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Build approval someone please!

Hey guys
I’ve been preparing to take my engine out to address rear main seal issue. So while it’s out I plan to do some mods. I been researching this for sometime now. Like everyone else I want to do it on a small budget.  I feel good about my plan but I want to post it for some feed back. Now for the plan, my goal is 300whp daily driver.  Parts:

-1995 explorer GT40P heads, upper and lower intake, fuel injectors, and throttle body
-New lifters
-1.7 rocker arms
-New push rods
-springs
-ford racing e303 cam
-88 mustang ECU
My research tells me that this combination of parts can potentially  yield me the desired hp I seek. Please any feedback will be much appreciated. Disclaimer I am a complete novelist when it comes to engine building. This will be my first engine build. 
[SIGPIC][/SIGPIC]88 Thunderbird Sport 302 ,flowmaster 50 series delta

Re: Build approval someone please!

Reply #1
Well a GT40P headed 302 is not going to get you 300 wheel horsepower. You're going to need to go to some decent aluminum heads to get to that level.

If you want to run a E303 cam you will need to convert to MAF using an 89-93 Mustang 5.0 computer. The 86-88 Mustang 5.0 computers were Speed Density (except the 88 California cars, which were MAF) and do not play well with non-stock cams. I would run 24lb injectors with a GT40P head 302 and an E303. The 19lb injectors are a little small.

In addition you would need headers to replace the cast iron manifolds currently on you car as well as a new H-pipe for the headers. Plus the rest of the exhaust. A new fuel pump, as the stock one is too small. 
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

Re: Build approval someone please!

Reply #2
What Thunderjet said. The parts list is essentially an Explorer engine with the improvements of an E303, 1.7 rockers and better valvesprings. The stated goal is 300 wheel hp.

Ford rated the 5.0 Explorer and Mountaineers from the late 90s and early 2000s at 215 hp and around 280-5 tq.  Those are flywheel numbers, NOT measured at the drive wheels.

Even if we allowed for only an 18% loss thru the transmission and rear axle, the rear wheel numbers, at best, would be closer to 170hp and 230-240tq as a starting point.

We'd be asking alot to see an E303 cam and 1.7 rockers bring the needed 130hp deficit to the wheels to reach the 300.

This is a ~ 200whp motor, assuming good exhaust components and auto trans, thats all.

Re: Build approval someone please!

Reply #3
Well in stock form Explorer 5.0s have exhaust manifolds, a single exhaust, and a cam that is very similar to the cam used in our cars, but with the HO firing order.

Adding headers, a 2.5" exhaust, and an E303 cam should put the engine closer to 280-300hp at the crank. Through an AOD that translates to 230-250hp at the tire, if you're lucky.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

Re: Build approval someone please!

Reply #4
Actually the Explorer 5.0 uses a steel tubular header that, while more convoluted in appearance and function than the steel HO header, is not a cast iron manifold.

For near stock motors such as this Explorer 302, typical aftermarket shorty headers have been shown repeatedly on dyno tests to add somewhere between nothing to 7-10hp depending on which rpm point on the curve you're looking at. Averaging the slight losses and modest gains of the curve nets you an overall gain of 6-8 hp, thats it.

Similarly, the average 2.5" H or X pipe will offer a 10-12 whp gain at best, again because this engine's output is not sufficiently high enough to be suffering huge losses from exhaust inefficiencies.

The E303 cam can offer gains of around 20 whp when used with well-ported factory heads modified to take advantage, primarily of the additional lift. Unfortunately, with the engine we are discussing, any valve lift past .480 isnt going to gain much if anything due to cyl head inefficiencies. In this motor, I'd be surprised if the peak gain was anything over 10 whp, with the average being less.

Together,I'd estimate these parts represent a potential gain for this motor of less than 30whp, which when added to the 175whp the engine is likely to produce when backed by an automatic trans, puts it at ~ 200 whp. Thats around 240hp at the crank, and I'm being generous here.

Fact is, like the drag strip, a chassis dyno run is a harsh introduction to reality for most everyone that hits it for the first or second time. I've worked hundreds of dyno and drag strip events.  Everyone thinks they will lay down a 12 sec pass or put down 300whp at least. For many, the reality is quite different.

I'm not trying to be a buzzkill here. Just understand that a 302 that makes 300 whp will need to be making between 350-375hp at the crank.  Poweradders like nitrous or turbos aside, a 300whp 302 is no accident and certainly won't be budget friendly.

Re: Build approval someone please!

Reply #5
There have been several documented cases where people have taken junk yard Explorer 5.0s, swapped in a E303/B303/TF Stage 1 cam and new springs, headers, and a full 2.5" exhaust and made 240-260 wheel HP on a dyno. Just search Corral https://forums.corral.net/forums/5-0-5-8-engine-tech/1313525-another-gt40p-dyno.html . I wouldn't doubt that the OP could get into that range with GT40P heads. 300+ wheel HP no way. That would require an insane amount of porting. At that point better heads are warranted to get 300 wheel HP.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

Re: Build approval someone please!

Reply #6
Sorry, but the guy whose thread you linked to was posting dyno numbers thru a T5 which makes them inherently higher, he was using a tmoss ported explorer which is probably adding around 15-20hp, maybe better at the peak, and even people in the thread mentioned the dyno numbers sounded somewhat inflated.

