this is more of a project as it will be a long time before i do anything about it. i still haven't finished rebuilding my engine (and i won't be putting anything on that, i cant afford to , and it's been off the road long enough now!!). BUT, one day after an accumulation of money and the right parts at the right prices this will be a go, so it's better to start now. Anyway while looking at stuff on the internet (damn Ebay) i've seen relatively inexpensive superchargers of mustangs etc (read Eaton M90 and M112) and considering there is nothing cheap for my model of engine (351m-400), i wondered if these may be worthwhile in the future. there are very few manifolds for the M motors and unless I bought a top line blower to match i would still have to have a bit of professional butchery done, so getting one made (with the help of some friends) isn't out of the question. my question is though can these blowers be run with a carby? all the ones i see are off injected and i won't/cant afford that any time soon although it would be nice. an early eaton (M90) had a top entry which looked a bit small unless you were running a two barrel (why would you do that on a supercharged 6.6l) but that would be a bit tall as well even if you could adapt it. the other models (majority of them) had side mounts for a throttle body obviously. unless there was such a thing as a 800cfm sidedraught (is there?)there is an added benifet in that these sit really low and may not poke out the bonnet. maybe an adapter could be made ie big elbow to suit a nice big 4 barrel. Would the fuel running through the rotors hurt them as they would be run dry normally I'd imagine, due to the fuel injection? or as it may have to be on something like LPG it may be better/worse on the rotors? LPG may suit for the actual running on boost due to better octane and burn temp? maybe someone has done/tried this before? I realise this is a bit of a project and the possibility is that it hasn't been done because it is a waste of time and easier to do it old school . No i don't want to go turbo, i realise these can be done relatively cheaply and effectively in the right hands with truly outstanding results, but the superchargers intrigue me and i dont want a centrifugal unit either (i like the sound as well). These blowers, especially the M90 is probably to small, but the M112 overdriven may just do it as the flow charts suggest over 800 CFM at max RPM. just remember i'm not trying to smash 1/4 miles here. i cant afford the breakages. so something streetable on the budget is all i'm after. if i get some sound advice on the positives on this i could start accumulating treasures to achieve something worthwhile. i can't afford to do anything to much in one go so a few thing cheap here and there is a bit more of a go. Cheers.

needs more paragraphs.

but... M112 or Twin M90's

M112 might be a bit small, good for thr 4.6-5L. M122H is often used on the 5.4L, dont see why it wouldnt stretch to a 351. Always some room for extra performance from them too, compared to the OEM trim

yeah you're right. it looks pretty ordinary doesn't it. i don't know about a twin set up. it would be getting pretty wide/tall, and while i know he 351m-400 is wide i still think it wouldn't be that wide.
i've seen those crazy one on top of the other jobbies (garry Myers?) and the odd one set up like a triangle but it is still getting a bit tall, and with the intake ports on the same side for most of them it would be a pain to integrate a fuel delivery system like a carby. unless there was a mirror set up off another vehicle with the intake on the other side. The earlier units with the port in the top may work in a triangle but i'm picturing a larke lump of intake, carbies etc wide and tall.

sorry waggin i sent submit just as your popped in. you are right and they probably are too small and this is why it isn't done more. mine is a 400ci as well so it might be too big for it. maybe a real funny looking wide/ tall manifold with two of the M90's on it side by side with mirrored side mounts using LPG mixers adapted as they seem to run in a side draught manner and would look in a symmetrical way like the twin turbo set ups do. it's still getting a bit tall tall though and starts coming through the bonnet and i would like to stay away from that. if i did that i may as well go conventional, although it would probably cost more.

On a 6.6 litre engine you need a 6-71 minimum, 8-71 would be better. A Newby cleveland 6-71 supercharger intake with 0.875" intake spacers would be a reasonable option. Check the casting quality though. Last one we had poor port alignment requiring ali welding and die grinding to get good port matching (on a 351C). The spacer plates sould help in this area if it's necessary.

