So what did he do to it? What components is he using?

 

Milwaukee Eight shop bike. It has our MX pipe, 2.0 baffles,TTS 200 cam. 120 piston kit. Stock heads and throttlebody. 122 HP, 136TQ. Not bad for a budget build!

 

The typical way to build a “high-torque” engine is with lots of cubic inches, high compression ratio, short-duration cam, small-port heads, small throttle body or carb, and not too-free-flowing exhaust. This engine is a classic example of a high-torque engine.

Such an engine will typically produce more torque than horsepower per cubic inch, as this one does. This engine produces 1.02 HP/CI and 1.13 #feet TQ/CI.

A high-performance Harley Big Twin street engine running “only” on pump gas (92-93 octane) will typically produce between 1.1HP/CI and 1.2HP/CI using an SAE Correction Factor and fifth-gear testing (the de facto dyno standards). Today’s pump-gas engines are limited first by fuel octane rating, which limits compression ratio, which limits cam timing. Bike weight, gearing and ambient temperature “can” also come into play.

This 120 ci engine was designed as a torque engine and not a horsepower engine, so the HP per cubic inch is slightly lower while the torque numbers are higher.

In reality, all internal combustion engines are torque engines since horsepower is a mathematical calculation of torque times rpm, so it boils down to where you want to maximize torque: in the lower rpm range or the higher range. As long as an engine’s rpm is increasing faster than torque is dropping, horsepower will increase.

Since a pump-gas engine is limited by fuel octane and compression ratio, to convert a so-called torque engine into a horsepower engine, all you would have to do is install a “compatible” longer duration cam (within limits), higher-flowing bigger-port heads, larger throttle body, and “maybe” less-restrictive exhaust baffle. Those changes would “typically” move the torque curve to the right side at the expense of the left side.

Keep in mind, however, that there is no such thing as a “magic” cam…..or a magic Stage Kit. It’s all about relationships and managing cylinder pressure and optimizing combustion, regardless of the displacement of your engine or whether you have a two-valve or 4-valve V-Twin engine.

What surprises me, though, is the high number of bike owners on this forum installing cams and building engines blindly, without knowing specifications, because one cannot optimize critical engine relationships without knowing key engine specs.

This 120 ci engine is a prime example of today’s “high-torque” M8 engine.

By the way, does anyone know what gear the dyno test was done in: 5th or 6th?

 

M8 All-SE Stage II Cam Install - Approximate Costs
(assumes SE Stage I A/C and slip-ons are installed)
$200 Bolt-in cam SE
$200 adj pushrods (cut out old pushrods)
$300 tuner – SEPST (about $150 additional for TTS or PV tuner)
$600 labor @$100/hr (does not include dyno tune)
$450 dyno tune (full dyno tunes range $300 to $500, depending on variables)
$1750 total

This is a ballpark dollar figure, depending on the city you live in. You may have to adjust the labor cost per hour depending on the dealership, and if you already have some of the parts, you can subtract their costs. There is no need to remove any top-end parts when installing a bolt-in cam with adjustable pushrods.

If you don’t have any Stage I parts installed, add about $500 for Street Cannon slip-on mufflers, $200 to $400 for a free-flowing A/C, and $25 labor (15 minutes) for unpacking those new parts from their shipping box. Installing new slip-ons and A/C doesn’t take any longer than reinstalling the same items that were originally removed from the bike, so there shouldn’t be more than 15 minutes additional labor for Stage I parts.

 

Define "budget". lol

 

This is the quote I got today from them.

 

Sorry but these statements are incorrect. Most of those wanting specifications do not understand what most of them mean to start with. Let's think about what having a cam specification does for you. It defines the opening point and closing point only (which by the way is not really when the valve opens or closes)and how far apart they are (duration). So take a piece of paper and put two dots on the paper in the same horizontal plane. Then draw another solid line just below the two dots on the same horizontal plane. This line is the zero point, so no lift. Now tell me how many different lines you can draw from the zero point and connect it to the first dot, then to the second dot, then back to the zero line again. Thousand upon thousands of lines can be drawn and they all have the exact same points used, so they would all have the same opening and closing points and the same duration. I can tell you that some will work much better than others! Now according to what some people want to think they are all the same because the piece of paper says so! Now if you want to include lift add another dot on the paper half way between the first two dots you put on the paper about 1/2" higher than the zero line. Now you must draw the lines to include that point. Problem here is the new added dot is supposed to be valve lift and since different people use different ways to determine that location you end up with different dots but the cam cam doesn't tell you that most of the time! With all three dots you can still draw thousands of lines, again! So add it all together and all these specifications do is give you a very rough idea about what any cam may or maynot do at best. They will never tell you what any one cam does and what it will make for power or how it makes its power!

