The BSA A7-A10 Forum

Bikes, Pictures, Stories & more => Wanted & For Sale => Topic started by: Gavin on 01.06. 2017 15:23

Title: Plunger frame Airbox - possible production
Post by: Gavin on 01.06. 2017 15:23
I'm getting a quote on having an airbox for my 51 Plunger 67-4594 (Air cleaner and battery carrier combined, plus the element cradle) professionally made using a complete one that I have as the template. Knowing how rare these critters are, if anyone else is interested in purchasing one, i'd be happy to hear from you. Serious expressions of interest with no obligation to purchase.

I figure 1 airbox will cost a pretty penny, but if I can get a second quote for an order of several, I'd hope the price will reduce and all benefit.
Yes risk for all of us. But finding then buying these things in any condition is filled with a far greater risk. I will post pix of the new airbox if the initial price does not prevent me going ahead.

Next negative, for those who know the sky has fallen in, I am in Western Australia, happily near the most remote capital city in the world. So postage won't be free !!!
Title: Re: Plunger frame Airbox
Post by: WozzA on 01.06. 2017 23:26
 *eek* I was lucky enough to pick one up without the filter last year, & yes their like GOLD..
I hope you get many orders to get the price down..  *wink2*
Title: Re: Plunger frame Airbox
Post by: orabanda on 02.06. 2017 00:56
I have been able to make the air cleaner element by modifying (chopping up) a K & N element and fitting in place of the original media. Think it was the rectangular K & N element to suit a trident air box. It is the same (or close enough to) height as the original. Use some silastic ("a little dab will do") to seal the new media into the old air box.
Title: Re: Plunger frame Airbox
Post by: Greybeard on 02.06. 2017 12:17
I have been able to make the air cleaner element by modifying (chopping up) a K & N element and fitting in place of the original media. Think it was the rectangular K & N element to suit a trident air box. It is the same (or close enough to) height as the original. Use some silastic ("a little dab will do") to seal the new media into the old air box.
Ditto here.
Title: Re: Plunger frame Airbox
Post by: muskrat on 03.06. 2017 11:07
But we're talking the whole unit here. I still have the original but I'd say quite a few don't. I would be interested in a spare at a realistic price. Please get a quote on say 10-20. It could be the start of a proper spares scheme, not dodgy eastern repros (until they get them done cheaper there)  *problem*
Cheers
Title: Re: Plunger frame Airbox
Post by: bikerboy on 11.06. 2017 02:18
There was one on ebay a while ago but the £320 price tag put me off I decided I will make one :)
Title: Re: Plunger frame Airbox
Post by: duTch on 11.06. 2017 02:43

 I have about a quarter of one that's been cut up for some reason.. I think they wouldn't be all that hard to make  *dunno*

 I have no use for one though (alloy head on Plungie) so count me out
Title: Re: Plunger frame Airbox
Post by: Gavin on 17.06. 2017 15:18
Sorry to those who may have been interested. My guy took a look at the airbox and decided it was out of his capability range. Gotta respect someone who declines a job rather than promises the world and produces a pigs ear.

So I will keep looking for one, and if I find 2 will keep you in mind Musky.
Title: Re: Plunger frame Airbox
Post by: muskrat on 17.06. 2017 21:54
Thanks for letting us know Gavin.
Cheers
Title: Re: Plunger frame Airbox
Post by: RoadRunner on 17.06. 2017 22:47
There was one on ebay a while ago but the £320 price tag put me off I decided I will make one :)

MB Transits per chance??
Title: Re: Plunger frame Airbox
Post by: Richard A on 25.06. 2017 13:27
Hi,

If you find either someone else to make, or come across a replacement then I'd be very interested as I've been looking for a fair while and getting no joy.
I have been in contact with the National Motorcycle Museum and they have offered that I can take measurements from their Maudes Trophy bike and may have someone who can make from that, but it will be a while before I can arrange either.