Your 351 at 100% VE requires 175ci of airflow/rev. An M90 just 90ci/rev. So would need to run at 2x crankshaft speed just to keep up with the 351ci! At max flow 636cfm @ 14000rpm.

You need either 2x M90's or at least 1x M112/M122 to feed your beast! Go for the M112/M122. Because people upgrade from this to twin screw Whipple's/Kenne Bell's you can get some at reasonable prices.

If you gear an M112 to 2.5:1 you'd have 280ci/rev versus 175ci/rev so 105ci/rev boost. ie 105/175=0.6Bar (8.8psi). I wouldn't go for any more boost without an intercooler.

Anyway, have fun and good luck!

Could always go with a blow thru centrifugal blower setup, would work great too.

Just dont have the punch down low.

to xafalcon-i have though of that and you are right it is a better bet to in some ways to get a 351 manifold and use spacer plates and look at old school blowers. there are a lot of manifolds out there for the 351 (over the 400) so spacer plates give a lot of variety. this may still be an option later on my engine. if i see a nice air gap manifold come up at the right price (are they even making them??) in the future i would like to try it and i would need a set of spacers. only thing with that though is that they are like unicorn pooh and holley don't list them anymore. maybe someone ou tthere can get me a template of one so i can copy?
because they are so handy people just dont let them go. there is at least one supplier that does them in the states and they are a thing of beauty but NOT cheap so the price jumps significantly. can anyone tell me why blower manifolds seem to be so expensive over standard ones? there looks like there is less material in them but maybe they have higher tolerances because they are under pressure?? good to hear from someone from the homeland!
to phillc-good call on the specs, that helps a lot. i wouldn't be going for too much boost anyway so i don't need to go to feral. what was the M122 on and what did they do? How much?
to schnoods- yup it would, but like i said in earlier post, i would like to have a go at a supercharger setup. i am really new to this and maybe a big pay rise in the future would help to do lots of things. i could see myself doing a turbo in the future but i have always been a fan of superchargers without even owning them. i owned turbo deisel 4wd's for years and some of the things like extra servicing due to signicantly higher oil temps from the turbo and having to idle down all the time (especially after a bit of a thrash)can be a nuisance. i know i didn't mind at the time but i don't have to go back to it.
all good stuff guys. what about the fuel through the rotor issue? i know that the big ones (read roots actually need it (dont they?) so maybe this is a non issue. if you get them cheap enough who cares.

M122H on the Shelby GT500 5.4L model pushed around 400KW

there wouldn't be too many of those (M122) coming up cheap if at all?

I seen a Xf ute with twin superchargers on a 302ci, fed with 1 gas research carby per charger, a number of years ago. Bonnet mods were required to fit it under. Looked good. No idea on performance tho. I have a feeling they were a pair of toyota superchargers, which would probably be too small for 351 or 400ci of monster v8!

Anyway, food for thought.

Cheers

ToranaGuy

BDS do a full kit, with a 6-71 or 8-71 to suit the 400. Should retail for around 5 1/2 to 6 thousand. You can also buy there blower manifold for the 400, but it would not be cheap, probably around $1200 or more.
Start saving your pennies, Craig.

thanks for the comment "400ci of monster V8! ha ha. i'm sure any owners of big blocks would start laughing at that. 400's still go ok once you rebuild them properly. Cheers Sooty. thats what i thought. it will be a long time before it happens i think. can any one tell me why blower manifolds are so dear. there is less of them (material) and i would imagine the flow characteristics would be a lot less trouble as they are under pressure so the r+d would be a lot less. some really good after market manifolds from smaller companies than BDS dont cost as much as that. how many top end conventional N/A manifolds are over $750.

I have asked this question before, and the answer I keep getting is "because they sell sweet f**k all of them"! I suppose, when compared to a n/a manifold, there would be a lot less blower manifolds being sold, so......

If you are keen, just keep your eyes open for a 2nd hand 351C blower manifold, and get the spacers made locally. Probably the cheapest way out of it. You can buy the blower and the rest in bits as you can afford it, or even a full kit, with out a manifold if you find one.

Or go for a big a*** procharger-style blower, if you win lotto!