ST2 barrels

Rascall · 16-12-2016, 10:18 AM

I have a 2001 M900ie, I'm going to remove the heads over the next few weeks to sort out the shimming and check the valves and guides (the closers were all at about 0.15 to 0.2 when I checked a few months ago), I have been offered a set of st2 944 barrels and pistons and might fit these at the same time, the ST2 is water cooled but I'm pretty sure these can be used with minor modification. My main concern regards the ecu/fueling with the increased capacity.

I suppose my questions are

1. What modifications do I need to do to the st2 barrels to make them suitable
2. Will I need to remap the ECU for the increased capacity (I have the DP ECU airbox and Termis)

thanks

Russell

Kato · 16-12-2016, 11:07 AM

The ST2 barrels will of course bolt straight on and it is possible BUT

The main differences are that the feed union on the Left side of the cylinder
you would need to add core plugs to seal the cylinder, and drill out the oil feeds so that oil can flow through the water jacket

You would also need to somehow clean all debri from inside the water jacket left by the water and additives it will need to be mega clean if you don't want bits of corrosion/rust/scale/dirt going straight to your oil pump and round the rest of your engine.

The ST2 pistons will increase your compression from 9.2 to 10.2:1 and as you already know capacity goes up 44cc so yes an ECU remap will be needed

Kamna used to convert barrels not sure if they still do but IMO easier to rebore & plate what you already have

Rascall · 16-12-2016, 11:52 AM

The ST2 barrels that are available are brand new so they should be clean, however I dont really want the aggro of a remap so not sure if I will proceed with the swap.

Thanks for the info

Russell

Luddite · 16-12-2016, 11:06 PM

Hi Russell

In Practical Sportsbikes July 2015, Alan Seeley fitted ST2 barrels to his 900SS, increasing capacity from 904 to 944 cc. His article explains what modifications were needed to convert the water jacket back to oil and to block off the coolant passages. There are pictures showing which coolant galleries have been plugged and where the oil galleries have been opened up.

If you'd like to see the article, PM me your email address and I'll send you a photo of the relevant pages.

If you want to learn more about what's involved, you could try contacting Alan Seeley direct for details: alan.seeley@bauermedia.co.uk.

Hope that helps.

Luddite · 17-12-2016, 10:57 AM

Hi, Russell.

Email with articles sent...

Rascall · 17-12-2016, 10:59 PM

Got them thanks 👍

Luddite · 17-01-2020, 10:08 PM

I really like this guy's channel - typical down-to-earth Aussie!

For anyone considering an ST2 944 cc barrel conversion, this video takes you through all the mods involved.

https://m.youtube.com/watch?v=U6jGJCGPkpQ

Dukedesmo · 18-01-2020, 03:10 PM

I bought an ST2 engine from a breaker and did consider using the cylinders for my 944 build but in the end had the originals bored/plated, I would think the worst part of using the ST2 parts would be ensuring the water/oil jackets were clean inside?

I bought the ST2 engine for the cams as they're good for short intake/split carb setup and couldn't find just the cams (except at silly prices) so I bought an engine, took the cams and have since sold most of the engine on for about what I paid for it - so free cams, actually probably made a small 'profit' as I also sold the original Monster pistons and cams.

I've still got some of the ST2 parts lying around - pistons, heads and one cylinder, if anyone needs anything...

16-12-2016, 10:18 AM	#1
Rascall Registered User Join Date: Jan 2014 Location: chelmsford Bike: M900ie Posts: 128	ST2 barrels I have a 2001 M900ie, I'm going to remove the heads over the next few weeks to sort out the shimming and check the valves and guides (the closers were all at about 0.15 to 0.2 when I checked a few months ago), I have been offered a set of st2 944 barrels and pistons and might fit these at the same time, the ST2 is water cooled but I'm pretty sure these can be used with minor modification. My main concern regards the ecu/fueling with the increased capacity. I suppose my questions are 1. What modifications do I need to do to the st2 barrels to make them suitable 2. Will I need to remap the ECU for the increased capacity (I have the DP ECU airbox and Termis) thanks Russell Last edited by Rascall; 16-12-2016 at 10:19 AM.. Reason: spelling error

16-12-2016, 11:07 AM	#2
Kato Dismantled Join Date: Feb 2006 Location: East Molesey Bike: Multiple Monsters Posts: 2,222	The ST2 barrels will of course bolt straight on and it is possible BUT The main differences are that the feed union on the Left side of the cylinder you would need to add core plugs to seal the cylinder, and drill out the oil feeds so that oil can flow through the water jacket You would also need to somehow clean all debri from inside the water jacket left by the water and additives it will need to be mega clean if you don't want bits of corrosion/rust/scale/dirt going straight to your oil pump and round the rest of your engine. The ST2 pistons will increase your compression from 9.2 to 10.2:1 and as you already know capacity goes up 44cc so yes an ECU remap will be needed Kamna used to convert barrels not sure if they still do but IMO easier to rebore & plate what you already have __________________ "Political correctness is just intellectual colonialism and psychological fascism for the creation of thought crime" Last edited by Kato; 16-12-2016 at 11:18 AM..

17-01-2020, 10:08 PM	#7
Luddite Registered User Join Date: Aug 2011 Location: Southampton Bike: M1100evo Posts: 2,465	A "How To" video I really like this guy's channel - typical down-to-earth Aussie! For anyone considering an ST2 944 cc barrel conversion, this video takes you through all the mods involved. https://m.youtube.com/watch?v=U6jGJCGPkpQ

18-01-2020, 03:10 PM	#8
Dukedesmo Registered User Join Date: Sep 2010 Location: Leics Bike: M900 Posts: 2,838	I bought an ST2 engine from a breaker and did consider using the cylinders for my 944 build but in the end had the originals bored/plated, I would think the worst part of using the ST2 parts would be ensuring the water/oil jackets were clean inside? I bought the ST2 engine for the cams as they're good for short intake/split carb setup and couldn't find just the cams (except at silly prices) so I bought an engine, took the cams and have since sold most of the engine on for about what I paid for it - so free cams, actually probably made a small 'profit' as I also sold the original Monster pistons and cams. I've still got some of the ST2 parts lying around - pistons, heads and one cylinder, if anyone needs anything... __________________ M900, 916, LeMans II.

16-12-2016, 11:52 AM	#3
Rascall Registered User Join Date: Jan 2014 Location: chelmsford Bike: M900ie Posts: 128	The ST2 barrels that are available are brand new so they should be clean, however I dont really want the aggro of a remap so not sure if I will proceed with the swap. Thanks for the info Russell

16-12-2016, 11:06 PM	#4
Luddite Registered User Join Date: Aug 2011 Location: Southampton Bike: M1100evo Posts: 2,465	Hi Russell In Practical Sportsbikes July 2015, Alan Seeley fitted ST2 barrels to his 900SS, increasing capacity from 904 to 944 cc. His article explains what modifications were needed to convert the water jacket back to oil and to block off the coolant passages. There are pictures showing which coolant galleries have been plugged and where the oil galleries have been opened up. If you'd like to see the article, PM me your email address and I'll send you a photo of the relevant pages. If you want to learn more about what's involved, you could try contacting Alan Seeley direct for details: alan.seeley@bauermedia.co.uk. Hope that helps.

17-12-2016, 10:57 AM	#5
Luddite Registered User Join Date: Aug 2011 Location: Southampton Bike: M1100evo Posts: 2,465	Hi, Russell. Email with articles sent...

17-12-2016, 10:59 PM	#6
Rascall Registered User Join Date: Jan 2014 Location: chelmsford Bike: M900ie Posts: 128	Got them thanks 👍