Planning a 5.0 Overhaul

[TekMan05]

I know you can buy pistons that have a raised top that reduce the volume of the combustion chamber. Is this what you are referring to? If you change pistons there are a lot of them to choose from and I would recommend getting lightweight ones to also reduce the rotating mass. Just make sure there isn't any piston to valve interference with whatever you choose.

Milling the heads down reduces the compression ration too and costs less. Once again, just watch for piston to valve interference.

Ok, and yes PtV clearance will be important to keep in mind. Maybe milling the existing heads will be a better route to go but I would probably need to decide that before having my custom camshaft designed with that in mind. I thought about aftermarket heads but there's no guarantee my headers will mate up to the flanges on them and I can't afford a new set of headers to do that. I really need to get out there and find a good machine shop in town and discuss my needs there. They could probably get me set in the right direction as well on what else I'm gonna need to make this rebuild go smoothly.

 

[94Eddie]

Ok, and yes PtV clearance will be important to keep in mind. Maybe milling the existing heads will be a better route to go but I would probably need to decide that before having my custom camshaft designed with that in mind. I thought about aftermarket heads but there's no guarantee my headers will mate up to the flanges on them and I can't afford a new set of headers to do that. I really need to get out there and find a good machine shop in town and discuss my needs there. They could probably get me set in the right direction as well on what else I'm gonna need to make this rebuild go smoothly.

I have wasted a lot of money building up my Mustang over the years. My best advice to you is to plan it out as best you can so you aren't replacing parts down the road as this is where you can really start throwing away money. Maybe you need to set a horsepower target first and then see what it costs to get you to that point. Unfortunately, on a naturally aspirated 5.0L, the heads are going to be your limiting factor. You can do all the other breathing mods and without swapping to better breathing heads you are not getting the most out of the money you spend.

One reason I really like going the twin screw or Roots blower direction installed on a stock engine is this will delivery a substantial horsepower, and more importantly torque, increase across the RPM range for the least expense in the long run. Also, it is something you can easily remove to take the engine back to stock for resale. Then you can recoup a good bit of your money by selling the blower kit to someone else. A Roots or twin screw blower will make the 5.0L feel like a good running big block engine. It will also let you keep your gas mileage close to stock if you can drive with a lite foot.

 

[TekMan05]

dasfinc was selling a motor that was overhauled and cammed that had an X-Charger on it. I was thinking of grabbing it but was sold the other day. My goal isn't HUGE horsepower levels. I'm rebuilding it mostly for the longevity but also squeeze some extra power out of the engine while doing the overhaul. Even if had a supercharger to put on it, I'd still probably have a custom cam built for it anyways. So with that all in mind, I want to retain great DD manners with peace of mind while beefing up the cam/valve-train some. I could try contacting trick flow to see what they'd suggest but I know they're gonna try to recommend an off the shelf cam and like I said earlier with all those after market parts it could get pricey quick especially if my headers don't fit on some aftermarket heads. Otherwise I would save a little extra for higher flowing heads. There's alot to consider with this , it's not as easy as modding a Mustang.

 

[94Eddie]

Is there problems with the engine that is forcing you to rebuild it? The 302 is a very durable engine and many can run for well over 200k before needing any serious work. If you have time then maybe an alternative would be to get an engine and rebuild it while continuing to use your current engine. Then you can build the engine you want and still get the most life from the current one.

IMO, it isn't any different than building a Mustang engine. Either way you have to know what you want from the build. Without using a blower or turbos, on a naturally aspirated engine you have to decide whether you want a high RPM, high horsepower engine or one that produces low to mid range torque. Once you figure this out the rest is just a matter of choosing the components to make it happen. For the 302 there are so many builds to look at other people have done it makes choosing the parts fairly easy. Whether the 302 is in a Mustang or Explorer makes little difference to the outcome.

 

[TekMan05]

It burns a little bit of oil and just recently started minor dripping underneath near the transmission. Thinkin maybe rear seal leak. I add maybe 3/4 quarts between oil changes. Mechanically she runs GREAT but it is something that needs to be addressed. I know it'll probably get steadily worse over time. I'm lookin to do more low-mid range pull than high end power. I have a 3V mustang GT for that kind of fun. My truck has been in the family since almost day one so I want to keep her around longer while upgrading a little bit at the same time. I do appreciate your help so far on this subject.

 

[Turdle]

It burns a little bit of oil and just recently started minor dripping underneath near the transmission. Thinkin maybe rear seal leak. I add maybe 3/4 quarts between oil changes. Mechanically she runs GREAT but it is something that needs to be addressed. I know it'll probably get steadily worse over time. I'm lookin to do more low-mid range pull than high end power. I have a 3V mustang GT for that kind of fun. My truck has been in the family since almost day one so I want to keep her around longer while upgrading a little bit at the same time. I do appreciate your help so far on this subject.

You might go under and check the oil pan bolts--snug em up a tad, and change the PCV valve.

This may slow the leak.

 

[TekMan05]

I changed the pcv last year so that's pretty new. But ill seeing if checking the oil pan bolts does anything. Worth a shot

 

[94Eddie]

It burns a little bit of oil and just recently started minor dripping underneath near the transmission. Thinkin maybe rear seal leak. I add maybe 3/4 quarts between oil changes. Mechanically she runs GREAT but it is something that needs to be addressed. I know it'll probably get steadily worse over time. I'm lookin to do more low-mid range pull than high end power. I have a 3V mustang GT for that kind of fun. My truck has been in the family since almost day one so I want to keep her around longer while upgrading a little bit at the same time. I do appreciate your help so far on this subject.

