Searching for M8 head specs
#11
01-11-2019, 04:35 PM
Seasoned HDF Member
Sometimes you make some great points, but that statement is completely false. It's no accident that nearly all modern engines are multi-valve. You're stuck in a universe two decades-old.
#12
01-11-2019, 04:53 PM
Banned
To what do you attribute the massive power gains the stock M8 has over the TC bikes? Hint: 4-valve heads.
Sometimes you make some great points, but that statement is completely false. It's no accident that nearly all modern engines are multi-valve. You're stuck in a universe two decades-old.
Sometimes you make some great points, but that statement is completely false. It's no accident that nearly all modern engines are multi-valve. You're stuck in a universe two decades-old.
How much more power per cube do they in fact have?
The four valves is a bunch of hype for people with no concept about slow churning engines.
#13
01-11-2019, 05:03 PM
Seasoned HDF Member
Four valves is basic science, and my M8 redlines at 7K RPM. That isn't a slow churning engine. You need to do some reading to get current. As I said, most modern engines are multi-valve for a reason. It's a more-efficient system. The only reason HD made a big deal about it is because it was a drastic change for them. Like you, they are slow to adopt modern technology.
#14
01-11-2019, 06:49 PM
Banned
The CVO 110 TC engine made about the same power/torque as the 107 M8 stock engine. 110 was 80hp/95tq, M8 is 81hp/98tq. I'l let you do the math. An increase in compression certainly helps with that.
Four valves is basic science, and my M8 redlines at 7K RPM. That isn't a slow churning engine. You need to do some reading to get current. As I said, most modern engines are multi-valve for a reason. It's a more-efficient system. The only reason HD made a big deal about it is because it was a drastic change for them. Like you, they are slow to adopt modern technology.
Four valves is basic science, and my M8 redlines at 7K RPM. That isn't a slow churning engine. You need to do some reading to get current. As I said, most modern engines are multi-valve for a reason. It's a more-efficient system. The only reason HD made a big deal about it is because it was a drastic change for them. Like you, they are slow to adopt modern technology.
I like all sorts of different engines, not just HD.
I love the science of engines and will discuss it all day.
Now, No one can give HD the genius award for amazing power without someone reworking it.
Anything less than one HP per cube is a dinosaur machine and is referred to as detuned. Simple
Now follow along.
HD is still at 75% which is a low low number.'!!
Even the bragged about M8 is way under one to one from the factory.
No big deal there. (sadly )
4valves,, two vales, it doesn't matter as it is a moot point.- For what purpose?-
It has been proven over and over two vales will easily do one to one.
Now where is HD? - LOL-
To get 4 valves to shine the RPM will have to be amped up to where an HD cant go.( RPM scale)
The Holy Grail was chevy way in the 1950s when they accomplished one to one.
Heck, my little Evo did 1.25 last run and this year the goal is 1.35!, two little valves, of course. - LOL-
So HD with all the hype has not really got anywhere, except more complicated. IMO
The old Shovels could be made to do 6000 RPM and more !
That was 40 years ago.
Where is HD now?
They are fascinated with flow and VE with a 4 valve design?
Old stuff.
Old news.
Porsche was producing one to at the wheels with a smogged car in 1975. N.A. too!
That was not a grey market either -USA for real import and they did with two valves.
6600 RPM. 8.5 CR
As far as fast turning I would hardly think 6 or 7K would be considered a fast RPM. Diesel do it.
There are many MC engine out there that produce all kinds of HP per cube.HD is way behind. But they want to sell you a stage kit .....hooo Hummmm
F1 engine produces way more then 3 HP per cube 12000 RPM is nothing.
SO if you want to slant your idea about High RPM and 4 valve being the catalyst for the M8 HP, it is not.
Simple.
For cubic the inches listed, they are very anemic. (untill someone works it over)
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#15
01-11-2019, 08:13 PM
Join Date: Jul 2018
Location: Wisconsin
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FWIW as I understand it number of valves is only part of the fight. Tuning the intake port(s) volume to get the fastest airflow at the given valve area is the main goal, and if two intake valves gives more valve surface area great傭ut the ports into it need to be big enough to flow but not too big to slow it down. It痴 the main reason just hogging intake runners out doesn稚 make the vehicle necessarily more powerful. It痴 intake density and charge speed.
