Harley Davidson V-Rod Forum banner

21 - 40 of 117 Posts

·
Registered
Joined
·
66 Posts
Doug - Those heads look sweet!

BUT....Just curious what benefit there is with a head job like that on a forced induction motor? I understand the significant benefits on a NA motor but was my understanding there's not really any gain to be had opening up the heads on forced induction motors - since forced induction typically eliminates the airflow restriction bottle neck from the equation.

I'm currently having my 2007 stock displacement 1130cc motor rebuilt. It is torn apart as I type. It is also forced induction but running the TTS rotrex supercharger kit instead of a turbo. Was making 175 hp @ max 13psi before I melted the OEM pistons by (stupidly) failing to upgrade the fuel system beyond the injectors included with the kit (detonation I guess, but never heard or felt it).

So just curious, what kind of performance gains you got (or expect to get) from this? Should I be considering something similar with my heads?

Current plans are to just use the OEM camshafts since it is my understanding there’s not much to gain from making changes there either - when running a supercharger. I know that’s not the case with turbo’s – they do better with a custom grind. Plan is to run 9.85:1 pistons with various other upgraded internals and remove the restrictor from the SC – maybe a few more lb boost at the top.

Bike is in capable hands of a highly recommended shop here in the forums; and it may be too late for me to discuss any changes with the builder, but any nuggets of knowledge anyone can share is much appreciated anyway – especially Water Methanol information as I saw it mentioned in one of the replies.
 

·
Registered
Joined
·
1,376 Posts
Having motor build now so find this topic interesting. I understand the point your making but coast rider is right about the physics involved. Better or worse when it comes to overall performance???

Think about it another way - two identical trucks with 4:11 axle gears crawling over 15" boulders. One has 25" diameter tires and the other has 40" tires. Both tires rise 15" as they roll over the boulder BUT do so at different angles of incidence/attack. This is why the larger diameter cam lobe effects the valve travel as it does.

To your point, more torque is required to turn the larger tires (or to overcome a given amount of friction / inertia) so the truck with the 25" tires will accelerate faster on flat surfaces regardless of the angle of travel (uphill, downhill or flat). However, when it comes to rolling over obstacles, the larger tires (or cam lobes) require less torque due to their increased circumference relative to boulder height (valve travel). This advantage arises from the lower angle of incidence (decreased friction) generated by the larger tire (cam lobe) as it rotates over (around) the obstacle (valve tip).

With a larger diameter lobe, the valve travels at a more constant rate of speed throughout the stroke even though it may open and close at the same crank position as the smaller diameter lobe. This is because the former provides a longer distance of lobe travel through which the stroke of the valve can be more evenly distributed. But to achieve this within the fixed space allocated in the head there is an offset required to balance the equation - and that is less total lift relative to the H-D S/E cams as noted by streetrodracer.

Here's a decent visual illustration





Excellent explanation, thank you. Glad to see there is someone else out there that understands basic physics. Once again thank you for the time you put into your explanation.:notworth:
 

·
Registered
Joined
·
186 Posts
Ok.........
I totally understand what streetrodracer said, about the jones having slightly less total lift. Now THAT makes sense.
As I have previously stated, there is no doubt that the jones cams are a better cam. The part I was arguing is the ramp being easier. Still say bs.........
I also get the analagy to the larger wheel going over a 4x4, or 2x4, or whatever. I dont believe that to be a valid argument in this scenario. We are not talking wheels going over bumps, where a larger wheel will most certainly go over the same bump easier than a small. My arguement, again........
No matter starting point. Try drawing a straight line on a piece of paper. Now, you must get to "point x" vertically, BUT you must get there (x-y co-ordinate table) in X amount of spaces. If your line starts at x0y0 and you must get to y3, but it must be done by x10, there are a bunch of SHAPES that could be used to get to the same point, but you must arrive there by x10. Sofi you start that line at y3,so you must get to y6, but in the same x10 distance, it matters not.
Ok...... x= degrees of crank rotation. Y= total valve lift. There are numerous shapes one can use to get there. BUT keeping in mind not all shapes are feasible, from a mechanical standpoint. And some general rules apply as to initial valve being GENTLY raised off seat, and the nose of the cam, it MUST be a radius, of some type. So, this severely limits the actual shape that can be used. We are talking thousandths here......
I buy what streetrodracer said. Makes sense. The jones cams have slightly less total lift, and this is done exactly because they cannot match total lift, without clearancing of cam cover. So, if they DO have a total less lift, then yes, it is entirely possible to have a "more gentle" slope. BUT, its apples and oranges............
 

