Page 1 of 2

Making a pm59 exhaust fit a lambretta auto

Posted: Sun Apr 17, 2011 8:03 pm
by WINTERMODEL150
Been in the workshop today making a pm59 fit a lambretta auto conversion ,got some pics for anyone who's interested.

Image
de-chromed pm59 and cut up using a 1mm disc cutter
Image

strenghtened downpipe as these are known to crack
Image
Image
new centre bracket made and spotted in place.

Image
end can rotated 180 degrees so tail can can face forward.

Image
all tacked into place ready for welding

Image
all welded up now looking good.

Image
outside ground clearance good and sounds lovely

Image

well that took longer than expected nothing ever goes straight forward,i kept all the diamentions the same tho and it goes like stink on roadtest :D

Re: Making a pm59 exhaust fit a lambretta auto

Posted: Sun Apr 17, 2011 8:37 pm
by rondon
looks chuffin spot on mate, did u do the frame for the con? . I'm about to make ( well my neighbou work at a place makes exhausts for Nissan n hopefully he'll get me some bent tubes) an exhaust for my vespa 4t auto but it'll be a bit more straight foreword than yours

Re: Making a pm59 exhaust fit a lambretta auto

Posted: Sun Apr 17, 2011 9:28 pm
by WINTERMODEL150
Its my friends bike and when he bought it the scoot it had a twin air cooled conversion in it by Dave Briggs,but i did most of the mods to the single air cooled engine mount set up :D

Re: Making a pm59 exhaust fit a lambretta auto

Posted: Sun Apr 24, 2011 7:04 pm
by bulldog65
i've seen you cut half the loop or stinger off, didn't effect it?

Re: Making a pm59 exhaust fit a lambretta auto

Posted: Mon Apr 25, 2011 8:21 pm
by WINTERMODEL150
I did make a few phone calls before i did this stinger mod and apparently this does'nt affect the performance of the pipe (so i'm told),off for some dyno runs this weekend so fingers crossed.

Dean

Re: Making a pm59 exhaust fit a lambretta auto

Posted: Tue Apr 26, 2011 11:46 am
by bulldog65
strange, because normally length does make a difference ;O)

Re: Making a pm59 exhaust fit a lambretta auto

Posted: Fri Apr 29, 2011 5:19 pm
by bulldog65
now, i just rang pm and they told us that to keep the performance the stinger needs to be kept!

Re: Making a pm59 exhaust fit a lambretta auto

Posted: Fri Apr 29, 2011 6:29 pm
by twin
bulldog65 wrote:strange, because normally length does make a difference ;O)
when i did mine, i did keep it the same length,and was 21.5 on the dyno, for an ac engine,

Re: Making a pm59 exhaust fit a lambretta auto

Posted: Fri Apr 29, 2011 8:48 pm
by rondon
mmmm interesting I always thought the cone dimensions etc was the formula for 2t & length of pipe was 4t :ugeek:

Re: Making a pm59 exhaust fit a lambretta auto

Posted: Sat Apr 30, 2011 6:28 am
by bulldog65
as an example take a look at a franspeed race and a road one for lambretta, stinger of the race is a good bit longer m8!