Joined Sep 2013
369 Posts | 209+
canolbarth cymru
Hi canolman, i can find the piston (102mm) from Bergos racing in Germany. I sent him a mail, he ships worldwide. The liner is made by Westwood in England. The oem gasket is ok with the 102mm bore. I think that noone makes the 105mm piston anymore.
Joined Jun 2007
4K Posts | 1K+
south east WA Australia
I'll upload the liner details when internet is speeded back up -- 3 days
FWIW westwood have the liner dimensions already
the actual bore size on mine was 104.8mm
the number on the top of my piston was 7943 M10483 5263D
to design your piston for whatever bore diam you just need to spec liner clearence, comp ratio, squish and valve pockets
piston to liner clearence was 0.14mm (bit too big I would go for 1 thou per inch bore diam)
the 104.66mm piston weighed 328gm (no rings or pin)
Ring end gap was 0.6mm ( bit too big)
Squish with a 1.4mm head gasket measured 1.8mm and comp ratio 11.32 :1
deck height was 14.1mm
piston volume -12cc
piston crown was 4.4mm thick
if you go for a 14.5mm deck height (24.5mm from pin centre to piston top) and the 80mm crank your squish will be roughly whatever the head gasket thickness is. i reckon you want 1.2mm max and about 11.8:1 CR
head volume was 38cc with 36/31 kibblewhites (KTM RFS 525) and some unshrouding. so some calculations to do but they are simple .. don't forget the head gasket volume at a diameter of the bore plus approx 2mm.
pics of my headgskets here
http://husaberg.org/mechanical/11677-jbs-700-kit-welded-80mm-crank-15.html
gaskets and headstuds info from spanner
I'll put up some more specific info later on .. im very very busy right now
FWIW westwood have the liner dimensions already
the actual bore size on mine was 104.8mm
the number on the top of my piston was 7943 M10483 5263D
to design your piston for whatever bore diam you just need to spec liner clearence, comp ratio, squish and valve pockets
piston to liner clearence was 0.14mm (bit too big I would go for 1 thou per inch bore diam)
the 104.66mm piston weighed 328gm (no rings or pin)
Ring end gap was 0.6mm ( bit too big)
Squish with a 1.4mm head gasket measured 1.8mm and comp ratio 11.32 :1
deck height was 14.1mm
piston volume -12cc
piston crown was 4.4mm thick
if you go for a 14.5mm deck height (24.5mm from pin centre to piston top) and the 80mm crank your squish will be roughly whatever the head gasket thickness is. i reckon you want 1.2mm max and about 11.8:1 CR
head volume was 38cc with 36/31 kibblewhites (KTM RFS 525) and some unshrouding. so some calculations to do but they are simple .. don't forget the head gasket volume at a diameter of the bore plus approx 2mm.
pics of my headgskets here
http://husaberg.org/mechanical/11677-jbs-700-kit-welded-80mm-crank-15.html
gaskets and headstuds info from spanner
Copper head gaskets have arrived Look very nice
These are made to suite my 103.65 bore.
Will be using a wire o-ring in a groove machined in the top of the liner.
Will use Hylomar spray for sealing the water area, fingers crossed. :wink:
http://stores.ebay.com/copper-gaskets-u ... 34.c0.m322
On the left, ARP head studs part # ARP-AM4125-LB $10 ea
1.5 mm pitch on the end that screws into the cases and 1.25mm pitch on nut end
ARP 12pt nuts part # 301-8332 M10x1.25 sold as a pair so order two packs. US$7.78 x 2
These ARP studs are made from 8740 Chrome Moly heat treated to 190,000psi tensile strength.
The plated bolt is the original 10.9 grade. Heat treated tensile strength of 1040MPA or 150,000psi
Stud washers and nut on right is JBS`s. Do not know material or it strength but the shank of this stud measures
10mm whereas the ARP and the original head bolt measure 9mm not sure that would necessary
make it any stronger as the thread minor diameter is going to be the weakest point.
The ARP threads are formed by rolling after heat treatment, where as the JBS`s are cut... :roll:
I am going to use the JBS washers as they are a good 4mm thick :wink:
and they are necessary to stop the ARP nuts bottoming on the threads of the ARP
studs.
I had already increased the diameter of the spot face where the washers seat, for
use with the JBS studs washers and nuts,
this may or may not be necessary depending on the washer diameter. The ARP nuts are .5mm
larger in diameter than the std Husaberg head bolt.
So NOTE Thick washers of suitable diameter will be needed!
Cheers spanner
I'll put up some more specific info later on .. im very very busy right now
Last edited:
Joined Aug 2009
1K Posts | 346+
Charters Towers, Australia
Joined Sep 2013
369 Posts | 209+
canolbarth cymru
Bushie,
I phoned Westwood awhile back and asked if they had ever supplied a liner for a Husaberg, 105mm piston, the bloke I talked to said they hadn't and had no info on file but didn't take the time to look!
