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There are various reasons for fitting the 550 exhaust to a 650 head, not least important is when doing the 550 to 650 conversion to gain some extra cubic inches. And you do not want to buy another expensive exhaust system.
THE PROBLEM:
It will be found that the exhaust ports in the 650 head are a fair bit larger than the 550 ports. You will read comments on fitting the 550 exhaust to the 650 head where people say "the 550 exhaust will fit, but it moves about a bit in the ports and you need to try and line it up before tightening the exhaust clamps". Not as easy as it sounds to line up four exhaust header pipes and tighten all the clamps up when using only two hands.
Also if using the standard 650 exhaust gaskets then when things are tightened up the 550 header pipe (on a 4/1 anyway) will push its way through the inside diameter of the gasket and the steel header pipe is then bearing directly on the aluminium face inside the port entrance. Possibly damaging this surface if the clamps are tightened with too much force. And there is no way of knowing as you cannot look inside to see what is happening at this point in exhaust assembly.
And you cannot use the 550 gaskets because they slop around inside the 650 port and it would be impossible to line the header pipe up with a gasket that is laying on the bottom of the port. And we all know what the standard exhaust gasket looks like don't we. It's a square section of heat resistant material which does not compress much if any when the exhaust is tightened.
Port Sizes: The 550 port size is around 36mm and the 650 port size is 42mm. That's 6mm difference which is a lot of movement X 4.
THE SOLUTION:
The solution (my solution) is to use different exhaust gaskets that have a larger diameter to fit the 42mm 650 port (OD) and smaller ID to accommodate the smaller diameter of the 550 header pipe.
Part II of the solution is to have four metal sleeves made up to fit inside the 650 port and which the 550 header pipe will then sit inside to prevent excessive movement. These sleeves in my case were made from some steam pipe that I found laying around at my workplace. It was not the absolute correct size for my application, so I had a friend turn them to the correct size on his lathe. He owed me a favour as I helped him sell his 1924 Alvis.
On the 4/1 header there is usually a ring welded to the pipe about an inch and a half from the end of the pipe that goes into the port. This is the ring that the exhaust clamp pulls against to hold the header pipe in the port securely.
Shown above are the exhaust gaskets that need to be used. They are from the following Suzuki models and there size is 42mm OD x 28.5mm ID.
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Another picture of the exhaust gasket to use.
Sleeves as made up to fit over smaller 550 pipes and inside the 42mm 650 port. The sleeve size is 40mm OD, 37mm ID, and 18mm long.
Metal sleeve being placed over 550 exhaust header pipe.
Sleeve partially fitted on 550 exhaust pipe.
Sleeve fitted on 550 pipe, pushed fully on. Note: Sleeve is flush with end of pipe so both of them seal on the new exhaust gasket preventing leakage which is not possible if the 550 pipes are just pushed into the 650 head with no modifications.
All four sleeves fitted and lined up ready to go into cylinder head. When final fitting is done exhaust cement/putty will be placed between the sleeve and the 550 pipe to achieve complete sealing. Then exhaust will be installed on head and everything tightened up.
Showing sleeve fitment to 650 port if this method of fitting is desired. The gasket has not been fitted at this point as this is a trial fitting only. Don't forget to install gasket. Note: All new exhaust threads. Every thread on this head has stainless steel Recoils fitted.
Gasket and sleeve fitted. It will be noticed that the sleeve is a loose fit in the 650 port. Port size is 42mm and OD of sleeve is 40mm. This is because this type of 4/1 often do not line up perfectly and this small amount of play allows enough movement to get each header pipe in the four ports and adds to ease of fitting. Fitting is more difficult when head is on motorcycle and not on bench.
Final picture of sleeve fitted to 550 pipe.
I hope this thread will be of use to someone. Another mini-project out of the way for me. Not as big as some I have had to do on this restoration.
