Max horsepower stock 5.0 internals

[volver]

How much horse power can I get out of the stock 5.0 before something breaks?

What will be the first part to fail and at what horse power? If I were to replace that part what would be the next thing to fail and when.

(Example,
Head gasket fails @ 250 HP
Connecting rod bolts fail @ 275 HP)


I will be installing an m112 supercharger, with new injectors, fuel pump, and tune before Christmas. I am looking for the maximum power I should tune for.

Oh... my engine has 180k miles on it, that might effect what will blow out first.

 

[Spdrcer34]

The block can split down the middle starting at about 450rwhp, Although many guys are at 600+ with a stock block. It is just a timebomb waiting to go boom.

That is the first MAJOR component that is known break, but if you are making THAT much power, you have opened the motor up and changed other things, like rods, pistons, cam, and heads.

Ryan

 

[eXcali]

I agree, if your making a ton of HP you already upgraded internals. I don't think your going to get into dangerous levels of torque/hp with just a super charger and tune. For the price of a tune, save that and try to find a set of pistons and cam. intake manifold spacer etc.... If you add those later you will have to retune it anyways.

I wouldn't personally put a supercharger on a 200k vehicle before atleast changing out the gaskets.

 

[volver]

If i am running 5-7 psi and have headers and tune, I think it would be making over 300 horse power.

Do i have to worry about anything at that point?

Are you saying that I can make 450hp on stock internals. Over that and my block will break. Or are you saying that even if i replace everything, i should not go for more than 450 hp becasue the block will explode.

What gaskets need to be replaced?

 

[KRAWLER]

There is no definate way to say at 375hp, so and so will break before this or that. Its all about carefull planning and wise choices. If I was you I would try to get as much information on your motor as possible to see its condition. Start off by doing a compression test and leakdown test. This will at least tell you that status of your rings and valves and how well they seal. Second maybe drop the oil pan and inspect bearings and the crankshaft. As long as everything is within specs you should have no problem supercharging your motor and still having reliability. I have made multiple 350hp motors on 150k or more miles and so far all to this date are still running strong.

 

[eXcali]

It's all about time, temp, and pressure. @12yrs and 200k ish miles just about every gasket in your vehicle is nearing the end of it's life span. You could run a supercharger for a while with no problems, heck maybe even years. The problem is a supercharger gives you more power by increasing the compression of your engine by forcing more air than normal into the combustion chamber. If you have rings wearing out, or any number of other issues this will make those issues worse and could cause a failure. If your serious in gaining more HP out of your engine look for a 5.0 at a junkyard and start rebuilding it on the side. A couple hours East of you they run about $100-200 at JY.

Your average supercharger is going to run you around $1,000 or more, so it just seems silly to make a $1,000 upgrade while skipping the under $100 maint that could sideline your vehicle.

There's also varibles that just can't be factored in unless you take your block to a good machine shop and have them do an inspection on it. Heck there's things that could fail next week whether you have the supercharger or not. A good shop will be able to inspect a block for you and tell you the max compression that it can safely handle and how you can possible increase it etc.

 

[volver]

I wouldn't mind putting my car on the side lines for a while, while i rebuild it.

I agree that the gaskets maybe at the end of their life. That is one item i will be adding to the list.

What about the pistons, rods, and crank. I don't think the crank would need to be replaced. The 302 has a shallow stroke. It should handle the extra power. I might want to replace the crank bearings. They could be worn after years of service. I would also want to resurface the rod connections. The pistons should be good up to 400hp maybe 500hp.

I am concerned about the connecting rods. What style are the stock rods. H? Are they forged? What power are they good for?

If i am replacing the head gasket I mind as well replace the bolts with ARP bolts for extra strength. I will also replace the connecting rod bolts with ARP.



I just want to know at what horse power the first component will fail?

 

[eXcali]

I wouldn't mind putting my car on the side lines for a while, while i rebuild it.

I agree that the gaskets maybe at the end of their life. That is one item i will be adding to the list.

