squax-on-crax

For a rotary site there is way to many people asking about switching V-8s into a easily built rotary motor. I'm not sure why people want to kick out one of the better engines ever invented. If more were invested in the idea I'm sure it would get just as good of gas milage and it would be by far the best motor but if you put 100 years in technology into one motor it is hard to beat it in only half that time with another.

LT1-7

QUOTE]Originally posted by squax-on-crax
For a rotary site there is way to many people asking about switching V-8s into a easily built rotary motor. I'm not sure why people want to kick out one of the better engines ever invented. If more were invested in the idea I'm sure it would get just as good of gas milage and it would be by far the best motor but if you put 100 years in technology into one motor it is hard to beat it in only half that time with another. [/QUOTE]

I would say people that have converted to a piston engine did not consider the rotary to be of one of the better engines built by any means (reason we take them out). When I go on this site all I read is people having problems with there cars. From small problems down to blown engines. Just go on the single turbo forum and ask people how many miles they have on there engines. You'll be surprised to see how many people are blowing low milage engines. Granted they are putting there engines through alot but still I bet the average single turbo is putting out less than 450rwhp. Now 450rwhp on a piston engine like an LT1 or an LS1 is a no brainer. Now just imagine if you build it build it!!!

black99

You'd be amazed after problems with rotarys how many times this swap comes in your head. I've thought about it before and it's once again in my head. I definately like the fact that it wouldn't be near as complicated as all the upgrades you need to go single turbo/and still have to worry about bad tuning being able to detonate even a fresh motor so quickly. Thought about 20B before and this is the big downside besides the 20k(if I did everything with lots and lots of fabbing) it would probably cost to set everything up. The things I kind of dislike about the v8 conv. are losing that sense of boost when the turbo(s) kicks in(rather enjoy that "pull" a turbo creates). Not sure about the sound it would emit either, call me picky but a car would have to sound "right", I've heard only one or two ls/lt motors that I liked the sound of and they had stroker cranks/larger cams/etc General rule of thumb in the automotive world as it is my understanding... I.E. 450hp from a larger ci motor is more easily attained with more reliability/less problem areas than it would be on smaller ci(13b = 80ci) motor.

Really I'm considering doing it, but not until at least late summer if not winter. Just don't want to have the car down for that long. The other thing is there doesn't seem to be anyone else who makes a lt1 cradle beside grannys(was thinking I might rather go lt, I don't know), yes I know hinson is working on one. I heard he's a good guy and would trust him but from what I hear his projects that are "coming soon" don't seem to get completed that fast..

wingsfan

Well the fact of the matter is that as it stands now, the rotary does NOT get better mileage, and is NOT as easy to make reliable power out of. You can make 400-450rwhp out of the 13brew, but at what cost to the engine? The torque curve is also going to be peaky and shifted towards redline.

I did my swap to present myself with a different challenge and to have something unique at the end of the whole thing, not because I hated the rotary.

projekt

i love the rotary. when mazda releases a rotary that makes 300hp and gets 20+mpg without a turbo, i'll forget all my conversion ideas.

the problem with the 'give it 100 years of engineering' theory is that none of us have 100 years to give.

squax-on-crax

well I'm just saying why buy a RX7 then buy a Impy SS, transam, camaro, er stang. I love those cars(minus the stang) but I could afford to build on a rotary(push the turbo up) as much as I need to and the displacement is right for me. I am trying to drop a rotary in a mini. V-8 won't fit and if it ain't a 8 I want a rotary.

LT1-7

it's not about the cost of building a rotary. The price most people spend on the conversion could build a pretty bad *** rotary. It's all the trouble the rotary comes with. I guess if you talk to hardcore rotary fanatics they will tell you that rotary engines are reliable but I know better. They might be somewhat reliable in stock form but in most cases after you start to modify, you'll get problems. So with the right size bank account you can build a very impressive rotary, the question is how long will it take till you have to build another or how often can you drive the car without problems. It' not a fact that a rotary is not reliable ut just browse the forum and I think you'll be convinced

Thaniel

That's my feeling as well. The rotary's are under powered. Also the parts are over priced.

People talk of the rotary engines lasting a long time. They do by other engines I have owned have lasted much much longer with little attention.

Rotaries are an engineering achievement and if they made them cheaper to rebuild I'd be all for it. Ever price a set of apex seals

I'm doing an engine swap because I love my Rx-7's handling but I'm tired of the underpowered engine and having to treat it special. Don't move it and shut it off or it will flood. I'm sooooo sick of that. I can't remember the last time any of my non rotary cars flooded.

projekt

mines never flooded ::knock knock::

Alias

Better engines invented? I like the rotary, but some of you guys are blind and stupid. If it were one of the better engine sinvented more manufacturers would use it.

tbielobockie

Because in the history of the internal combustion engine the rotary is the dumbest idea to ever make it to production.

Aside from package size the rotary has zero advantages over piston engines. But the piston engines have many advantages over the rotary.

Thats what 99.99991% of cars has piston engines.

duh.

tbielobockie

A similar capacity rotary engine will never beat a piston engine in MPGs.

Very simple reason why; piston engines turn more heat from combustion into kinetic energy. The reason? Combustion chamber shape. The rotary chamber is long and narrow which presents more surface area to soak heat into. By contrast the piston engine keeps the combustion gasses in a ball. Better combustion and less heat into the coolent.

I'll say it again. Aside from package size the rotary has zero advantages over a similar output piston engine.

squax-on-crax

well my point is that a piston engine actually loses alot more energy in making energy then rotaries. It's like the CVT tranny it's existed the longest but it is not as cheap to make so they don't use it. All it comes down to is dollars now! which is bull Plop. If you don't invest in a idea it never works out. The theory of flight and a working contraptions blueprints had existed centuries before it was actually able but the reason it never worked out is because nobody had the money to invest. if only one company likes the idea then it is obviously not going to develop as fast because one company sees it one way other companys see it another and they steal from eachother and make a teh car of the future, they build on eachother and steal from eachother. That is how you end up with a better tv or computer so if you did that with the rotary it would do the same. the problem is they've never been challenged by ne other companys to make a better rotary only by the government to pass smog.

IronDonut

Here is the thing. You're looking at this from a very simplisic point of view. It's a common mistake that most people make. Let me explain.

When you look at the rotary you only the see the mechanics of the engine. You see fewer parts and less internal friction. All true. Rotary engines only have a fraction of the mechanical losses of a piston engine.

Problem is you're worried more about the losses than what is really important. The production of kinetic energy from heat. The real horror show of the rotary design is how poorly it converts the heat from combustion into kinetic energy. It's terrible for three basic reasons:

The long narrow shape of the combustion chamber transfers more heat from combustion to the engine casing and into the coolent.

More heat is lost into the exhaust.

The compact cyl chape of the piston engine combustion chamber allows for a better burning of the air/fuel mix.

The design of the rotary is so bad from a themodynamic and combustion perspective that even tho it only has a fraction of the mechanical/frictional losses of the piston design, the piston engine is still more eff.

projekt

i don't recall asking for better mpg than a piston engine... but you just seem to want to fight so have fun.

Crash Test Joey

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projekt

hahaha me no like gas!!!