Engine tries to explode after M112

[lifted4.0]

how do you know that a 9 inch crank is good for your application? you dont want to max out the eaton..you wanna get your power from spinning it as slow as possible

 

[turbo cat]

have you looked intop the Moates Quarterhorse. You cna tune in real time with the QH and the hardware isnt all that expensive. Did you ditch the pcv tubing yet that could be bad news if you were driving along and the tube snapped and went to wot and sent you sideways into whatever is nearby.

 

[volver]

Junk Supercharger?

At WOT it only makes 2.5 pounds of boost.

I closed the bypass with my finger while idling no boost.

held revs at 2500 while holding bypass closed, engine draws 20 pounds of vacuum.

This eliminates possible leaks in my manifold.

maybe its not spinning fast enough? I have stock crank 6 inches with the smallest pulley at 2.75 inches on the SC. The ford lighting has a 7.5inch crank. Every time the engine rotates with a 6 inch pulley the supercharger should spin 2.18 times. Every time the 7.5 inch rotates the SC should spin 2.72 times.

At 4500 rpm my supercharger should spin 9818 rpm. according to http://www.capa.com.au/eaton_mp112_4th.htm I should be drawing 550 CFM.

according to a number of online calculators that is enough to make 9 PSI on a 5.0 engine.

So I think there is something wrong with the supercharger. what could it be?

 

[volver]

Opps. LOL I had the vacuum lines reversed on the bypass valve.

In second gear, WOT, I get a solid 5 pounds of boost and no supercharger whine.



Sigh,

Disappointing.


I need a larger crank pulley. I already have the smallest available pulley on the SC (2.75").

Is there a car (doesn't matter what brand, year, make) that has a 7-8 inch crank pulley that will bolt to my harmonic dampener?

Also there is a buzzing rattling like sheet metal rubbing when the engine revs above 3000 and is WOT. sound is coming from between rear of engine to center of transmission. possibly the left side cat rattling from increased air flow.

any ideas

 

[lifted4.0]

what kinda power does the stock 5.0 make? maybe i forgot what you had going, but i bet that 5.0 makes pretty good power with just 5 psi boost

i have a 2.7 pulley for mine, not installed, but im gonna see if it will fit without grinding the snout..some 2.7s fit, some dont SO i hear...

but you could also send it to steigmeir to get the snake bite package done if you cannot get more boost by the pulleys....kinda an expensive way to up your boost, but itll do it

and the whine is the best part! ahah

 

[volver]

update:

Pulled engine, found 5 cylinders that had blown the head gasket out into the water jacket.

So I was making what felt (the seat of my pants) only slightly better than stock power from only 3 cylinders.

The cylinder walls look great. I can still see the factory hone marks. I am contemplating replacing the piston rings.

What is the expected life of the piston rings? I have 183000 miles.
Does some one make performance rings the are designed to hold boost?

 

[BobWiersema]

Rings & Things

I don't know much about the 5.0 but I recently discovered a couple documents regarding the 4.0 that may help you out. Links attached. The problem may just be you need some high performance head bolts. Also on the 4.0 they recommend cupped pistons to reduce compression ratio. These two pdf files are on the 4.0 but it might give you better ideas about what should be changed.

On page one of this pdf they talk about the pistons and head bolts.
http://www.supersixmotorsports.com/pdf/40SOHCTech.pdf

This is basically just an add for ported and polished heads but they recommend the ARP bolts for power adders like yours.
http://www.supersixmotorsports.com/pdf/SSM200840SOHCCatRev1HeadsCams.pdf

If you do a search for ARP Head Bolts you should be able to find suppliers.

Good luck, dont blow it up.

Bob

 

[LilRoush]

Other than being made by Ford, the pushrod 5.0L V8 and the SOHC 4.0L V6 have almost nothing in common.

 

[BobWiersema]

?

Other than being made by Ford, the pushrod 5.0L V8 and the SOHC 4.0L V6 have almost nothing in common.

You should go back and read those two publications before posting something smart like that.

 

[LilRoush]

Ok, first link talked about the 4.0L having too high of a stock compression to use much boost. Then it talked about using dished pistons to lower compression, making it more blower friendly.
Second link talks about the weak head bolts used in the 4.0L and the weak deck resulting in head gasket leaks in boost applications.

Sorry to come off like a jerk, but neither of these relate to the 5.0L with the M112 on top.

The 5.0L in stock trim is much more 'blower friendly' that a stock 4.0L SOHC motor. It's more in line with the 3.8L pushrod V6 when it comes to boost applications.

If anything, I would bet the motor was on it's way out, and the new M112 set up helped push it over the edge.

 

[Munchies]

Any updates?

I would LOVE to see any and ALL pictures you have! Especially the adapter to the 5,0 and pulley's, belt routing etc
jrespecki@gmail.com

 

[wpurple]

With my Powerdyne with a 9# pulley, I get just a little more than 5#, the TMH (that are for a blown app) and a cat back, it reduces the boost numbers so although it is acting like 9#, there is only a little more than 5# of back pressure, and my powerdyne has been shimmed for more boost.

I think there is a myth with boost numbers to some extent...the more the exhaust is opened up, the lower the boost numbers, but more the HP

 

[LilRoush]

Boost is just the measure of restriction. If you open up the motor, you get less restriction and more power. The pulley # numbers from the factory are assuming that pulley on a stock motor.