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  1. #1
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    Default On Paper Pan Build

    Some of you may have guessed I've been exploring the possibilities for a 4 1/4 inch stroked 61 Pan, 61 to 74 inches. Before somebody says I'm doing it all wrong and I need to go with a bigger bore watch this first, then maybe we can talk about it.

    https://www.youtube.com/watch?v=UV3R...eringExplained

    I've also ran a few simulations with this configuration and pretty much know exactly what it needs to make more than decent torque & HP at lower rpm.

    After adding up the main components kicking around in my head I was pleasantly surprised, so just want to share this little bit of trivia in case anyone else is also interested in building something similar.

    Boring the stock El jugs less than 0.040 over to run 86-87 Sportster 1100 flattops and using the stock length rods gives me a zero deck height with a 0.020 base gasket. In other words, this thing is just begging to be built. (notwithstanding any flawed addition on my part)
    Last edited by oneuptom; 11-02-2021 at 3:30 PM.

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    Don't believe everything you see on youtube...... Half of it is BS........... The other half is questionable...........

    But it's a good thing to get your mind turning for sure........

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    If ya gotta do all that welding on those heads to bathtub them. weld up the intake and bore a straighter hole. just saying......

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    Quote Originally Posted by flatman View Post
    If ya gotta do all that welding on those heads to bathtub them. weld up the intake and bore a straighter hole. just saying......
    I tried some bathtub heads from Doug on a 114 inch shovel top, pan style lower drag bike in the 90's, never could get it to run as good as normal heads with a mild port job, even after having Doug send me a camshaft of his design, finally put them on the shelf and moved on. Doug is a very smart and nice guy and went out of his way to try and help.

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    Not sure what your end goal is, but strokers to me, for a street Pan, is not the way to go. Just me, but I have never seen, in person, on the road, a reliable stroker in a shovel or pan. Yep, they are out there, but the ones I have ridden with didnt work out

    I beleive you might be better off with big bore with a steetable cam: Regardless of which way to go, remember, the cam is the heart of an engine build. Carb and stroke should be considered in thought with what cam you will run. That includes your heads if you are going radical on the cam side

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    Quote Originally Posted by docmel View Post
    Not sure what your end goal is, but strokers to me, for a street Pan, is not the way to go.
    Yep me too I agree.........

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    Quote Originally Posted by pan620 View Post
    I tried some bathtub heads from Doug on a 114 inch shovel top, pan style lower drag bike in the 90's, never could get it to run as good as normal heads with a mild port job, even after having Doug send me a camshaft of his design, finally put them on the shelf and moved on. Doug is a very smart and nice guy and went out of his way to try and help.
    Was that at least a few decades ago?..

    Doug is retired now but I'm sure he learned a lot from doing it wrong way back then.

    I think people are getting hung up on the word "bathtub", maybe going by what it meant in the very beginning like when Doug tried it on your Shovel. Makes me wonder why he didn't know better then given those valve angles & chamber shape anyway.

    Bathtub is generic now, sort of like skill-saw is for that type of saw. I first mentioned "a little squish" and someone asked, "do you mean like a bathtub?".. Not wanting to go down that rabbit hole, I said yes. I'm talking about something much more refined here, something more like the late 85cc Chrysler hemi chamber on the left (no shrouding). It has very little squish because it doesn't need much with the velocity it has past the valves for turbulence. I have modeled this paper motor's heads exactly like that!.. And I'm using very small valves in the model also. They are so small it would take some serious bathtubbing to shroud them in any event (I know better). The valves are actually two valves from a M8 4Valve head. They will seat 0.200 closer to the pistons before I do anything else. Do you have any idea what that in itself will do for how this motor performs?

    Everything is worked out on paper and I'm not asking for unqualified advice, just sharing!!.. Doesn't mean I'm reluctant to talk details with someone else who also has a clue. I mean, what's the point otherwise if someone doesn't even understand the fundamentals???

    A ratty old knuck kicked my (new at the time) 6spd 88 Dyna's ass good out on I-40 in March 0f 06. It was making a bit more power than stock but nowhere near enough for that knuck. Even knocking it down into 5th at 100 and twisting the grip off was futile against it. I would wager a guess it was probably a small port stroker.

    I know what this old iron is cable of first hand if it's not just pile resembling a motorcycle

    edit: I missed you saying the 90s. sorry...

    Click image for larger version. 

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    Last edited by oneuptom; 11-03-2021 at 12:18 PM.

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    Quote Originally Posted by Tattooo View Post
    Don't believe everything you see on youtube...... Half of it is BS........... The other half is questionable...........

    But it's a good thing to get your mind turning for sure........
    How would any of us know anything at all now if it wasn't for youtube... right, some of us don't!! Best thing we could do for America is shut down all those babysitting services we call (schools) and get everyone school age a pc and youtube subscription... Seriously, that dude isn't known for blowing any smoke from his ass. Fact check him if you want, report back

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    Quote Originally Posted by oneuptom View Post
    How would any of us know anything at all now if it wasn't for youtube... right, some of us don't!!
    I agree...... I will admit youtube can be great, but like I said don't believe it all..... I use it quite a bit myself on many things but you need to watch as much that there is out there on one subject that your looking for then figure out yourself what seems to be right and what is wrong.... Don't let anyone make up your mind for you.......

