The bore and stroke on a new 96ci TC is 3.75" x 4.375". What is the connecting rod length?

 

TC96 ='s 7.667" connecting rod length with a 4.375" stroke
TC88 ='s 7.667" connecting rod with a 4" stroke

I just confirmed this myself the other day as I finally got a chance to break into a new TC96 eninge. All they did was move the pin out .375" to gain the extra stroke just like the SE stroker crank as expected. Gotta love that geometry............I would set the rev. limiter on these beasts to 5k whether its the SE crank or the OEM one.

 

actually they only moved the pin .1875 - half the increase in stroke.

 

yep, thats correct actually.

 

Well, that's a rod ratio of 1.75 for the 96ci. The 88's is 1.9. Why are you saying that this ratio is too much? I'm not trying to argue, I just want to here some answers other than the ones that pop out of my own head. I have all my engine building experience with mopar v-8 engines (ok, so i built a few shivvy's....but they were not mine! LOL).
A typical stock 340 has a rod ratio of 1.84, which is considered very good. A typical old school small block shivvy runs a 1.63 ratio, not as good but still very acceptable.

Can you see why i might be a little puzzled her? Is it because of the number of cylinders? Fill me in, will ya?

 

Its actually about 1.92 for the 4" and 1.75 for the stroker setup. 1.75 would be very good actually for a larger potentially oversquare automotive street engine. But for an undersquare motorcycle vtwin the closer you can to the 2:1 ratio the better IMO. There is alot of things you have to take into consideration besides just the RS ratio on its own...........things like cylinder and piston wear, pin wear, sideloading etc, all become amplified on an undersquare engine the lower the RS ratio becomes.

 

So, if I go ahead and get the crank all tricked out and do the bearing upgrade, I should go ahead and bore the cases while I'm at it and make it even bigger! Then it will be a monster all the way around and, hopefully, run smoother and longer! Right?

 

113 and 117 works really well. i woudlnt use that crank tho----notorious for twist, rod breakage, pin letting go.you will have $1400 in it, so just use that money to do it right-- buy a jims or s$s and then have it worked.

 

OK, who would you guys recommend I go with? It would be nice to able to send my stuff off all at once and have it done. Obviously, if i'm going this far, it's gonna be full out....heads, trick pistons, cams...etc.

 

If you want the ultimate twin cam beast using the stock case, go 4.375" SE crankshaft(modded), and a 4.375" bore for a square design. 131" of pure joy if you can afford to do it up the right way. Only a few places I would recommend for casework, this is one of the few places: http://www.emcv2.com