What to expect from headwork?
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Novice
Joined: Apr 2014
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From: Europe
What to expect from headwork?
Hello together,
posted this on HTT but didn´t get too much response so I thought I might give it a try here.
I have some questions about headwork.
Some answers might seem to be obvious but I am trying to get a better understanding of what the benefits and the pitfalls are.
I have a 2013 Road King, S&S Stealth AC, fullsac DX Pipes, V&H Monster Ovals.
I am thinking about replacing the cams in winter, maybe SE 255 as advised by a (more or less) local tuner, but not sure yet.
Any suggestions what headwork might offer to me?
Thanks in advance
D.Mon
posted this on HTT but didn´t get too much response so I thought I might give it a try here.
I have some questions about headwork.
Some answers might seem to be obvious but I am trying to get a better understanding of what the benefits and the pitfalls are.
- When is it advised to do headwork? What can I expect from it? Pros and Cons.
- What "kinds" of headwork are there, What e. g. is "mild" headwork?
- Are there special configurations (intake, headers, mufflers, cams, ...) that benefit more from headwork than others? When not to do headwork?
- Does headwork push certain rpm ranges or is it effective over the whole rpm range?
- If I choose a cam which pulls strong at low rpms can headwork compensate weakness in higher rpm ranges (a little)
- What else to consider?
I have a 2013 Road King, S&S Stealth AC, fullsac DX Pipes, V&H Monster Ovals.
I am thinking about replacing the cams in winter, maybe SE 255 as advised by a (more or less) local tuner, but not sure yet.
Any suggestions what headwork might offer to me?
Thanks in advance
D.Mon
Banned
Joined: Sep 2009
Posts: 3,569
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From: deland,florida
will you benefit from headwork,probably yes.without good headwork,no matter what parts are used,power will never get to its full potencial.but your question is hard to answer correctly.if matched to the rest of your build,it will be the most important part of the build & very big gains can be expected.if done by someone who dosnt have a clue (and theres a lot out there),or porting is done contrary to whats called for by the rest of your build,you can actually loose power
In my very humble opinion, since you have not yet added cams, your best bet is to find a reputable head guy and follow his "recipe" to the letter. They know what cams work well with their port work as well as what compression and all other variables. You tell them how you ride and what you want to accomplish and they'll tell you what they suggest. None of these guys want to steer you wrong. Their living is made solely on their reputation, and their reputation is made solely by their customers.
Elite HDF Member
Joined: Sep 2012
Posts: 3,791
Likes: 57
From: N Texas
Could almost write a book on what you are asking.... But I get it, I was the same way prior to my engine build - you want to learn stuff and not just blindly go into calling shops up before you have a decent grasp on things.
I make no claims to be an expert but I will at least try to answer one of your specific questions, lets talk about your first one:
It would be "advised" to do headwork if you are looking for extra hp/tq over just doing a Stage 1 + cams. Along with that it is also necessary if you have your heart set on a cam that needs more compression to work properly, for example if you want to run S&S 585s then it becomes more advisable to do headwork then say Woods 222. Generally if you need/want a mid to high rpm performance cam, then headwork becomes more necessary.
You can "expect" higher tq/hp #s from headwork across the rpm spectrum but the biggest benefit would be in the upper rpms - just think, better headwork flow helps the most when the demand is highest.
Pros - Better performance, higher max hp/tq #s, cooler CHTs, and proper compression.
Cons - loss of $$$, reliability MAY suffer, and the time/effort involved getting it done.
I am sure I missed some points, other may chime in, but hope this helps some.
I make no claims to be an expert but I will at least try to answer one of your specific questions, lets talk about your first one:
It would be "advised" to do headwork if you are looking for extra hp/tq over just doing a Stage 1 + cams. Along with that it is also necessary if you have your heart set on a cam that needs more compression to work properly, for example if you want to run S&S 585s then it becomes more advisable to do headwork then say Woods 222. Generally if you need/want a mid to high rpm performance cam, then headwork becomes more necessary.
You can "expect" higher tq/hp #s from headwork across the rpm spectrum but the biggest benefit would be in the upper rpms - just think, better headwork flow helps the most when the demand is highest.
