BIG Build?!
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From: Bedford UK
BIG Build?!
There has been some excellent discussion in this forum on upgrading stock engines for bigger and bigger cubes, with some impressive dyno figures to match, but I would like to take the debate onto a different plain, which is BIG displacement for its own sake. So set aside common-sense for a few moments! 
It is inevitable that a truly big engine will give big performance, but what I have in mind is a big lazy engine, rather than a drag-strip queen, for my bagger. I am thinking of a monster motor without too much monster performance.
Why? Because it takes my fancy!
I have recently come across the Ultima 140 and S&S 145, which are cheaper (its all relative!) than the billet motors. So rather than the dragon-slaying HP some of these promise, is it feasible to detune either of them to around say 1 HP/TQ per cubic inch, with a wide easy torque curve and a forgiving nature?
Or is that a dream too far and those monsters cannot be tamed or made to change their ways?!
It is inevitable that a truly big engine will give big performance, but what I have in mind is a big lazy engine, rather than a drag-strip queen, for my bagger. I am thinking of a monster motor without too much monster performance.
Why? Because it takes my fancy!
I have recently come across the Ultima 140 and S&S 145, which are cheaper (its all relative!) than the billet motors. So rather than the dragon-slaying HP some of these promise, is it feasible to detune either of them to around say 1 HP/TQ per cubic inch, with a wide easy torque curve and a forgiving nature?
Or is that a dream too far and those monsters cannot be tamed or made to change their ways?!
Road Warrior
Joined: Dec 2006
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From: Diamond Bar, California
the difficult trick here is getting it camed properly, with that kind of displacement it would want to make some big cylinder pressure.
Someone would have to get the pressure bled off without a loss of ride-ablity, and giving it a radical lumpy idle at the same time. interesting topic
Someone would have to get the pressure bled off without a loss of ride-ablity, and giving it a radical lumpy idle at the same time. interesting topic
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From: Bedford UK
the difficult trick here is getting it camed properly, with that kind of displacement it would want to make some big cylinder pressure.
Someone would have to get the pressure bled off without a loss of ride-ablity, and giving it a radical lumpy idle at the same time. interesting topic
Someone would have to get the pressure bled off without a loss of ride-ablity, and giving it a radical lumpy idle at the same time. interesting topic
The Ultima has 10.8:1CR and the S&S 11.1:1, which is serious stuff.
What I have discovered is that S&S makes four versions of their V124; stock, EPA, CARB and TuV (German Government). The stock version is 10.8:1CR, but the TuV has 9.5:1CR, same as my S&S V107T. So around 9.5:1CR and a 'gentle' cam might do it!
Then there is the drive-train to beef up, frame to cut about....
Ultimate HDF Member
Joined: Feb 2007
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From: Northeast Ohio
I had one of those big "lazy" engines if lazy is really the right word to use. The HQ 120 was 125 hp, 145tq. That is right in your thoughts of 1hp/cu in. It was at 10.5:1 and was extremely streetable and relible getting 42-44mpg regularly. It was running a moderate cam, the HQ 575.
Your thoughts on "detuning" is actually practical only if all components are designed for the detuning. For example, just putting a lower lift, less duration cam will most likely push the CCP higher and could create tuning issues. If you could get one of these engines built with matching components to be the lazy motor you desire, it is workable. There is also the possibility of using the tuning itself to pull a bit of timng but again, then you are getting to a point that the inherent efficiencies of an engine design are not being used as designed and even removing a bit of timing can cause driveability issues if going too far.
I still believe you should define what it is you want and then either have that built bsed on the stock engine or if using an aftermarket built complete engine, get one that is built as close as possible to your wants.
Your thoughts on "detuning" is actually practical only if all components are designed for the detuning. For example, just putting a lower lift, less duration cam will most likely push the CCP higher and could create tuning issues. If you could get one of these engines built with matching components to be the lazy motor you desire, it is workable. There is also the possibility of using the tuning itself to pull a bit of timng but again, then you are getting to a point that the inherent efficiencies of an engine design are not being used as designed and even removing a bit of timing can cause driveability issues if going too far.