Do you think the JBS piston was a stock size or made to order?:unsure:
Just wondering if JBS have the spec and would part with it seeing as they no longer supply the 'kit'?
I phoned Westwood awhile back and asked if they had ever supplied a liner for a Husaberg, 105mm piston, the bloke I talked to said they hadn't and had no info on file but didn't take the time to look!
Do you think the JBS piston was a stock size or made to order?:unsure:
Just wondering if JBS have the spec and would part with it seeing as they no longer supply the 'kit'?
Last edited:
I have max 0.3mm endgap with a cylinder/compression ring that has been used for 230 hours in my stock 570 al it says in the manual is this:
MAXIMUM:
compression ring 1mm
Oil scrap ring 1.2 mm what would minimum be I think aroun 0.15 or something no idea but it has to be able to expand a littlebit I guess
MAXIMUM:
compression ring 1mm
Oil scrap ring 1.2 mm what would minimum be I think aroun 0.15 or something no idea but it has to be able to expand a littlebit I guess
Joined May 2010
592 Posts | 246+
San Francisco, California
Bushie,
I phoned Westwood awhile back and asked if they had ever supplied a liner for a Husaberg, 105mm piston, the bloke I talked to said they hadn't and had no info on file but didn't take the time to look!
Do you think the JBS piston was a stock size or made to order?:unsure:
You could also try LA Sleeve. Los Angeles Sleeve Co., Inc.
Joined Jun 2007
4K Posts | 1K+
south east WA Australia
the liner companies probably don't want to make anything unless the customer supplies the specs to avoid fitment liability
ring end gap was large because the rings were being used at the max bore size for the rings, yes all the rings had 0.6mm endgap.
the only piston details we are missing are the valve pockets .. just copy the 650 elko dimensions or ask for maximum pocket depth.
canolman the piston numbers are similar to wiseco and CP you could ask them if the numbers mean anything .. personally i am going to order a custom JE piston to my specs
good info goose and there are also datron sleeves (spanner found) and the company I found who impregnates the iron with carbide
my internet is too slow to search ATM but ill be more use on the 14th
ring end gap was large because the rings were being used at the max bore size for the rings, yes all the rings had 0.6mm endgap.
the only piston details we are missing are the valve pockets .. just copy the 650 elko dimensions or ask for maximum pocket depth.
canolman the piston numbers are similar to wiseco and CP you could ask them if the numbers mean anything .. personally i am going to order a custom JE piston to my specs
good info goose and there are also datron sleeves (spanner found) and the company I found who impregnates the iron with carbide
my internet is too slow to search ATM but ill be more use on the 14th
Joined May 2010
592 Posts | 246+
San Francisco, California
I'm watching this thread very carefully. I just ordered the head studs and bolts. Any reason why nobody has tried the multi layered metal gasket? With a ring or perhaps a raised ring around the sleeve along with the copper insert into the sleeve, wouldnt that work? Ok, I'll bite. When I can afford it, I'll order a few and see what happens. Bushie can't be the only one trying crazy ****! (Yes, Dr C, you crazy too, didn't mean to omit you or all the other crazies here trying out stuff and taking risks).
Joined Sep 2013
369 Posts | 209+
canolbarth cymru
Spoke with Performance Unlimited, CP importer and the part number is a custom spec. They are going to look up the piston spec as long as the original supplier is no longer offering them for sale.
Sent an email to CP USA and asked if they have spec on record and can they supply.
Sent an email to CP USA and asked if they have spec on record and can they supply.
Joined Nov 2012
2K Posts | 821+
Iceland
I'm using MLS head gasket right now, because I'm CRAZY!!!
Custom made by czech company Merako.
(P.s., how much did you pay?)
Joined Oct 2003
955 Posts | 1K+
Sweden
Hm... Some 20-25€ a piece, if I remember correctly. I CADed it in 2D and sent them a pdf drawing. One sample came to try it out, then I ordered. Luckily I have a czech friend, who did the translation for me!
Joined Jun 2007
4K Posts | 1K+
south east WA Australia
Joined Jun 2007
4K Posts | 1K+
south east WA Australia
Joined May 2010
592 Posts | 246+
San Francisco, California
Joined Jun 2007
4K Posts | 1K+
south east WA Australia
you'l need solidworks or other program capable of reading an stp file
which program do you have? maybe it needs an IGS file
which program do you have? maybe it needs an IGS file
Joined Jun 2007
4K Posts | 1K+
south east WA Australia
Spoke with Performance Unlimited, CP importer and the part number is a custom spec. They are going to look up the piston spec as long as the original supplier is no longer offering them for sale.
Sent an email to CP USA and asked if they have spec on record and can they supply.
if possible ask for 2mm deeper valve pockets at +2mm bigger diameter to allow use of bigger than stock cams and oversize valves
FWIW i think a deck height of 14.4 to 14.5 and piston volume giving us just under 12:1 CR would be an improvement, lots of calculations to make there
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