laiky

To quote from another post............................................

"Arguing on the Internet is like competing in the Special Olympics. Even if you win, your still retarded."

Low C1500

rx7speed

Do you have any times for your car? Also what are the engine specs on a wankle?

titeride85

Okay, May I clear things up?

First, I appologize for coming off harsh.

Second, RX7, The reason the I made the same statement is because your posting was correct. But you misinterpereted my original statement of rod/stroke ratio. Both you and Low C1500 insinuated I was ignorant because my statement was not correctly taken.

Third, I have respect for people who like to build for a challenge. I too like to build small powerful motors. But the original post was that he wanted something powerful on a budget. Hence, more cubes will give more results for comparable cost.

Fourth, Low C1500, I did not change any statement. I had said longer rods reduce side loads and improve rod/stroke ratio. I did not say it will be better than the short stroke, just better than a short rod with a long stroke.

And finally, I did not attack anyone in my post until I was asked if I was sniffing glue and insinuated as ignorant.

Again I appologize, but I was giving relevant and correct information to the original post.

PEACE

titeride85

I would also like to say, yes, the wankel is cool. But there are many "cool" things in the world that are not practical. That is why the rotary is no longer produced in new vehicles. It was sweet. But for cost and efficiency, it got dropped. And I will say again, any motor you build will be worth it as long as you have fun with it.

DTL504

iTrader: (1)

MAYBE THIS WILL HELP YOU WITH THE sbc 400.
By all means build the 400 too EaSy to Make Hp and Tq...
Knuff Said
David

http://www.chevytalk.org/forums/Foru...ML/013971.html

rx7speed

cool

rx7speed

hey man it's very practical


main reason they stopped making it was almost every manufact that bought rights to the orig NSU rotary couldn't figure out how to get it to work right.

mazda was the only one who made it mass produced with any good long term results


problem is they ran into issues as far as cost...... the rx7 in 93 was costing about 35,000 to buy
also the two seat sport car market started to drop off at that point.. hence why I think a lot of import two seaters are no longer around (supra,300zx,rx7 and such)

rx7speed

80cid or 1.3L

stock 146hp at 6500rpms
138tq at 3800 rpms

my best times on a track (last year) was a 16.4 @86.x mph with lots of wheel spin (launching at 5500rpms) and I think I missed a shift

best on a g-tech was a 16.1@91.6mph no missed shift no change in mods other then launching at 3300rpms and slipping the clutch


after I put the turbo motor in I am hoping for high 14's low 15's on all stock motor

Kingtal0n

<b>Knuff Said </b>
oh is THAT how you spell it? I was wondering...

<b>80cid or 1.3L

stock 146hp at 6500rpms
</b>

So lets see, almost 2HP/Cube.
Let me ask, was the 6500 RPM redline imposed because of the intake or..? I know in any pushrod motor its the whole intake/cam/head that makes a redline...

but in the rotary.. whats the difference between a rotary that spins 11,000 RPM and 6,500 RPM? My good friend here at horsepower sales has one, Ill have to ask him about it when he gets in. He shifts @ 11K and runs low 11's... now im curious cause i KNOW you can make 5HP/cube with these things easy...

rx7speed

7000rpm is the redline.... it is b/c of all the extra stuff like alt, a/c, p/s as well as the port not being large enough to make much more power above that point....

there are a few other things that make it hard to rev up a sh<x>it load higher due to balance of the motor, clearance between the rotor and the housing, some gears inside the motor might hit each other, and under high rpms due to the rotors being about 9.8lbs or so it puts a lot of stress on the e-shaft, and bearings


sure 11k rpms could prolly be done........ but you need a lot of fricken work to do it

would be more worthwhile to just make all the power at 9000 or below

(BR)G-Machine

Well over displacement I would worry about other coomponents first. I would rather have a SBC that is a 350 with nice heads than a 427 with dog heads. You would make more power from say a Vortec headed 350 than a 383 with some ported stokers... and better quality hp, having the torque where you need it.

Lingenfelter says that head choice has the biggest effect on power and I think that he is right. You can have the most cubes you want in a motor but if you have some crap heads stalling the airflow you have no power anyway.

My thoughts from a NOOB!

1QWIKZ

I beg to differ my 327 runs with the best of em, so if your ever in the Atco N.j. arear look me up and I'll show ya how it looks against other SB's & BB's.

BlackcamaroIROC

you sir, have no clue what you're talking about. a 305 has a ****ty tiny little bore, a 302 has a big bore, meaning you can run big valves and have a much stronger top end. tell guys in the small displacement drag racing class that their 302s can't make power like a 350, many of them are running single digits all motor, granted it's a drag car, but I'm yet to see any 350 (4x3.48) running single digits all motor, or even with a healthy shot of crack

Kingtal0n

oh boy. now youve done it. bringing back a 1 year old post to flame someone... isnt there a rule against this sort of thing?
for the record more cubes = more power provided the VE, air density, and RPM between the two motors being compared is identical. ALWAYS.

iroc22

There's a 66 Chevy II in the street legal class here that runs high 9's with a 355.

89formula383

Talk about dragging stuff up from the graveyard...

But I agree, all things being EQUAL, the bigger engine always wins. I hate when people talk about "huge hp 4 cyls and low hp 8 cyls" and then **** about "it's all how you build it" like displacement is meaningless. That 800hp neon is running lots of boost if not nitrous as well. And remember, running 14.7psi or 1 bar (1 atmosphere) of boost is like doubling your displacement. Your engine is now taking in twice the air it normally would be, thus essentially twice the size.

Yes, any engine can be made to make stupid power, but cubes will win if all things are equal. Physics says so.

And rotary engines are just plain cool (not to mention more efficient than piston engines...)

BlackcamaroIROC

which is why a 377 makes more power than a 383, a 427 makes more power than a 454, and a 302 makes more power than a 305 and ford's 302 made equivalent power to a TPI 350 with heads that flowed worse than a TBI 305? oh well, sorry for a long dead post, I'm a n00b, I did a search and this was on the top of the list, I can see why no one discusses it.

laiky

The problem with this debate is its like comparing apples to oranges. All else being equal more displacement will make more power. But........ longer strokes although they increase low end torque also increase friction at high RPM. A port that allows a 302 to rev really high will probably shift power lower in say a 406 and as aresult of the lower rpm Peak HP may be less. large bores unshroud valves but can add piston weight. If you notice, drag racers seem to really like longer stroke motors, 383's, 406's 454 (small blocks sometimes) while circle track and road racers tend more towards shorter stroke motors 358's 302's etc. In an extream case look to formula 1 or motorcycle racing where strokes are getting shorter all the time to increase RPM potential. i believe a better way to decide on a motor is to pick a target HP and Torque number and decide what RPM you want it at. i wanted an affordable/ streetable/ usable 400 or so HP. so i built a 383. My redline is 6000 RPM based on the crank/rods and valve springs i run. this helps keep cost and maintenance down. The displacement and stroke add torque in the low to midrange where i spend most of my driving time. a decent cam and heads allows me to make good power up to about 5700-6000 rpm. If i were to spin this motor to say 7500 rpm and stay there it would be a very inefficient choice. in that case a 350 or 302 would be better due to the shorter stroke and reduced friction. Its all relative to what YOU want. No one motor in ALL circumstances is better than another. except maybe chevy over ford!