V twins vs inline 4

[Joemang]

Hello,

Can anybody tell me why more teams seem to choose inline 4 engines to V twins??

Is it simply because they're easier to find, or does it have to do with cost and accessibility?

It seems as though a twin would be better suited for this competition, mainly due to its bottom end torque and packaging. Given the history of these competitions, the tracks don't really lend themselves to high hp.

Also, I've managed to find a Ducati 600cc Pantah engine, and I've been playing around with the idea of modifying a Briggs v twin with a cvt, but I'm hesitant in selling my 2 Honda F4's in order to get one of the twins.

Mainly the hesitation comes from a lack of knowledge in terms of the pros and cons of the 2 types of engines.

Would appreciate any advice.

Thanks

[Erich Ohlde]

look at choke rpm on the Vtwin vs the F4i.

[jsmooz]

One consideration to make is the weight factor. While the F4's, etc. weight a fair amount they include the gearbox. The Briggs still needs some type of gearbox, so that adds to the lighter weight you get from the engine alone.

The Briggs is also a loss in power. You'll need to spend some $ and time on the dyno to get some respectable power, tho it'll still be ~20hp less then a stock 600. The difference is, as you stated, it's got torque. Our torque curve last year was flat from just off idle to redline. My belief is that the Briggs power output is almost enough and the 600's are too much.

[VFR750R]

Be careful you don't get caught up in the twins are for torque 4's are for power. It's mearly a case of intended usage with manifolding, cams, and valve areas. Any 600cc engine has the same potential for torque as any other 600cc engine, but the one with more cylinders has more valve area, higher speed potential (power), and more even pressure on the restrictor. But more cylinders are less thermodynamically efficient, weigh more, add complexity to manifolding and electronics. I'm sure there are 100's more reasons either way.

On the subject of V twins, there are not that many the have conviences of modern 4's and I don't think packaging is any better. Kawi just came out with a parallel twin 650 and Triumph a 650 triple which would both be engines to consider if not for the 610cc rule.

[Mechanicaldan]

The Aprilia SXV 550 is a great engine that fits all the FASE rules. For more info.

http://fsae.com/eve/forums/a/tpc/f/412600868/m/19210732631

[JerryLH3]

How on earth did I not look at that thread when it was originally posted?

That's a pretty slick engine.

[Nima]

almost all of the fsae teams select a 4 inline or 1 cylinder engine because those are common racing engines with requested hp and displacement. there may be some v twin engines but I don't have found any in the 100hp and less than 610 cc displacment. If you find any V twin engines with this specifications, link them here.

[Mechanicaldan]

Nima - I did post a link for a V-twin with less than 610cc. A very good V-twin!

No restricted FSAE engine makes 100HP, whether it be an inline-4, triple, twin, or single.