Were is the best place (info) to go to get info on blowers ? I just picked me up a blown SBC and need all the info I can get . I did a small search on the computer and all I found was suppliers of parts and such. The one I have is a 671 Littlefield. I need a carb adapter. Every thing is fresh from the builders, well is was around 15 years ago and been sitting on the shelf. I am probabally going to run the motor without the blower just to check it out first. Thanks for all the help , Danny
Danny, There is a great book that has been published call "Street Supercharging". It has a lot of great info that may be helpful to you. As for parts. Any of the blower builder/suppliers can handle most of your needs. Mooneyham, BDS, Littlefield, etc. good luck to you, Steve <DIR>Hosting 11th annual Pontiac Heaven, show, swap, drags, party and all around good time. Saturday April 4, 2009 at Speedworld near Phoenix, Az more info- www.pontiacheaven.org Also hosting- 7th annual Nostalgic Show and Go! and swap. Drags, cool car show, parade, special exhibitions, gassers, rails, stockers, customs and much more. coming Sunday April 5, 2009 to Speedworld. Phoenix, Az -This is Arizonas longest continuest running nostalgic event, our 7th year! www.nostalgicshowandgo.org </DIR>
If the engine is setup to run a blower then im not sure it would run right without it. Low compression, big cam, and should have a big carb. Ive never owned a blower so im no expert but not a good mix without that blower.
You should be able to use any 6-71 carb adapter. Read up on what carbs you want, and what mods they might need. Problem is you'll probably get conflicting information....I know that I've read a few places that the setup I have won't work! If you have an intake and stuff you should be able to run the engine without the blower, just to check it out, without any trouble. It might not be as crisp without the blower if it was built with low compression, but it still should run ok.
A friend of mine got a Gale Banks turbo set-up. They even built a brand new LT1 to handle the stage II boost. However, after they built the motor and before the turbo was installed, they wanted the motor "broken-in" before the turbo install.
The engine, if it was built with the supercharger in mind, will have, at best, about 8.5-1 compression. That, along with the way-too-big cam that many guys seem to think should go on a blown engine, will make for a poor running engine without the supercharger. See if you can find the specs on the cam... figure out how much under/over driven the blower will be based on what pulleys are on the engine. Talk to a reputable cam grinder... I like George at Clay Smith. If you cam is too big have a new one ground that suits your driving style... you don't need that big, lumpy 5 mpg cam to have a great street driver. If you don't plan on running 7,000 rpm you can even run a smaller single carb and have a great running, torqey engine with good gas mileage to boot. Blowers are not the spooky, exotic voo-doo technology that most people make them out to be.
I run a pretty generic cam in mine, power band around 2500-5500. Blower motors are just like unblown motors, the cam timing determines the power band. Boost just adds torque across the whole band. There are some nuances, but you can mostly ignore them and just pretend it's a bigger engine than it really is, and cam it to match your intended use/gearing.
It's all the little bits and pieces that no one ever tells, took me awile to get my head round blower volumes, pulley ratios and boost pressures, then you find you need a belt one tooth pitch longer than off the shelf but not five pitches longer, ( Gates had answer but not cheap ), I tend to only go for 7 psi or so of boost for the street still makes for plenty enough power without making the thing un-reliable.
I've just recently started running my first blown motor (671) which I set up myself so have a few links you can go to for some reading. I've run mine without the drive belt and it ran OK. It's just a low comp motor that way and online articles say if you break a belt while you're out it won't hurt your motor to drive home without one. Pat Ganahls street supercharging book has some good stuff in it. Heres some links for other good reading. Read the recommendations and tech info on the BDS site. http://www.holley.com/data/Catalogs/Superchargers.pdf http://www.holley.com/data/Products/Technical/W538.pdf http://www.blowerdriveservice.com/index.php http://www.chevyhiperformance.com/t...n_poweradders/0610ch_superchargers/index.html http://www.summitracing.com/streetandstrip/charts_guides/charts_scbasics.htm http://automotiveu.com/BlowerTuning.htm http://victorylibrary.com/mopar/blower-carb6.htm
danny: The old duntov 30 30 cam was a good blower cam and you can play around with advance buttons for low end power. Most street blowen engines with 1-1 pullys run in vacume all the time. It will go to boost momentarley when you punch the gas then back down to vacume. If the blower needs to be rebuilt just come over its not rocket science. you can make a steel plate gear puller to pull both gears at same time then its just seals and bearings. some checking with feeler gauges and it should be good to go. dwrfab Don Ross
Listen to Krooser and Squirrel, they won't steer you wrong. I've run quie a few blowers, on both race machines and streetfreaks, you have to match your parts. A mildly built blown bigblock will feel like a all out cammed and tunnelrammed small block, but you won't have that dasterdly high RPM to worry about. With a blower, your turning your engine into a big airpump. Your pumping in so much more fuel/air that you would normally need, that increases Horses, plain and simple. Don't worry about porting or polishing, because your pressurizing you intake. You need to have good airflow into the blower. For street, 2 smaller 4 barrels, several small ones, but if you run 1-4 barrel, you need to flow pretty decent. You don't have to go hog wild, when you start pulling air in, your doing it in a big way! I've seen gaskets sucked out, I've seen air cleaners distorted, you get the picture. A little shinyness inside your runners ain't gonna matter, your pressurized. Don't run too much compression, I can't over stress this enough! 8.5 to 1, 9.0 to 1 is as high as you want to go and thats on a pretty radical ride, with a all out engine on the verge of grenading. 7.0 to 1 to 8.0 to 1 with a good blower cam and big tube headers and big pipes, you will think you've been shot outta a gun barrel if your hookin up! And this is with a 4-link, slicks and some mose juice........... Blowers have been around since the 20's. They aren't voodoo, not magic, not rocket science. They're very dependable, been hanging off the sides and tops of diesel engines to this day. Your engine has to be able to handle all that extra strain that comes from all that extra power. Your bottom end has to be in good shape. When you build you engine, get your blower and drive ready right after that, call Clay Smith, Sig Erson, Lunati, Reed, whom ever you feel loyal to for cams, tell them what your putting it into, what your engine size is, and let them tell you the card and headers that'll work with their product. You'll be happy you did! Everything will work great! Last, but not least, RPM!!!!! Your engine will work at 2000 to about 5500 or 6500 at the absolute highest. As your RPM goes up, so does your HP, in a big way! 1000 or so higher ain't gonna make a difference if you spit rods thru the side of the block or break a crank, and THEY WILL DO JUST THAT, if you over spin that engine. Seen the top fuelers with a blower flying off? Well, under 6 to 8 PSI of boost at a high RPM, should you get a spark up in the intake side.... that blower will sail just as far on gasoline. Blowers are great and fun and dependable, but they do need respect!