·
Registered
Joined
·
1,376 Posts
Ok.........
I totally understand what streetrodracer said, about the jones having slightly less total lift. Now THAT makes sense.
As I have previously stated, there is no doubt that the jones cams are a better cam. The part I was arguing is the ramp being easier. Still say bs.........
I also get the analagy to the larger wheel going over a 4x4, or 2x4, or whatever. I dont believe that to be a valid argument in this scenario. We are not talking wheels going over bumps, where a larger wheel will most certainly go over the same bump easier than a small. My arguement, again........
No matter starting point. Try drawing a straight line on a piece of paper. Now, you must get to "point x" vertically, BUT you must get there (x-y co-ordinate table) in X amount of spaces. If your line starts at x0y0 and you must get to y3, but it must be done by x10, there are a bunch of SHAPES that could be used to get to the same point, but you must arrive there by x10. Sofi you start that line at y3,so you must get to y6, but in the same x10 distance, it matters not.
Ok...... x= degrees of crank rotation. Y= total valve lift. There are numerous shapes one can use to get there. BUT keeping in mind not all shapes are feasible, from a mechanical standpoint. And some general rules apply as to initial valve being GENTLY raised off seat, and the nose of the cam, it MUST be a radius, of some type. So, this severely limits the actual shape that can be used. We are talking thousandths here......
I buy what streetrodracer said. Makes sense. The jones cams have slightly less total lift, and this is done exactly because they cannot match total lift, without clearancing of cam cover. So, if they DO have a total less lift, then yes, it is entirely possible to have a "more gentle" slope. BUT, its apples and oranges............
You are completely missing the point. The wheel analagy was purely to explain that less effort is required if the circle is larger and the reduction in effort translates to less mechanical stress. Therefore not BS.
What radius is available to the cam grinder is defined by the base circle of the blank (bigger the circle, gentler the curve) and I don't believe the difference in diameter of base circles between the Jones and the SE is thousandths.
 

·
Registered
Joined
·
2,492 Posts
no, still not convinced.you have not taken into account wheel speed or inertia.at max rpm i doubt your big wheel theory counts and these cams only improve anything at high rpm.there are many motors running smaller higher ramp cams with no ill effects. the throttle shafts are rubbish to begin with and therefore will fail eventually wit miles on.i believe the se cams run constantly at below ideal rpm causes damage.
 

·
Registered
Joined
·
1,943 Posts
Discussion Starter #27
Guys, Thanks for the discussion. Everyone here is thinking & it helps us all. A few points; Dan Jesels new "blank sheet" V8 has a 3 1/2" cam bore. Thats almost as big as our freakin pistons. He can design any size he wanted- big base diameter for improved valve control is the reason. Billy Godbold ( Comp Cams - OEM supplier for HD Vrod) argued for new blanks for SE cams, HD would not spend the $, so the ground down base diameter was the only option. The HD engineers I spoke to one year at the AETC said they would not run the SE parts in their motors. There are probably some Spintron videos on Youtube showing comparisons of valve action with same lift & differing base diameters, HUGE differences.
Porting is even more CRITICAL for boosted motors ! Any deficiencies in a NA motor are only affected by the vacume differential ( think a slow moving creek). A boosted engine is ramming around twice as much mass at only 14 pounds boost ( think a flood torrent). defects or constrictions are magnified. We usually think of boost as the amount of air we are pushing into the motor. Talk to some of the turbo ProMod guys at NHRA, it is better to view it as the amount of restriction you are overcoming. Tell me, if two BA Hemis are running, hit the same MPH in the quarter & one is is at 40 psi & the other is at 45 psi, which one is more efficient & making more HP ? If they both twisted the boost up to 45 psi, now what would the HP ( or mph) difference be ?
 

·
Registered
Joined
·
1,943 Posts
Discussion Starter #28
rynyoung Everything said about porting goes for cams as well. There are differences between what you need from blower to turbo, contact Jones. With the additional lift & porting, mathmaticly you should be looking at a 25-30 % hp gain at the same boost, being conservative. This would put you over 200 at the rear wheel. I would not drop that low on the compression, you need it with a small motor to get moving initially. Look up conversations with Ken Dutwieller about cr's on his turbo motors. You will need a good plenum and tune. There are members here running methanol & larger turbos making in excess of 300 hp at the rear wheel. I believe water/meth injection would be an asset if injected precompressor for charge cooling, compressor sealing and detonation control. Simply haven't had time to work on that project.
 

