4-stroke & jackshaft in a stock 50's straight-bar Panther frame???

KnockKnock · Sep 11, 2013

I asked the same thing in my intro, but took good advice to post here.

I'm curious if anyone has put a jackshaft or shift-kit into a flat-bar Panther/Hornet with a 4-stroke HS. It looks like there's some clearance issues there already, so I'd like to know if anyone has tried the SBP kit or PMR and what worked. It's be nice to have some gears to go through and do away with the left drive-chain.

I am seriously fixing to pull the trigger on a frame here, but I've got to know if I can build what I want with it. Input is much appreciated.

TIA, Kk

KnockKnock · Sep 11, 2013

Norm at Venice says he hasn't tried it, but he seems to think it'll work, so I am now the proud owner of a 1954 Schwinn Panther! I will keep the boards posted on the progress of the build for those that may be interested. Kk

KnockKnock · Sep 11, 2013

Jim @ SBP says it's a maybe too, so I'm just going to have to try it out myself. Now if only that dude in the brown truck would show up...

buba · Sep 11, 2013

I hope it all works out for you as you invision

chainmaker · Sep 11, 2013

For looks the SBP kit looks waaaaaay better on a panther than a pro mod. How are you planning on mounting the engine? You are going to have to mount it low, there isn't much clearance with that bar. Not too sure how wide the motor is so you will need some wide cranks as well. What are your plans for forks, wheels, etc?

Edit...I found a thread with a panther with A HS but a Qmatic tranny not much info but there is a picture.

http://motorbicycling.com/showthread.php?t=30773

KnockKnock · Sep 12, 2013

The SBP kit already comes with a motor mount and a wide 3-piece crank. The SBP motor mount is the main component in question there ...will it sit low enough to clear the upper bar, but high enough to clear the sprocket(s).

As for the front, I plan on using an original styled re-pro springer and for wheels, likely some S-2's with a drum brake front & 5-7 speed internal rear hub (heard good things about Nexus, but I'm still wide open to options when it comes to number of speeds and/or brand). Whitewalls seem to get grime on them too quickly on a motorbike, but I sure do like the look.

KCvale's Big Red is such a beautiful bike, and was a major muse to what inspired me. I'll be turning up the volume a little bit with some ape-hangers, and chrome dress, and to keep it my own, I have some unique ideas in mind for the build.

I just recently (like this evening) got schooled in the motorbike laws of Texas, so I'm reconsidering engines. I like the OHV slant-cylinder Honda's, and it might even provide better clearance, but I'll have to see what I can see. Honda's 200cc would be cool, but I have no idea if it'll fit, and I'm all ears when it comes to suggestions there too. <--- Yes, Thank you, I'm a Super-Noob

scotto- · Sep 12, 2013

KnockKnock said:
The SBP kit already comes with a motor mount and a wide 3-piece crank. The SBP motor mount is the main component in question there ...will it sit low enough to clear the upper bar, but high enough to clear the sprocket(s).

As for the front, I plan on using an original styled re-pro springer and for wheels, likely some S-2's with a drum brake front & 5-7 speed internal rear hub (heard good things about Nexus, but I'm still wide open to options when it comes to number of speeds and/or brand). Whitewalls seem to get grime on them too quickly on a motorbike, but I sure do like the look.

KCvale's Big Red is such a beautiful bike, and was a major muse to what inspired me. I'll be turning up the volume a little bit with some ape-hangers, and chrome dress, and to keep it my own, I have some unique ideas in mind for the build.

I just recently (like this evening) got schooled in the motorbike laws of Texas, so I'm reconsidering engines. I like the OHV slant-cylinder Honda's, and it might even provide better clearance, but I'll have to see what I can see. Honda's 200cc would be cool, but I have no idea if it'll fit, and I'm all ears when it comes to suggestions there too. <--- Yes, Thank you, I'm a Super-Noob

I can tell you that a Honda GX200 will not fit in that frame without some serious modifications to the frame.....and even then. A Honda GXH50 barely fits in that frame without a shift kit.....hope that helps.

chainmaker · Sep 12, 2013

Like Scotto said the 200 won't fit without frame mods. I've tried to put half a dozen different size larger motors in Panthers and for clearance here are the largest I could fit HF79 , china 66, whizzer h ( that looks the best and period looking plus they are selling repops on eBay) Briggs 3hp will fits as well.

racie35 · Sep 12, 2013

Will a whizzer engine fit?

chainmaker · Sep 12, 2013

The old whizzers will fit, but you have to grind the lower mounts to get the motor to sit low enough to clear the bar. It took a while to get it to sit but it worked. I'm not sure of the newwhizzer engine sizes.

KnockKnock · Sep 12, 2013

chainmaker said:
Like Scotto said the 200 won't fit without frame mods. I've tried to put half a dozen different size larger motors in Panthers and for clearance here are the largest I could fit HF79 , china 66, whizzer h ( that looks the best and period looking plus they are selling repops on eBay) Briggs 3hp will fits as well.

