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Re: TY175 - DT175 port timing and head differences
Posted: Tue Nov 02, 2021 9:44 pm
by David Lahey
hot101rod wrote:You say the DT175 has a longer pipe over the TY175, does the shorter head pipe create more toque than a longer head pipe? You can now buy both "standard stainless" and a "longer" pipe? I'm confused? Normal state of mind.
Rod
Lots of theories on what is the ideal length header on a trials bike. I guess that's why they make two lengths, so people can buy what they want
Re: TY175 - DT175 port timing and head differences
Posted: Thu Nov 04, 2021 9:37 am
by Betaman
Do you still have those pics David? Ozvmx doesn't show them anymore and won't let you join to see them
David Lahey wrote:Roger subanator
I've posted some photos on the OZVMX forum of the TY175 with the late model DT motor in case you are interested. Someone on that forum was interested in making their TY175 better for road use.
http://ozvmx.com/community/index.php?to ... n#msg60597Regards
David
Re: TY175 - DT175 port timing and head differences
Posted: Fri Nov 05, 2021 6:55 pm
by David Lahey
Betaman wrote:Do you still have those pics David? Ozvmx doesn't show them anymore and won't let you join to see them
David Lahey wrote:Roger subanator
I've posted some photos on the OZVMX forum of the TY175 with the late model DT motor in case you are interested. Someone on that forum was interested in making their TY175 better for road use.
http://ozvmx.com/community/index.php?to ... n#msg60597Regards
David
I'm sure I've got the photos somewhere but finding them won't be easy. I'll have a go later tonight. It helps to know the forum posting was 2009. That narrows it down to pre 2009 photo
Re: TY175 - DT175 port timing and head differences
Posted: Fri Nov 05, 2021 8:56 pm
by David Lahey
David Lahey wrote:Betaman wrote:Do you still have those pics David? Ozvmx doesn't show them anymore and won't let you join to see them
David Lahey wrote:Roger subanator
I've posted some photos on the OZVMX forum of the TY175 with the late model DT motor in case you are interested. Someone on that forum was interested in making their TY175 better for road use.
http://ozvmx.com/community/index.php?to ... n#msg60597Regards
David
I'm sure I've got the photos somewhere but finding them won't be easy. I'll have a go later tonight. It helps to know the forum posting was 2009. That narrows it down to pre 2009 photo
Here you go Betaman
Re: TY175 - DT175 port timing and head differences
Posted: Sat Nov 06, 2021 6:38 pm
by Betaman
Thanks David. Looks like a straight bolt in fit?
Re: TY175 - DT175 port timing and head differences
Posted: Sat Nov 06, 2021 6:46 pm
by David Lahey
Betaman wrote:Thanks David. Looks like a straight bolt in fit?
Almost. There's a section of DT engine casing that requires a little dent put in the left frame tube under the motor for clearance. The person who fitted the motor did it before I got the bike.
Then again maybe that frame was not perfect and the tube under the engine was a little bit higher than standard and a completely straight frame wouldn't need it? I haven't had that motor in a different TY frame yet.
Re: TY175 - DT175 port timing and head differences
Posted: Sun Nov 07, 2021 8:02 pm
by David Lahey
The finning is bigger on that series of DT175 motor making the exhaust is a closer fit and the cylinder fins are closer to the front downtubes.
I'm not sure you picked up from my posting way back about this motor but it has a TY175 crankshaft. This is similar to the DT175 crankshaft but the flywheel taper is bigger. The bigger TY175 flywheel means that the DT175 flywheel cover needs some internal trimming to provide clearance.
The other interesting thing on that motor is that it has an IT175D/E/F YZ125D/E/F clutch cover which are much more plentiful than the very rare YZ125C/X clutch cover that fits the TY175 right side engine inner casing.
I think the DT175 E/F/G motor is quite suitable for fitting in a TY175 but would need extra flywheel mass added to the DT175 flywheel for trials