What about the pistons, rods, and crank. I don't think the crank would need to be replaced. The 302 has a shallow stroke. It should handle the extra power. I might want to replace the crank bearings. They could be worn after years of service. I would also want to resurface the rod connections. The pistons should be good up to 400hp maybe 500hp.

I am concerned about the connecting rods. What style are the stock rods. H? Are they forged? What power are they good for?

If i am replacing the head gasket I mind as well replace the bolts with ARP bolts for extra strength. I will also replace the connecting rod bolts with ARP.



I just want to know at what horse power the first component will fail?

Well if you're looking for a guesstimate, and that's all people can do without inspecting the motor, I'd say with no previous damage or issues 375hp should be safe on all your components. I'd start looking at a failure range near the 400-450 ball park. I don't think the stock internals will last long over 400hp just due to the shear power, also I think a stock tranny starts getting issues over 400. If you have the $$ to pour into it you could upgrade everything to performance parts which would help knock that 400 wall down. I believe the the GT40 heads add some HP in themselves, and since you're going supercharged you could benefit from forged pistons, rods, crank etc, if you had the money or found a great deal. I'm pretty sure the stock 5.0 didn't have forged parts as they are a bit costly. I could be wrong tho.

 

[Turdle]

Internals are-
hyper pistons
forged rods
cast crankshaft with 2 bolt main bearings

Main bearing journal deflection will occur with a 350 hp launch unless a girdle is used.
In fact, the block will deflect a measurable amount if supported by only the rear bell housing bolts on an engine stand.

So, IMO 350-400 hp is the max you should go for if you want the engine to last a while.

There is a lifter valley stud girdle available, which might just give a little more stability to the block at this power level.

 

[volver]

Internals are-
hyper pistons
forged rods
cast crankshaft with 2 bolt main bearings

Main bearing journal deflection will occur with a 350 hp launch unless a girdle is used.
In fact, the block will deflect a measurable amount if supported by only the rear bell housing bolts on an engine stand.

So, IMO 350-400 hp is the max you should go for if you want the engine to last a while.

There is a lifter valley stud girdle available, which might just give a little more stability to the block at this power level.

This is good information. I am thrilled that the stock rods are forged. I assume that the rod bolts are strong as well. I don't think Ford would have used forged rods but crappy bolts, would they?

I read about the 302 failure on Corral mustang forum. The weakest link after gaskets and worn out parts is the block. The guys over there say that the internals can handle 500 horses but like Spdrcer34 said, the block is a time bomb over 450 horse power. They also recommended girdles. But I don't really understand what they do. I know that they support the block to prevent it from flexing do to the power. Do they do more than that or is that their purpose. Were can I get a girdle, summit?

Also what kind of gaskets am I looking for?

 

[volver]

ah.. found Turdle's post about girdles

 

[Elessar65]

If you really want to make some power I would say the best thing to do is buy a 5.0 from a yard somewhere, slap it on an engine stand, and spend a few weeks building it step by step in your garage, that way you can be sure about every component in it. Then when the time comes spend a weekend with your buddies and swap it into your truck. Sell the old one and make some of your money back. Thats just me though, I'm not a big fan of bolt on supercharger "kits" and the like. Odds are that it will be fine and give you years of service, but personally i would rather build my own block and everything, that way i know whats in it and what kind of shape its in. Its your truck though, do what YOU want to do and don't let anyone stop ya.

 

[po-po 5.0]

I had an '88 mustang with a shortblock from a '96 explorer that made 396hp/372tq on a dyno with a procharger. I put 50k miles on this combo with no problems. The first power-related failure on a 5.0 will definetly be the block anywhere north of 450rwhp. The real problem is with detonation related failures. Any time you're running forced induction you run the risk of detonation. Detonation at ANY horsepower level has the possibility of cracking pistons, squeezing headgaskets, or snapping rods on these motors. Thats why most people swap to forged internals when making big power: so if the motor DOES ping, you still get to drive home.


So the short answer is: 450 is where things start to break on power alone, but they'll break a hellava lot sooner with a bad tune, or bad gas!

