Thumper Club Forum
Club House => Chatter => Topic started by: guest207 on May 01, 2007, 10:07:30 PM
-
Here ya go Rog, before we get that freewind thread totally derailed.
-
Bugger - replied in the Freewind thread before I saw this one - yadda yadda about the headers, trying to decide on an 860 or 640 cam.
R
-
Have a couple more jobs to do on the frame and then I need to drop the engine out and pull that to bits - see what I can do to her. Do not know if they are any good (being as it is Mez Porting they will be brilliant) but I would like a Mez Porting 3 plug 2 carb head - would look really trick and be a bugger to fit... But I guess there are not many about and Mez is no more.
R
-
not sure if the info below is any use to you, I stole it from CCM site.
OUTLET INLET
NUMBER OPENS CLOSES STROKE OPENS CLOSES STROKE
660 36.5 BBDC 2.5 ATDC 7.9 3.5 BTDC 48.5 ABDC 7.9
665 36.5 BBDC 8.5 ATDC 7.87 4 BTDC 56 ABDC 7.8
670 60.5 BBDC 20.5 ATDC 8.9 13.5 BTDC 67.5 ABDC 8.9
675 74.5 BBDC 30.5 ATDC 9.58 45.5 BTDC 71.5 ABDC 9.65
700 36 BBDC 4 ATDC 6.51 5 BTDC 55 ABDC 5.5
800 55 BBDC 14 ATDC 9.64 12 BTDC 57 ABDC 9.3
805 54 BBDC 14 ATDC 9.64 12 BTDC 56 ABDC 9.64
860 72 BBDC 40 ATDC 10.55 44 BTDC 68 ABDC 10.55
865 65 BBDC 24 ATDC 9.67 20 BTDC 69 ABDC 9.67
PS I think the 675 is the standard road cam fitted to "most" 604 CCM'S
-
Sorry meant 675 not 640.. ooops
Possibly is, not sure - I know my lump has a 660 cam in it - being as I stole it from a Jawa 500. Has the 500 barrel but a 2mm shorter stroke and a 34mm Amal - is about as gutless as you can make a Rotax without leaving the head off. SImple jobs are trying to up the compression and sort a cam / exaust etc. Picked up a 40mm Amal for it and a couple of cams. First thought I would like an 860 then found my old artical about MF racer - on which he won many things - and that was running a 38mm Amal and a 660 cam. OK he was a bit good as a rider - but it really took off when he was riding it (illegally) on the IoM and wondered if the 860 would be too much. I got it from a guy who had put it in his CCM and decided he did not like it. So we will see. First off I have to finish the frame and get the tank welded shut (has interesting carborad base at the moment as I get it to clear the carb.
I have a load of old Andover Norton bumf on the Rotax - not sure if much has changed - similar cam specs to those you have - but not as many - so I guess not much has..
R
-
Be good to see yours sorted, I keep toying with taking my 636 motor out and sticking it in a Aprillia RS125 chassis. I sort of miss my pure road single a bit. My old SRX620 from a few yrs ago is actually in gallery 1 on here so I am not a total stranger to this place. I have heard the 860 cam is not good for a road bike, makes them a bit too rev hungry and as I like the good spread of power its got now thats about it unless I can find that cheap VM44.
This place does some interesting stuff mixing 600 bore with 350 cranks to get shortstroke 500's.
http://www.barebones.net/machines.htm
And if you want real Rotax porn look here
www.porterbrothers.co.uk
I still have that Forsythe artical too... loved it.
Mick
PS I thought you said 675 anyway.
PPS you DID say 675.
-
Porter Brothers - just real porn that...
Funny the injection stuff - a couple of guys on the RD500 site have been encouraging me to go FI - cost is a big stopper here - both are fans of Microsquirt/ Megasquirt injection - having mounted it on many cars and now a clutch of Yam strokers. Have to work within a government funded budget (Incapacity benefit) and feeding a family so most is slow and steady. Was looking at a RS125 or RS250 chassis when this TZR one came up. Advantage of the 125 chassis is the RHS drive - hence the RS125 rear wheel for mine - which is being machined as we speak...
Mind I have too many projects on the go and not enough haranging to get them done.. LOL
R
-
I know what you mean about too many projects and not enough funds..my clutch is naffed on the CCM now, slips like mad when it gets warm and its not a 5 min job like your good old SRX etc but thankfully I have already bought the bits. Turbo is in limbo as I dont want to take it off the road till after next weekend as I need to use it....and the Duc is begging me to buy a pair of 41mm FCR's and a new pair of belts.
Meanwhile the family need food the Mrs wants HER project done...the house!
-
Here you go Mik - home for a happy Rotax
R
ebay 300108612049
-
Here you go Mik - home for a happy Rotax
R
ebay 300108612049
Arrgghhh why did you do that!... its now on my watch list and my head is going YES NO YES NO!
Was a good job this one wasnt in UK too 160110420003
-
Mmmm nice - shame Aprilia dont do it them selves - either a 125 or a 250 chassis - same size I think just different construction for the 250 making it stiffer etc
R
-
Well Cagiva almost done it but lost the plot didnt they..putting a V twin Hyosongythingy engine in for cheapness is just so wrong.
-
The story of Cagiva - almost done it but not quite.
R
Off to turn some nice steel into swarf and scrap
-
Off to turn some nice steel into swarf and scrap
Steel? nothing exotic then like a nice bit of ti...or in Fluffers case conduit
-
Just making an arbor or is it a mandrel? - Cutting back inlet port to the right size and match up with the casting etc - rather than the rough steps etc. Worked OK - amazing what can be done with a old centre drill and an offhand grinder...
So CG now has a 25.7mm inlet - should be 26 but... smiles all round. Mind less smily having found that the liner is only 3.bugger all mm at the bottom so boring it out any bigger may need a new liner and the pot will not fit my lathe.
All this fuss about a CG - but I am learning for the Rotax
R
-
Arbor or mandrel in effect the same deal as far as im concerned.. I am now having to make do with 2 conventional lathes and windy handle bridgeport turret mill and bits of paper after being spoilt with CNC and CAD/CAM for years..but brings back the old skills...was just a pain in the harris finishing my top yolk tho.
-
A mill - Mmmmm have to do my best with an upturned router and a pillar drill - Rog the Bodge...
Strangely and spookily having read the note about GS's and low comp pistons etc, I pulled out a box of tut to see if I could throw anthing away / sell it on ebay and there was the Suzuki Owners Manual for my long departed GS750D
R
-
Steel? nothing exotic then like a nice bit of ti...or in Fluffers case conduit
Im going to remind you of that comment next time I ask you where i can get a billet of alloy to make some yokes from, and to last time which you replied "ebay"..
-
Im going to remind you of that comment next time I ask you where i can get a billet of alloy to make some yokes from, and to last time which you replied "ebay"..
Ahh but I found a nice chunk of 6082 in amongst my bits and bobs, I will measure it for you and see if its anygood for what you want, what size do you need? as I am presently at work so I cant measure it till tomorrow morning earliest.