3-5-7 port buggy engines?

Ron_J · 08-11-2006, 04:19 AM

In a buggy engine is there any distinct advantage or disadvantage to the the different port configurations? Why 3/5 or 7?

Thanks

tex1 · 08-11-2006, 05:22 AM

3 ports are efficient, and don't produce as much power. When used correctly this motor is very good on tight or slick tracks. You can push max run times to gain an extra advantage.

5 ports give more power in all ranges. They are easy to tune and just have a little less efficency than the 3 port. Usually a little more expensive as well.
Some of the most popular motors are 5 ports. P-5 Novas.

7 ports are very strong. They are good on big tracks where sraight away speed can give you a few positions in a heat. Large jumps are a breeze if you have room to stretch the legs of a 7 port. You will give up fuel though.
You want to go 7 port when you have max traction. These motors are usually the highest priced.

T. Thomas · 08-11-2006, 05:29 AM

Along with what tex1 stated, ports in nitro engines are also similar to windings in electric motors, ie single double triple, in where the power is delivered. A 3 port will have more power in the lower RPM range(fells like having more acceleration from a stand still, but no top end speed at all), a 5 port wil move the power to the middle of its RPM range(probably best all around choice for offroad), and a 7 port will have most of its power up in the RPM range(feel soft in the lower RPMS).

Ron_J · 08-11-2006, 05:30 AM

Great info! That's exactly what I was looking for.

Ron

Davidka · 08-11-2006, 05:47 AM

A multi port engine *should* have more top and usually do but don't forget, the OS V-spec is a 3 port engine and is one of the fastest engines you can buy from top to bottom. Those are good guidelines but there are always exceptions to the rule.

TMizzle · 08-11-2006, 06:17 AM

exactly... just when you think it makes sense... The V-spec shows up.
Its a 3 port and will murder almost every other engine all over the track.

At Nationals, 1st 2nd and 3rd ran Vspecs.

WheelNut · 08-11-2006, 11:03 PM

The idea is with more ports that the fuel can be "shot" into the combustion chamber more accurately than with less larger ports. So an engine with more ports should run cleaner and make more power than an engine with less ports. There are so many factors that play into the performance of a nitro engine though that the number of ports is just another feature of the engine, the dyno or on track results tell the whole story.

BringItOn · 08-11-2006, 11:39 PM

vspec is just about the perfect buggy engine. awesome powerband from bottom to top. awesome fuel economy. and is one of the cheapest to buy high performance engines going around. finally its getting the respect it deserves.

Z_Schneider · 08-13-2006, 07:17 PM

It really doesnt matter as long as you buy a quality engine. Usually more ports mean harder tuning. You will be safe buying almost any Novarossi based .21 (RB, Max, Top, Rex,ect..) Tuning should be easy on any of those as long as you break it in properly. V-specs are good too, but I've seen some bearing problems lately. That is fixed when you put a ceramic in, then they last 4ever.