Richard
Title: Re: Plunger frame Airbox
Post by: WozzA on 25.06. 2017 23:29

 I have about a quarter of one that's been cut up for some reason..
DITTO...   *eek*   which bit you missing?   we might be able to make up a full one between us?  *work*
Title: Re: Plunger frame Airbox
Post by: Greybeard on 25.06. 2017 23:33
Just thinking aloud: The flat metal work would not be too difficult to fabricate. The filter box, with the rounded edges; could that be made in fibreglass if a suitable mould were created?
Title: Re: Plunger frame Airbox
Post by: duTch on 26.06. 2017 04:45

 
Quote
Quote from: duTch on June 11, 2017, 12:43:00


     I have about a quarter of one that's been cut up for some reason..

DITTO...   *eek*   which bit you missing?   we might be able to make up a full one between us?  *work*


 I'm not even sure where it is at the moment,  but what I have is basically just part of the attachment strap and a bit of sheet metal each side of it- stuff that should be easy to make.
 I don't need one anyway,  just curious. ..if  I needed one and had measurements I'd be silly enough to have a go- if I had time
Title: Re: Plunger frame Airbox
Post by: RoadRunner on 26.06. 2017 19:54
Hi,
If you find either someone else to make, or come across a replacement then I'd be very interested as I've been looking for a fair while and getting no joy.
I have been in contact with the National Motorcycle Museum and they have offered that I can take measurements from their Maudes Trophy bike and may have someone who can make from that, but it will be a while before I can arrange either.

Richard

Hi, there's an old guy who was brilliant at fabrication and welding - real time served engineer who I would consider more than capable of constructing one but pursuading him to do so may be trickier. He's called Ray J Pettet and is based in Nottingham. I last used his services a few years back to take my tank apart, remove big dents and re-weld it back together - did a fab job. But no idea if he's still in business or not. He may be worth a punt?  Let me know your where abouts (roughly) if interested and I'll give you the heads up and if you need measurements, I may be able to assist.
Cheers
RoadRunner.
Title: Re: Plunger frame Airbox
Post by: Richard A on 30.06. 2017 21:27
Hi,
Sorry for delay in response, but yes if its possible to provide measurements that would be fantastic as any help would be appreciated.
At present I have the wrong box in place which doesn't match and carb is unable to either attach the rubber shroud or Amal supplied alloy rim.

Many thanks for the help offered.

Richard
PS based in Norfolk
Title: Re: Plunger frame Airbox
Post by: Richard A on 13.07. 2017 15:35
Folks,

I've been very fortunate in that one member of this forum has very kindly spent a lot of time and effort in giving me lots of photos and measurements for both the box and filter. Hopefully this will be enough to enable my friendly neighbourhood engineer to create a new one for me.

I'll update you on progress when I get more info. Might be worth asking him to make 2-3 as sure they'll be well received!

Regards

Richard
Title: Re: Plunger frame Airbox
Post by: Rex on 13.07. 2017 21:52
If you're running an informal tally of possible customers, then please count me in too. Thanks!
Title: Re: Plunger frame Airbox
Post by: oldbikerbill on 15.10. 2017 21:54
Could you publish the photos and measurements here?
Title: Re: Plunger frame Airbox - possible production
Post by: a on 17.10. 2017 04:11
-We have a complete used one here https://mikesclassiccyclespares.com/product/67-4594/ (https://mikesclassiccyclespares.com/product/67-4594/)
Also have a spare used element https://mikesclassiccyclespares.com/product/67-4600/ (https://mikesclassiccyclespares.com/product/67-4600/)
and have the strap for the battery carrier that I am about to list now 29-4657
Title: Re: Plunger frame Airbox - possible production
Post by: Gavin on 17.10. 2017 05:15
Thanks Mike, Bought it.
Title: Re: Plunger frame Airbox - possible production
Post by: a on 17.10. 2017 05:25
Yeah I didn't think that would last too long ;)
Title: Re: Plunger frame Airbox - possible production
Post by: Richard A on 21.12. 2017 18:10
Hi,

Frustration indeed.
After one of you kind gents provided  me with detail drawings and photos of the airbox I was more than hopeful that someone would fabricate the airbag for me.
I have now tried several fabrication firms to be told they can only work to duplicate an existing one, or need 3D drawings. Neither of which I have.
I guess the search to various jumble sales will now have to continue in the New Year.

