I want to run a blower in my 55 G***er, but I really dont wanna go the 4-71,6-71,8-71 etc.. route. My motor just isnt built to handle those big huffers...I want a smaller blower like the 142, 144, 177, but then im stuck with traditionality issues...Im kida leaning towards the 177 ( http://www.holley.com/types/Small Block Chevrolet - 177 Series .asp ) It more or less resembles the bigger blowers but would be great for my engine.......Some oppinions please?????
My opinion is a 6-71 for the look. and spin it slow. You can make any boost # you want with the right pulley set.
What is it about your motor that you're worried about? and why would a small blower turning fast be any different than a big one turning slow?
It is all about the pulleys not the size of the blower .If you do not have a budget go bigger spin slower .You will always be able to change your motor and use your blower on another motor .I am running 871 on a bbc 31 coupe
The little blowers are decent but will create a lot more heat on the intake charge because they spin faster. Go with a 6/71 and slow it down. Also used 6's are easier and cheaper to find as well as the needed accessories.
maybe im not readin fine print - what motor are you wantin to huff? why are you thinking your motor isnt up to it - if true, and you have a know motor problem, no blower will make the problem better but a 4-71/6-71 ona small block with low boost/underdriven should actually be less detrimental to the bottom end than the smaller units wound up
i keep looking at the blowers for the ford lightning, there always on ebay and i dont think they look so bad.
Anything smaller than a 4:71 is a waist of time and money. Go the under driven and/or extra clearance on the rotors, and your mill will live forever, sound sweet and look *****in'
Its a 350 with Dart Iron Eagle Platinum 180 heads, LT1 cam 254-254@.050" 114LSA .485"-.485" valve lift, roller tip 1.5 rockers, flat top pistions, 9:1 compression rebuilt about 2000 miles ago. I am weiry about the bigger blowers because of the multiple carbs. Last summer I was running a 2x4 intake with 2 500cfm edelbrocks and it couldnt handle that much cfm, but that was also before I put the Dart heads on it, so I dont know....
Oh man, hell yes your motor can handle a 6-71. Like Jay said, those little blowers make alot of heat for the little they produce. As was said, underdrive it, only 4 or 5 psi and you'll be fine, hell you could go even more as you get bored. One thing you will have to do it go bigger on the carbs, at least for fuel delivery. Those little ones will peter out way before you get high enough rpms to do any damage. It's fun though.....goes like hell and then tapers off about 6k or so... Don't be surprised if it idles smoothly with that huffer and the cam you have. Blowers have a way about them, they increase displacement and your hot cam in a 350 ends up being an rv/stockish cam in a 454............
putting two carbs on a blower is completely different from putting two carbs on a stockish smallblock. The blower does a great mixing job, very good throttle response. Sounds like you have a bit much compression, but if you underdrive enough to keep the boost down to about 4-5 psi you'll see a big performance increase over what you have now, and it MIGHT not rattle itself to death.
squirrel, 4-5 pounds sounds good to me..I should be alright if i run super (92 octane)???. What do you mean by rattle itself???
It's hard to say for sure without trying it, but you would probably be ok with 92 with that kind of compression and boost. The modern cylinder heads seem to be better than older designs about not detonating (yeah, that's what I meant by rattling).
I have a pair of 500 cfm Barry Grant Blower carbs on my 6-71 blown 302 ford. I had to jet them up as I was running a bit lean, but they seem about right for my CI. VERY responsive to say the least!!!!
been running 625 eldelbrocks on a 6-71 350 smallblock with 8.75 compression at 8-9 psi at idol for over a year with no problems. It runs 190 degrees on a summer day.
With a 6-71, the official BDS boost chart says 9.0 compression and 6lbs of boost is OK for a street car on pump gas. That would be towards the high end of teh spectrum, however, so you would have to mind your total timing and fuel quality. Remember, if you have 9.0 and 6lbs, you can run around all day long on 87 octane and never get anywhere near danger as long as you are not running her hard. Only at 6000 rpm with your foot on the floor will you really need to have checked your timing recently and topped her off with 92. I have had my blown Pontiac on the road for a year and a half. Everyday back and forth to work.. including three thousand mile round trips to teh HAMB Drags with never even a hiccup. Good luck, -Abone.
Bumpity... Are the 142's pretty decent? I'm familiar with 6-71's but I'm just thinking in case I found a smokin' deal on one. Or I might have to put an LS7 from a Z06 into the Merc.
Id run around 6-5 lbs, and runa boost retard ignition box such as an MSD 6BTM. It allows to to reduce the abount of timing per lb of boost. Makes it safe by preventing meltdowns of cast pistons as well as blown head gasket prevention. Are you running forged or hypereutectic or cast slugs? Rat
common problem alot of guys have when they go blower, no matter which one is haveing incorrect cam overlap specs....damn thing will wreak of rich if the overlap is wrong...trust me i KNOW on this one
My Merc has a 350ci SBC crate engine of some kind, so I ***ume flattop hypereutectic pistons. 6-7 lbs of boost would probably be okay. I had a custom YSi Vortech and a custom 88mm turbo setup in an OT car so am familiar with the issues. 6-71's look sick but they are not cheap I'm thinking. I'm thinking a 750dp would be enough.
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