THE PROBLEM:
It will be found that the exhaust ports in the 650 head are a fair bit larger than the 550 ports. You will read comments on fitting the 550 exhaust to the 650 head where people say "the 550 exhaust will fit, but it moves about a bit in the ports and you need to try and line it up before tightening the exhaust clamps". Not as easy as it sounds to line up four exhaust header pipes and tighten all the clamps up when using only two hands.
Also if using the standard 650 exhaust gaskets then when things are tightened up the 550 header pipe (on a 4/1 anyway) will push its way through the inside diameter of the gasket and the steel header pipe is then bearing directly on the aluminium face inside the port entrance. Possibly damaging this surface if the clamps are tightened with too much force. And there is no way of knowing as you cannot look inside to see what is happening at this point in exhaust assembly.
And you cannot use the 550 gaskets because they slop around inside the 650 port and it would be impossible to line the header pipe up with a gasket that is laying on the bottom of the port. And we all know what the standard exhaust gasket looks like don't we. It's a square section of heat resistant material which does not compress much if any when the exhaust is tightened.
Port Sizes: The 550 port size is around 36mm and the 650 port size is 42mm. That's 6mm difference which is a lot of movement X 4.
THE SOLUTION:
The solution (my solution) is to use different exhaust gaskets that have a larger diameter to fit the 42mm 650 port (OD) and smaller ID to accommodate the smaller diameter of the 550 header pipe.
Part II of the solution is to have four metal sleeves made up to fit inside the 650 port and which the 550 header pipe will then sit inside to prevent excessive movement. These sleeves in my case were made from some steam pipe that I found laying around at my workplace. It was not the absolute correct size for my application, so I had a friend turn them to the correct size on his lathe. He owed me a favour as I helped him sell his 1924 Alvis.
On the 4/1 header there is usually a ring welded to the pipe about an inch and a half from the end of the pipe that goes into the port. This is the ring that the exhaust clamp pulls against to hold the header pipe in the port securely.
Shown above are the exhaust gaskets that need to be used. They are from the following Suzuki models and there size is 42mm OD x 28.5mm ID.
GSX R 750WP/WR 93-94
GSX R 750 WS 95
RF 600 RP/RR 93-94
RF 600 RS/RT 95-96
RF 900 RR/RS 94-95
RF 900 RZS/RT 95-96
GSX R 750 WS 95
RF 600 RP/RR 93-94
RF 600 RS/RT 95-96
RF 900 RR/RS 94-95
RF 900 RZS/RT 95-96
VESRAH PART NO. VE - 3024
OEM PART NO. 14181-17E00
OEM PART NO. 14181-17E00
[
Another picture of the exhaust gasket to use.
Sleeves as made up to fit over smaller 550 pipes and inside the 42mm 650 port. The sleeve size is 40mm OD, 37mm ID, and 18mm long.
Metal sleeve being placed over 550 exhaust header pipe.
Sleeve partially fitted on 550 exhaust pipe.
Sleeve fitted on 550 pipe, pushed fully on. Note: Sleeve is flush with end of pipe so both of them seal on the new exhaust gasket preventing leakage which is not possible if the 550 pipes are just pushed into the 650 head with no modifications.
All four sleeves fitted and lined up ready to go into cylinder head. When final fitting is done exhaust cement/putty will be placed between the sleeve and the 550 pipe to achieve complete sealing. Then exhaust will be installed on head and everything tightened up.
Showing sleeve fitment to 650 port if this method of fitting is desired. The gasket has not been fitted at this point as this is a trial fitting only. Don't forget to install gasket. Note: All new exhaust threads. Every thread on this head has stainless steel Recoils fitted.
Gasket and sleeve fitted. It will be noticed that the sleeve is a loose fit in the 650 port. Port size is 42mm and OD of sleeve is 40mm. This is because this type of 4/1 often do not line up perfectly and this small amount of play allows enough movement to get each header pipe in the four ports and adds to ease of fitting. Fitting is more difficult when head is on motorcycle and not on bench.
Final picture of sleeve fitted to 550 pipe.
I hope this thread will be of use to someone. Another mini-project out of the way for me. Not as big as some I have had to do on this restoration.
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