Where do I find service notes for a Typhoon?

N0rt0nelectr@

VIP MEMBER
Joined
Sep 15, 2014
Messages
1,147
Country flag
A friend has been asking me questions about a 61 Typhoon. I know that they are a bored & stroked G80CS but concrete info is a little thin. I have looked at Christians archives and haven't seen anything specific. I was told that in the archives there are Service Bulletins, I haven't seen them, ideas?

John in Texas
 
A friend has been asking me questions about a 61 Typhoon. I know that they are a bored & stroked G80CS but concrete info is a little thin. I have looked at Christians archives and haven't seen anything specific. I was told that in the archives there are Service Bulletins, I haven't seen them, ideas?

John in Texas

Hello John,
Article from Wikipedia :
"Matchless made a 600cc version of the G80 called Typhoon from 1959 to 1962. The engine prefix code was TCS on these bikes. The bore was increased to 89mm while the stroke was increased from 85.5mm to a whopping 96mm. Based on the number of currently known TCS's on the Typhoon register kept by Rick Mann it is now estimated that 225 to 300 were made by the factory over a four year period and almost all of them were sold in the US. The rarest of these is the single down tube framed version, the 1959 G80TCS, and it's even rarer identical sister the 1959 AJS 18TCS. This one year only variant with a slightly smaller cylinder capacity, had a frame that when thrashed was less robust than the models that followed. Nevertheless, it is often favored over the duplex framed TCS models (1960 to 1962) because of its lighter weight and easier maneuverability. There was a road model with lights and a competition model without lights."
Some years ago I've modified a G80CS engine onto a Typhoon, with a rebored barrel to 90mm (to fit a G50 piston, a new crankshaft with a G50 conrod (to keep the hight of the original G80CS cylinder)
All the best - Jean-Paul from France
 
Hello John,
Article from Wikipedia :
"Matchless made a 600cc version of the G80 called Typhoon from 1959 to 1962. The engine prefix code was TCS on these bikes. The bore was increased to 89mm while the stroke was increased from 85.5mm to a whopping 96mm. Based on the number of currently known TCS's on the Typhoon register kept by Rick Mann it is now estimated that 225 to 300 were made by the factory over a four year period and almost all of them were sold in the US. The rarest of these is the single down tube framed version, the 1959 G80TCS, and it's even rarer identical sister the 1959 AJS 18TCS. This one year only variant with a slightly smaller cylinder capacity, had a frame that when thrashed was less robust than the models that followed. Nevertheless, it is often favored over the duplex framed TCS models (1960 to 1962) because of its lighter weight and easier maneuverability. There was a road model with lights and a competition model without lights."
Some years ago I've modified a G80CS engine onto a Typhoon, with a rebored barrel to 90mm (to fit a G50 piston, a new crankshaft with a G50 conrod (to keep the hight of the original G80CS cylinder)
All the best - Jean-Paul from France

Thank you and Knut for you help. Lyndon Taylor says that there are Service Bulletins for the Typhoon that I would love to get my hands on. One good thing is I know the second owner of this bike and he says it hadn't been apart while he owned it and in a recent email the current owner says he hasn't ever run it since acquiring it. So the odds are it is pretty much an un-molested bike, cool.
John in Texas
 
Some years ago I've modified a G80CS engine onto a Typhoon, with a rebored barrel to 90mm (to fit a G50 piston, a new crankshaft with a G50 conrod (to keep the hight of the original G80CS cylinder)

Hi Jean-Paul,

I knew of your former project but not the details. The G50 conrod is approx. 162mm long (6-3/8" according to my information) and thus shorter than the G80CS conrod (6-7/8"). By using the G50 piston, unless you extended the stroke, the barrel would be too tall. I think this is backed up by Ken de Groome. If using the G50 conrod with standard G80/85 flywheels the barrel has to be shortened 1/2" which equates to 1 fin. Personally I think the engine looks better when it's shortened. I'd like to see some wider finning though.

-Knut
 
Last edited:
Lyndon Taylor says that there are Service Bulletins for the Typhoon that I would love to get my hands on.

If any, then members of the AJSMOC-NA section will know. Your friend should inquire with them.
Bulletins emerging should be copied to Christian's archive, for the benefit of us all.

-Knut
 
Hi Jean-Paul,

I knew of your former project but not the details. The G50 conrod is approx. 162mm long (6-3/8" according to my information) and thus shorter than the G80CS conrod (6-7/8"). By using the G50 piston, unless you extended the stroke, the barrel would be too tall. I think this is backed up by Ken de Groome. If using the G50 conrod with standard G80/85 flywheels the barrel has to be shortened 1/2" which equates to 1 fin. Personally I think the engine looks better when it's shortened. I'd like to see some wider finning though.

-Knut

Hi Knut,

You are absolutely right. The reduction of the cylinder height of the G80CS and G85CS engines comes from the realization of the RICKMANN-Métisse motorcycles with Matchless engines - There was not enough space between the engine and the frame to be able to remove the cylinder head, without falling down the engine. To resolve the problem, on the advice of Andy LEE, Ken DeGroome and I have modified the engines by mounting a shorter G50 rod, to reduce the cylinder height by 12.7mm (1/2 ") and so to be able to easily dismount the head !! In addition, the crankshaft had less inertia and the engine was more smooth - I have often mounted G50 pistons to bring the engine to 540cc.
As for my Typhoon engine, I had simply adapted the height of the piston and its dome (piston manufactured especially in Switzerland) so as not to touch the G85CS cylinder height.

Jean-Paul
 
I got the information that I was looking for. It was already in the archives, I just didn't know where to look. Not much there and not Typhoon specific but any information is always good to have. I spoke to the bikes previous owner and he says it was running when he sold it. The current owner has put minimal mileage on the bike and it is stored in a warm dry place which is good. It is doubtful that the bike has ever been apart which I see as a good thing.
John in Texas
 
Back
Top