 

There is some great info shared on the cams available lately, for me however I’d like to know what type of gains people are getting with adding a cam to a stage 1 set up. I haven’t been looking to get a set of headers. Is there ‘enough’ improvement with the stock headers or should I wait to add them with a cam install? I’d prefer a tourque cam over HP.

 

Wow, I must be over target to draw so much flack.

I’ll let you go bleary-eyed chasing all your dots, but the fact remains that no engine builder worth his salt is going to install a cam without first knowing the specs. John Force Racing would not do it, Hendrick Motorsports would not do it, V&H would not do it, and neither would other knowledgeable performance enthusiasts.

Running a cam blindly is like someone giving a person a fish a day, instead of teaching them how to fish. The engine builder would have no idea what cam timing or duration is working or not working, or why. You would never be able to keep up with the guy who sold you the cam. You’d always be a step or three behind.

Simply put, knowing cam specs “is” important. For starters, there are key relationships between engine displacement, intake valve close (IVC), compression ratio, fuel octane, and rpm. Moreover, compression ratio and exhaust valve opening are related. And overlap, combustion chamber design (chamber and piston dome), and exhaust system scavenging have a relationship.

Without being able to compare cam specs to “known” performance, there is no way to identify trends or patterns, no way to draw conclusions, no way to analyze a cam and determine which direction to make changes. You’d be flying blindly by the seat of your pants.

Selling cams with unspecified specs may work for mild bolt-in engine upgrades and for selling cams over the Internet, but never for any “thoughtful” performance engine building.

If V-Twin owners are satisfied buying cams myopically, that’s okay, that’s fair enough. No one is stopping them. Last I checked, America is a free country.

But there are smarter ways to go about engine hop-ups. For example, I remember early M8 107ci adopters of the 222 cam were complaining that low-rpm (left-side) power was down with that cam. Without knowing the cam’s specs, one would wonder why. The problem could be due to several possibilities.

For reference, refer to the Fuel Moto’s M8 107 ci Cam Tests Dyno Charts:
https://www.hdforums.com/forum/milwa...testing-9.html

But any knowledgeable person who knew the 222’s cam specs “beforehand” would have “immediately” known why: it’s primarily because of the late 40-degree abdc IVC on a relatively low-compression ~10:1 107 ci engine. Conversely, the “late intake closing” and relatively “long intake duration” are why the 222 was the best high rpm cam in the testing. Not surprisingly, the 222 cam was the worst at low rpm but best at high rpm. But if no one knew what the 222 cam specs were, no one would know why.

And the 0.5-point higher compression ratio of the factory 114 ci Fat Boy engine (over the 107 ci engine) and additional displacement complimented the later intake closing and longer intake duration of the 222 cam. And larger displacement engines will work better yet with the 222 cam. Again, if no one knew what the 222 cam specs were, no one would know why it performed the way it did. They’d be clueless!

For another example, checkout the M460 cam in Fuel Moto’s M8 114 ci Cam Tests Dyno Charts:
https://www.hdforums.com/forum/milwa...fuel-moto.html

With all due respect, that cam has the lowest “overall” power production, but not by much. But let me be clear, this is “not” a dig against this cam because there is a valid reason for its power curve: the M460 cam is the smallest and shortest cam of all the cams tested. Its intake valve closes earlier than all but one cam in the tests. And the M460 has 6-degrees less duration on both the intake and exhaust sides than another cam whose intake closed at the same 20-degrees abdc. Further, this test was on a larger displacement 114-ci engine, which could benefit from more duration. Again, if no one knew what the M460’s specs were, no one would know why it performed the way it did. They’d be clueless!

Add some duration to the M460 cam, and I’ll bet it will pickup in a 114-ci engine.

And we haven’t even discussed cam lift rates, which are beyond the scope of this discussion. However, faster lift rates put more area under the curve for a given duration, but after a point, make for noisier mechanical cam operation. Since all the test cams are mild cams and rated as being “quiet,” I can only assume their lift rates are similar.

That said, I’ll stand by every word I said!

I’m out of here…..Let the flaming begin…..

 

You can stand by it all you want............... still doesn't make it correct. Any good engine builder would ask for much more than the cam card as they already know that only gives them a WAG as to what might happen. The days of saying you must know what's on a Cam card are long gone for any professional engine builder as they already know better!