short rod or long rod?

[plummer1111]

i am in the process of putting together an r for my wife. she does mostly trail riding. i want to make it pretty much bullet proof so i dont have to worry about breaking, should i go short or long rod, looking for your opinions. thanks in advance.

[punker69q]

the long rod put less stress to the cylinder wall (the rod angle at 90 and 270 degrees from tdc is smaller) so they should last a little longer. they also have a little more torque, which is good for trail riding.

[zedicus00]

me personally im a shortrodder, i agree with him though, for what u want go long rod. you could even do a spacer plate 86 style piston setup to help even more for trail riding performance.

[wilkin250r]

For maximum reliablility, go with the long rod. The powerband is a little easier, and less stress on the piston and cylinder walls. They are also cheaper.

Also, if max reliability is your goal, go with a genuine Honda crank. The Hot-Rod cranks just don't seem to last as long.

[Buttermilk]

Can someone explain to me the advantages of using a spacer plate and an 86 style piston combined with the long rod vs. using the long rod and the appropriate 87-89 piston?

I'd really be interested in what the pro's and con's of running certain setups vs. other setups. Reason being is my son has an R that is setup in a rather interesting way, which I'll explain later after I see what comes off this posting.

Regards.:)

[wilkin250r]

There are two main advantages.

First, by spacing the cylinder up, you create more crankcase volume. This, in turn, gives you MORE fuel/air, at slightly lower pressure. It doesn't rush into the cylinder quite as fast, giving a slightly smoother powerband, and a little broader power range.

Second, the 86 style pistons are available in more sizes for more overbores.

[wicked265R]

thats the setup im currently using and love it. with a decked and milled head and some port and polishing its even better. but i dont think your wife would want that much power. i cant believe the variety of bore sizes you can get for these things. i guess its the advantage of the '86 :p

[dober250R]

I run an 86 style piston with the short rod and have the head milled down, and the cylinder is an 86 with full porting. Really snappy power!! She revs very quick!!!

[Buttermilk]

Thanks for the response.

I was just curious regarding the advantages of each setup.

We (my son) currently run an 87 model that has a +4 mill long rod crank. It is setup with a spacer plate and appropriate gaskets combined with an 86 wiseco piston to give zero deck height. Combined with a 19cc dome/CoolHead, a Sparks TT pipe, and a 38 PWK A/S carb, this motor really runs well. The cylinder is ported as well (my own porting set to my own port specs for what we want out of the motor - the quad is used for TT racing).

I've considered setting it up with no spacer and using the 87-89 piston and a cut dome to handle the stroke but it runs extremely well as it is.

Regards.