Richard
Title: Re: Plunger frame Airbox - possible production
Post by: Greybeard on 21.12. 2017 23:14
I'm very pleased that my bike still had those bits on it. I just needed to buy the shiny battery strap and bolt arrangement.


I can imagine someone using a good filter case to make a mould to then create new GRP filter cases. The other parts could be fabricated from flat stock.
Title: Re: Plunger frame Airbox - possible production
Post by: Gavin on 22.12. 2017 14:17
Hi Richard, I am about 8 weeks off retiring, and plan to tinker on a few bikes I have in the shed as 2018 unfolds. Since starting this post I have acquired 2 more airboxes, and before anyone starts salivating, they are both accounted for on next years projects.

However, I would be prepared to try and make another from fibreglass etc. I will mess about for a while, and if I convince myself it's strong enough to support a battery I will try one the Plungers I am rebuilding, and see how it goes.

Meanwhile all the best at the jumble sales. I'll also keep an eye out in Aus if one appears here.

Have a safe n significant Christmas mate. 
Title: Re: Plunger frame Airbox - possible production
Post by: Greybeard on 22.12. 2017 15:36
...I would be prepared to try and make another from fibreglass etc. I will mess about for a while, and if I convince myself it's strong enough to support a battery...
Good job! As there will have to be a metal bracket for the battery the fibreglass part may not have to carry much weight. As I see it, (from memory) the tricky bits will be setting a threaded boss in the corner for frame attachment and the inner part, where the rubber hose goes.

If these rare things can be manufactured I reckon they will be in demand.
Title: Re: Plunger frame Airbox - possible production
Post by: Sluggo on 22.12. 2017 22:14
I can get them made, But there is a catch,.  While Its admirable someone made drawings, and diagrams, in reality in manufacturing its often "open to interpretation" so only a Print in solidworks, or similar CAD files are worthwhile.   
But *IF* someone can locate a friendly associate who has access to a 3D scanner then along WITH drawings, pictures and diagrams then you can get something accurately replicated.

Not everyone still uses Solidworks, and tech has marched on, but its still a industry standard, If you have other software, let me know and likely I can work with it.

I DO have access to the manufacturing to make these,  If you guys want to move fwd, PM me.  (I have some  other bits in the works)
Title: Re: Plunger frame Airbox - possible production
Post by: Richard A on 02.01. 2018 20:46
Guys,

Thanks for the offers/suggestions, its much appreciated.
At present I've not yet been able to find anyone who can do me a 3D drawing, but will keep looking locally and as I understand then standardworks is the application.
Im still looking for the airbox, but I continue with no success. Hope to visit a few bike jumbles in the early part of the year so my fingers remain crossed.

Regards

Richard
Title: Re: Plunger frame Airbox - possible production
Post by: Richard A on 02.01. 2018 20:58
Sorry,

should have been  Solidworks, not Standardworks.

Richard
Title: Re: Plunger frame Airbox - possible production
Post by: vinver on 29.01. 2018 01:59
I have a spare rigid frame airbox- for early A7. Is it significantly different from the plunger airbox? And, do they use the same filter element, as I don't have one of those, was planning to make one as others suffested.
Title: Re: Plunger frame Airbox - possible production
Post by: a on 29.01. 2018 06:18
They at slightly different in shape, and use a different filter/filter plate.I have a genuine filter plate for one of those here with filter in it.
https://mikesclassiccyclespares.com/product/67-4545/

If you look at our site You'll see we previously had the other type (plunger)  as well (now sold), but if you look you'll see the differences in shape etc. https://mikesclassiccyclespares.com/product/67-4600/
Title: Re: Plunger frame Airbox - possible production
Post by: a on 29.01. 2018 06:43
I'm very pleased that my bike still had those bits on it. I just needed to buy the shiny battery strap and bolt arrangement.


