and system and once freed from this will give nearly 400. That is actually more thn I need.
The 5.0 is also likely to show similar gains so I suspect that in the end it will give very similar power to the SBC that Overfinch used (330bhp) and that would mean not needing to update the whole drive train as the transfer case and shafts can handle that so you just need to update the box to the stronger P38 internals.
Conversely, to get that sort of performance from a Rover you need to spend a lot of money and frankly you're buying long term trouble. Again, because it's pushrod you need to increase the displacement to get safe power and that's not feasible so it's reliant on massive head work to try and overcome the air flow restrictions. In my book it simply isn't worth it.
Plus, as you say, the M113 is a really, really good engine.
Interesting. Good luck with it.
I have thoughts about the M113 and possibly the gearbox being a ripe candidate for older Mercs, e.g. the Fintails and 60s/70s saloons. As you sy, it doesn't need to be an AMG one either and having seen the log-style manifolds on my C43, I can well imagine that some proper manifolds could release a lot of power.
I remember reading that there was up to 50hp extra available in the old 300SEL 6.3 doing the same thing.
I have thoughts about the M113 and possibly the gearbox being a ripe candidate for older Mercs, e.g. the Fintails and 60s/70s saloons. As you sy, it doesn't need to be an AMG one either and having seen the log-style manifolds on my C43, I can well imagine that some proper manifolds could release a lot of power.
I remember reading that there was up to 50hp extra available in the old 300SEL 6.3 doing the same thing.
braddo said:
Interesting. Good luck with it.
I have thoughts about the M113 and possibly the gearbox being a ripe candidate for older Mercs, e.g. the Fintails and 60s/70s saloons. As you sy, it doesn't need to be an AMG one either and having seen the log-style manifolds on my C43, I can well imagine that some proper manifolds could release a lot of power.
I remember reading that there was up to 50hp extra available in the old 300SEL 6.3 doing the same thing.
There is a place in the Cotswolds that is already fitting those engines into the earlier Mercs. I have thoughts about the M113 and possibly the gearbox being a ripe candidate for older Mercs, e.g. the Fintails and 60s/70s saloons. As you sy, it doesn't need to be an AMG one either and having seen the log-style manifolds on my C43, I can well imagine that some proper manifolds could release a lot of power.
I remember reading that there was up to 50hp extra available in the old 300SEL 6.3 doing the same thing.
The problem with the modern 5G Tronic box that these engines are originally mated to is that only a couple of firms have built a TCU that allows you to run it out of the original car but they are crap. As per usual with stuff from the U.S. all they do is increase the line pressures to get snappy changes for street racing. Mapping them for wafting hasn't been done and the current options aren't good enough regardless of the hours of tuning you might be able to do yourself.
Interestingly as these engines come from the Chysler period there are a few Jeep bits that you can mate to the engines etc.
The other issue in the UK is finding a Merc mechanic who isn't just an electronic tuner.
Willy Nilly said:
Not been through the whole thread, but could someone explain the pros and cons of over head cams (double or single) over push rods engines? Thanks. Start a new thread if you like.
My basic understanding is that it's a combination of being able to rev higher and also flow more gas, so you can tune them to greater extremes. Things that hugely benefit small engines. Obvious downsides is that they are more complex and also taller and wider due to all the gubbins on top. Lets not forget 2 valve engines produce more torque at low RPM's
The perfect engine would be 2 valve at low rev's, and 4 valve at high rpm.
Here is an article from Wards talking about GM's new pushrod engines.
http://wardsauto.com/vehicles-amp-technology/new-g...
The perfect engine would be 2 valve at low rev's, and 4 valve at high rpm.
Here is an article from Wards talking about GM's new pushrod engines.
http://wardsauto.com/vehicles-amp-technology/new-g...
Edited by skyrover on Monday 27th April 18:56
Gassing Station | General Gassing | Top of Page | What's New | My Stuff