Supercharger on a 300

[84FordVan]

Has anyone on this forum put a blower on a 300 l6? If so does anyone have any pics I can look at? I need intake ideas. I want to go throttle body with a Megasquirt 2 EFI setup that I have. I am hoping for a blow-through setup with my Eaton M90 T-bird blower, but I need suggestions as to the best approach. Just so everyone knows, I am giving the engine a complete rebuild as of right now, and I am only going to run about 5-6 PSI unless it's ok to go a little more.

 

[Broncitis]

First off the throttle body doesn't do much without injectors, or you going TBI or MPFI, its really quite easy, you have to make a bracket to sit the m90 on and line up the snout to most likely a custom dampner pulley, my calculations would be that you would need about an 8.75 dampner pulley with about a 3.2 snout pulley to get 5 or 6 psi and then decide whether you want to go straight to the intake are intercool it, you will just haveto get outside the box and come up with the plumbing.

 

[84FordVan]

Sorry, used the wrong terminology, I meant TBI. But yes, what you have told me sounds like a great idea. What do you think about me using a different pulley setup to spin the blower a bit faster and putting a BOV in the boost pipe to regulate pressure? Could I do this to make my boost at a lower RPM? I don't plan on spinning this engine over 4400 RPM.

 

[Broncitis]

The pulley set up I mentioned is not stock and really gives you a leg up since I have done this with success, I have to believe you know very little about the M90 asking about the BOV, the M90 if you have the stock piping on the intake side you will find has a valve which is operated by vacuum once the throttle plates close to send boosted pressure back into the intake side, I run an extra BOV to help get rid of boost quicker upon deceleration, not to control PSI, to change PSI you need to experiment with different snout pulleys. The #'s I gave you will get you very close with 300 cubes to 5 or 6 PSI, also some of the GM TBI's will support 275 HP with added fuel pressure within reason and can be blown through with ease since it has the same opening as most 4 barrels, I think if I may, that you have alot of study to do.

 

[Broncitis]

Follow up,the whole idea of a positive displacement blower is to get you bottom end quicker, while the centrifugal blowers, whether they be a turbo or a belt drive centrifugal in most cases don't bring on boost til a little further up the RPM band and since most of us six people don't go much over 5k revs, its why I really like the roots style blowers, although past a certain point it will fall on its face while the turbo will just keep going if you have an exceptional build as some here do. I love my m90 blown 200, talk about people totally confused about what I have under the hood.

 

[84FordVan]

Thanks for all the information. Much appreciated.

 

[Broncitis]

I would just love to see someone put an M90 on a 300, I think it would pull like a mule on crack and it would also help with some of the flow characteristic of the 300 head with forced induction, can you imagine the torque if you had a 275 horse 300, I bet it would be close to 375 or more. I would not use stock pistons, you may even use a cast piston of another application, but the 300 pistons will throw the skirts, I have done it twice. Get with the 300 crowd and see what they say for pistons and also one more tip, go with about 8.9 to 9.2 CR with 5 to 6 psi. I highly recomend bullet cams for a custom grind on the cam with as much info as you can provide them, most important part of build in my opinion. The correct cam to me is paramount.

 

[84FordVan]

Hey I got Sealed Power Hypereutectics, are those ok? I've heard they are tougher than sand cast pistons. This engine won't see rpm over 4000 hardly ever.

 

[84FordVan]

My pistons will get me somewhere around 8.5:1CR.

 

[Broncitis]

Sounds good on the pistons, but with 8.5.1 C/R you will be able to easily run 7 or 8 PSI boost, which will be pushing the M90 pretty hard on 300 cubes.With the #'s I gave you, on the dampner you could probably run a 3.0 blower pulley, now your gonna be pushing an easy 275 HP, probably all before 4500 rpm.