Esr 330

[69-ss-396]

Will adding a 4mil crank make a 330 a 350?

[C-Leigh Racing]

What bore is your cylinder at right now ??.
If 76mm STD bore for a 330,
76.00mm, + 4 stroke, 344771.75cc
76.50mm, + 4 stroke, 349323.14cc
77.00mm, + 4 stroke, 353907.38cc
77.50mm, + 4 stroke, 358515.46cc
78.00mm, + 4 stroke, 363156.39cc
Neil

[69-ss-396]

Thanks Neil!

[acecarlos]

Will adding a 4mil crank make a 330 a 350?

Yup it will make it a 340CC just like the 350CC, however; IMO more important is that a +4MM stroked 330CC (75.50MM is the first bore of a 330CC) cylinder will out perform a 350CC (77.50MM is the first bore of a 350CC) cylinder with equal displacement. The power band in a +4MM/330CC is more useable, down low to mid range (more TrQ) and with a great top end verses it's sister 350CC cylinder at the stock 72MM stroke.

76MM x 330CC (75.50MM) = 340CC
72Mm x 350CC (77.50MM) = 340CC
76MM x 350CC (77.50MM) = 358CC

Your avatar shows an ATC250R...a +4MM/330CC is an awesome engine in an ATC250R and one of my favorite combinations for a Trike...

Carlos.

[C-Leigh Racing]

Just something about keeping a 250R engine square. When you do, they sure run good.
Neil

[acecarlos]

Yup... we both like Square engines Neil...

Carlos.

[69-ss-396]

Yes Carlos, that is my 310 Powered long rod 86r.. I just picked up a complete ct 330pv on ebay for dirt Cheap.. Said it lost spark. but the topend is brand new. I think I will go through it and get a drag port done and add a +4 crank. Should i get my crank stroked or get a hot rods? I take it you cant run a long rod with a stroker?? I will be building this motor for my 85r.

[acecarlos]

Yes on the long rod in a stroker. If you have a good OEM crank and don't mind paying +$500 to have it stroked, welded and rebalanced, then go with the OEM. Or buy a new HotRod for $300 and replace it after 5 years of riding. I also don't think you need or want a Drag port on a 330R/+4MM unless you are truly into Drags.

On an ATC250R, the 330R/+4MM is an awesome combination, a very good MX Pro Port & Flow will give you all you can handle. A strong 330R/+4MM on Race Fuel in an ATC has a lot more "pucker factor" value than on a TRX250R.

Carlos.

[rumphius]

What bore is your cylinder at right now ??.
If 76mm STD bore for a 330,
76.00mm, + 4 stroke, 344771.75cc
76.50mm, + 4 stroke, 349323.14cc
77.00mm, + 4 stroke, 353907.38cc
77.50mm, + 4 stroke, 358515.46cc
78.00mm, + 4 stroke, 363156.39cc
Neil

Neil when i read your response, the first thing that came to my mind was C3PO. haha where on earth did you pull that from? a galaxy far far away

[69-ss-396]

Not planning doing much riding with this bike it will spend most of its life on the drag strip. I don't want to run a oof race pipe. I have a atc5 pipe and a pt high rev. What would be best for this setup? Are you finding more power with the mx port?