Who says stock Yank motors don't make power...
Discussion
Evoluzione said:
skyrover said:
I disagree...
Owned 10v and 20v volvo 850's
The 10V's pulled much harder from low RPM and were much more pleasant to drive around town than the 20V's, despite having a 30hp disadvantage.
With respect, until you post up some intimate figures it's hearsay.Owned 10v and 20v volvo 850's
The 10V's pulled much harder from low RPM and were much more pleasant to drive around town than the 20V's, despite having a 30hp disadvantage.
It seems other's would agree with me
somebloke said:
Firstly avoid the 2.0 whether in 10 or 20v guise. The 126 10v is woefully
underpowered, the 20v has enough but all the power is after 4500rpm and
making progress is hard work, tiring and not very good for mpg. Plus the
gearing is low and its noisy at cruising speed.
Over 70k in our previous 2.0 20v 850 (manual, saloon) it averaged 29mpg,
with a low of under 20 and never better than 33.
The 2.5 10v s70 which is now in the family (manual again) is a far better
and brisker beast despite still only having 144bhp. The engine is more like
a NA diesel, in that its got good low down torque and feels lazy, you can
leave it in 4th & 5th and trundle up hill and down dale pretty easily.
Oppositely to the 20valvers it pulls strongly from 2500rpm to 5000rpm then
runs out of puff. The gearing is slightly on the high side but that does
give very relaxed and serene cruising. An indicated 100 is only 3500rpm
which its happy at all day. Mpg is currently showing 31mpg consisting of
entirely 5-15mile trips to town with the occasional longer distance. I've
had nearly 40mpg on a long run at 60.
http://www.thevolvoforums.com/volvo-s70/6746-diffe...underpowered, the 20v has enough but all the power is after 4500rpm and
making progress is hard work, tiring and not very good for mpg. Plus the
gearing is low and its noisy at cruising speed.
Over 70k in our previous 2.0 20v 850 (manual, saloon) it averaged 29mpg,
with a low of under 20 and never better than 33.
The 2.5 10v s70 which is now in the family (manual again) is a far better
and brisker beast despite still only having 144bhp. The engine is more like
a NA diesel, in that its got good low down torque and feels lazy, you can
leave it in 4th & 5th and trundle up hill and down dale pretty easily.
Oppositely to the 20valvers it pulls strongly from 2500rpm to 5000rpm then
runs out of puff. The gearing is slightly on the high side but that does
give very relaxed and serene cruising. An indicated 100 is only 3500rpm
which its happy at all day. Mpg is currently showing 31mpg consisting of
entirely 5-15mile trips to town with the occasional longer distance. I've
had nearly 40mpg on a long run at 60.
anotherbloke said:
I think a lot depends on your preference. The 2.5 10v is quite torquey and good for towing, but the 2.5 20v revs better and produces 170bhp as opposed to the 2.5's 140bhp. Both should return 32-35 mpg. Some owners say they get more some say less. My 2.5 10 would get 36 on a run and 26 round town.
http://www.matthewsvolvosite.com/forums/viewtopic....Edited by skyrover on Monday 27th April 22:11
DonkeyApple said:
I think you are right.
The easiest commercial comparison to make is between the LS series and the Ford Coyote which was built specifically to compete against each other in the absolutely enormous market of truck vending in the US.
Two solutions to the same problem. Look at the equivalent pick ups and they have near identical performance, near identical economy. Yet as expected, the DOHC Ford can do it with 5 litres versus the LS 6.2, helpin to show that the pushrod engine benefits from larger displacement but this isn't leading to a loss of economy in contrast.
Look to the aftermarket and the GM unit is much cheaper, much easier for the average punter to work on (although if you read any of the LS forums the average modder soils himself at the sight of GM's cam phasing system and their displacement on demand so as someone mentioned earlier the new LS Gen 4+ are not a huge amount more simple than their DOHC competitors today). And the crate LS is much cheaper than the crate Coyote and due to its compact size fits in many more applications.
You couldn't fit a Coyote in a 911.
I'm not a fan of GM or the LS engine. I've always been more of a Ford person and also, frankly as a bit of a snob, the LS always made me turn my nose up. However, over the last four years of researching what engine to fit in one of my Rangies every single route took me back to the LS as the engine that just ticked every box better apart from my snobbish opinion and want to do something different. And as every route brought me back to the same bloody engine I ended up reading up quite a bit about it and learnt that in fact it is a very, very good product indeed.
I love them because they are so easy to tune and with 6 bolt mains as standard, bloody strong. They are built for tuning enthusiasts with a big selection of after market goodies to choose from. Even GMPP sells their own tuned engines!The easiest commercial comparison to make is between the LS series and the Ford Coyote which was built specifically to compete against each other in the absolutely enormous market of truck vending in the US.