·
Registered
Joined
·
1,376 Posts
no, still not convinced.you have not taken into account wheel speed or inertia.at max rpm i doubt your big wheel theory counts and these cams only improve anything at high rpm.there are many motors running smaller higher ramp cams with no ill effects. the throttle shafts are rubbish to begin with and therefore will fail eventually wit miles on.i believe the se cams run constantly at below ideal rpm causes damage.
Well, as they say. You can lead a horse to water, but you can't make it drink!
 

·
Registered
Joined
·
66 Posts
Ok.........
I totally understand what streetrodracer said, about the jones having slightly less total lift. Now THAT makes sense.
As I have previously stated, there is no doubt that the jones cams are a better cam. The part I was arguing is the ramp being easier. Still say bs.........
I also get the analagy to the larger wheel going over a 4x4, or 2x4, or whatever. I dont believe that to be a valid argument in this scenario. We are not talking wheels going over bumps, where a larger wheel will most certainly go over the same bump easier than a small.
Agree in the sense that the torque required to turn the wheel is not applicable to this discussion – was tring to help another commenter who is getting hung up on wheel size / torque as it applies to camshaft lobe diameter - which it does not. Was trying to explain why it doesn't apply. But, there is a relationship between the reason why the torque argument does not apply and why it’s easier for the wheel to roll over obstacles – angle of incidence / attack. The physics involved with the wheel moves as it rolls over obstacles are exactly the same for the cam lobe rotating around the valve tip. On the former the wheel is forced up (vertical) and over (lateral) the obstacle whereas in the latter the obstacle (valve tip) is forced down (vertical – no lateral movement) by the lobe.

My arguement, again........No matter starting point. Try drawing a straight line on a piece of paper. Now, you must get to "point x" vertically, BUT you must get there (x-y co-ordinate table) in X amount of spaces. If your line starts at x0y0 and you must get to y3, but it must be done by x10, there are a bunch of SHAPES that could be used to get to the same point, but you must arrive there by x10. So if you start that line at y3,so you must get to y6, but in the same x10 distance, it matters not. Ok...... x= degrees of crank rotation. Y= total valve lift. There are numerous shapes one can use to get there. BUT keeping in mind not all shapes are feasible, from a mechanical standpoint. And some general rules apply as to initial valve being GENTLY raised off seat, and the nose of the cam, it MUST be a radius, of some type. So, this severely limits the actual shape that can be used. We are talking thousandths here......
I buy what streetrodracer said. Makes sense. The jones cams have slightly less total lift, and this is done exactly because they cannot match total lift, without clearancing of cam cover. So, if they DO have a total less lift, then yes, it is entirely possible to have a "more gentle" slope. BUT, its apples and oranges............
The Straight line in your comment represents time or degree of cam rotation. It is constant (or the same length) regardless of lobe diameter which is the point I believe you are making. In the attached illustration, your straight line is NOT shown, but it is stretched across 12 units along the x-axis for the small lobe and 18 units along the x-axis for the large lobe (would need a 3D graph to represent it on same image). Keep in mind, we’re dealing with non-linear equations / calculus here so cannot think about it same way as linear equations from algebra class.

From my previous post:
“This advantage arises from the lower angle of incidence (decreased friction) generated by the larger tire (cam lobe) as it rotates over (around) the obstacle (valve tip).

With a larger diameter lobe, the valve travels at a more constant rate of speed throughout the stroke even though it may open and close at the same crank position as the smaller diameter lobe. This is because the former provides a longer distance of travel along the lobe allowing the stroke of the valve to be more evenly distributed from start to finish. But to achieve this within the fixed space allocated in the head there is an offset required to balance the equation - and that is less total lift relative to the H-D S/E cams as noted by streetrodracer.”

Now, as to exactly why/how this "valve travel / stroke difference" allows the air pump to more efficiently convert fresh air to exhaust - beyond my level of knowledge. Perhaps that is what you are getting at? For those answers suspect we would need someone like Dan Jessels or Billy Godbold (re: Post #27) to chime in which probably aint happenin’.

Edit Note: Chart curve shapes (slopes along the curve) do not accurately reflect the changes that would result from differences in grinds achieved with different diameter cam lobes. Build with what had available - single jpeg image which could shrink / stretch in excel.
 