I can imagine someone using a good filter case to make a mould to then create new GRP filter cases. The other parts could be fabricated from flat stock.
We have that strap, and bolt arrangement....
https://mikesclassiccyclespares.com/product/29-4657/
Title: Re: Plunger frame Airbox - possible production
Post by: chaterlea25 on 29.01. 2018 21:26
Hi All
(duplicate post  *conf*)

Recently I have bought some replica vintage BSA parts from a chap in Czech Republic who sells them on eBay
his eBay name is   joseph60.7771
I have to say his parts are 100% and very good value
It might be worth contacting him with a view to getting the replica's made ???

John
Title: Re: Plunger frame Airbox - possible production
Post by: a on 30.01. 2018 03:40
Just made some Air filter element plates if anyone is interested... Replaces item 67-4600 I'll be listing them on our website in the next few days.
https://www.facebook.com/mikesclassics/posts/1688826421140732
Title: Re: Plunger frame Airbox - possible production
Post by: Richard A on 11.02. 2018 12:51
Hi,

Just ordered the air filter plate from MikesClassicCycleSpares, so hopefully one part less to search for.
Nice if you made the filter box too!

I've also found someone local to me prepared to do the 3D drawings so will see how that one goes as feed into someone who can then fabricate the part..

Richard
Title: Re: Plunger frame Airbox - possible production
Post by: Simon59 on 11.02. 2018 16:18
Just dismantled the airbox on my '54 plunger and was pleasantly surprised to find everything there. If anyone wants me to take some measurements, more photo's or even borrow the part to measure/fabricate a replacement, please let me know. I'll be powder blasting it clean in a week or two and it looks good with no rust, etc. I won't be painting it for a while yet...

By the way I have found an 'engineering blacksmith' near to where I work (Warrington) who has done a great job recovering my front mudguard.  If anyone needs some similar welding/grinding/straightening work, I can recommend him, but I'm not sure of the etiquette of such things on the forum. He has a degree in metallurgy, a workshop to die for and charges £40 per hour. 
Title: Re: Plunger frame Airbox - possible production
Post by: Sluggo on 14.02. 2018 23:56
If its in good nick, then by all means post up in the appropriate section (Tech) as this is the for sale section,
But take some good photos from several angles and orientation of the parts, measure what you can (especially the mount brackets) and try to make a "Blueprint" of it to illustrate it.  If good enough one could make new ones from it.  (Parts are only as good as the print).  I have manuf sources but what they ask for now is 3d scans, as that is the final word in manuf these days.
But the reality is, you can only approximate a reverse engineered part if you dont have an example in your hand.  (Close enough is good enough)  There is 2 things to remember when dealing with 60-70 year old parts,, most were wildly inconsistent to begin with. (Show me 10 Norton Featherbed frames and Ill show you 10 different layouts on a jig).  #2 unless its new out of the box, its probable that it could be modified, tweaked or different slightly than the identical bike parked next to it, Not to mention parts bin engineering where stuff was changed mid stream in production.

As i said, this is a very low production endeavor, and very low demand but I will be producing some other hard to find parts in the next 12 months, and not  a big deal to add this to the "To-do" list. 
My other airbox project is some Q racing air boxs.  I have 2 examples and there is decent demand for them.  Currently working on some modern machinery airboxs/filtration and slow going with some of the testing.
Title: Re: Plunger frame Airbox - possible production
Post by: Greybeard on 15.02. 2018 11:07
I know that Plunger A10 and A7 air filter rubber connector hoses are different so are filter back plates also different?
Title: Re: Plunger frame Airbox - possible production
Post by: muskrat on 15.02. 2018 18:54
No GB. The A10 is longer in the stroke so the head sits 1/2" higher in the frame than the A7 hence the need for different rubbers (ribbed or plain  *shh*)
Cheers
Title: Re: Plunger frame Airbox - possible production
Post by: duTch on 15.02. 2018 21:48

 
Quote
I know that Plunger A10 and A7 air filter rubber connector hoses are different so are filter back plates also different?

 As ^^above^^, and all components have same part #'s for A7,A10 7 Star Twin
Title: Re: Plunger frame Airbox - possible production
Post by: a on 18.02. 2019 06:14
We may have another of these, complete with filter (all in used condition), possibly next week. Just seeing if anyone here needs it before it gets advertised...