 

[volver]

From an engineering standpoint the girdles do not help the blocks strength. The girdles in the lifer valley are parallel to the block's twist, they wont do any thing. The girdles around the rocker posts may help twisting slightly, but it would help more if you duck taped them to the side of the block. The bearing girdles are 1/4 of an inch thick. They will be twisted along with the block in their weakest direction they don't do any thing.



What the girdles do is hold the block together after in breaks saving your internals. But it will not be a loss if i lose my internals because i will be keeping them stock.



What would help would be some more motor mounts on the bottom and the top of the engine. The hole car would have to twist along with the block.

So.... Stock block will only net me 400 safely. Less than 375 for extra safety. That's plenty.

What is the highest octane gasoline that is readily available. 93? at Shell
how well do octane boosters work. They are kind of pricey if I have to spend 5 more dollars at every fill up. Is there something i can get at the hardware store to boost the octane.



Acetone?

What about mixing in a gallon of diesel for every 20 gallons of gas.



PS. will the head gasket fail before the block?

 

[po-po 5.0]

What would help would be some more motor mounts on the bottom and the top of the engine. The hole car would have to twist along with the block.

not really, no. Its forces inside the motor that split blocks. Not even a motorplate is going to help that.

What is the highest octane gasoline that is readily available. 93? at Shell
how well do octane boosters work. They are kind of pricey if I have to spend 5 more dollars at every fill up. Is there something i can get at the hardware store to boost the octane.






Acetone?

What about mixing in a gallon of diesel for every 20 gallons of gas.

93 is highest at pump. The best off-the-shelf octane boosters raise octane 2 points. 2........points. That'll take you from 93 to 93.2 (yea, point). So they're basically useless.

There is an additive called Torco thats specifically designed to increase the octane of pump gas for racing. Also, adding zylene (paint thinner) in the proper proportions will help too. Its 104 octane. It does have a lower energy density than gasoline so you don't want to run straight zylene.

PS. will the head gasket fail before the block?

Headgaskets don't fail based on power. Headgaskets fail because of detonation/overheating.

 

[eXcali]

You can order 100+ octane in the 55gallon drums. Back when I used to mess around with muscle cars and performance that's what we'd use. Some Sunoco stations have 114 octane pumps, but those are few and far between. I would get it at a station that was on a big lake in Michigan. It's meant for racing applications only. But I'd mix about 1-1 with premium in my race snowmobiles.

I payed $1.90 for 114 from the pump when regular was $1, this was more than 10 years ago so none of those prices are accurate any more.

 

[volver]

It sounds like I should be ok to boost the power up to 375hp without replacing anything. (other than adding supercharger, exhaust, and fuel management, and good tune). Is this correct?

Before I boost, I should barrow the compression tester from Autozone and do a compression test and leak down test. If i do not have leakage, I should be good to go. If I do have leakage then I should pull the heads, re-seat valves or replace, check cylinder wall condition, might have to hone and replace pistons. Might as well just do a complete engine rebuild.



Should this be my plan of action?

 

[volver]

Eaton M112

 

[po-po 5.0]

It sounds like I should be ok to boost the power up to 375hp without replacing anything. (other than adding supercharger, exhaust, and fuel management, and good tune). Is this correct?

Pretty much, yup. That is if by "fuel management" you mean pump and injectors. Although I will say good luck getting an M112 from a lightning to bolt on. To my knowledge, no one makes an intake that'll make this work.

Before I boost, I should barrow the compression tester from Autozone and do a compression test and leak down test. If i do not have leakage, I should be good to go. If I do have leakage then I should pull the heads, re-seat valves or replace, check cylinder wall condition, might have to hone and replace pistons. Might as well just do a complete engine rebuild.

Should this be my plan of action?

As cheap as 5.0s are, yea, just do a rebuild. IIRC these motors are 8.5:1 compression motors which is ideal for boost so rebuild to stock compression.....maybe with a little cam?

 

[volver]

Should I start a new thread if I would like to talk about octane, or should i just keep this one going?