Attachments

·
Registered
Joined
·
66 Posts
Excellent explanation, thank you. Glad to see there is someone else out there that understands basic physics. Once again thank you for the time you put into your explanation.:notworth:
Thank You.....learning myself so writing down thoughts along the way helps that process. :dance:
 

·
Registered
Joined
·
66 Posts
rynyoung Everything said about porting goes for cams as well. There are differences between what you need from blower to turbo, contact Jones. With the additional lift & porting, mathematically you should be looking at a 25-30 % hp gain at the same boost, being conservative. This would put you over 200 at the rear wheel. I would not drop that low on the compression, you need it with a small motor to get moving initially. Look up conversations with Ken Dutwieller about cr's on his turbo motors. You will need a good plenum and tune. There are members here running methanol & larger turbos making in excess of 300 hp at the rear wheel. I believe water/meth injection would be an asset if injected precompressor for charge cooling, compressor sealing and detonation control. Simply haven't had time to work on that project.
Thank You for response. I’ve been a little skittish of the lower compression too – especially since most of my riding will be on highway (lower rpm range). I will look into that more if it’s not too late – will have to check with builder. Have been out of touch due to work load.

While motor apart, contemplating mods where I can get biggest bank for buck in terms of HP / $ Invested. Got significant ROI from adding boost / supercharger. Interested in mod options where I can get similar ROI measured at seat of pants.

So in a nutshell, your saying that my cylinder pressure prior to start of compression stroke is < plenum pressure? I’m implicitly assuming they are pretty close.

I may have 13psi measured in the intake runners (which may be < plenum psi due to intake restrictions), but restrictions beyond that point (valve train) result in < 13psi inside the cylinder at time piston is @ BDC (max cyl vol)?

So by eliminating inefficiencies in the heads I can raise the cylinder pressure closer to pressure in the plenum?

Or are you saying the issue is also caused by stock cam timing / duration – intake valves closing too soon or exhaust not being completely/efficiently evacuated from cylinder prior to intake stroke? If my budget allowed for only one mod, should I do a cam or porting in your opinion?

Do you by chance have before / after dyno numbers on your motor where only change was heads (or know where someone else has posted their before/after numbers? I'm not racing and have to pay retail for everything so squeezing out another 5-10 HP for an additional $3-5K doesn't meet my ROI hurdle since won't make difference in winning / losing a races as I'm riding down the highway, but 20-30% gain (40-60hp) might squeeze out enough additional terror/adrenaline to justify it if I could find some way to "prove it out to myself".

I’m “convinced” on the water methanol (WM) side of things for sure. Not just for performance gains, but in terms of protecting my investment on the engine itself by keeping temperatures down and preventing detonation under high load – reasons I am having to rebuild engine now (see Pics). Seems would get these benefits whether injected before or after compressor but I saw a system design I found interesting where guy was injecting his car pre-compressor as you mentioned.

He was using compressor pressure to pressurize the WM tank. (seems like could use some sort of multiplier system similar to vacuum pwr brakes) This pressurized the tank pushing water to an injector spraying into the compressor fan. More pressure = more flow. Eliminated need for a water pump making system simpler – less parts to fail. Fan also atomizes the water. Also eliminated the on/off single flow rate problem with water pump setup; allowing flow rate to vary depending on needs of engine (perhaps more of an advantage with the supercharger setup since there is a constant liner relationship between rpm’s and boost pressure. Downside is spraying water into a fan spinning xxx,000 rpm’s. Do you not see that as a problem for the compressor fan?

If you ever get around to putting together a system I would be interested. I don’t have the knowledge necessary to do it myself and don’t have any shops in my area that I can rely on for that type of outside the box stuff.
 

Attachments

·
Registered
Joined
·
66 Posts
rynyoung...... I would not drop that low on the compression, you need it with a small motor to get moving initially. Look up conversations with Ken Dutwieller about cr's on his turbo motors.
Is this the conversation you are talking about:

I can see the difference on cam timing. How about compression & head gaskets to lower it?
Reply:
It depends on what you're planning on doing.
Lower compression with higher boost will make more top-end power until you can't get a big enough turbo.

Higher compression with less boost will make more low-end power andwill have less turbo lag.
Several years ago I ran across a thread here on (I think) 1130cc.com with extensive discussions where a builder / engineer / racing team talked about their results with different compression pistons in the V Rod revolution engine. It had a ton of information where people were discussing the original expectations and how/why they did not pan out as expected - specifically relating to this engine design. I know they were saying the lower compression results were not as expected (disappointing) but I can't remember how low they went and exactly what they were trying achieve or why they were disappointing.

Frustrating because I remember it exists somewhere but I can't find it now that I need it.
 

·
Registered
Joined
·
66 Posts
Bigfoot & Aliens

Follow up to last post with........