A wealth of good info there, thanks Chainmaker. I got all happy when you said the HF engines will work (I've heard that a 79cc & [now defunct] 99cc are interchangeable), and then I realized that they sit backwards on the frame, and the clutch on the 66cc china won't clear the shift kit - bummer, but now I know what fits between the rails. Since the SBP jackshaft kit calls for the HS/Honda engines anyhow, I guess I'll just go that route first, and then tweak the engine options once everything is in place. I'd love to do a whizzer, but ideally, I'm trying to only have one drive chain (or belt) so that'll require some ingenuity if I decide to go that route. A B&S sounds nice (I think I read where you started to use a Kawasaki-type - vintage 70's-era[?]), and I'll do some more research on that to see what options I have there. Scotto, the pic you posted of that Panther is very helpful, thank you! Now I know where the engine sits in the frame, which is very close to where the kit would have it. It looks like I've got a shot at getting it to "barely fit" with the jackshaft kit, so I'm starting to feel a little more relieved that I haven't spent good money on a bad idea. Thanks for the replies everyone! Kk

KnockKnock · Sep 18, 2013

Now that I have the frame right in front of me, it is obvious that the 4-stroke I had in mind is not going to fit in the frame. Still, I'll move forward with a 2-stroke, and my build plan will pretty much stay the same. Thanks again to all those that replied, Kk

mapbike · Sep 18, 2013

excited to see this build as it moves along...

Map

atombikes · Sep 18, 2013

KnockKnock said:
A wealth of good info there, thanks Chainmaker. I got all happy when you said the HF engines will work (I've heard that a 79cc & [now defunct] 99cc are interchangeable), and then I realized that they sit backwards on the frame,

You can always stand up the HF 79cc vertically. Might fit that way since you can get it lower in the frame?

chainmaker · Sep 18, 2013

The hf 79 will definitely fit, I posted a picture of it in your other thread.

KnockKnock · Sep 18, 2013

chainmaker said:
The hf 79 will definitely fit, I posted a picture of it in your other thread.

http://i725.photobucket.com/albums/ww256/thechainshoppe/0530010721jpgpanther6.jpg

Agreed. No argument here. It just isn't the 4-stroke I had in mind is all. A Whizzer engine would be great except they're pricey, and mating a jackshaft would undoubtedly require more fab work than I'm qualified for, and the HF just doesn't look like the picture I had in my head.

But for the sake of discussion, we'll negate my first issue which is aesthetics - the simple fact that the HF doesn't look like what I wanted in my mind's eye, but moving right into: How do you put a jackshaft kit on an HF? The only thing I can see working out there is to buy SBP shift kit and then try to find a way to make it suit the new engine. I don't have a kit to look at, so it may be really easy, but being a noob, I had it in my head that I would "kit" something at first, and improve from there, hopefully selling lesser parts to help pay for upgrades along the way. If the HF engine makes the SBP shift kit work with a simple pulley swap or some-such, then I can easily justify using an HF, but as of now I just don't know how it would work out.

That in-frame tank your bike is wearing is why I bought a Panther, and the lack of a "perfect" 4-stroke is a little bit of a bummer for me, but I'll start digging up info on jackshafted HF's so's to see what I can see. Kk

KnockKnock · Sep 18, 2013

I found this thread in which the OP seems to think that the best way would be to use an AGK kit in conjunction with the SBP kit, but now we're talking about $300+ in jackshaft parts. To shave at least $135 from the hypothetical budget, I'm curious to know the answer to post #3:

homejones said:
Could I just hook-up the clutch to the jackshaft sprocket on the shift kit...?

I guess the shift kit mount is the biggest question/issue...

This seems to ask whether or not you can eliminate the AGK kit altogether, and simply run the chain from the clutch to the SBP kit.

Again, if anyone has any thoughts on this, please don't hesitate to reply. Kk

chainmaker · Sep 18, 2013

If you are looking for bolt on, with no fab work really your only option is the SBP kit. For the same money you could get a 79 cc remove the shrouds and mount it vertical...look at sportsman flyers bikes those are the 6.5 HF it would look similar but smaller. Weld on a jackshaft or have one welded for you. I know you talked about keeping the frame original but it really isn't collectable without the original parts and it's only original once. You would end up saving yourself a couple hundred bucks even if you had the welding done for you.

KnockKnock · Sep 19, 2013

After some internet digging, I think I'm ready to answer my own questions.

~~The idea of running a chain to a jackshaft directly from the clutch simply wouldn't work as the engine would be poised too far to one side,~~* however, it would appear that from MotoMagz' pic of an SBP shift kit:

...along with BeaverRat's pic of an AGK jackshafted Predator:

...that the combination (while expensive) actually poses a high possibility of successfully working together. So the OP in the previously linked thread had the right idea from the beginning, seeings how it might be as easy as welding two small tabs to bolt together the engine mount and SBP shift kit bracket.

I'm not sure if I'm brave enough to try this for myself as new as I am to the game, but it's definitely something worth thinking about. Kk

*EDIT: This Thread contradicts the theory that the engine maybe too far to one side when not using AGK's jackshaft (see page 3).

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