twinscrews dont have any teflon seals either and they make crazy boost ;) plus they only need one carb and if run fuelinjected im pretty sure they can be low enough to keep everyting under a flat hood,only real downside is that they are pretty expensive and you have to custom fab everyting since there is no manifolds or pulleysetups anywhere to be found out of a catalog, oo wait i just changed my mind i like to custom fab everything since its so rare that anyting that is suposed to be bolt on fits and performs right,right out of the bow anyway ;)
School me on supercharging a 360
- Thread starter Coyote Jack
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twinscrews dont have any teflon seals either and they make crazy boost ;) plus they only need one carb and if run fuelinjected im pretty sure they can be low enough to keep everyting under a flat hood,only real downside is that they are pretty expensive and you have to custom fab everyting since there is no manifolds or pulleysetups anywhere to be found out of a catalog, oo wait i just changed my mind i like to custom fab everything since its so rare that anyting that is suposed to be bolt on fits and performs right,right out of the bow anyway ;)
Yeah, I've read about them a little. They are supposed to be really efficient. The ones I really like though are the Vortecs. They don't stick outta the hood, but they make gobs of power and torque.
rdakota340
Well-Known Member
I guess I have not spond one high enough we have not had no problems with teflons coming off are apart but there is a first time for everything they are great for the street.
I have been looking at a few manufacturers of roots type blowers websites. Weiand, Dyers and BDS off the top of my head. The Weiand's seem to be cheaper, but I have been told they are not as good either. The Dyers look like a decent piece and the BDS blowers look like they are very good, but a little pricey. What are your opinions on the different makes?
Jack
Jack
fstfish66
Well-Known Member
remember with pump gas 93 octane will only support 9 lbs of booost with out a computer controlled engine,,
and when choosing a roots type super charger you need to rememeber,these were designed for diesel engines so the formula is this
6 .71 = 6 cylinder x 71 C,I.
8.71 = 8 cylinder x 71 c,.i.
when converting it to a gas engine 6x71 = 426 thats the engine C,I thats the biggest gas engine it will work on making boost and not over heating the engine,,,
all the roots type you see from BDS and such are new offf the shelf units made to be effective on a gas engine,,and made to look show pretty,, but they are also most all of them the small bore case,,
dyer is the guy that started the street super charger movement back in the 1970s,,,but they were converting real GMC super chargers off of diesel engines full size true 6.71 cases,,my dyers blower is a 1965 GMC unit,thats why if you look close it is not as pretty as a off the shelf made for the street eye candy,.,
BDS boost chart is a guide and not 100% accurate,, boost figures depend on real time compression,,not advertised compression,, real compression comes from the piston and chamber size of your heads,,
if you dont have your motor CC ed by your machine shop before assembly your only guessing at what compression you really have,, but you can always put a boost guage on and hammer it,,see if you can read the guage while driving on the street,, no so easy in my car LOL,,,
ive never had a good experience wit hthe people at BDS,, ask 10 questions you will get 20 incorrect answers,,
pick up a copy of street super charging and read it,,you will learn a lot,,
and when choosing a roots type super charger you need to rememeber,these were designed for diesel engines so the formula is this
6 .71 = 6 cylinder x 71 C,I.
8.71 = 8 cylinder x 71 c,.i.
when converting it to a gas engine 6x71 = 426 thats the engine C,I thats the biggest gas engine it will work on making boost and not over heating the engine,,,
all the roots type you see from BDS and such are new offf the shelf units made to be effective on a gas engine,,and made to look show pretty,, but they are also most all of them the small bore case,,
dyer is the guy that started the street super charger movement back in the 1970s,,,but they were converting real GMC super chargers off of diesel engines full size true 6.71 cases,,my dyers blower is a 1965 GMC unit,thats why if you look close it is not as pretty as a off the shelf made for the street eye candy,.,
BDS boost chart is a guide and not 100% accurate,, boost figures depend on real time compression,,not advertised compression,, real compression comes from the piston and chamber size of your heads,,
if you dont have your motor CC ed by your machine shop before assembly your only guessing at what compression you really have,, but you can always put a boost guage on and hammer it,,see if you can read the guage while driving on the street,, no so easy in my car LOL,,,
ive never had a good experience wit hthe people at BDS,, ask 10 questions you will get 20 incorrect answers,,
pick up a copy of street super charging and read it,,you will learn a lot,,
Here is the one I was looking at from Dyers for comparison purposes. It's about 1/3 the way down the page. http://www.dyersblowers.com/1694.html
Polished may not be the way to go unless you are looking at a trailer queen. A lot of cleaning to do there. LOL
I believe I am looking at a 6-71 because I am thinking of a 360 Magnum engine as a base engine. I like that idea as I would already have a roller cam setup and the possibility of fuel injection and computer control. There is also a running 5.7 Hemi available locally for $1000 right now. That would be a one of a kind setup for around here. I have a lot more to learn on this before I start buying anything though.
