i was lookin at the hp rating they have listed on the site n noticed they were all rated at 4000 rpm was that for insurance reasons or is that max rpm cause i kno that the tachs all redline at 4500 or 5500

 

*double post, sort of*

 

Peak horsepower. And no, not every engine is at 4000 rpm. Only the lame ones (early LG's, early LB9's, and the iron dukes, etc.)

 

Thats where peak Horsepower is rated. For simple example: At 2000 RPMs you may only be making 50% of peak and the same at 5500 its going to less. Its like curve on the Dyno chart.

 

right i just didnt know if 4000 rpm was really peak of the motor cause i know in the late s early 70s they rated the motors at lower rpms so that the hp was lower to amke it more affordable on insurance

 

Thats not true at all. In the late 70's those motors really made that 150hp crappy peak at 2900 RPMs. They were pieces of trash, so smogged out it was ridiculous. I think it was 80 or 81 that saw the 350 4 speed manual camaro that made 160hp. That is pathetic.

 

yes in the late 70s i was tlakin late 60s early 70s ie 67 68 69 70 71 72 73 the muscle car era adn 73 is even questionable the beggining of the end

 

Let's not forget those mighty 400's from back then, too!

 

Exactly. The 180hp 400ci turd.

 

When easily turns into a 500hp 406! Too bad those blocks are hard to find in good shape..

No offense to everyone, but nothing good ever came out of the 70s.. The cars were slow and ugly, the clothes were just horrid. Hell, home decor was just absolutely puke.

Another 2 cents:

The ratings on this site are as bogus as the ratings on GM's site for current cars. If you think absoultely every motor came off the assembly line and runs the exact same way, and puts out the exact same dyno graph, then just give up now.

GM motor engineering works like this:

Monday. Start of the week. Motors are about 90% of rating.
Tuesday, wednesday. Motors a little better. Roughly 99%, some
exceeding.
Thursday. So so. 97-99%.
Friday, everyone wants to go home. They're not thinking of machining, or honing, or assembling.. 80%..

I'd imagine Friday motors have the highest failure rate.


-- Joe

 

Yup, my parents used to have carpet that had a striking resemblence to italian food

You gotta admit though, lots, not all, but lots of the music kicked ***!

 

Yeah i agree the 70's had the best music!!!!!!!

 

Damn strait, my stereo rarely ever leaves the "oldies" stations. Unless I am putting in a classic rock CD.

 

thanks for all the intrest in the 70s but does anyone really have an answer for me?

 

There is your answer. It applies to all of the years, sorta. They certainly rev higher than that, they are simply making thier peak power at say, 4000. Its kind of pointless to go past that.

 

Usually, if its says, lets say, 350hp@4000 rpm, then 4000 rpm is where the peak hp (350hp) is made. The redline may be 5500, but the engine is making the most hp at 4000 rpm, not 5500.

Its rumored some of the older hi-perf engines, like the LT1 and the Hemi were 'under rated' that way, but I kinda doubt they did anything that clever. Really all they did is just pick a number that both buyers and insurance co's would like, and stuck that on the air cleaner sticker.

 

I hear this a lot. Mass has no basis on HP, in regards to liability insurance. What are other states like?

-- Joe

 

I am not sure than any really do. Its more based on chassis. Where I live, for example, a V6 camaro is the exact same as a z28 as far as insurance goes. The HP rating has no effect. A lot of that is myth, just like the myth that some ratings in the early 70's were rear wheel, and some werent. They were all flywheel, some with accessories, some without.

 

They don't do it anymore that I know of, but they used to do that alot back in the '70s. Thats actually part of the reason for the demise of motors like the Hemi.

 

Really?? I hear this a lot still, even around here. People say "My VIN is for a v6, so its less insurance".. I'm like, uhh. no..

I never jumped on the hemi bandwagon. Whats the point of 600hp, if the car weighs 5500lbs.. Why not get a car that weighs 2800lbs (like a nova of the same year) with a hopped up SBC..

-- Joe

 

Actually, I think that part is true. Thats why you hear in the Engine Swap board alot that if you do a V6-V8 swap, you really should tell them.

You've never heard of the Hemi Dart, have you? 2600lbs, 500+hp, and no factory warranty of any kind. Oh yea, Chrysler also had a sticker on the car that said the paint used on it must have a flex agent added LOL (they came unpainted)

 

The demise of the Hi-po motors of the early 70s was because of federal restictions on emmissions and mileage requirements, not because of insurance.

As far as the difference in prices, there are none where I live. I checked with various online insurance companies (Geico, Progressive, etc) when listing as a 6cyl SC or a Z28, its the same rate.

 

Thats not really true. Insurance rates did have a big part in the dying off of alot of high perfromance stuff, and the Hemi is a perfect example. Insurance isn't what killed the Hemi, the Hemi was a low production thing anyway. It was emitions that killed it (actually, Chrysler not wanting to neuter it to comply) but insurance costs killed the market for the Hemi. Insurance is the reason for so many of the high performance engines becoming really low production stuff though, because no one wanted to pay those insuarance rates to have them. Look at the production numbers of some of this stuff... there were something like 2500 hemi cars built in 1969, but only around 1000 in 1971. Or the 396 Camaros - 1969 produced a whole lot more of them then there were in 1972.

Yes, it was emitions laws that actually killed off cars like the Hemi cars, or the big block Camaro once and for all, but insurance co's had a huge hand in reducing the market for them by making it so that the people that bough these cars, usually young people, could no longer afford to have them.

 

Didn't that car run 10-sec timeslips, STOCK? If it wasn't 10s, then it was 11's, but I know it was one of those..

 

If the problem was insurance companies, the market for the vehicles would have fell through. That wasnt the case though. People were buying them just as fast as they ever did. The insurance companies didnt kill the cars, the govt did.

 

No, but they tried... they tried like hell to kill them.