Two solutions to the same problem. Look at the equivalent pick ups and they have near identical performance, near identical economy. Yet as expected, the DOHC Ford can do it with 5 litres versus the LS 6.2, helpin to show that the pushrod engine benefits from larger displacement but this isn't leading to a loss of economy in contrast.
Look to the aftermarket and the GM unit is much cheaper, much easier for the average punter to work on (although if you read any of the LS forums the average modder soils himself at the sight of GM's cam phasing system and their displacement on demand so as someone mentioned earlier the new LS Gen 4+ are not a huge amount more simple than their DOHC competitors today). And the crate LS is much cheaper than the crate Coyote and due to its compact size fits in many more applications.
You couldn't fit a Coyote in a 911.
I'm not a fan of GM or the LS engine. I've always been more of a Ford person and also, frankly as a bit of a snob, the LS always made me turn my nose up. However, over the last four years of researching what engine to fit in one of my Rangies every single route took me back to the LS as the engine that just ticked every box better apart from my snobbish opinion and want to do something different. And as every route brought me back to the same bloody engine I ended up reading up quite a bit about it and learnt that in fact it is a very, very good product indeed.
Edited by DonkeyApple on Monday 27th April 22:02
DonkeyApple said:
Evoluzione said:
Out of interest, have there been any/many 4v pushrod heads and what were they?
I'm pretty sure the big diesels like the Duramax and Cummins are 4v pushrods. I'm sure there was a Yamaha bike engine that was also. 
The multivalve pushrod configuration suits a low revving diesel very well, pushrods bending at high RPM and multivalve heads producing more torque, lower emissions and better economy must make a very good engine.
DonkeyApple said:
Evoluzione said:
Out of interest, have there been any/many 4v pushrod heads and what were they?
I'm pretty sure the big diesels like the Duramax and Cummins are 4v pushrods. I'm sure there was a Yamaha bike engine that was also. Evoluzione said:
I'm surprised at a pushrod 4v bike engine, when was that, the 1950s?
The multivalve pushrod configuration suits a low revving diesel very well, pushrods bending at high RPM and multivalve heads producing more torque, lower emissions and better economy must make a very good engine.
It's why it stuck in my head. I remember it from a conversation years ago but I think the bike was from the 80s. The multivalve pushrod configuration suits a low revving diesel very well, pushrods bending at high RPM and multivalve heads producing more torque, lower emissions and better economy must make a very good engine.
DonkeyApple said:
Different cams?
Air flow is different because one engine is 4 valve and has a large valve area, probably less air velocity at lower rpm's but comes on strong as revs increase. The 2 valver will be stronger low down but maybe run out of puff as revs increase. Then again, there may be other reasons and also cam choice as you suggest.skyrover said:
Evoluzione said:
skyrover said:
I disagree...
Owned 10v and 20v volvo 850's
The 10V's pulled much harder from low RPM and were much more pleasant to drive around town than the 20V's, despite having a 30hp disadvantage.
With respect, until you post up some intimate figures it's hearsay.Owned 10v and 20v volvo 850's
The 10V's pulled much harder from low RPM and were much more pleasant to drive around town than the 20V's, despite having a 30hp disadvantage.
It seems other's would agree with me
somebloke said:
Firstly avoid the 2.0 whether in 10 or 20v guise. The 126 10v is woefully
underpowered, the 20v has enough but all the power is after 4500rpm and
making progress is hard work, tiring and not very good for mpg. Plus the
gearing is low and its noisy at cruising speed.
Over 70k in our previous 2.0 20v 850 (manual, saloon) it averaged 29mpg,
with a low of under 20 and never better than 33.
The 2.5 10v s70 which is now in the family (manual again) is a far better
and brisker beast despite still only having 144bhp. The engine is more like
a NA diesel, in that its got good low down torque and feels lazy, you can
leave it in 4th & 5th and trundle up hill and down dale pretty easily.
Oppositely to the 20valvers it pulls strongly from 2500rpm to 5000rpm then
runs out of puff. The gearing is slightly on the high side but that does
give very relaxed and serene cruising. An indicated 100 is only 3500rpm
which its happy at all day. Mpg is currently showing 31mpg consisting of
entirely 5-15mile trips to town with the occasional longer distance. I've
had nearly 40mpg on a long run at 60.
http://www.thevolvoforums.com/volvo-s70/6746-diffe...underpowered, the 20v has enough but all the power is after 4500rpm and
making progress is hard work, tiring and not very good for mpg. Plus the
gearing is low and its noisy at cruising speed.
Over 70k in our previous 2.0 20v 850 (manual, saloon) it averaged 29mpg,
with a low of under 20 and never better than 33.