By the way, I finally got up the nerve to pass this by the wife while I was on vacation. I'm glad to say that she thought it was a cool idea. The trade off was that if I built the blower engine, I would not build another car. I can live with that. LOL The rest of my car was built with more HP and TQ in mind, so I don't have to change much there.
Jack
Polished may not be the way to go unless you are looking at a trailer queen. A lot of cleaning to do there. LOL
I believe I am looking at a 6-71 because I am thinking of a 360 Magnum engine as a base engine. I like that idea as I would already have a roller cam setup and the possibility of fuel injection and computer control. There is also a running 5.7 Hemi available locally for $1000 right now. That would be a one of a kind setup for around here. I have a lot more to learn on this before I start buying anything though.
By the way, I finally got up the nerve to pass this by the wife while I was on vacation. I'm glad to say that she thought it was a cool idea. The trade off was that if I built the blower engine, I would not build another car. I can live with that. LOL The rest of my car was built with more HP and TQ in mind, so I don't have to change much there.
Jack
fstfish66
Well-Known Member
have you checked,, can you get a magnum blower intake? you may have to get a magnum carb intake and do a plate like an old style dyer intake,,thats what im using,, not on my car but this intake was on annother 340 dyers blower went 10.63 full body all steel 9 inch slick duster,,
I haven't checked for Magnum specific as of yet. They do list a 360 and the 5.7 Hemi but I don't see a 5.9. This is something I will check right away.
Jack
Jack
fstfish66
Well-Known Member
this is a regular 4 bbl intake done by gary dyer in the 1970s,,
fstfish66
Well-Known Member
as far as i know dyers does not build intakes any longer,, the yuse the hampton intake,,its taller then mine but is still not a tru blower intake,,you may be able to get dyers to build you a magnum intake using a 4bbl inake or use the pics of mine,,and do it ur self,,
Actually, my sister and b-in-law run a truck body fabbing business. They can fab up about anything in aluminum. I bet it would be a lot cheaper than buying an off the shelf intake. That way I would basically be buying the blower and pully setup. Much cheaper than the entire kit.
Jack
Jack
fstfish66
Well-Known Member
well if he can weld aluminum ide do it that way,, just get a carb intake for the magnum 296 bucks at summit,,, and cut a plate ,,then justy build a few stand offs like on mine to support the plate,, if some oen makes but i doubt,,get a dual quad inline intake and built it that way,,, on the early intake like mine the thermostat housing is the only problem,,like it or not,,, the GM t housing is the same bolt patteren as the mopar,,but the thermostat is a different diameter,,,
and mopar and gm are oppisite,,gm the t stat is sunk in the intake mopar the t stat is in the housing,,, 2 ways to over come this is,,,
have your intake cut to accept the gm t stat,,, or like i did,, i bought a new iron gm t housing and had that machined to accept the mopar larger thermostat,,,and i used thermostat housing sealant,,
the better way would be machining the intake to accept the thermostat like a chevy intake,,,
and mopar and gm are oppisite,,gm the t stat is sunk in the intake mopar the t stat is in the housing,,, 2 ways to over come this is,,,
have your intake cut to accept the gm t stat,,, or like i did,, i bought a new iron gm t housing and had that machined to accept the mopar larger thermostat,,,and i used thermostat housing sealant,,
the better way would be machining the intake to accept the thermostat like a chevy intake,,,
I now somebody makes an inline dual quad for a magnum as I have seen one. Now just to track down the owner of that car. I was wondering about the squeeze on that single 4-barrel intake as that would raise the temp of the air going in.
