more crank discussion

[8686]

Well I'll be putting together a new engine for motocross next year. Originally I was going to do a Pro-X 310, but I've recently got the bug to go bigger. I was ready to buy the ESR 370 kit for $999 until I called and found out the +5 crank they provide is a stroked Wiseco unit. I became a little hesitant and realized why they could price it cheap. Now I'm thinking of getting their 350 non-pv cylinder unported and having my local builder port it. From there I'm not sure which crank to use. I'm leaning towards using a stock stroke oem crank but was wondering if anyone had any input on this subject. This is going to be a motocross engine. Thanks in advance.

[Fear250r]

I had my stock crank rebuilt with a prox rod and seems to be holding up just fine.

[morse250r]

mines a +4 pro x rod on an oem piston set up by esr

Go Honda OEM rebuilt crank with a Honda new OEM, Pro-X or Vesrah connecting rod.

Get the Pro-X cylinder kit with Wossner piston (better than Wiseco), or get the ESR 350 Kit without porting, however; set up for a +4MM or +5MM crank…

Send your OEM Honda crank to be rebuilt by your favorite builder, have them do the porting & bench flow work along with any pipe and intake/carb work you may want.

Carlos.

[Jason Hall]

I would recommend going with a +4 Hot Rod's crank, you can then play with the exhaust & transfer's a bit to make better MX power. The shape and angle's of the port's has alot to do with overall performance. Long Rod and longer stroke adds Torque, IMO thats what you want. Talk to Derrick about his setup, It works very well! I'm working on his flywheel weight this weekend. It Should make his R real nice.

[Derrick Adams]

As was brought up in a previous thread the biggest cylinder suggested to run for an MX application is 330. The guys at ESR explained to me that it was mainly a cooling issue.

I really didn't see much gain from the P/V set-up for MX either.

I built my ideal combo and of course thats what I would recommend because mine seems to have great results. 310-330 cylinder with a +4 crank. I've been running a +4 HotRods for two seasons now with no issues, although I may just be lucky as some others said their not that good.

Agreed; my 330R is on an OEM Honda +4MM crank, it is my favorite Big Bore…the 363R has 10HP on the 330R, however; I like the feel of the 330R over the 363R…

Carlos.

[wilkin250r]

Originally posted by acecarlos
with Wossner piston (better than Wiseco),

Is that Wossner piston a cast or forged piston?

[red88r]

Originally posted by wilkin250r
Is that Wossner piston a cast or forged piston?

I believe they are forged.

Wossner’s are forged, and made from a higher Silicone content than Wiseco’s or Pro-X…less expansion.

In my opinion; Wossner’s are the best pistons on the market for 250R.

Carlos.