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rebuilding the LOWER end on a Banshee

5290 Views 5 Replies 0 Participants Last post by  cleartoy
Yup, thats what im in progress of doing right now.

Ive decided on 3 options.

Do a stock rebuild with new bearings for crank and rods, with just .030" pistons
(currently .020" with porting). That would be least expensive and i have all the power i need.

Have Alba build my motor to 370 stroker for $1200.

Order the parts from Trinity to have a 420 stroker. $700 regular, or $1000 with long rods. Whats the deal with long rods on a stroker crank anyways? Do you have to put a spacer in between the case and the cylinders to keep the pistons from hitting the head?


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If its anything like a car, you use a shorter piston with the longer rod. In car engines, when you get to certain stroke lengths with certain blocks, the piston becomes so short that its said to rock in the bore, creating a much shorter life. Also with the shorter piston, the rings are packed closer together, and can create an oil consumption problem and quicker ring wear. For example on a 302, its said that with a stroke longer than 3.35" is when you start to run into this. Im not sure if or when it would apply to a banshee or even a two stroke. Might be worth mentioning to the people that sell the stroker kits.

Also, longer rods build more torque.

I'd be leary about using the 420 stroker kit. The 370 sounds a little safer

why are you rebuilding, anyways?

wanna sell that pro-design setup?


Oh, now i get it.

I went out to the desert on Monday, and the next day, i blew a head gasket on the right cylinder. The piston melted on the Exhaust side of the ports, and put a gouge in the cylinder. The rods have a little too much play for my tastes. The right side of the crank looks a lot darker than the other, likely due to being alot hotter.

So instead of doing just a quick top end, i am going to do the bottom end as well. Im unsure as to do a stock lower end or stroker. It has plenty of power,
i was just musing about a stroker. IT really depends what the difference between stock parts and stroker parts cost. Plus going to take the time and trouble of splitting the cases, id like to have something to show for it.

Unfortuneately, we live in different states. Im not interested in shipping the parts to you, truthfully. I would only sell it locally.


What do you think was the cause of the meltdown? Was it one of the mods, or did it simply just overheat because its hot out there in CA? I'd like to prevent this from happening to me if possible. Too bad you cant hook up a temp gage to watch it. I hate it when antifreeze boils over onto my pipes. Its happend a couple times now.

My buddy with the 400EX was already trying to give me crap about having melted mine down already and that was why it smoked. I shut him up when I told him I was mixing 24:1 and should be mixing 32:1.

I put a rebuilt crank in mine last year. Maybe you know a good local shop that will rebuild yours for you. Mine was wasted, I just did the exchange thing and went from there. Got it from a shop in Guthrie, OK, can't remember the name, saw it in the back of 4-Wheel ATV Action mag. $470 plus shipping. Sounds like that stroker kit might not be a bad deal for $700?

through my OWN fault, and nobody elses, i forgot to check the coolant level that morning( i noticed it was low the evening before) and it got hot.

The temp was about 65 degrees.

I plan on hooking up a temp gauge.

4 strokers always think they have something to prove.


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