My brother wants me to put his Eaton supercharger on his 89' bronco .302 184k. Though I can do it and I have heard of it being adapted to mustangs with the 5.0, I have also heard that the boost can cause problems on that engine without doing some modifications. It just doesn't look to me like the 5 or so pounds he would get out of it would cause ring problems or seals or gaskets to fail. He doesn't want anything by way of major power and he payed only $40 for the blower. It was his first car and he wants to help me do some modifications before he decides what to do to the internals come rebuild time. Would appreciate any pointers, criticisms or funny comments. Everything helps. Thanks .

 

I think general rules about forced induction may apply; make sure the fuel system is up to providing enough fuel for the additional air, although 5psi is not very much boost. You may want to retard the timing a little. In any case, what kills an engine faster than anything else is detonation, and you want to do everything you can to prevent that.

Do you plan to install an aftercooler? That should help.

 

I have an after cooler lined up for it. I will definitely have to be careful to avoid any detonation problems. Any recommendations for fuel system upgrades? He plans to buy a new computer for it soon and I may convince him to do a few other things before he gets to confident in installing this thing.

I just wondered mostly about the intake gaskets. People have told me they have experienced problems but I just don't see how unless I just don't take the 5 pounds boost very seriously.

 

If the intake gaskets aren't leaking without forced induction, they should not leak with just 5 psi of boost. When the throttle is mostly closed, as in idling, the normal manifold vacuum is around 16" to 18" of mercury, or about 8 to 9 psi below atmosphere. That's the pressure the gaskets would be fighting normally, so 5 psi going the other way should be no problem.

If the engine is the 302 HO, Ford used low tension piston rings to reduce friction, and loose forged pistons that need to warm up before they sealed properly. So you should drive it easy until the engine warms up before pushing it hard. Non-HO engines had cast pistons with normal rings, but they also should probably warm up before being pushed hard.

As for fuel, a rough estimate indicates that 5 psi boost is about 1/3 additional pressure over atmosphere. That's like making the engine 1/3 bigger, or if the thermodynamic efficiency stays the same, you may get 1/3 more power. If I use a 302 HO engine as reference, the stock power rating is 225 HP, and you would bump it up to 300 HP. Using the stock fuel injectors rated at 19 lbs/hr and BSFC of 0.5 comes out to right around 300 HP that they can support. You can get an adjustable fuel pressure regulator to bump up the pressure and a higher volume fuel pump if the stock versions can't keep up. It's probably a good idea to replace the stock fuel pump anyway just due to its age.

 

Thanks for the tips. So I shouldn't have to make any injector changes as long as I stay at a moderate hp? Or do you recommend making the change anyway?

 

plan on converting to MAF, us an A9L or A9P.

you may need to upgrade to 24lb injectors and of course have the ecu calibrated to run those.

there have been some builds using this blower over at FSb

 

It is a good idea to make sure the fuel system can keep up with the additional air, whether that means increased fuel pressure or bigger injectors. Either way, get a new high volume fuel pump.

I seem to recall Paxton was selling supercharger kits in the late 80's for 5.0 HO Mustangs that put out around 5-7 psi boost, and did not require major fuel system modifications.

 

Thanks. I will look around and see what others have done and had experiences with before jumping into it. And I will make sure that my brother is willing to put up the money for parts if he has to before getting stuck with a project. I like to play it on the safe side but I'll talk it over with him.

 

I would also upgrade the ignition with a controller that can retard the timing when the boost goes up. along with above mentioned fuel upgrades it should be fine

also remember that eaton blowers have a bypass valve built in and only build boost when you give it enough throttle, rather than building boost all the time.

 

I forgot those were bypassed. I'm so used to dealing with the big blowers like the 6-71. I would tell him just to go turbo but I don't think he wants to mess with his headers and exhaust. Do you know about what rpm the eaton gets it's boost? Still would be quicker than spooling up a turbo.

 

don't know for sure, im pretty sure the max rpm for them is about 16,000 rpm. I would think that since they came on 3.8's they would need to be fairly overdriven to build the boost/rpm as the little engine. there are some guys - I believe either at the corral or allfordmustang forums that has built m90 setup's that would know much more than me, my terminator m112 is still sitting on the shelf. however the boost that they do build is atleast immediately there since its already spinning.

however

 

I'll keep checking around and see what I can do. I think the m112 is a much better option for a bronco. Maybe one day he'll fork out the extra money for one.