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71 t250r cylinder bore

Posted: Tue Oct 16, 2012 4:48 pm
by meningitis
hi folks.
hope to find some help here for my t250.
its running very low compression and need to do a rebuild. i decided i may as well go as large a bore as i can on this thing, instead of just a honing. does anyone know, or have experience with boring out the t250s? specifically, what is the max piston size/bore size i can get in there? i was hoping to get the t350 pistons in there, but they appear to be 61mmx54mm, and my t250 stock is 54mmx54mm. will these work? too large? alternatively, how about the t305, stock apparently 60mm? i feel like the t350 should be ok, as i know they have similar top ends to the 250, but want to verify before i purchase any items and get this thing going.
any info/assistance is very much appreciated....and thanks in advance!
-nathan

Re: 71 t250r cylinder bore

Posted: Fri Oct 19, 2012 9:07 pm
by alanr
By coincidence I have just had my T250 rebored to .5 oversize.The pistons for a 350 will not fit.(I also have one).the max that I know of is 1. oversize.I had to get new conrods which came from a Gt250m.I also needed new pistons etc.Because the rods are different to the T250 I had to get 14mm piston pins(instead of the 16mm that they have in them) to fit the GT pistons.The most important thing to measure is the centre of the piston pin hole to the top lip of the piston.