I still believe you should define what it is you want and then either have that built bsed on the stock engine or if using an aftermarket built complete engine, get one that is built as close as possible to your wants.
Outstanding HDF Member
Joined: Oct 2007
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From: Edmond, Ok
I guess your definition of big, lazy motor is relative. I remember seeing a dyno printout of a 117" that GMR built that may fit your description. I don't remember all of the components, but I believe it was their Stage III heads, Andrews 54 cam, stock t/b, Axtell cylinder/piston kit, and was set at 10:1. It made something like 112/133.
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From: Bedford UK
Many thanks for your thoughts. This thing needs to be bigger than can be achieved with a stock motor, so will have to be based on a new one and there are not many candidates to work with. Just as there are lots of engine builders out there who adapt stock engines it seems to me the cheapest route may be to adapt an existing after-market engine. The only alternative I can think of is to buy a more expensive billet-engine.
This is a scatter-brained idea, I realise that, but it is worth sharing. I think it would be great to have a truly big motor, just for the sake of it. I have a giant purring pussycat in mind, rather than a starving sabre-tooth tiger! My use of the word 'lazy' was just my way of describing an engine that is not tuned for maximum performance - more a giant V107T, than a drag-motor.
Thinking through ideas out loud like this is a way of shaping and eventually defining something feasible that might just take wings eventually!
This is a scatter-brained idea, I realise that, but it is worth sharing. I think it would be great to have a truly big motor, just for the sake of it. I have a giant purring pussycat in mind, rather than a starving sabre-tooth tiger! My use of the word 'lazy' was just my way of describing an engine that is not tuned for maximum performance - more a giant V107T, than a drag-motor.
Thinking through ideas out loud like this is a way of shaping and eventually defining something feasible that might just take wings eventually!
Sponsor
Joined: Dec 2007
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I guess your definition of big, lazy motor is relative. I remember seeing a dyno printout of a 117" that GMR built that may fit your description. I don't remember all of the components, but I believe it was their Stage III heads, Andrews 54 cam, stock t/b, Axtell cylinder/piston kit, and was set at 10:1. It made something like 112/133.
Did over 1/2 dozen 117" with a Wood 6, when the 96" first came out in 2007. Touring/trailer towing builds.
Our latest version of a 117" with a Wood 6, @ 10.2 cr, was tuned by Bruce, at HP Express.
118.5/134.8 in a Dyna.
Anther big/lazy combo is a 124"/Wood 408 cam combo.
Only have one of those in service.
Brutal torque off idle thoughout the rpm band, with 10.5 cr.
Scott
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From: Bedford UK
Did over 1/2 dozen 117" with a Wood 6, when the 96" first came out in 2007. Touring/trailer towing builds.
Our latest version of a 117" with a Wood 6, @ 10.2 cr, was tuned by Bruce, at HP Express.
118.5/134.8 in a Dyna.
Anther big/lazy combo is a 124"/Wood 408 cam combo.
Only have one of those in service.
Brutal torque off idle thoughout the rpm band, with 10.5 cr.
Scott
Our latest version of a 117" with a Wood 6, @ 10.2 cr, was tuned by Bruce, at HP Express.
118.5/134.8 in a Dyna.
Anther big/lazy combo is a 124"/Wood 408 cam combo.
Only have one of those in service.
Brutal torque off idle thoughout the rpm band, with 10.5 cr.
Scott
Is there a Wood cam that might provide a wide smooth torque band in a 145"? Or is that a dream too far! A bit less of the 'brutal' would be fine....
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From: Bedford UK
I'm going off the idea of adapting a racing engine and beginning to see the benefit of a billet engine, which will be closer to a runner straight out of the box. A project in the early days still....
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From: Bedford UK
No I'm not, having seen this video! This is a German take on how to use an S&S 145" motor, the first time I've seen and heard one moving. As Lynyrd Skynyrd say - turn it up (sound volume!). 
http://www.choppertownnation.com/vid...ibute-racebike
http://www.choppertownnation.com/vid...ibute-racebike
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