Thanks for all the replys. I havent been able to look much farther into the motor and the person I got it from dosent remember much about what was done to the motor. What he does remember is it has ross dish pistons, vonella rods . I saw it is a solid roller cam and some one marked the valve lash inside the valley . My best friend Cindy passed last week so it wont be till tuesday before I can check farther . Funerals tomorrow. Thanks , Danny
How many CFM is considered unsafe to lean and how much CFM is sending liquid out the pipes? Backwards. Not enough CFM is richer, too much is lean.
Really????[/quote] Maybe this has to to with not enough vacuum pulling air threw the carb to get the right air mixture ?
Damn Beep,....that musta been bad. I am in Houston, looking for someone to help tune and dial in my supercharged big-block when it's time to fire it off,...any suggestions on who? It's my first supercharger, I don't want to make an expensive mistake.
Different stuff I think. I've got a Banks on my truck and it ran fine before I put it on. Only thing I did was turn the pump up a quarter turn.
Sorry about Cindy, bad news. Whats to know about blowers? They cram more air into the engine, what else to know? You're a hot rodder, get a dual carb adapter from holley/weiand, sideways mounts and put a couple 750 double pumpers (no vacuum secondaries) fatten the idle circuits and let it eat. That littlefield is probably equalivent to a weiand 8-71 so respect it. If you are going to race this thing thats a different story, for puttin on the street - have at it no worries, the motor just wants some good fuel and leave timing about normal when you retard thats when you generate some heat.
I just read that bit about the feeler gage, i was in staging when they fired a promod in front of me and the squirt bottle got hung in the butterflies and in a millisecond all the connecting rods were outside the pan. The car gave a little lurch as the clutch tried to engage and i knew what happened. One other time i was crewing and doing the starter on a funny when the blades were too far open and motor went rpm instantly and it lurched, that'll scare the shit out of you being up inside the body with nowhere to go and holding onto the starter. Just gotta love those belted motors.
Hey oj, I know the feelin'......I work and build for the Alky FC's, etc, etc....you know the drill.......gets really spooky gettin up close and personal with those gilmer belts, gotta squeeze a little go juice past the butterflys to get em to lite.............
Thanks again for all the replys. Looks like I may go ahead and find me a dual carb adapter plate and go for it . Going to pull the pan in the next day or two and check it out . Thanks, Danny
I have a 6-71 on my small block. It is a 350 nothing really trick and has 8 to 1. comp. It has the 650 double pumer supercharger carbs on it . I dont run lean and have gobbs of power. Make sure you get your timing dead on and your fuel system up to par of you will kill any motor with a blower. I also have a 4-speed trans so I am having fun with it. This motor will be going in my 57 chevy "x" clone that I am planning . Tim
I hate to say this but you're way off... TWO 750 double pumpers on a street engine? You'd have to run it at 6000 + all the time! A couple 500 single feeds is the max... I'm running my blown 354 on a single 750 Edelbrock... the carbs willl limit the HP and rpm's, and since I could give a hoot about running over 4,500 rpm, the 750 will be OK... maybe go to an 850 but that's it. My Hemi is cammed pretty mild for good fuel economy and "kick-in-the-seat-of-the-pants" acceleration in traffic. A blower motor can be a torque monster if set up correctly... and deliver good fuel economy to boot. 16 to 18 mpg isn't out of reach on the highway. But putting TWO 750's on it will require a HUGE cam... not my cup of tea. Who wants to drive something that needs a 4000 rpm converter, idles at 1500 rpm and eats more than Rosie O'Donnel at a $1.99 Chinese buffet? Not this old man. Oh yeah, one more thing, a blown street motor should start on the first revolution of the starter... you will NEVER need to squirt any fuel into the carb... your thinking of old mechanically injected engines... Having a MSD box or equivalent that retards the timing at top end also helps keep things inside the oil pan.
When strating your blower motor, give it a couple real good throttle/gas pedal pumps as blower motors like lots of fuel when they are cold. Once started, hold the RPM up there (1,800 plus) for a minute or two allowing heat to build which properly atomizes the fuel in a blower application. Run you motor a little on the rich side as you do not want to lean the motor out on the top end if you have a tendancy to play around a bit..... I run a blower on my street driven hot rod (stroked 409) which is almost entirely different from my nostalgic drag race, hot rod (392 hemi). If you are talking to drag racers, well they will not lead you in the wrong direction, however; remember they are realting to drag racing application with a constant 7,000 RPM range.
The Jalopy Journal
