RGS vs. SR head

[bikerboy]

For those that are interested in twin carbs here are pics of how I fitted mine. I was lucky enough to pick up a battered 67-1549 head and I machined the manifold off (it was badly damaged anyway) I drilled and tapped the head and used manifolds off a T120 or T140 I cant remember which. I did have to use allen bolts for the two inner bolts because I would never get a spanner in at them but it works fine.

The 930 concentrics fit fine clearing the frame etc and beyond a shadow of a doubt the difference in acceleration etc is extremely noticable compared with my single carb version which is otherwise exactly the same spec. I am still working on getting the mixture perfect as thats a matter of trial and error with jet sizes but it runs fine and ticks over lovely

Before I get to many critics I know its not standard I build my bikes to suit me not the concourse :) so please forgive the amount of T140 parts that are bolted all over it :). I did try to level things out if you look at one of my other bikes behind it which is a T140 engine wedged into an A10 frame :)

[Gasket4450]

Thanks Trev/Muskie.   
                                 I looked at the Ebay link to 67-1112, but the flanges don't look far enough apart for my cylinder head. I have already wasted money on two 67-35 inlet manifolds which don't fit ( I had to buy the two as they were being sold as a pair ! ), and found the bolt holes are not far enough apart, and they appear longer than the one illustrated. Could just be a bad photo though, so I will e-mail the seller and ask for distances between centres on the bolt holes. My head studs measure
( approx.) 4.16" between the lower pair, and 1.95" across the shorter pair. However, I'm sure you're both right.
Norman

[muskrat]

I'll try to dig mine out tonight and measure.
Cheers

[Gasket4450]

Thanks mate.      You obviously spotted my deliberate error, then, measuring the centres with the head upside down?.....Doh !
Hence the confusing references to " upper " and  "shorter " !!!!  ( Just threw that in to see if you were on your toes, really, ahem.....). Appreciate your efforts on my behalf, though, thanks. It would help, as one of our big bike jumbles is coming up this weekend at Kempton Park, and if I have some idea of what I'm looking for, it will save me wasting my hard earned cash.
                            It would look good with twin carbs, though, and I already have several monoblocs, so you never know.........!
All the best
Norman

[Gerry]

Hi guys, I have attached a couple of pics of the casting and stampings on my 67-1106 head. To me it reads under one of the inlet ports PR 4 with the 4 stamped 90 degrees rotated to the right or clockwise as you look at it???  Also one pic' of the original twin carb manifolds which come up now and again. Can't post the second view of the manifold...too many pics. Will post again with 2nd one. Cheers. Gerry

[Gerry]

Hi again, Its hard to read the part numbers of the twin carb manifolds but they read 67L1330 and 67R1331 assuming L stands for left etc. Cheers Gerry

[Gerry]

Another thought, I wonder if they had lost the 'R' stamp and by the look of the second letter (R) it appears as though the right leg of the R has been added on but on the pics here previously as well as mine the first letter surely is a 'P" ???

[Gasket4450]

Much obliged, Gerry. Those are the parts I am looking for, as shown in your last pic. That certainly looks like a BSA part number with, as you say, L and R for left and right. I can start scouring the autojumbles now then !
Cheers
Norman

[trevinoz]

Gerry,
                 Your head doesn't have a date cast into it which leads me to believe that is one of the later "speed kit" heads. Having the adapters with it tends to confirm this.

Trev.

[Gerry]

Hi Trev,
Unfortunately I didn't get the head with the adapters, that's just a pic' off feebay so I can recognize them again when I see them if at all. I also got a single carb' manifold which I just guessed at it being correct when I studied the pics again on feebay. Or at least thought I could get it to fit and lucky me it fitted straight on. The head came to me from the USA where a good friend had been searching for one for me and he put me onto a fella who owned a classic bike shop and had a brand new one still in the box but was reluctant to sell it being so rare (he wanted $1500US for it). He told me he had another one with a broken top corner of one fin which he would sell me for $600 so I couldn't resist and ended up $700 lighter with postage.
Hi Trev, Yes they are the "bees knees" genuine BSA originals. Muskrat put a post with these part numbers earlier.
Harley Davidson? Never heard of it but I have heard of Harley Furguson lol. Cheers Gerry

[muskrat]

G'day all.
Not sure if it's relevant now but I measured my single carb manifold (just a rule).
Cheers

[Gasket4450]

Hello Muskie,
                         Yes, I'm still interested in the description of inlet manifold. Pleased to say that your measurements almost exactly match mine, so that's obviously the one I'm looking for. I didn't go for the one on your Fleabay link, as on closer examination it was a bit ratty looking, but I am still looking. Yours look excellent - wanna flog 'em ???????
                          Anyway, thanks for all your efforts on this one.
Best Wishes
Norman       

[dynodave]

Hi Guys
Sorry I know I haven't posted in a while. I'd like to mention I still have 15 sets of dual manifolds. I'm sure these are the last batch that I will be doing. My price from the machine shop has gone up and I'm not so happy with the outline contour of the head side of each manifold. Useable, but not as cosmetically correct as I would like.
Email me off list for further info.
Thanks
Dave
61 GF
63 SR
63 RGS
dynodave at atlanticgreen dot com

[muskrat]

G'day Dave.
Thanks for letting us know.
I like browsing your site. just had a look at your services page. What!! No cycle thread  .
Cheers

[dynodave]

G'day Dave.
Thanks for letting us know.
I like browsing your site. just had a look at your services page. What!! No cycle thread  .
Cheers

Muskrat
I wasn't sure what you meant...cycle thread...no forum threads there!
So I went and took another look.
Sure I have cycle taps, only 26 series no 20 series and I do have cycle thread  Recoil inserts too.

I have been very busy with my new shop and apartment for the last 4 years,
http://atlanticgreen.com/images/shop957.jpg
and I just went under agreement to sell my house which I had been using as a warehouse for all BSA Ducati Lotus and Norton parts/projects.