And again, for what feels like the ninth time or so everyone, it痴 just a project to keep me occupied, teach me 3D design, and do something unique/stupid/cool. Oh, and have relatively close measurements available to the people. Relax everyone. XD
And again, for what feels like the ninth time or so everyone, it痴 just a project to keep me occupied, teach me 3D design, and do something unique/stupid/cool. Oh, and have relatively close measurements available to the people. Relax everyone. XD
#16
01-11-2019, 08:19 PM
Banned
FWIW as I understand it number of valves is only part of the fight. Tuning the intake port(s) volume to get the fastest airflow at the given valve area is the main goal, and if two intake valves gives more valve surface area great傭ut the ports into it need to be big enough to flow but not too big to slow it down. It痴 the main reason just hogging intake runners out doesn稚 make the vehicle necessarily more powerful. It痴 intake density and charge speed.
And again, for what feels like the ninth time or so everyone, it痴 just a project to keep me occupied, teach me 3D design, and do something unique/stupid/cool. Oh, and have relatively close measurements available to the people. Relax everyone. XD
And again, for what feels like the ninth time or so everyone, it痴 just a project to keep me occupied, teach me 3D design, and do something unique/stupid/cool. Oh, and have relatively close measurements available to the people. Relax everyone. XD
I tell you this though the first people to make an M8 head that looks like a Shovel head has my money.
Well as long as it has good performance anyways.
#17
01-11-2019, 08:27 PM
Banned
FWIW as I understand it number of valves is only part of the fight. Tuning the intake port(s) volume to get the fastest airflow at the given valve area is the main goal, and if two intake valves gives more valve surface area great—but the ports into it need to be big enough to flow but not too big to slow it down. It’s the main reason just hogging intake runners out doesn’t make the vehicle necessarily more powerful. It’s intake density and charge speed.
And again, for what feels like the ninth time or so everyone, it’s just a project to keep me occupied, teach me 3D design, and do something unique/stupid/cool. Oh, and have relatively close measurements available to the people. Relax everyone. XD
And again, for what feels like the ninth time or so everyone, it’s just a project to keep me occupied, teach me 3D design, and do something unique/stupid/cool. Oh, and have relatively close measurements available to the people. Relax everyone. XD
#18
06-09-2021, 10:47 PM
Road Master
Chasing the VE of an engine is done 24 hours a day, But I would strongly suggest you not reinvent the wheel.
Read all you can by Mondello and others that share.
Remeber water is about 800 times heavy then air (Cheep flow bench) (and perhaps more real)
CFM is not even 1/2 the equation to chase, its the 1000 other little details and nuances.
Fueling made 4 valve heads as well as others.
None paid well or worked well or we would all be running them.
Like I said -HD has a new shiny object for everyone that has no clue for what the formula 3,4,5 adds up to.
To them -
Its 4 valves to them and should go faster LOL, ........when they get it on the other side of 1.35 HP per cube (NA) I will concede they finally got somewhere.
Wating.......................
https://www.engineeringtoolbox.com/w...air-d_854.html
Read all you can by Mondello and others that share.
Remeber water is about 800 times heavy then air (Cheep flow bench) (and perhaps more real)
CFM is not even 1/2 the equation to chase, its the 1000 other little details and nuances.
Fueling made 4 valve heads as well as others.
None paid well or worked well or we would all be running them.
Like I said -HD has a new shiny object for everyone that has no clue for what the formula 3,4,5 adds up to.
To them -
Its 4 valves to them and should go faster LOL, ........when they get it on the other side of 1.35 HP per cube (NA) I will concede they finally got somewhere.
Wating.......................
https://www.engineeringtoolbox.com/w...air-d_854.html
Never say never.
Dave
#19
06-09-2021, 10:52 PM
Seasoned HDF Member
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#20
06-10-2021, 05:52 PM
There have been lots of 4 valve heads already made for the shovel.
A newer 4 valve is a shell trick, look here!
No over here!
Harley has just discovered a new fad to sell the M8 that is all .
It is a slow turning engine and breathing is not so much the problem.
More of the combustion chamber arrangement, porting problems is.
The proof is the unattainable 1.35 hp per cube no matter what they do,
-which is very EZ in other configurations on other engines.
Look up Other engines and compare.
A newer 4 valve is a shell trick, look here!
No over here!
Harley has just discovered a new fad to sell the M8 that is all .
It is a slow turning engine and breathing is not so much the problem.
More of the combustion chamber arrangement, porting problems is.
The proof is the unattainable 1.35 hp per cube no matter what they do,
-which is very EZ in other configurations on other engines.
Look up Other engines and compare.
The LiveWire make 105 hp from 0 ci. That's way more than 1.35 hp per ci.
Last edited by $tonecold; 06-10-2021 at 05:59 PM.
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