With these very high output engines, frequently everytime you come to a stop you have to put the transmission in neutral and keep the idle 1500-1800 rpms. i really havn't heard of having a lumpy cam and a good idle. even with an automatic trans and a high stall speed converter, stop and go driving is difficult. I've seen some vehicles lerch so badly when put in gear, they can easily get away from you.
How does an engine make a car unstreetable?
- Thread starter Cannoball888
- Start date
BullittStangV8
Founding Member
You can have a lumpy cam and a good idle...you just idle at 1200-1500 rpms instead of 700 rpms..
Unstreetable to me is an engine that won't idle under 1000 rpms, power curve comes in at 3000+ and pulls to 8000. Overheats consistently in traffic, headers heat the interior to about the "cleaning" setting on your moms oven.
Gas mileage? What gas mileage?
An engine like that will consume in gallons per mile, not miles per gallon
Gas mileage? What gas mileage? An engine like that will consume in gallons per mile, not miles per gallon
iskwezm
10 Year Member
when the hell were you driving my carUnstreetable to me is an engine that won't idle under 1000 rpms, power curve comes in at 3000+ and pulls to 8000. Overheats consistently in traffic, headers heat the interior to about the "cleaning" setting on your moms oven.
65ShelbyClone
Founding Member
About 3 weeks ago I went to the VARA Big Bore Bash and I got near-first-person look at what "unstreetable" really is. I saw tons of GT350s, big block '60s Vettes, and Mustangs in general. They were fast as hell on the track, but when I saw them in the pits, they could barely run below 20mph in first, even the big block Chevies!
I have long thought that, assuming the chassis is properly set up to fully handle it, 500rwhp is probably the practical limit for a sub-3600lb streetcar. My old '65 notchback had a mild 289, 4-speed, and 3.50 T-lok, but it was scary in the wet. I can only imagine what the '68 will be like in the rain with 75hp+ more.
I have long thought that, assuming the chassis is properly set up to fully handle it, 500rwhp is probably the practical limit for a sub-3600lb streetcar. My old '65 notchback had a mild 289, 4-speed, and 3.50 T-lok, but it was scary in the wet. I can only imagine what the '68 will be like in the rain with 75hp+ more.
reenmachine
20+ Year Stangneter 
Great thread. I call for a sticky! This should be required reading for everyone, especially those under 30 whose testoserone forces them to spend all of their money on horsepower while riding around on 4-wheel drum brakes! Yes, that's a generalization, but at least I can say that it's a generalization that comes from personal experience. Only in recent years have I embraced the philosophy of building chassis first and horsepower later, and I'm much happier and have a better time driving.
Every magazine cover these days has a headline along the lines of "500-600-700 hp For The Street!" splashed across it in giant bold type. It's being crammed down our throats so hard that it's easy to be subliminally convinced that a 600 hp street car is totally reasonable. It's not. It's going to be rough, tempermental, noisy, and unreliable unless you put $25k or more into the engine alone. Not something you'll load up with the wife and kids and take for a nice long Sunday drive. More likely it'll be relegated to the occasional cruise to a show, and most of the run time on the engine will be starting it up in the garage to show your buddies how big your "special purpose" is.
Personally, I like 350 hp in a small block. It'll start right up, idle smooth, get decent mileage (depending on how you drive it) and cruise city streets in the summer heat with the A/C on without a problem. It's also fast enough to scare you when you get on it. Ever ridden in a '65 GT 350 with an aggressive driver? Scary. Roughly 305 hp gross. Fox body 5.0s are a riot to drive even stock. 225 hp.
Think about it.
Every magazine cover these days has a headline along the lines of "500-600-700 hp For The Street!" splashed across it in giant bold type. It's being crammed down our throats so hard that it's easy to be subliminally convinced that a 600 hp street car is totally reasonable. It's not. It's going to be rough, tempermental, noisy, and unreliable unless you put $25k or more into the engine alone. Not something you'll load up with the wife and kids and take for a nice long Sunday drive. More likely it'll be relegated to the occasional cruise to a show, and most of the run time on the engine will be starting it up in the garage to show your buddies how big your "special purpose" is.
