T2 vs t2x what are the differences in the powerhead

**mrcrsr** · 12-03-2017, 01:39 PM

I know this is a well beaten question but does anyone know? Its surprising that no one seems to know.

**FMP** · 12-03-2017, 03:52 PM

An "X". But the differences were detailed in another thread. Firing order chest pairing for one I believe.

**Tom Smyth** · 12-03-2017, 04:57 PM

most of the people involved with the development of this engine are long gone. I tried several different avenues a few years back to try and find specifics on the differences and no one at Mercury said they retained any of that info. Mike Butler was still working there and was a tremendous help trying to find things like a serial number list of each motor type. did get specifics on what years they were built and how many, as well as the mercury issued parts lists for each but any other info is left to conjecture at this point. The T2 was designed for use on boats with 15 inch transoms and the BIG difference initially to the T2X was the shorter 12 inch mid designed for more competitive tunnel boats that were emerging. The stated factory jet size is only .003 different between the two, but those are nice, safe jet sizes. I am sure racers changed them to run the motors much leaner and thus quicker( and shorter life as well) Later T2X motors saw many changes, not quoted by Merc including single ring pistons used in the 700X motor and others. The only difference from the factory built motors I have ever been able to identify is that there was" a bit more grinding in the exhaust area" as quoted by a "expert". Others say the twin tube carbs were a change from the T2 to T2X, but no one knows who played with what between then and what's left for us today. That still seems to be the most common factor people use to define a T2 from a T2X power head. In short, no one really knows FOR SURE, but its fun to speculate and guess...
My opinion based on a few years of research. others have their opinions as well. I am not an expert by any means....but am learning....

**Mark75H** · 12-03-2017, 04:59 PM

This

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Like I said before, if you had porting for this, you'd already know.

**mrcrsr** · 12-03-2017, 06:12 PM

Definitely Sam, but my understanding was it was an evolution over time as well. I always feel that time is short, alot of the people from back in the day are no longer around, it would be nice to get as much information out there as possible so in the future people will have an understanding and some knowledge of this stuff.

**Mark75H** · 12-03-2017, 06:23 PM

Evolution on factory team T2 motors, but the step between the T2 customer motors and the T2X powerhead.

I think the story is told somewhere in the middle of the Merc singles thread. Dick Lanpheer's name is on the patents, but when I spoke to him, he generally only took credit for the exhaust design.