Based on information I have gleaned from various sources, and how I use my bike, I think the best option would be to keep compression close to stock (not higher, but maybe a little lower) and add a water methanol (WM) setup to it.

This would retain higher stock torque at lower rpm AND provide cooling / detonation prevention when the bike it under load. Set it up to inject water ONLY under high load. So the bike would retain its' OEM power profile under low load / cruising conditions but unchain the Monster within when throttle is cracked open.

Problem there is, don't have the knowledge / experience needed to R&D a properly functioning kit myself and haven't found anybody who makes / sells one turnkey setup for the V-Rod. I hear about people who are using them third hand here and there but don't know how to go about getting in touch with one of those people who is willing/able to help out with mine - which would include getting the bike tuned with it (one more layer of complexity).

Finding a V Rod WM setup feels sort of like trying to find proof Bigfoot or Aliens...... Lots of reports from people who have seen or claim to have been abducted by them, but nobody can tell where to go so I can see them for myself.
 

·
Registered
Joined
·
4,252 Posts
Making a few calls today. I'll see if I can get a certain someone to chime in on the forum.

I do have to say, the reason we do NOT see alot of these innovators on this forum is due to the hostility and doubt expressed all too often.

The person I want to chime in here has been questioned repeatedly despite proving himself for years.

This should be interesting hopefully.

As for my pictures/specs....coming hopefully this spring. I have 3 massive projects I am working on that should blow a few minds. I'm hoping it's appreciated as I've literally lost weeks of sleep due my schedule the last few months (I enjoy it though, just saying the work load is insane).

Software or wrench....software or wrench.....typical day/night lately.
Think I know the guy. Anyway, I've asked his competition a question regarding methods of tuning for boost, keeping the Delphi. On that note, from what I know, Delphi handles to 100kpa no problem and a second 2-3 bar controller is used for the boosted areas with possibly a third injector. Still no reply from the expert but it's done every day, retaining the speed density and ion sensing.
Ron
 

·
Registered
Joined
·
1,943 Posts
Discussion Starter #36
Texted James Ramsey this afternoon. He uses the Thundermax for boosted Vrods. I asked him about features of the Tmax. His reply " With the tunes I create the fuel and timing is offset relative to pressure. The maps are also offset relative to the ambient conditions. Different applications require different offsets. The manual ( Tmax) doesn't cover any of the forced induction information adequately. It really doesn't cover much on the advanced tuning. With a properly built map, the closed loop portion does a good job of maintaining the fuel curve." I asked him about contact info & possible dyno maps to share; "people who use dyno charts to reference quality of tune don't know what they're talking about. Anyone can tune a bike at wide open, with no load and not factoring in aerodynamic drag. Shop line is (602) 617-7776 [email protected]"
 

·
Registered
Joined
·
4,252 Posts
Texted James Ramsey this afternoon. He uses the Thundermax for boosted Vrods. I asked him about features of the Tmax. His reply " With the tunes I create the fuel and timing is offset relative to pressure. The maps are also offset relative to the ambient conditions. Different applications require different offsets. The manual ( Tmax) doesn't cover any of the forced induction information adequately. It really doesn't cover much on the advanced tuning. With a properly built map, the closed loop portion does a good job of maintaining the fuel curve." I asked him about contact info & possible dyno maps to share; "people who use dyno charts to reference quality of tune don't know what they're talking about. Anyone can tune a bike at wide open, with no load and not factoring in aerodynamic drag. Shop line is (602) 617-7776 [email protected]"
Tmax support is likely the worst there is and in his case everything costs extra in the support department. Done the Tmax thing once and it was ok but once was enough. Same old cookie cutter explanations if there's problem or all you hear is crickets. If I was to go AlphaN again, most likely it would be DTT,(sorry John) mostly because I like the rest of their products. In the end, nothing can compare to the Delphi for reliability, so a second controller for boost is still the best solution to me. The amount of DTT or Tmax Ecu failures for the cost of the damn things doesn't sit well with me.
Ron
 

·
Registered
Joined
·
1,943 Posts
Discussion Starter #38
Ron, Thanks for your opinion. How about if you give us a step by step on the install & tuning of the piggy back controller of your choice so we can all see that option ?
BTW James Ramsey is an independent tuning provider specializing in race / boosted applications for Harleys
 

·
Registered
Joined
·
186 Posts
Dont poke him. He's liable to make you look silly. And Ron, you know my feelings on DTT. While I assume a good tuner, it IS NOT the right one for every Vrod in every level of performance. Like everything, there is a time and a place for them.
 
21 - 40 of 117 Posts
Top