Personally, I like 350 hp in a small block. It'll start right up, idle smooth, get decent mileage (depending on how you drive it) and cruise city streets in the summer heat with the A/C on without a problem. It's also fast enough to scare you when you get on it. Ever ridden in a '65 GT 350 with an aggressive driver? Scary. Roughly 305 hp gross. Fox body 5.0s are a riot to drive even stock. 225 hp.
Think about it.
iskwezm
10 Year Member
65ShelbyClone
Founding Member
iskwezm
10 Year Member
1320stang
Founding Member
Steve Petty, he is teamed up with Tim Lynch, they run big blocks now, but his last SBF with twins was making right about that.
Thats precisely why Mini Coopers kept up ith jag E-Types on road courses back in the day. It's all about balance.
Route666
Active Member
To me the main parameter of streetability is - How easy is it to drive slowly? As engines become more powerful they tend to act like on/off switches. You lose low-speed torque, which is necessary for slow driving, to gain the maximum power. Fun cars are built for torque. Power, a reasonable amount anyway, comes as a result of the torquier motor.
Secondly I think uncontrollable wheelspin is the next factor, however it is usually a byproduct of factor 1.
Thirdly reliability and fuel economy.
Secondly I think uncontrollable wheelspin is the next factor, however it is usually a byproduct of factor 1.
Thirdly reliability and fuel economy.
blown65
Founding Member
Too many variables for me. Streetable can mean so many things.
I'm going to be yanking my 342 in the next few days and having bullit build a 14:1 motor for it, and yes I will drive it on the street. Except it will be running race gas and its just for fun here and there. (I will be racing it also.
)
You can make almost anything streetable but it just depends on how "affordable" it is. Mine will probably drink down 112 like its going out of style, but for the few miles I put on it its worth the shaking of my walls and the smile on my face when I light that baby up. Just like when the 6-71 was on it with the mild engine below it. Ran great in town, and was a blast.
If things are done right and corners aren't cut they are going to be pretty damn reliable on the street cause you can never push them much anyways. Its when your doing lots of passes down the strip with them that the wear really comes into play.
If its a daily driver, then all bets off. If its a weekend cruiser, then why the heck not IMO.
I'm going to be yanking my 342 in the next few days and having bullit build a 14:1 motor for it, and yes I will drive it on the street. Except it will be running race gas and its just for fun here and there. (I will be racing it also.
)You can make almost anything streetable but it just depends on how "affordable" it is. Mine will probably drink down 112 like its going out of style, but for the few miles I put on it its worth the shaking of my walls and the smile on my face when I light that baby up.
Just like when the 6-71 was on it with the mild engine below it. Ran great in town, and was a blast.If things are done right and corners aren't cut they are going to be pretty damn reliable on the street cause you can never push them much anyways. Its when your doing lots of passes down the strip with them that the wear really comes into play.
If its a daily driver, then all bets off. If its a weekend cruiser, then why the heck not IMO.
balance in a race car is important.as to what streetable is;
1: starts up reasonably easily on a cold morning
2: doesnt overheat in summer traffic in arizona while running the a/c
3: idles well in all conditions
4: is reliable enough to drive everyday with little fear of break down
5: turns in reasonable fuel economy, imo at least 15 city 20 hwy depending on the engine and the car. it is hard to get a 79 lincoln towncar to get 15mpg city
6: handles all driving conditions well overall.
mrmustangman357
Member
- Feb 11, 2007
- 763
- 3
- 18
You want to see unstreetable?
Here is unstreetable:
http://www.nelsonracingengines.com/videos/turbo/BUTCHINHIGH.wmv
notice he says "that was only half throttlr"
I bet he has another daily driver
Here is unstreetable:
http://www.nelsonracingengines.com/videos/turbo/BUTCHINHIGH.wmv
notice he says "that was only half throttlr"
I bet he has another daily driver
I'm building a 408 (if I ever get my block back from the machine shop) and I expect it to have good hp and streetability. The CR should be around 9.6 to 1. I just ordered some AFR 185 heads. I haven't decided for sure on a cam yet but I know it won't be to radicle. My machinist tried to talk me into some Vic Jr's but I didn't want to compromise my streetability. They might have been OK but his definition of streetability and mine might be two different things since he is into drag racing.