Pros - Better performance, higher max hp/tq #s, cooler CHTs, and proper compression.
Cons - loss of $$$, reliability MAY suffer, and the time/effort involved getting it done.
I am sure I missed some points, other may chime in, but hope this helps some.
Road Warrior
Joined: Feb 2010
Posts: 1,953
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From: Houston, TX
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From: Europe
Thanks for the response.
Yes I want to get some understanding although I know I won´t become an expert just by reading (no need for it anyhow).
The se-255 cams were advised to me by a well reputable tuner.
In forums there are many that are quite happy with this cam and many others that don´t like them so much because they seem to run out of breath at around 4.000 rpm.
I am also looking at the Wood TW-222 and the Andrews 48H (and many others) which might be better choices for me.
My plan is to swap cams and then decide wether to do headwork or not.
btw: Are there dyno comparisms between with / without headwork?
Did´t find any.
Yes I want to get some understanding although I know I won´t become an expert just by reading (no need for it anyhow).
The se-255 cams were advised to me by a well reputable tuner.
In forums there are many that are quite happy with this cam and many others that don´t like them so much because they seem to run out of breath at around 4.000 rpm.
I am also looking at the Wood TW-222 and the Andrews 48H (and many others) which might be better choices for me.
My plan is to swap cams and then decide wether to do headwork or not.
btw: Are there dyno comparisms between with / without headwork?
Did´t find any.
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Road Warrior
Joined: Feb 2010
Posts: 1,953
Likes: 28
From: Houston, TX
Thanks for the response.
Yes I want to get some understanding although I know I won´t become an expert just by reading (no need for it anyhow).
The se-255 cams were advised to me by a well reputable tuner.
In forums there are many that are quite happy with this cam and many others that don´t like them so much because they seem to run out of breath at around 4.000 rpm.
I am also looking at the Wood TW-222 and the Andrews 48H (and many others) which might be better choices for me.
My plan is to swap cams and then decide wether to do headwork or not.
btw: Are there dyno comparisms between with / without headwork?
Did´t find any.
Yes I want to get some understanding although I know I won´t become an expert just by reading (no need for it anyhow).
The se-255 cams were advised to me by a well reputable tuner.
In forums there are many that are quite happy with this cam and many others that don´t like them so much because they seem to run out of breath at around 4.000 rpm.
I am also looking at the Wood TW-222 and the Andrews 48H (and many others) which might be better choices for me.
My plan is to swap cams and then decide wether to do headwork or not.
btw: Are there dyno comparisms between with / without headwork?
Did´t find any.
Yes, there are people happy with the 255.... When I first got my 255s, I was happy too - it was faster :-) More torque and more HP than stock = happy...
but after a few months, I wanted more.... MOST everyone said things like SE cams are EPA cams, and that the Andrews and Wood Cams are more aggressive, better, etc.....
I had the 255, and a canned map from Fuel Moto, and Republic HD had a free dyno day, where they do a dyno pull just to see what your numbers are.... I was 100 TQ, 83 HP.......
Well, like I said, I wanted more, and everyone said I picked the wrong cam.... I already bought a cam, and paid for a cam install - I hated to buy another cam, and install it again, but I bit the bullet and went with the 777 Wood cam..... (Ultra Nutz helped me out big time here).... but anyway, I instantly felt a HUGE seat of the pants improvement....... but I'm not sure my numbers...
Republic HD is doing another free dyno run special this Saturday, if it's not raining, I'll have some concrete numbers to compare a 255 cam with FM map and a 777 cam with FM map......
I am not saying I know it all - I don't. But I have personally had a SE 255 AND a Wood 777 in the same bike with no other mods, and the 777 feels like it makes the same power, or MORE off the line, and certainly carries it through to the end......
Banned
Joined: Sep 2009
Posts: 3,569
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From: deland,florida
the 48`s are a good "cam only" build,but IMO your leaving a lot on the table.even without headwork,if you going to up the compression a bit,they would be my choice.bumping the compression even just a bit opens your build up to a lot of better cams (that would benefit a lot with adding headwork)