The 2.5 10v s70 which is now in the family (manual again) is a far better
and brisker beast despite still only having 144bhp. The engine is more like
a NA diesel, in that its got good low down torque and feels lazy, you can
leave it in 4th & 5th and trundle up hill and down dale pretty easily.
Oppositely to the 20valvers it pulls strongly from 2500rpm to 5000rpm then
runs out of puff. The gearing is slightly on the high side but that does
give very relaxed and serene cruising. An indicated 100 is only 3500rpm
which its happy at all day. Mpg is currently showing 31mpg consisting of
entirely 5-15mile trips to town with the occasional longer distance. I've
had nearly 40mpg on a long run at 60.
anotherbloke said:
I think a lot depends on your preference. The 2.5 10v is quite torquey and good for towing, but the 2.5 20v revs better and produces 170bhp as opposed to the 2.5's 140bhp. Both should return 32-35 mpg. Some owners say they get more some say less. My 2.5 10 would get 36 on a run and 26 round town.
http://www.matthewsvolvosite.com/forums/viewtopic....Edited by skyrover on Monday 27th April 22:11
I've had the argument before; two identical engines apart from the head. The 16v owners always bated the 8v guys, they always came back with 'Yeah, but i've got more torque or more torque at a lower RPM'. Until I posted up the figures and it wasn't the case, you can't argue with fact and physics. With two intake valves over one you are going to get more air into the cylinder at any RPM, full stop, you will get this from a gain in both CFM and velocity.
Boosted LS1 said:
DonkeyApple said:
Different cams?
Air flow is different because one engine is 4 valve and has a large valve area, probably less air velocity at lower rpm's but comes on strong as revs increase. The 2 valver will be stronger low down but maybe run out of puff as revs increase. Then again, there may be other reasons and also cam choice as you suggest.IF there is any advantage of a 2v over a 4v it's due to mixture motion in the cylinder, the 2v swirls, the 4v tumbles and it's said in certain quarters that swirl is more efficient at lower RPMs, although this is offset by the total amount of air being let in.
Evoluzione said:
With respect, until you post up some intimate figures it's hearsay.
I've had the argument before; two identical engines apart from the head. The 16v owners always bated the 8v guys, they always came back with 'Yeah, but i've got more torque or more torque at a lower RPM'. Until I posted up the figures and it wasn't the case, you can't argue with fact and physics. With two intake valves over one you are going to get more air into the cylinder at any RPM, full stop, you will get this from a gain in both CFM and velocity.
Sometimes it is how you get the air into the cylinder, at low rpm less valve area and duration mean higher peak air velocities and better distribution of fuel in the cylinder. This is what vvt is all about, gives you the high lift, long duration needed at higher rpm and the higher air velocities into the cylinder at low rpm. I've had the argument before; two identical engines apart from the head. The 16v owners always bated the 8v guys, they always came back with 'Yeah, but i've got more torque or more torque at a lower RPM'. Until I posted up the figures and it wasn't the case, you can't argue with fact and physics. With two intake valves over one you are going to get more air into the cylinder at any RPM, full stop, you will get this from a gain in both CFM and velocity.
Evoluzione said:
No it isn't, see my previous post.
IF there is any advantage of a 2v over a 4v it's due to mixture motion in the cylinder, the 2v swirls, the 4v tumbles and it's said in certain quarters that swirl is more efficient at lower RPMs, although this is offset by the total amount of air being let in.
I'm sure that valve/port area has an impact on flow/velocity. Swirl and tumble are valid comments but that's not the be all and end all.IF there is any advantage of a 2v over a 4v it's due to mixture motion in the cylinder, the 2v swirls, the 4v tumbles and it's said in certain quarters that swirl is more efficient at lower RPMs, although this is offset by the total amount of air being let in.
DonkeyApple said:
Evoluzione said:
I'm surprised at a pushrod 4v bike engine, when was that, the 1950s?
The multivalve pushrod configuration suits a low revving diesel very well, pushrods bending at high RPM and multivalve heads producing more torque, lower emissions and better economy must make a very good engine.
It's why it stuck in my head. I remember it from a conversation years ago but I think the bike was from the 80s. The multivalve pushrod configuration suits a low revving diesel very well, pushrods bending at high RPM and multivalve heads producing more torque, lower emissions and better economy must make a very good engine.
Max_Torque said:
Totally irrelevant number generator^^^
They ran the engine on a dyno, without any cats or exhaust system,no air box either, no FEAD/ancilaries, on an aftermarket EMS running who knows what spark advance / fuelling & injection timing, on premium fuel, and at who knows what intake air temp or coolant temp, and still got just 85bhp litre. That's hopeless!
