Bigger cc better?

[andyken]

I see a lot of engines in the same price range anywhere from 26cc to 30cc?


I would think more cc is more power? But I think the smaller ones rev higher?


A few dyno's I looked at, all fall off about 14k rpm...?


I was thinking of a pro stock /pro lite.


Is a 30.5 better than say the same brand/mod, in a 27cc etc?

 

[RampageHopUps]

Bigger cc better?

Depends what you want to do. 27.2 are good for racing. 30.5 motors are great for bashing.

 

[Guest]

What you get from the higher displacement is more torque. With a heavy 4wd like the MT, you need torque to get it moving. With a lighter platform like the XB you can run a smaller displacement engine. Where and how you drive should be a factor when deciding on a motor.

 

[andyken]

Mostly a basher XB, but I like speed too...[hoping for the 2spd soon!]

Pretty happy with the stock 30.5, [990 + jet pro]

Just wish it had a little more top end....and was easier to start.

Thinking the hard start may be low compression?

Once started its fine, but need to use a little gas in the plug hole or startin fluid in the air filter to start now.

So I get the bigger cc = more torque, do the smaller cc rev higher? Is the low end torque the only diff?

 

[Guest]

The 27.2 is a screamer. It is capable of 20k rpm. I have the 27.2 FMLR from OBR in my XB. It s a great motor. I would recommend it for the XB.

 

[andyken]

The 27.2 is a screamer. It is capable of 20k rpm. I have the 27.2 FMLR from OBR in my XB. It s a great motor. I would recommend it for the XB.

What about the 27.2 pro stock? Is it better than a 30.5 pro stock?

Why do all the dyno's fall after 14k rpm, but do go up to 20k???

http://www.oneillbrothers.com/catalog/product/gallery/id/188/image/2047/

 

[RampageHopUps]

Bigger cc better?

There is no better engine. It depends what you want to do with it. Tell us what you are planning to do with it and we can tell you what to look for in the dyno charts

 

[andyken]

Mostly a basher XB, but I like speed too...[hoping for the 2spd soon!]Pretty happy with the stock 30.5, [990 + jet pro]

Just wish it had a little more top end....and was easier to start.

Thinking the hard start may be low compression?

Once started its fine, but need to use a little gas in the plug hole or startin fluid in the air filter to start now.

QUOTE]

Basicly want a little more rpm? Seems to run in the 35+mph range now.

Just put on a belt drive [haven't run due to winter here in NH]

I guess I want to know if smaller cc = more rpm?

I assume the pro lite 30.5 or 27.2 would be a big [?] improvement over stock?

Just the porting etc would be more hp ,are they more rpm than stock?

 

[andyken]

The complete 30.5 is like $120 more than a naked 30.5 long block, but the pro lite seems better on the dyno.

So I don't think I'd want the long block?

Lookin at maybe the 30.5 or 27.2 pro lite.

Still searching...something around $300 ish

 

[Guest]

The complete 30.5 is like $120 more than a naked 30.5 long block, but the pro lite seems better on the dyno.So I don't think I'd want the long block?

Lookin at maybe the 30.5 or 27.2 pro lite.

Still searching...something around $300 ish

Most of us, myself included can not notice the minor differences on the dyno. Keep in mind, those numbers are best case scenario. They have the perfect tune and the pipe that they could get the highest numbers from. You can see some of their graphs show different pipes.

Have you checked out the full mod RCMK? It is another good option. What ever you decide on will blow you away. The difference a ported engine makes is night and day.

 

[Trip..]

Mostly a basher XB, but I like speed too...[hoping for the 2spd soon!]Pretty happy with the stock 30.5, [990 + jet pro]

Just wish it had a little more top end....and was easier to start.

Thinking the hard start may be low compression?

Once started its fine, but need to use a little gas in the plug hole or startin fluid in the air filter to start now.

So I get the bigger cc = more torque, do the smaller cc rev higher? Is the low end torque the only diff?

Sounds like it's hard to start because the 990 doesn't have a choke. You need an intake with a choke flap.

As far as low compression... Not likely. I have several motors with 30+ gallons of fuel through them and they will fire first pull.