new member introduction

[compressorman]

Hi to you all
my name is ian and i live in leeds,the bikes i currently own are bas a10 1958
a sunbeam s8 1951,and a harley dynaglide 1994 although the latter may have to go in order to make space for another a10 this one a 1952 model
 i previously owned a 1959 a10 reg wow280 if she is still out there i had to sell her due to a posting overseas with the RAF
 i own my own company(DAX AIR ) we specialise in the repair  maintenance and sales of compressor units and equipment
if any member requires any help with their compressor or is thinking of buying one then i shall only be too glad to help
my a10 is currently being rebuilt as i have only had her six weeks having pulled her out of a barn after being laid up for the last forty years  so i may well be asking for some info
 my sunbeam is nearly finished as i build my bikes to use rather than look at and dust
anyway basically thats me
i hope to meet up with as many members as poss
regards
ian 

[a10 gf]

Hello and welcome. Thanks for the intro post, and am hoping you will find the forum useful.

[muskrat]

G'day Ian welcome to the forum.
                                            Move the HD and you'll have room for two more BSA's 
Cheers

[compressorman]

ah  sounds like a good idea  just a shame its my missus favourite
but i am working on it
cheers
ian
whilst i have got your attention
if i could ask a question
i am totally rebuilding my motor etc and would like a bit more power, would 10-1 pistons be too much?any way enough of your time
thanks again

[bsa-bill]

Hi Ian and welcome
You don't say what model A10 you have, if it's an iron head or thin flange barrels then 10:1 piston are a definite no IMHO
I would even suggest they are not such a good idea for the Rockets and 9.5:1 is suffice really, however I'm sure someone who has tried them will give better advise
All the best - Bill

[trevinoz]

Hi Ian,
             I wouldn't use any higher than 8:1 or thereabouts with the fuel we have to put up with [in Australia, anyway].
These engines have a tendency to ping, just look at any alloy head combustion chamber, some look like a jackhammer has been at work in there.
If an iron head, do a little porting and use Rocket size valves. A 357 cam is the go for power but you may have to modify the cam tunnel if you go that way, just needs a little opening out to clear the lobes in the early cases.
Musky may put in his two bob's worth on compression ratios, he likes them high.

Trev.

[Pilgrim]

Hiya Ian,
Welcome to the forum, plenty of good advice and info. available
from the knowledgable guys on here. Good luck with the build.
Cheers.

[compressorman]

Hi guys
 thanks for the info,i suppose the fuel in oz is the same as the stuff of taxes her in GB i i think in my hearts of hearts that 10-1 would be too much but i needed to chew the fat with someone a bit more knowledgeable the cam work should be no problem though,sorry i didnt mention mines a 58 bog standard swingarm model with iron head that i have just found in a barn   last used in 62  (loads of rust n stuff)
but i hope to have her done in six weeks or so   loadsa coffee and late nights ahead
cheers guys
regards
ian

[trevinoz]

Ian,
            When you get to the timing of your engine, have a look at Orabanda's posts on the subject.
He has had a lot of dyno testing done and has the results posted.

  Trev.

[muskrat]

 Yep Trev's right. 8-8.5:1 for thin flange & iron head. Although the 357 is more top end (revs).
Cheers

[trevinoz]

I use 7.25:1 in my iron engines & About 8:1 in the alloy.

  Trev.

[Brian]

My 61' iron head A10 has 8.5-1 and a 357 cam.

Works well but I wouldnt go any higher with compression. I use 98 octane fuel, 5/16" advance (I think that works out about 32 degrees)

I also run it slightly rich in the mid range otherwise it will ping.

Performance is good, I've never rung its neck to find out what the absolute top speed is but it cruises easily in the 65-70mph range. I run standard gearing.

My plunger bikes are set up as Trev has suggested, 7.25-1 with a 356 cam. Overall that is a better set up for everyday riding, gives a smoother more tractable engine.

[compressorman]

thank you all for your help i shall try and follow your recomendations  i am running a mag with manual advance and hope that this will help in tuning out any pings
 i am still a bit away from running though as tonight i only got the small end bearings changed,crank main and conrods polished   i am still waiting for the delivery of my timing side bush and still have to sort out some pistons so that i can get my bores done to suit,tomorrow night i shall strip the head and get my stones out and do a bit of flowing
keep you informed
regards
ian

[Tomcat]

Welcome aboard Compressorman, this is a great forum for A twin owners.  i am totally rebuilding my motor etc and would like a bit more power, would 10-1 pistons be too much? IMHO leave the engine standard, change the oil sooner rather than later and enjoy the bike for what it is. Keep the Harley for your two up rides and when you want to go a bit faster, I have a Triumph Sprint for those reasons.  And we all want to see some pictures of your project too  Cheers Tomcat