Try to save the 3.8SC or swap in a 4.6?

Nevada1906

Registered User
Greetings fellow SC guys,

This forum has been a huge help, as I'm new to the SC. You've all been a tremendous resource so far, so much so that I decided to become a member. Thanks.

My white '93 auto is my first SC, and I think it's got the potential to be great. My overall impression of the vehicle is that it has great off-idle torque, I love the shape, and the fact that it has an IRS. I've loved the MN12 T-bird since it was new, but I have a few issues with the vehicle.

I did the head gaskets when I bought the car, and I just finished rewiring the starter circuit, complete with new starter. Also, I installed a new power steering pump with Aeroquip stainless Teflon braided pressure hose and return line (If I EVER get hold of the crackhead who designed the PS system...) for a nice, sanitary hydraulic circuit.

My question is: Given the overall complexity and temperamental (Read: half-engineered) nature of the 3.8 SC V6, should I continue efforts on this engine, or do a heart transplant?

You know, a powertrain that doesn't require constant handholding, as I don't want to be under the car all winter. My easiest options are 4.6 SOHC, 4.6 DOHC, or a 5.0.

I've also been considering few hybridized drivetrains:

Ford 6.8 Triton V10 + T56
GM Vortec 4200 I6 + T45/56
Nissan RB26DETT 5-speed
Toyota 1JZ-GTE/2JZ-GTE 5-speed

No, I'm not joking.

Opinions?

I'm open to any and all suggestions.

Thanks.
 
Ditching the SC 3.8 is kinda taboo around here but I say go for it! Just as long as its a Ford based motor!
 
It's not an SC if you ditch the SC'd power plant.

You have already done the major issue with the motor, i.e. hg's. If you used a good modern gasket and hopefully studs, the engine should be trouble free for years.

Minor problems like the DIS burning up don't occur often and aren't that costly. All engines have their quirks.
 
The DOHC is a good idea, but you might as well tank the SC, get a Mark VIII LSC (improved driveshaft, bigger brakes, HID; air leveling/IRS; 4-cam, etc.) and be done...

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The SC learning curve

In response to Flex, yeah, I used the ARP 153-4001 studs with the Fel-Pro 9642PT-1 gaskets, but the outboard studs were too long. My stock manifolds are thus running without lower bolts, but so far, it hasn't been a problem.

I'm somewhat confused about the 3.8SC engine. On the one hand, SCCOA members sing its praises as a tough, reliable powerplant that gives years of troublefree service, even under high-level modifications. On the other hand, I constantly read about snapped cranks, banana'd rods, disintegrating pistons, and the ever-popular wiped-out rod and main bearings.

What gives?

Is the 3.8SC truly "a bomb that could go off any second, or maybe never?" Or are we talking about guys who post entries about the above catastrophies, but neglect to mention that the failures occurred in the wake of a steady diet of 5000-RPM-clutch-dumps, redline-neutral-drops, and/or that infamous Saturday night experiment with the 300 shot o' NOS?

I realize that SCCOA is a performance-oriented group, and believe me, I have killed my fair share of cars with my overly heavy right foot (Fragged Third and Fifth gears in my '96 Crown Vic 5-speed conversion). But first and foremost, this is my daily driver and I need it to be a dependable car FIRST.

I like the idea of a boosted V6, and when I did the head gaskets, I thought there was just something cool about the way the engine looked in the chassis, aesthetic and inelegant nightmare that it may be. I'd very much like to keep my car 3.8SC powered, but not if that choice will leave me walking.

In case you ask, no, I don't know how long the previous owner drove the car after he blew the H-gasket, or how well it has been maintained, but my guess is, "not as well as can be hoped."

Oh yeah, how long can the stock bushings be expected to last? I'm getting some fairly dramatic clunking over manhole covers and other pavement irregularities.

Any advice would be appreciated. Thanks.

"Freedom in a mechanized society requires three elements: Will, Weapons, and Wheels."
 
...
I'm somewhat confused about the 3.8SC engine. On the one hand, SCCOA members sing its praises as a tough, reliable powerplant that gives years of troublefree service, even under high-level modifications. On the other hand, I constantly read about snapped cranks, banana'd rods, disintegrating pistons, and the ever-popular wiped-out rod and main bearings.

The motor is reliable. Damaged cranks I've seen over the last year have been due to improper repairs or catastrophic failure of the harmonic balancer. Motors with bolt-ons increasing boost, increasing heat, and failed cooling systems will lead to increased opportunity for detonation. Detonation leads to piston failure, failed head gaskets, and or bent rods.

The SC has always been a sporty car, so many that you find likely, at some point in their life, been ridden hard and put to sleep wet.

The problem is that if you can't work on these cars, finding competent mechanics is a challenge. The engine compartment packaging is very tight, with most mechanics wanting nothing to do with it. Add the Distributorless ignition system that requires some specialized knowledge to trouble shoot, and you have a car that can be quite frustrating to own for some folks.

The Lincoln Mark VIII isn't much better, other than the motor is more common.
 
Ditch the crappy stock exhaust system and install a better fuel pump and you will eliminate most of what can tank the 3.8 SC should you choose to go for more boost as Mike points out.

To this later add 36 or even 42 lb injectors and the motor will be a lot less susceptible to knock and catastrophic failure. These parts can be picked up cheap if you want to wait a bit to collect them all. You could also put a fan on the intercooler to reduce IACT's for more power and less chance of the dreaded d word.
 
