8 valve Harley?

[Tom]

With full after burners kicked in, An F4 is described as a "fast bus" in the air.

[Cool Runnings]

Dyno run 2017 Harley-Davidson Milwaukee Eight 8 107" -> https://www.youtube.com/watch?v=qj5PBUHfQfg

Max power 80.87

Max torque 98.58

[Kev m]

Dyno run 2017 Harley-Davidson Milwaukee Eight 8 107" -> https://www.youtube.com/watch?v=qj5PBUHfQfg

Max power 80.87

Max torque 98.58

Well, that's a couple more hp loss than I was predicting, but it's only the first report, let's see some more.

It does still match the TC110B, which isn't too bad, but I'd have expected more freon a 4V head.

That said, bet a Stage I puts it at the mid-to-high 80's I was guessing.


EDIT-hmmm, so the source is a company who is trying to sell you their products that instead performance, so they would benefit from a lower initial dyno run. I'll have to compare some of their charts on other motors and vet them against known unbiased sources to see if there are any patterns of reliable or anti-hero data. Will report back.

EDIT-EDIT - ok, so I compared their dyno runs to my data and they seem like a pretty reliable source, though I found a couple of variations which could be individual bike or dyno run.

Here's some comparative data (MCN or other source vs. Fuel Moto):

TC96 - 66-68 hp      vs.      65-69 hp
TC103B - 71 hp      vs.      71 hp
*TC103 - 75-78 hp   vs.      76-77 hp (TCTC)
TC110B - 80-82 hp   vs.      NO DATA
TC110 - 82-86 hp   vs.      87-89 hp


* Not sure if my data was the Twin Cooled/Twin Cam, but numbers suggest it.

Which makes me wonder again about the CARB data, was one of those numbers for a Twin-Cooled M8? I think they said they were debuting one, but maybe it was only in the larger displacement.

Interesting.

And so funny that I'd still be happy with an EVO.

Reinstalled completely stock exhaust on my XLr yesterday because after about 12+ years of use on 2 bikes one of my modified mufflers cracked and started leaking and I'm not in the mood to do all that work again for a few hp.

[Rough Edge racing]

 The test on the new Harley above is on a Dynojet.....They are inertia dynamometers and 5-10 percent optimistic compared  Superflow or Mustang eddy current or load chassis dynos. I've had my race bike on both and there is a difference. The manufacturers use load dynos and usually quote crankshaft power and of course dynos are all slightly different....But the rear wheel power as measured on a Dyno Jet should be close to the manufacturer crankshaft power claims...

[Cool Runnings]

The test on the new Harley above is on a Dynojet.....They are inertia dynamometers and 5-10 percent optimistic compared  Superflow or Mustang eddy current or load chassis dynos. I've had my race bike on both and there is a difference. The manufacturers use load dynos and usually quote crankshaft power and of course dynos are all slightly different....But the rear wheel power as measured on a Dyno Jet should be close to the manufacturer crankshaft power claims...

Most likely real RWHP 70 to 75.

[Kev m]

Most likely real RWHP 70 to 75.

Which only likely matters if EVERYONE else in the world reporting this crap is NOT using a DynoJet (MCN, CW, Motorcyclist, etc. etc. etc.).

Of course if they ARE, then the comparative figures aren't 70-75 if you want to talk apples-to-apples.

[Cool Runnings]

 The dyno graph shows the ECM reprogrammed to remove just the VSS limiter, no other changes. No need to unplug a VSS to play games, just reprogram it out. So we have a run from yesterday in 5th gear with vss limiter in place, runs from today in 5th gear and 6th gear with limiter removed. As you can clearly see the MPH is higher before power cut occurs.

[rboe]

With full after burners kicked in, An F4 is described as a "fast bus" in the air.

This guy described it like a Mack Truck.

A kid that tried out for a seat in the Air Guard in Duluth (he was a graduate of Top Gun and a natural pilot) took on the base commander in a mock dog fight. They were transitioning from RF-4's to F-16 at the time. The commander took the F-16 and gave the kid the F-4 (and according to my co-worker - ex-air force engine tech, he had not flown an F-4 before). The Kid cleaned the commanders clock with the F-4.

