What is a street motor?

[Jsup]

I haven't been around in a while, sorry for the delay on PMs. Been trying to pay the bills!.....

This is still one of my favorite websites. I'm not ignoring you guys, I'm ignoring everyone!

So....I'm having a discussion with someone off line. I am told that all the theory about building motors to race has no bearing in cars that require "street motors" in "street cars". They don't use 5000 Stall converters and don't need power in the mid-high RPM ranges.

I am told that a "street motor" makes most of its power between 5500 and tops out 6000 RPMs and has a ton of torque down low. Sounds more like a tow truck to me.

My CTS has a redline of 7000, and most cars from the factory are redlined at least at 7000.

It is my opinion that TODAY's street motors are at least 7000 RPM motors, that 5500-6000 is antiquated thinking or for tow trucks.

Can you help me define what constitutes a "street motor".

Thanks.

 

[mrvette]

Well, I give you MY ideas from over the years.....kinda like my old Pontiac daze, the old 289,400,455's from the 60-70's....all the torque down lo, that's why a GTO was so much fun on the street, maybe they were not the absolute fastest on the tracks, but that SOB would plant you pretty good off the line, as a dead stock machine....

and all that crap has to do with bore/stroke and of course CAM, then head designs, then headers then induction....

I like 'street engines better than race cars for every day driving....spinnin 7 grand is something a small cube ricer/4 cyl or ~3 liter V6 would do,

I like the smooth idle no higher than my 850 rpm I have now, and want to swap to a milder cam than I have now, and get the idle lowered to 700 or so...

won't loose any punch off the line, but get better economy....like my old OEM/fresh rebuilt L48 did with the TPI.....24 mpg with the muncie....
on the freeways cruising 3500 rpm or so...I should have stayed with it...really...just added the overdrive....

but really, when we have a heavier car....like my '70 Lemans convertible weighed 4100 lbs...you need torque NOW to get it rolling....

:friends:

And it is good to hear from you, hope your business is doing well, those injectors are running FINE, engine smooth as silk for some time now....

:yahoo:

 

[damoroso]

It is my opinion that TODAY's street motors are at least 7000 RPM motors, that 5500-6000 is antiquated thinking or for tow trucks.

Really?? You know, I think a "steet motor" is whatever it takes to accomplish the goals you might have for the particular car. For instance if you want to cruise the highway at highway speeds and get good gas milage, that's a different build than someone who want's to run street light to street light and hit the drag strip on weekends. Another option is someone who wants to be able to run mountain roads well. To me, its a package deal. Power band, horsepower and torque.

By the way, if you run across a well built or even well tuned BB vette, standby....he won't have to turn 7000 rpm for you to see tail lights. Hardly a tow truck....

 

[pcf_mark]

I am surprised more people did not give their opinion. I was talking cams with a rep from Comp Cams and we discussed some options he was estimating 10" of idle vacuum. To me that is the absolute edge of a street car. The manners are going to suck light to light and anything under 2,000 rpm regardless of how you gear it. You need to drive other peoples stuff to get a feel. I have a CTS-V that has 6,500 (?) rpm red line but is docile as a pussy cat. I could get more power but it would cost me the driveability. To some that is a good trade off to others the price is too high.

What is a street car to you? If you like loud and smelly that is one end (say a BBC with a huge roller). If you smooth delivery with great flexibility that is the other end (CTS-V).

 

[damoroso]

You know, newer engines can run much higher compression ratios that allow them to get more power, plus, the head and intakes are designed to take advantage of computer controlled fuel injection and ignition. And yep they've moved the power band up, I suspect mostly to take advantage of new transmission technology (more computer controlled stuff) and gain fuel economy. I still contend you can build power anywhere you (and your bank account) want to, (doesn't have to be loud and smelly) in whatever rpm range you want. Especially if you use computer controls. Just wait for variable valve timing, and no mechanical valve train!!!

With out getting into the age old argument small block or big block, (kinda like the agrument about horsepower vs. torque) there's no substitue for cubic inches, but there are certainly trade offs. It's still a matter of what the end goal is.

By the way, the corvette racing C6's engine in '08 was a 427 inch LS, that made 590 HP @ 5400rpm, and 640 ft. lbs. of torque @ 4600rpm. If I remember correclty, pretty sucessfully too. Quite the tow truck...

 

[Finn]

Street motor IMHO is anything you can use as your daily driver.

 

[big2bird]

Street motor:

NOT a street motor:

 

[Twin_Turbo]

Yeah, the purple is a no go on the street...paint it black or red and presto...street motor!

 

[damoroso]

Yup, never was a fan of purple.....:thumbs:

 

[mrvette]

Yup, never was a fan of purple.....:thumbs:

OH but Thay thweetie.....put pink polka dots on it....it would looks tho CUTE!!!!

:rofl::rofl::rofl:

Like customers ask ME what colors to paint/decorate with....I just grin and say paint it purple with pink polka dots.....

TOTALLY serious....it always get a laugh.....and I then lower my voice and say it's YOUR house....I really have NO opinion.....and I don't paint for ANY one, for a good reason....

:gurney::rain::drink:

 

[JAKE]

You won't get an universally accepted definition of that term: street motor. To me RPM capability isn't a factor, since so many engines differ in their redline, yet all are still street engines as they come from the factory. Shorter stroke engines can almost always safely be revved higher than longer stroke engines and, so, have higher redlines.

To me, any engine or car that is LEGAL to be operated on the public way, including being emissions legal is a street motor.

Whether it can be driven from Maine to California or regularly to the grocery store is a daily driver issue, not whether it's a street motor. Some engine combinations can be so radical that, while being legal to be operated on te public way, would experience durability issues in long distance outings.

Just my view.

Jake

West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!! Graduation Day Parade 20 May 2010!!!