Jack
Jack
fstfish66
Well-Known Member
well u may be right but i have NO temp porblems, i drive all over to cruise nites, in traffic,,interstate,,in the cold season and 100 degree weather,, 6% under driven making 13 pounds of boost on 93 pump gas,, a factory style radiator 4 row 22in x 19 in A body/ dodge van radiator
cruises at 178 degrees on the interstate last week in 101 degree temps out side i was at 195 in trafic,, using a mechanical fan,,
cruises at 178 degrees on the interstate last week in 101 degree temps out side i was at 195 in trafic,, using a mechanical fan,,
Indy have a blower manifold now for those of you intrested in it, both for LA heads and Magnum heads 
its in there modman series that can be used with 1 or 2 fourbarrels or even a sixpack they also have an adaptorplate to make it work with a blower
its in there modman series that can be used with 1 or 2 fourbarrels or even a sixpack they also have an adaptorplate to make it work with a blower
fstfish66
Well-Known Member
nice didnt know they had them for an LA or MAGNUM,, only knew about there modman for the new hemi,but knowing indy,,,,you will need a loan to get one ,,,thanks for the info
Yes thanks for the info.
I have a email into Dyers on weather or not they have a kit for a Magnum.
In the meantime I came across this intake for a 273/318. If you redrilled the Magnum heads to accept the bolt pattern would it work? http://www.summitracing.com/parts/OFY-5615/
Jack
I have a email into Dyers on weather or not they have a kit for a Magnum.
In the meantime I came across this intake for a 273/318. If you redrilled the Magnum heads to accept the bolt pattern would it work? http://www.summitracing.com/parts/OFY-5615/
Jack
fstfish66
Well-Known Member
see if there is one listed for the 340 may have larger ports,,offy still makes any thing u want, they still have all there old molds,,no web site from what ive been told,,and they had one for a 340
I heard back from Dyers, they don't make one. I checked out the Indy Modman and it is $694.00, not a bad price for Indy.
Jack
Jack
fstfish66
Well-Known Member
no not a bad price at all even for indy,, i called them last week,,,just to see,,and the price the ygave me on a mod man 5.7 single 4bbl intake seemed way to cheap, 399.00 im now guessing that didnt include the top.,
if you bought a standard small block blower intake from hampton,,,they are like 1200 bucks,,,,so the mod man will do the job for you i assume,,,,
if you bought a standard small block blower intake from hampton,,,they are like 1200 bucks,,,,so the mod man will do the job for you i assume,,,,
I have done some checking around. The stock 5.9 magnum is a good platform to start with strength wise. The block is plenty strong to take 600 HP. Indy makes an intake that will bolt right on for $634. I am having problems trying to find a piston though. I would like something to bring the CR down to 7.5 to 8.0 to 1 static with the 58 cc heads. A cam shouldn't be a problem, a roller with about .510 total lift and 235 duration @50 and a 112 centerline should be the ticket. Carbs seem to be about anything I want to put on top. All the way from 2 450 Edelbrocks up to a couple of Thermoquads seem to work. More investigation needed there. I don't know if my current exhaust will work or not. I have 1 5/8 primary's to 3 in collectors to 2 1/2 inch mandrel bent pipes and flowmaster 40's with a x-pipe.
Jack
Jack
fstfish66
Well-Known Member
you will probably have to have the pistons made,,if you do get 10 2 extra,,,so you dont have to pay a bundle to get one if some thing happens..
you can go as high as 8.5, compression ,just slow the blower down,, my compresssion is actuall 7.76 arias pistons,,,
as for a carb,,this is critical,,,look at hollys blower ready carbs, it makes a ton of difference,, i have 2 regular 650s,,,i always had to wait for the blower to build heat before it would idel,,,and othere small problems,,
sent the carbs to a guy that does blower carb,,,950 bucks later,,,turn the key,,and smoth as silk,,,,now these carbs flow 862 cfm each,,and tuned for 93 octane and street driving,,
you can go as high as 8.5, compression ,just slow the blower down,, my compresssion is actuall 7.76 arias pistons,,,
as for a carb,,this is critical,,,look at hollys blower ready carbs, it makes a ton of difference,, i have 2 regular 650s,,,i always had to wait for the blower to build heat before it would idel,,,and othere small problems,,
sent the carbs to a guy that does blower carb,,,950 bucks later,,,turn the key,,and smoth as silk,,,,now these carbs flow 862 cfm each,,and tuned for 93 octane and street driving,,
have you had a look at runing on E85? that way you can run alitle more compresion and it will also run alitle cooler from what i have been told, but its not a very good moneysaver since the fuelsystem will eat the savings and some more pretty quick
E85 is not readily available around here. I don't think I have ever seen a pump for it.
Jack
Jack
TT'74
Well-Known Member
If you get a magnum I personally wouldn't mess with the rotating assembly. I know of several people running the stock bottom end in the 15ish psi range no problem. A 5.9l at 15psi with good heads, intake, cam will put you way past the 600 range. On the magnum engines with FI the stock block is the weak point long before the rotating assembly assuming it's tuned properly.
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