Look, we can move goal posts all day to give OP the impression he's gonna crowd 300 rear wheel thru an AOD with an Explorer takeout motor sporting an E cam and a decent exhaust.  Not gonna happen, done it myself, watched I dont even know how many people do same/similar and been at the track to see the tale of the tape. If the OP is using an AOD, and is using the parts he listed, he'll be close to 200rwhp and nowhere near 300 on an accurate dyno without a fudged correction factor. I'm sorry but that is the limitations of that combo and that budget. 

Re: Build approval someone please!

Reply #7
Just as an aside, and for the benefit of the OP, if budget is truly a compelling and unyielding factor in your build, my recommendation would be to check your local drag strip or speed shop for a name and number of a reputable head porter in your area.

The Gt40 heads and lower intake can respond very favorably to a basic cleanup in the hands of a skilled porter, not break the budget, and put a healthy amount of additional power under the curve at all usable rpm points.

Aside from a T5 swap, the power gains from porting your listed components will yield the best bang for the buck.

On the heads:
*Valve bowl cleanup, valve guide bosses tapered, across all.
*If stock valves are serviceable, I've had good results on a 32 degree back cut on the intake valves that slightly reduces the width of the stock 45 degree seat cut.
*Light cleanup/squaring at the pushrod pinch on intake ports to allow smooth transition from ported lower intake.
*Carefully smooth and transition roof of exhaust port, with an eye toward centering valve in the port, since Ford production exhaust ports tend to be somewhat skewed to one side. There are water jackets close by in certain areas of the exhaust port, dont get too greedy here.

Lower intake:
*Blend in the short turn radius where the upper meets the lower.
*Straighten the #1 and 5 dog legs, blend the transitions.
*Keep port exits around a 1/16" smaller than cyl head intake port dimensions.

While this is only a fairly quick and very basic porting job as described, it will put a very worthwhile additional amount of cfm airflow thru the engine which should both broaden and raise nearly the entire curve, which is far more important than peak numbers anyhow.

Re: Build approval someone please!

Reply #8
I'm not saying that the OP is going to get close to 300 wheel HP with untouched GT40P heads. He could get in the 230-250 wheel HP range through an AOD with the right selection of parts. He should be closer to 250 than 200 hp though.

Unless the OP is porting the heads himself I wouldn't bother. Take the money for GT40P heads, springs, and porting and put it towards a decent set of heads from AFR/Edelbrock/Trick Flow. The OP would be money ahead and much closer to their 300 wheel HP goal.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

Re: Build approval someone please!

Reply #9
My buddy has a gt40p headed 302 with a f cam 600 brawler carb Vic Jr intake putting 260 to the wheels.

300 is a steep goal with the parts listed. But the parts listed will make a very streetable daily with some extra nuts

Re: Build approval someone please!

Reply #10
I know a way to make 100 HP with the push of a button on a budget! Also if you don't already have all the parts I know in my A9L post vinnietbird was selling an X3Z computer with 24# injectors for a good deal. But will require the MAF conversion of course which is super simple and affordable as well. 300 WHP on an AOD is very hard to do on a budget, all motor. They are a huge slushbox that do nothing but rob power. I think Vintage is dead on.

Re: Build approval someone please!

Reply #11
I appreciate everyone input, and i now recognize I may have misspoken about potential hp gains with parts list given. If 200hp -240hp can be gain with my parts Including mass air, new computer,h-pipe with headers and gears. I think that would be a noticeable bump up in horse power from the stock 155hp.  Just got mass air sensor from yard picking up the Explorer engine tomorrow for tear down not sure what to do with bottom half of the engine though.  Anyone have any ideas? Like can I use the the pistons? Is the block worthless? 
[SIGPIC][/SIGPIC]88 Thunderbird Sport 302 ,flowmaster 50 series delta

Re: Build approval someone please!

Reply #12
Leave the bottom end alone if it's solid. Put your cam of choice in it and go. The only thing you'll have to do is swap the pan. Know which engine you get I dont remember the years but the gt40s came on one and gt40ps came on another and the spark plug angles change. Just a minor headache changing plugs if you buy non p headers

Re: Build approval someone please!

Reply #13
You can use the explorer block if you want. The crank doesn't stick out as far, cant Remember of that is just a different pulley/harmonic ballancer or not. The block is fine, and so are the pistons, however the pistons are not forged.

I would stick with the motor you already have if the pistons will clear. This needs checked, especially with a bigger cam and the gt40 heads.

I would suggest a 24# injector and the mods needed for that. You would be right on the edge if What 19# injectors will want to do.
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com

Re: Build approval someone please!

Reply #14
You can use the explorer block if you want. The crank doesn't stick out as far, cant Remember of that is just a different pulley/harmonic ballancer or not. The block is fine, and so are the pistons, however the pistons are not forged.

I would stick with the motor you already have if the pistons will clear. This needs checked, especially with a bigger cam and the gt40 heads.

I would suggest a 24# injector and the mods needed for that. You would be right on the edge if What 19# injectors will want to do.

24# injectors? Then I’m definitely going to need a lager fuel pump? And if so how big? And will I need forged pistons for my application?
[SIGPIC][/SIGPIC]88 Thunderbird Sport 302 ,flowmaster 50 series delta