Classic case of the ride being more capable than the rider - for the commander. 

[LowRyter]

I don't get why 4 valve head is needed on a low revving long stroke pushrod engine.  Perhaps if the valve timing is staggered between the valves this could create scavenging and flow?  Emissions? 

The numbers don't seem to bear out the expense.  It certainly can't smooth out the torque delivery much. 

I'll bet it's an EPA/emission ploy.

[Kev m]

I don't get why 4 valve head is needed on a low revving long stroke pushrod engine.  Perhaps if the valve timing is staggered between the valves this could create scavenging and flow?  Emissions? 

The numbers don't seem to bear out the expense.  It certainly can't smooth out the torque delivery much. 

I'll bet it's an EPA/emission ploy.

I think you may be right.

[ITSec]

I don't get why 4 valve head is needed on a low revving long stroke pushrod engine.  Perhaps if the valve timing is staggered between the valves this could create scavenging and flow?  Emissions? 

The numbers don't seem to bear out the expense.  It certainly can't smooth out the torque delivery much. 

I'll bet it's an EPA/emission ploy.

Nothing wrong with being able to maintain power/performance while meeting more stringent demands for limiting emissions and noise - just plain good engineering.

Now, if we could just get the electro-magnetically fired valves and eliminate cams altogether! 

[Rough Edge racing]

 Four valve isn't necessary for emissions ...The current Chevy LS V-8's are two valve push rod engines and make more HP per cubic inch than the Harley and must meet car emission standards that I believe are more strict than bike standards...Do the new Harleys have a catalytic convertor? If not then perhaps the four valve helps in this situation....Or maybe the toque curve as mentioned... Or just keeping up with the competition...

[Tom]

The liquid cooling certainly helps in the emissions control depart. IIRC

[Kev m]

I wouldn't use an automotive engine as comparison, not only because of the water cooling (which is a major factor with heat management, but a car already has an advantage with heat management with regards to the operator/passengers) but also because of so much more room and volume for emissions equipment. It's practically night and day.

[Tom]

Okay if the liquid cooling of the engine is only for tighter tolerances on the engine build.  Wouldn't a benefit be lower emissions?  or is that wrong thinking?  Granted may not be main reason for the liquid cooling but lower emissions would be a side benefit.

[oldbike54]

 Water cooling regulates cylinder head temp to a narrower range , making it easier to control emissions . The 8 valve engine should help in this regard also .

 Dusty

[Tom]

Yeah but is it an apple or an orange......uh..... day or night.   

[Kev m]

Water cooling regulates cylinder head temp to a narrower range , making it easier to control emissions . The 8 valve engine should help in this regard also .

 Dusty

This - the better control of combustion chamber temperatures means better control of the entire combustion process.

[Tom]

So a more complete burn of the fuel and less hydrocarbons in the exhaust.  More efficient engine with less emissions.  Main goal is efficiency with side benefit of less emissions.  May not be day or night but in the same 24 hour cycle.   

[Rough Edge racing]

I wouldn't use an automotive engine as comparison, not only because of the water cooling (which is a major factor with heat management, but a car already has an advantage with heat management with regards to the operator/passengers) but also because of so much more room and volume for emissions equipment. It's practically night and day.

 A car/truck engine operates in a  densely packed situation with A/C compressor, power steering pump, and all sorts of stuff bikes don't have. 

 Here's the current EPA emission standards...Not only are bikes allowed much more emissions, they are tests for less so to speak...

    https://www.epa.gov/emission-standards-reference-guide/light-duty-vehicles-and-trucks-emission-standards

















 
 
 

[Kev m]

A car/truck engine operates in a  densely packed situation with A/C compressor, power steering pump, and all sorts of stuff bikes don't have. 

 Here's the current EPA emission standards...Not only are bikes allowed much more emissions, they are tests for less so to speak...

    https://www.epa.gov/emission-standards-reference-guide/light-duty-vehicles-and-trucks-emission-standards

















 

Meh, that densely packed environment means nothing thanks to the large volume radiator, water pump, thermostat(s), and significant volume of cooling passages which mean a much more stable temperature range which is the first thing necessary to control combustion conditions.

EPA standards aren't the only things out there, EU emissions standards are getting tighter and tighter.