    LOL Hell when I was growing up there wasn't anything like youtube...... Just a bunch of hard ass men to ask questions to that wouldn't answer BS questions they would just run you off, or you could learn it on your own the hard way the way I did....
    I guess that's why I'm like I am today????? I guess????

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    Quote Originally Posted by docmel View Post
    Just me, but I have never seen, in person, on the road, a reliable stroker in a shovel or pan. Yep, they are out there, but the ones I have ridden with didnt work out
    They may have had some subpar builders and parts then. A well built stroker not only runs great, but will be just as reliable as stockers, until you get to a certain point on the stroke. You can't turn your back on them and not properly maintain, but that goes for all motors... There is a price to pay for that.

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    Quote Originally Posted by oneuptom View Post
    Before somebody says I'm doing it all wrong and I need to go with a bigger bore watch this first, then maybe we can talk about it.

    https://www.youtube.com/watch?v=UV3R...eringExplained
    Is that you?

    I've also ran a few simulations with this configuration and ..
    What are you using to perform the simulation?

    Is there a particular software package or what exactly?


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    Quote Originally Posted by rockman96 View Post
    They may have had some subpar builders and parts then. A well built stroker not only runs great, but will be just as reliable as stockers, until you get to a certain point on the stroke. You can't turn your back on them and not properly maintain, but that goes for all motors... There is a price to pay for that.
    Fore sure!.. and since 2007 4 1/4 inch stroke is the shortest available from the factory IIRC. How quickly a thread can go off the rails here. I was talking about smaller bores, not stroke!!

    edit: bore/stroke relationship to be exact...

    Reasons I'm using the EL cylinders instead of the bigger, longer 1200 cylinders

    1. I already have 2 nice sets and a 3rd NOS rear

    2. Because they're shorter I can build a zero deck motor with them very inexpensively using H-D Sportster pistons

    3. For all the reasons mentioned in video, + they have thicker walls and won't distort as much as 1200 jugs will ( you can only attempt to keep any of them round)

    4. It's cool to distance yourself from the herd
    Last edited by oneuptom; 11-04-2021 at 10:39 AM.

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    Quote Originally Posted by confab View Post
    Is that you?



    What are you using to perform the simulation?

    Is there a particular software package or what exactly?

    Ha, no!.. just a fan of his channel

    I've never found a need for anything more than pipemax. It's easy to manipulate for very accurate results if you understand a few fundamentals... I first started using it to build headers that work

    http://www.maxracesoftwares.com/foru...php?f=14&t=263

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    Quote Originally Posted by oneuptom View Post
    Ha, no!.. just a fan of his channel

    It is interesting. I subbed it.


    Thank You.

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    Alan Sputhe knew how to make his "polyspherical bathtub chamber design" work, no probs, and it looks like the valves have been splayed even more than on a stock shovelhead

    Nothing more brutal or more beautiful was ever bolted together IMHO

    http://www.counterman.net/v-articles...teamroller.pdf
    Last edited by oneuptom; 11-07-2021 at 9:07 PM.

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    Quote Originally Posted by confab View Post
    It is interesting. I subbed it.




    Thank You.
    You might be interested in an interview with the man who developed the software.

    It's suggesting that if I do everything right I can expect?.. as I have it configured now, pretty damn good for this size motor!. I think I can do a little better with the torque if I apply everything I know about reducing reversion

    AS configured now
    80 HP @5300 RPM
    87.1 FT LBS @3900 RPM

    And It's actually the first cam I entered (based on what I knew this motor wanted) I also tried another cam on two different lobe centers but came back to this one. I'm confident I don't need to look at any other cams!

    https://hotrodenginetech.com/pipemax...-head-porting/
    Last edited by oneuptom; 11-07-2021 at 9:07 PM.

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    Quote Originally Posted by oneuptom View Post
    Alan Sputhe knew how to make his "polyspherical bathtub chamber design" work, no probs, and it looks like the valves have been splayed even more than on a stock shovelhead

    Nothing more brutal or more beautiful was ever bolted together IMHO

    http://www.counterman.net/v-articles...teamroller.pdf
    http://www.counterman.net/v-articles...teamroller.pdf

    It's hard to find data this complete for an individual runner H-D so it was interesting running it through PipeMax

    Based on how easy it was said to launch and on the cam specs I tend to think the PipeMax numbers are a bit more correct. In any event, a hot little beast for sure with only 9:1 compression!

    Article numbers
    108 BHP @7000 RPM
    100 LBS FT @3800 RPM

    PipeMax numbers
    108.7 BHP @7000 RPM
    89.2 LBS FT @3800 RPM


    Edit: Same Andrews DX cam but with LCA widened from 101 to 112 & compression bumped to 12:1. Will still run fine on 91 pump gas

    122 BHP @7000 RPM
    100 LBS FT @ 3800 RPM
    Last edited by oneuptom; 11-08-2021 at 9:27 PM.

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