So what IS the best minimum-mod drop-in engine?

[1987cp]

Base goal though is 302 WHP on NA with no power adders, and preferably using 87 octane. I wonder if the 302 has the capacity for that?

I was following a buildup a while back of a NA 347 that dynoed at 694hp. That exact build isn't for all of us, but I found it a neat demonstration of what can be done with OOTB $1500 cylinder heads and a highly thought-out combination.

[gadget73]

302 making 302 rwhp NA? sure, no problem. Its easier if you ditch the AOD for a 5 speed tho. The T5 is good for about 30 hp at the rear wheels over an AOD in the same car. Weighs less too. A head/cam/intake swap with the proper parts should easily get you 300.

[turbo2256b]

351C with 2V heads

[Crownvicman289]

Early 5.0 explorers have the same injector plugs as our cars. And you can also use a SEFI panther TPS.

I can't be the only one who's ever used the Explorer TPS. . . it's super easy, just depin the Explorer plug off the TPS and repin the Panther connector onto it. It's the same style 0-5V 3 wire sensor and the wire colors even match, plus the Exploder has that nifty cover and is way newer.

The explorer uses Hypereutectic pistons also a cast piston yet it's an mix of aluminum and silicone iirc.
Where in Jersey are you?

Hypereutectic just means there's more silicon in the mix than it can take and still be homogeneous. The high silicon content makes the piston harder, but also more brittle. It also makes the piston expand/contract less which is good for cold emissions which, in a newer car, is where the majority of overall emissions comes from. Forged pistons can be hypereutectic too since it only refers to the silicon content. The highest percentage of silicon that an alloy can take while remaining homogeneous is a eutectic mixture and a hypo-eutectic alloy has a silicon content of less than 12%, with 12.5-12.7% being a eutectic mixture. Read all about it here.

[Midnight Drifter]

I have access to a '90 civilian 302/AOD. Is it a good starting point? I know for a fact they're less than 100k and I could probably have 'em both for around $300

[MattsLincoln]

I have access to a '90 civilian 302/AOD. Is it a good starting point? I know for a fact they're less than 100k and I could probably have 'em both for around $300

that is a good price. i would jump on that. that is SEFI which is what is in my towny and they have very good drivability.

[Midnight Drifter]

I'm mainly concerned about how much work needs to adjust the engine's powerband, and the rotating assembly's ability (or lack of) to withstand higher-than-sea-level atmospheric pressures during combustion cycle.

By the way, appealing as it sounds, I'd never manual-convert a Grand Marquis. If i wanted a manual car, I'd pursue an old P71. It fits the personality more.

[sly]

the trans is fine for a start if you want an auto... but an explorer 5.0L engine would be a better base ... an HO 5.0L from a stang, tbird, Mark 7 would be better for an engine (stang as a last resort since they're usually beat anyhow) since they have forged pistons to at least 92 (there's some debate on whether the 93 got the hypereutectic or not). Of course... a good truck 351 roller engine from the mid 90s is also a great engine to start with. The lopos don't do boost reliably much at all.

[turbo2256b]

92 was the only year for forged in a 5.0 HO

[sly]

I guess that was because of the 92 stang cobra r (which is still a coveted beast)

[turbo2256b]

Cobra R engines were built by hand in the Whiticar building next to Advance Engine. Think they were 351s too but dont remember just remember watching some of them being built.

[sly]

that would make sense. *shrugs* one year of forged and then hypers... cast up till then I guess. then the cast should handle 3-6psi till the cows come home. upgrade to forged to get any meaner than that.

[turbo2256b]

That can depend on the compression of the engine and the RPM desired. Have seen 7.5 compression used with 10lbs of boost and cast pistons and RPM was 5200 severl different cars some 10s in the quarter on street tires. One was a 6cyl rambler waggon in the 11s boost was regulated with a radiator cap for a blow off valve.

[1987cp]

Conventional wisdom has always been that 5.0HOs got forged pistons starting in '86 at the latest.


OP, what's this talk about atmospheric pressures???

[86VickyLX]

I'm mainly concerned about how much work needs to adjust the engine's powerband, and the rotating assembly's ability (or lack of) to withstand higher-than-sea-level atmospheric pressures during combustion cycle.

You driving up Mt. Washington or Everest or something? If you're running a stock 90 lopo and AOD, your power at most would go up to 160hp. That's if you convert it to SEFI.
The Explorer 5.0 is still the better way to go.