But even US standards have gotten right enough that additional strategies are necessary to stay compliant and competitive.

[sturgeon]

Meh, that densely packed environment means nothing thanks to the large volume radiator, water pump, thermostat(s), and significant volume of cooling passages which mean a much more stable temperature range which is the first thing necessary to control combustion conditions.

Both my car and my liquid-cooled motorcycle can display oil temperature, digitally. If one believes the displayed numbers, the car runs through a wider range of oil temperatures than does the motorcycle, in more or less equivalent conditions of dense slow-moving urban traffic and highway speeds, in very similar ambient temperatures, around 30C. They both have boxer engines and are of the same vintage. I can't hear the (twin) cooling fans in the car so I can't compare the rates at which they cycle on and off.

This is not a concern to me, just an observation of apples and oranges. It's how I amuse myself when stuck in rush-hour traffic.

[oldbike54]

 The HD guys are beginning to call this engine "the Frog Head"  Also , my source tells me that at some time in the near future HD will no longer warranty modified bikes . Really can't blame them , as surely they are going to lose money not being able to sell tuners and non-compliant exhaust systems . This may get interesting .

 Dusty

[bad Chad]

Will the whole stage system still be viable under the tighter EPA regulations?

[Kentktk]

Good visuals and explanation of new 8 valve.
https://www.youtube.com/watch?v=bAsWcrj_Y5c

[LowRyter]

The HD guys are beginning to call this engine "the Frog Head"  Also , my source tells me that at some time in the near future HD will no longer warranty modified bikes . Really can't blame them , as surely they are going to lose money not being able to sell tuners and non-compliant exhaust systems . This may get interesting .

 Dusty

I would agree unless they had those "Screaming Eagle" parts on them. 

As discussed the other thread. 

[oldbike54]

I would agree unless they had those "Screaming Eagle" parts on them. 

As discussed the other thread.

 Seems it will effect those also .

 Dusty

[LowRyter]

Shouldn't.

 $$$$

[Kev m]

Keep in mind that in 2007 when they introduced the feedback injection motors across the entire line they ALSO quietly made a change to some of their Screaming Eagle accessory parts. They came out with sets of 50-state street legal "accessory" mufflers that with no other modifications increased HP and torque (up to something as high as 10-15% depending on the model).

What this meant was they were (still are?) purposely leaving legally available power on the table to sell accessories after the sale. There's no reason they can't continue to do THAT.

Though if this situation focuses enough light on that there could be some legitimate customer backlash.

[Rough Edge racing]

Both my car and my liquid-cooled motorcycle can display oil temperature, digitally. If one believes the displayed numbers, the car runs through a wider range of oil temperatures than does the motorcycle, in more or less equivalent conditions of dense slow-moving urban traffic and highway speeds, in very similar ambient temperatures, around 30C. They both have boxer engines and are of the same vintage. I can't hear the (twin) cooling fans in the car so I can't compare the rates at which they cycle on and off.

This is not a concern to me, just an observation of apples and oranges. It's how I amuse myself when stuck in rush-hour traffic.

 Some do vary quite a bit, some not very much. Many but all new vehicles have the engine info gauges controlled by the ECU to display" normal "readings  unless something is really out of specification.. Engines with electric cooling fans can see a 20 degree temperature swing depending driving conditions as the fans switch on an off.
  If you have an accurate oil pressure gauge in a car/truck or bike , running on the highway at 70 mph for and hour will cause the oil pressure to be lower at idle than being in slow moving traffic...This tells me high speed heats up the oil more than slow speed...You may also notice the water temp being higher in slow traffic than high speed, just the opposite....With an accurate water temp gauge you may also see slight variations in temperature as the thermostat cycles partly open to partly closed.
  You can observe on bikes with dry sumps and side mount oil tanks, older bikes....High speed will make the oil tank very warm to the touch...slow speed riding does not heat up the oil , but in slow traffic the an air cooled non fan assisted engine upper end will get hot. Pulling a long grade at higher speeds on old Brit bikes, the engine might sound nosier as it heats up when working hard...
   If you listen,look and feel, the engine has a lot to say .....However on new stuff it's been muffled ,less is better