408 stroker
I jst completed a 408 stroker for my 67 fastback......we went all out and used Eagle bottom and AFR heads etc..................heres some of the good and the bad.
Bad...
*you get significant exhaust gasses from the tailpipes (result of the cam mostly)
*this engine does not produce enough vacuum to run the brakes well (around town)....you need to install an extra canister to get a 2nd pump or the brakes go flat on you.
*rough idle is fun at first but becomes a bit of a strech on the nerves after an hour or 2 of city driving
*a 408 should have 3" exhaust to reach efficiency and this engine is loud.
this engine also runs hot, hot, hot.....most guys use an aluminum rad....I had a 4 row copper rad. built and a really good (not a cheap one) mechanical fan and it cools really well...even idling in traffic for 15 minutes.
*lots and lots of heat coming into the cab....you need to insulate the floor boards and front pan as well as ceramic coated headers are a must.
*this 351 block is higher and a bit wider than your 289 and requires small exaust fabrication and the use of a low profile intake (or you won't get the hood closed)!!!!!
The good.....the torque on this engine is wild....I got about 500 hp out of this engine with the AFR heads and 520#'s of torque
you're gonna need bigger tires
*its better on gas than my 289 was....runs down the highway effortlessly.
*match your cam, torque convertor and intake all to come on at about 1500-2000 rpms and you will have an amazing street machine that rolls along well on the highway. Use the best parts available to you and you won't have reliability issues.....plan, plan and more planning. Also put in new motor mounts...you'll need them.
I used a March serpentine system.....expensive but solved the issues of mounting for the p/s and alternator.
Don't be fooled....switching from the 289 to a 351 block is not as simple as some will tell you.....it will fit right in and bolt right up but theres a lot of things that need to be changed and fiddled with. Do it right the first time and you won't need a flatdeck to bring you home.
It will be a couple of thousand dollars extra just to do the switch over after the engine is built (if you do the work yourself)....believe it.
Your car will be a completely different car with this engine....good luck.
I jst completed a 408 stroker for my 67 fastback......we went all out and used Eagle bottom and AFR heads etc..................heres some of the good and the bad.
Bad...
*you get significant exhaust gasses from the tailpipes (result of the cam mostly)
*this engine does not produce enough vacuum to run the brakes well (around town)....you need to install an extra canister to get a 2nd pump or the brakes go flat on you.
*rough idle is fun at first but becomes a bit of a strech on the nerves after an hour or 2 of city driving
*a 408 should have 3" exhaust to reach efficiency and this engine is loud.
this engine also runs hot, hot, hot.....most guys use an aluminum rad....I had a 4 row copper rad. built and a really good (not a cheap one) mechanical fan and it cools really well...even idling in traffic for 15 minutes.
*lots and lots of heat coming into the cab....you need to insulate the floor boards and front pan as well as ceramic coated headers are a must.
*this 351 block is higher and a bit wider than your 289 and requires small exaust fabrication and the use of a low profile intake (or you won't get the hood closed)!!!!!
The good.....the torque on this engine is wild....I got about 500 hp out of this engine with the AFR heads and 520#'s of torque
you're gonna need bigger tires
*its better on gas than my 289 was....runs down the highway effortlessly.
*match your cam, torque convertor and intake all to come on at about 1500-2000 rpms and you will have an amazing street machine that rolls along well on the highway. Use the best parts available to you and you won't have reliability issues.....plan, plan and more planning. Also put in new motor mounts...you'll need them.
I used a March serpentine system.....expensive but solved the issues of mounting for the p/s and alternator.
Don't be fooled....switching from the 289 to a 351 block is not as simple as some will tell you.....it will fit right in and bolt right up but theres a lot of things that need to be changed and fiddled with. Do it right the first time and you won't need a flatdeck to bring you home.
It will be a couple of thousand dollars extra just to do the switch over after the engine is built (if you do the work yourself)....believe it.
Your car will be a completely different car with this engine....good luck.
