Hello I was just given a 671 blower and am planning on doing the gas conversion to put it on my 331 hemi. After researching I have figured everything out except one thing. I noticed the gear that the snout bolts to is on the opposite side as every other blower I have seen. They all bolt to the driver side gear mine is on the passenger side so the supercharger is going to spin backwards. This is where I am confused. Is this going to work or am I shit outta luck? Just want to know if this is correct or if it's fixable or worth it. Thank you in advance Posted using the Full Custom H.A.M.B. App!
That thing looks to be straight off a truck. That means you've got to do a few things. First is to find a good bearing plate. The stockers are NOT up to the RPMs used by a gas motor. The gears are not up to the work either. Lots of cleaning is in order. Also, look up converting a gmc to gas engine use.
Most inline Detroits have the blower on the right side of the engine. But they can be assembled with the blower on the left side by reversing the block. The drive for the blower is coming off the gear train on the rear of the engine, and if the blower comes from a left side engine then it will be set up to drive in what looks like a backward direction. Most everything on a Detroit can be put together with whatever is needed on either side as necessary to fit the application. The blower can be on left or right side, the cam on left or right, the head can be reversed, and the exhaust can be on either the left or right side. Blower can be on same side as exhaust, or they can be on opposite sides. Your blower can be reassembled to make it spin the way you need it to without buying any other parts, although that's not saying you won't have to buy certain parts for the conversion to gas engine use.
Thank you for the responses I know about the bearings and seals and plates and have been doing a ton of research on that but no one I have found describes in which orientation it is suppose to go together on a gas motor. I am building the hemi for mostly street use nothing radical as it's my main driver. The mculloch is whining and I have always wanted a blower. Posted using the Full Custom H.A.M.B. App!
The way I figured out the way the case goes is by Bolting it onto the intake. The lip that is on the case goes on the drivers side of the motor. Then the rotors should flip in order to force air into the motor and the front cover should fit so the big hole is on the drivers side. Posted using the Full Custom H.A.M.B. App!
some of the bigger engines had 2 blowers (have saw as many as 4) one turned one way the other turned in opposite direction, but all parts interchanged from left to right
I understand that I have not measured clearances and that a new one is available. But I was only asking if they could be reversed. I don't mind cleaning it I would much rather spend time doing that than buying one. I have to make another intake anyways which is also time consuming unless they also make a kit for a 51 Chrysler hemi 331? Here is the car it's going on there isn't really anything on it that is from a kit so maybe everyone who says just buy a new one can see Posted using the Full Custom H.A.M.B. App!
Don't listen to those guys. You can build it yourself for a lot cheaper than buying a new one. You will need a mill for some of the clearance work though.
You can adapt the intake you have for your blower project. You will need two pullere to get the gears off...they come off together at least in a race blower. Cut the two bars out and leave just the center bar. Also what's wrong with the Paxton? g
The old mculloch that is currently on the motor has started to whine. It is suppose to be silent while running and to rebuild it will cost more than the 671 plus I think it's time for anew look! Posted using the Full Custom H.A.M.B. App!
Check again on how much to rebuild that McCulloch. The Paxton SN is the Short Nose (SN) version of the McCulloch meaning it does without the 2 speed drive. Paxton's aren't much to rebuild yourself and shoudn't be that much to have someone else do it, either. check out superchargerhelp.com and also try Craig at Paradise Wheels- he owns all the Paxton SN stuff now, and probably can rebuild the McCulloch, too. -rick.
I bought a 671 from Dean's a couple years ago, good quality conversion for very reasonable money. He will take yours as a core, or rebuild yours or sell you a kit to do it yourself. He also sells a video showing how to do it yourself.
Dean built mine too. I am a learn how to do it yourself kind of guy, but for a worry free supercharger, spending the few hundred bucks for someone who has been building blowers all day long for the last 40 years is a good investment. Good luck, -Abone.
Rotor timing & rotor clearance is done / set by the rotor gears . By Shiming the gears . You mill the case on each end to set rotor end to bearing plate clearance , You should not have to set end clearance unless you install new bearing plate's Or rotor's. But you will have to set rotor timing when you replace with new gears ( different set) You can take & make a plate to adapt the blower to the intake on the roadster in the Photo , Myself one time I made a plate to go on a single 4 barrel intake to bolt a 6-71 too, Worked great ( non race set up )
This is good to know and I will have to check it all out. I have an older blower intake for a BBC and a 671 that needs to be converted. Funny though I got rid of all my BBC stuff years ago and just remembered I have this on the shelf!
I recently rebuilt a 6-71 GMC. It was pretty time consuming both rotors were different length and shimmed. I had to machine the case,both rotors and a gear. Setting the clearances were a pain in the ### Mine wasn't in the best of shape.I,m cheap and a toolmaker so I had to do it myself. All the extras really add up, snout, pulleys, crank hub ,bearings, intake. If I had it to do over again I would buy a complete unit off Rick Dean, craigslist or something. I bought my bearings,cd and such from Rick Dean he was very helpful on the phone also. I haven't fired mine up yet but it sure looks cool. They are also a major Pain to sand and polish
The case has some slight pitting but rotors are in good shape after an hour of cleaning and machined the lip off Posted using the Full Custom H.A.M.B. App!
Not saying anyone here has this problem, butI have seen people get confused as to which direction the rotors turn on a GM blower. In use the air goes around the outside of the rotors, not down through the middle!
Yes a roots air goes around and a screw goes in the middle Posted using the Full Custom H.A.M.B. App!
Rebuilt and clearanced my own 6-71 off Diesel. Yea its a lot of work but it is 14,000miles and still working well. 7 psi boost. Instead of shimming the gears for timing, face machine the gears. shims can fret and change clearance. A 1973 PHR mag gave good info on buldin
You can get the rotors tipped too....with whomever is closest to you. I have no clue whom that would be in Cali'. Obviously, since you're tearing into it already......you have your sight lines already. There really isn't much to 'em. Looking good so far.
Teflon tipped rotors don't last long if you put some miles on a street motor. Don't bother, you can make enough boost for the street with standard rotors. Ago
The Jalopy Journal