My '89 5.0L Mustang burned a quart of oil between 3,000 mile changes ever since I drove it off the dealer's lot in 1989. If you want low/mid RPM torque then nothing will deliver it like a twin screw or Roots blower. My Mustang made 460 ft-lbs at the rear wheels just above 2,000 RPM with a Kenne Bell twin screw installed. That was when the dyno started measuring it. It made huge torque numbers just off idle too. No head/intake/cam combination alone can approach that torque number in the low to mid RPM range.

It sounds to me like the problems you have aren't all that severe and all that is needed is a little maintenance to address a few oil leaks. Another area to look at is the oil sending unit that screws into the oil pan. The seal on them can deteriorate and leak oil when the engine is running. They won't leak much when the vehicle is sitting in the driveway.

 

[TekMan05]

The main issue is that superchargers are hard to come by for our trucks and I've always been a fan of naturally aspirated power. I'm not seeking to achieve jaw dropping power levels. Just want to add a little more grunt while re sealing the engine and preserving it for the long term future if that makes sense.

 

[94Eddie]

One thing I learned quick when I started building up my Mustang is horsepower costs money. A lot of people analyze various modifications and the horsepower gains they deliver by computing a horsepower per dollar ratio. Outside of nitrous, a supercharger will usually return the most horsepower per dollar spent. Maybe if you are patient and keep a lookout for another Explorer supercharger kit to show up you can score one. I think you have a lot of miles left in your current engine. Especially since it has been well maintained. Form a plan to build up the engine and look for opportunities to score the parts and components you need. Buying used stuff can cut the cost in half, or more, than buying all new.

 

[TekMan05]

Yes that's why you've been helpful because I'm using this thread as a planning discussion before I even drop a dime towards the engine. I only say I'm trying to avoid an over the top project is I already got a 4.6 Stang that is much faster and satisfying that need to rev high. I know one thing, I'm not concerned with exceeding the normal rev limitations of this 5.0. II got 164,500 ticks on her now and she does indeed run good. Jon can also vouch for how clean it is when we did my valve cover swap. I just noticed the smell of freshly burned oil at times of WOT and the minor leaks. It's just a shame that a cam swap on these aren't as simple as it was on my mustang.

 

[94Eddie]

I ran 16 psi of boost on my 5.0L that had over 150k miles on it. It still burns the same amount of oil it did when new. A cam swap on the OHC engines are easier is some respects than a push rod motor. At least you don't need the room in front of the motor to pull the camshaft out.

If you ever want to turn your Stang into an absolute monster, Kenne Bell make on heck of a blower kit for the 4.6L engines.

 

[ssp.interceptor]

.

 

[TekMan05]

I would like to swap heads along with the cam IF my current headers mate up to the exhaust flanges. Also having another set of heads would greatly reduce down time of my truck. I can prep the entire upper end of the motor while still driving my Truck.
I guess I mis-read your post when it says it retains stock header location. So my TMH's should bolt right up to them. Any dyno numbers on those heads? And could I swap those and have a custom cam made for those heads right there?

 

[TekMan05]

My '89 5.0L Mustang burned a quart of oil between 3,000 mile changes ever since I drove it off the dealer's lot in 1989. If you want low/mid RPM torque then nothing will deliver it like a twin screw or Roots blower. My Mustang made 460 ft-lbs at the rear wheels just above 2,000 RPM with a Kenne Bell twin screw installed. That was when the dyno started measuring it. It made huge torque numbers just off idle too. No head/intake/cam combination alone can approach that torque number in the low to mid RPM range.

It sounds to me like the problems you have aren't all that severe and all that is needed is a little maintenance to address a few oil leaks. Another area to look at is the oil sending unit that screws into the oil pan. The seal on them can deteriorate and leak oil when the engine is running. They won't leak much when the vehicle is sitting in the driveway.

I thought I'd share a picture that puts the oil leak into perspective for you. The oil spot at the center of the picture or the farthest away is the current one from sitting overnight. The other dark spots in the foreground are from other times from the truck being positioned a little differently in the garage.

 

[TekMan05]

I'm going to call tri-state cylinder heads back today if I get a chance. If they will fit with my current headers then this is the route I'm gonna go for more of simplicity. I talked to bob and while he didn't comment from that link you posted he did say none of the aftermarkets would work except the GT-40x heads should be okay. I take it the flow tek 5.0 X Heads you posted are the same heads?

 

[TekMan05]

Bump! so I talked to them on the phone just now and he said the flow Tek 5.0 heads replicate the gt-40x heads. The only thing I'm not sure would work right is the EGR setup. He made it sound like the earlier gt40 setup by saying there's a passage in the heads and not setup for an external setup like my P heads? Hmm... Anyone on here familiar with these heads at all?

 

[tomsteve]

one of the best books i ever read on getting extra power was smokey yunick's power secrets. i learned a LOT. working the heads and valve train is a great way to increase power, but without work on the bottom end, it is money wasted. i would suggest a rebuild along with the heads and cam. have the crank ground, hone the cylinders( if they are in tolerance), put in new rings, main and rod bearings, oil pump, upgrade the rod and main cap bolts, timing chain and gears, valve springs, freeze plugs.
any upgrades to increase horsepower/performance will only be a good as the weakest part in the engine. theres nothing wrong with bulletproofing a motor, but skimpin here and there will cost in the long run.

 

[ssp.interceptor]

.

 

[TekMan05]

Ok cool thanks for that tidbit. This is the route I'm really thinking about going for the rebuild. Now I can go back to flowtech inductions and see if they can get me a custom cam around these heads. Everyone needs to remember I'm not trying to over complicate and over achieve with this project. I just need it to run good and sound good too. I have a mustang that I will be focused on heavily once its paid off. My ex doesn't need to lift off the ground or run 12's at the track. Just be more aggressive daily driven SUV that retains all the same capabilities as factory.