engine weight

[homemade wrx]

does anyone know what the engine by itself weight?...I'm curious as I'm looking to buy and extremely modify one for ODU's 07 Formula SAE car (www.odumotorsports.com). I'm trying to decide the 400ex and the yfz450...any insight or help is greatly appreciated.
Thanks, Micah

[am_muscle]

Not sure about what each engine weighs. 99% possitive the 450 is lighter and produces a ton more hp and is also water cooled I would go with the 450.

[homemade wrx]

Originally posted by am_muscle
Not sure about what each engine weighs. 99% possitive the 450 is lighter and produces a ton more hp and is also water cooled I would go with the 450.
well, my thinking was that the aircooled 400 would be lighter, as it doesn't have a water pump, radiator, thermostat and well, water... ;)
that is why I'm trying to get numbers from here and the FZ boards...
just hoping someone has a spare motor sitting around...

[GPracer2500]

400EX engine dry weight is 91 lbs (according to Honda).

[homemade wrx]

Originally posted by GPracer2500
400EX engine dry weight is 91 lbs (according to Honda).
thank you, a bit heavier than I was previously quoted (elsewhere)...
also, what kind rev's are the block good for? and how well does it handle stresses? (i.e. high rev's and forced induction)
thanks, Micah

[GPracer2500]

Revs? Stock is 9,100. I think some aftermarket ignitions take it up to around 11,000.

Extra stress? That's a weak point (IMO) of the 400EX engine design. Leave em' stock and they'll last forever. Increase cylinder pressures substantially and, well....The problem is the head studs don't pass through the cylinder into the crankcases--they only thread into the cylinder. The cylinder is then secured to the crankcases separately. The head studs can start to pull out of the cylinder when the pressures go up. Heavy Duty head studs are a common and necessary addition for big bore and high compression applications (head-to-cylinder interface mods are a good idea too). Without them head gaskets don't last.

You may be able to beef up a 400EX engine enough to handle what your envisioning, but I'd probably just go with a higher performance engine to start with. [shrug]

[homemade wrx]

Originally posted by GPracer2500
Revs? Stock is 9,100. I think some aftermarket ignitions take it up to around 11,000.

Extra stress? That's a weak point (IMO) of the 400EX engine design. Leave em' stock and they'll last forever. Increase cylinder pressures substantially and, well....The problem is the head studs don't pass through the cylinder into the crankcases--they only thread into the cylinder. The cylinder is then secured to the crankcases separately. The head studs can start to pull out of the cylinder when the pressures go up. Heavy Duty head studs are a common and necessary addition for big bore and high compression applications (head-to-cylinder interface mods are a good idea too). Without them head gaskets don't last.

You may be able to beef up a 400EX engine enough to handle what your envisioning, but I'd probably just go with a higher performance engine to start with. [shrug]
yeah, everything you just said is pretty much what I have gotten from reading around...

Originally posted by GPracer2500
400EX engine dry weight is 91 lbs (according to Honda).

holly *****. i gess thats why it was kinda hard to take out of my frame. whats the yfz450 weight?

[homemade wrx]

Originally posted by not z?
holly *****. i gess thats why it was kinda hard to take out of my frame. whats the yfz450 weight?
packaged for shipping and dry...83 lbs...so take off a few pounds for box/packaging stuff

[am_muscle]

So basically the yfz is the same weight as the 400ex when you add the weight of radiators, coolant, oil,ect. Plus it produces a ton more power, higher rpms, and is water cooled. I would put in a yfz engine, You can also use a yz450f dirt bike engine if you aren't familar, they are practically the same. Good Luck!