The OEM claimed numbers will be for an installed engine, with a production EMS running to the required tailpipe emissions limits with an intake and exhaust system that meets all the necessary noise limits too. That, my friends, is a WHOLE different kettle of fish........
They ran the engine on a dyno, without any cats or exhaust system,no air box either, no FEAD/ancilaries, on an aftermarket EMS running who knows what spark advance / fuelling & injection timing, on premium fuel, and at who knows what intake air temp or coolant temp, and still got just 85bhp litre. That's hopeless!
The OEM claimed numbers will be for an installed engine, with a production EMS running to the required tailpipe emissions limits with an intake and exhaust system that meets all the necessary noise limits too. That, my friends, is a WHOLE different kettle of fish........
Edited by Max_Torque on Sunday 26th April 16:03
deadtom said:
'Running ... through a set of dyno headers'
'Sending instructions to the LT1’s direct-injection fuel system was a Life Racing F88 GDI8 ECU. The headers were equipped with O2 sensors for each cylinder, giving Muzio complete control over fuel metering.'
'“The power increase was from the tuning and headers,” says Muzio.'
I thought it was just a generous dyno at first but that explains the figures. 'Sending instructions to the LT1’s direct-injection fuel system was a Life Racing F88 GDI8 ECU. The headers were equipped with O2 sensors for each cylinder, giving Muzio complete control over fuel metering.'
'“The power increase was from the tuning and headers,” says Muzio.'
Move along, nothing to see.
Things seem to have become a little circular with this discussion and comparing things that aren't comparable.
So just to add another silly comparison into the mix and send the OHC frothers into a tailspin, a common or garden push rod top fuel dragster engine which is 8.2L pushes out around 10,000hp. Don't think I've ever seen or heard of any OHC engine of similar size, or purpose put out any more than a fraction of that.
Ergo, push rod engines are ultimately more powerful.
So just to add another silly comparison into the mix and send the OHC frothers into a tailspin, a common or garden push rod top fuel dragster engine which is 8.2L pushes out around 10,000hp. Don't think I've ever seen or heard of any OHC engine of similar size, or purpose put out any more than a fraction of that.
Ergo, push rod engines are ultimately more powerful.
Edited by dvs_dave on Tuesday 28th April 06:41
DonkeyApple said:
DonkeyApple said:
Evoluzione said:
I'm surprised at a pushrod 4v bike engine, when was that, the 1950s?
The multivalve pushrod configuration suits a low revving diesel very well, pushrods bending at high RPM and multivalve heads producing more torque, lower emissions and better economy must make a very good engine.
It's why it stuck in my head. I remember it from a conversation years ago but I think the bike was from the 80s. The multivalve pushrod configuration suits a low revving diesel very well, pushrods bending at high RPM and multivalve heads producing more torque, lower emissions and better economy must make a very good engine.
Toltec said:
Sometimes it is how you get the air into the cylinder, at low rpm less valve area and duration mean higher peak air velocities and better distribution of fuel in the cylinder. This is what vvt is all about, gives you the high lift, long duration needed at higher rpm and the higher air velocities into the cylinder at low rpm.
VVT doesn't alter the cam lift nor duration, it changes the timing of the cam to give more overlap at high rpm which is what you want for power. Large amounts of overlap at idle are not desirable.Boosted LS1 said:
Evoluzione said:
No it isn't, see my previous post.
IF there is any advantage of a 2v over a 4v it's due to mixture motion in the cylinder, the 2v swirls, the 4v tumbles and it's said in certain quarters that swirl is more efficient at lower RPMs, although this is offset by the total amount of air being let in.
I'm sure that valve/port area has an impact on flow/velocity. Swirl and tumble are valid comments but that's not the be all and end all.IF there is any advantage of a 2v over a 4v it's due to mixture motion in the cylinder, the 2v swirls, the 4v tumbles and it's said in certain quarters that swirl is more efficient at lower RPMs, although this is offset by the total amount of air being let in.
There are a few good reasons why the Meercans still use carbs, 2v per cyl and inches - one is because they're 20yrs behind everyone else.
Evoluzione said:
VVT doesn't alter the cam lift nor duration, it changes the timing of the cam to give more overlap at high rpm which is what you want for power. Large amounts of overlap at idle are not desirable.
Hmmm, so how does vvt on the LT series increase overlap? By magically regrinding the cam? I may be wrong but vvt generally works by opening the valves earlier in the stroke to give more time for the air to get in at higher rpm compared to the standard valve timing. What you are thinking of is probably VTEC YO. Two different sets of cams with different LSAs. Seeing as the dohc cams generally work from one chain, the LSA cannot be changed. At least, that is my understanding.Gassing Station | General Gassing | Top of Page | What's New | My Stuff