Reliability of 3.8SC

I understand the idea of "ridden hard and put away wet," but other cars don't have this laundry list of problems. I'm simply concerned that one of the rotator bearings is gonna let go at some inopportune time without warning.

The factory balancer/crank sensor group is problematic. Okay, can the 3.8SC engine run based on inputs from 3.8NA parts? Or from a 4.6? Or a 5.0?

I'm not necessarily trying to do things on the cheap here, but the potential for catastrophic (and very inconvenient) major parts failure seems way too high not to try to reengineer the touchier componentry.

What do you think?
 
>I'm not necessarily trying to do things on the cheap here

Have you thought about simply flipping a coin...while you still have a few left...?

Ok, so you don't want to step in a hole - fair enough. But you know, the only safe way to avoid doing that is to not leave the porch.

And you're looking for that magic approach to something, that seems to have eluded others... Eureka moments are few and far between when it comes to the SC.

While it seems true that to keep the average SC on the road you either need to come to know them well, or know someone who does, any car suffers when abused - and any car is a bundle of trade-offs at the end of the day.

The fact is, these cars are pushing two decades of service, and when you hear owners complain that fixing one thing always seems to lead to another, it is easy to wonder if they are worth the trouble, time and expense. And those are questions only you can answer.
 
Fair enough, KMT. You're quite right. That WAS beginning to sound like whining on my part.

I DO like my SC, or I wouldn't have fixed it at all. And it really is satisfying, though; figuring out how to make your car into the vehicle you think it should be. That is, after all, the essence of hot rodding.

I'm going to stick to my original plan: Nurse the 3.8 along until I can get a 4.6 DOHC/T56 into it. And then build the 3.8 into something INTERESTING... If that's blasphemy, then send Torquemada to come and get me!

It's good to know that if I should need to ask for advice, I have such a knowledgable group to consult.
 
Thanks for the leads. I've looked for complete 4.6 DOHC/trannies, and have come to the conclusion that I should simply lift the powertrain from a '96 or '97 Mark VIII. Same forged longblock as the non-Terminator Cobra, and it can be an evolutionary project: Slushbox first, just to get it mechanically installed, then go from there. Hope the Mark VIII instrument cluster fits...
 
First off, I would just say that swapping a 4.6 of any sort is wayyyyy more work than properly maintaining your 3.8. I've seen many SC's go under the knife for a supposed "killer upgrade" and not come out with any kind of a beating heart. The few who have done it spent a LOT of time figuring things out and in the end many aren't any further ahead than they could have been with the V6. There are some notable exceptions but just ask how much they spent and how much work it was....

I speak from experience when I say that the SC is reliable enough. I've owned one since 1990 and now with over 200K miles still find it entirely reliable enough for both daily driving and cross country trips. And yes, mine has seen PLENTY of modifications over the years. But if you feel that the car is a ticking time bomb with things that you should have already replaced but haven't, then you can hardly blame the car. If the car hasn't been maintained then the engine really isn't your biggest worry anyway. Parts break for a reason, and there are plenty of 4.6's out there with broken parts.

If you want the V8 and don't want the hassle then do what was suggested above and just go buy a Mark Viii. Like I said, maintaining your 3.8 is less hassle and/or expense than swapping out a complete drivetrain. If you want to do it to be different or cool, then by all means go ahead, but if you think doing the swap is going to create an easy way out then you are sadly mistaken.
 
Like how involved?

Correct me if I'm wrong, and I may well be, but isn't the DOHC swap essentially home-manufacturing a production T-bird LX, but with a four-valve top end and PCM? Why not get all the 4.6-specific parts from a '96 or '97? I'm serious; I want to know if I'm not thinking this through properly.

It certainly would be easier to keep the 3.8 in the car, and do one system at a time until I decide I'm done. Right now, as a reliability measure, I'm doing the sensors one at a time. I know they're not all bad, or even on the verge of quitting, but walking to work through ONE Chicago winter was enough fun, thanks.

As I mentioned, I've already replumbed the power steering system (two feet of Aeroquip Teflon line, and a foot of Goodyear fuel injection hose) and rewired the starter circuit with revitalized/new cables/grounds and a new starter. All the new connections are holding nicely.

The vehicle drives very well, and for right now is strictly a daily driver. Dreaming aside, I think the next upgrade would be to simplify the heater hose routing so it just plugs into the engine as directly as possible, instead of meandering around the bay like some drunken frat boy on a bender. Yeah, I know it does that to cool the oil, but a remote cooler/filter relocator will take care of that.
 
Keep in mind you are dealing with an old car that may have been neglected in its past. SUperchargers plus neglect = no good .

Motor wise the SC engine is pretty stout. It can easily handle upgraded power levels. What it doesnt do well nor does any unaturally aspirated engine is handle detonation. Ive yet to blow a headgasket however that is a weak spot on this engine. The engine as a whole however is not.

To put things in perspective. How much money do you think it will take to get a two valve 4.6 over 300rwhp. Ill tell you. Allot. A stock PI motor with about 5psi netted me close to 310rwhp (I dont even remeber the exact number anymore)With the SC..Well not so much. Plus a heck of allot less work. STock sc shortblock, bigger IC, home ported blower, ported stock size valve heads and a 520 cam. A tad bit more then that dynoing at close to 320rwhp. Stock 4.6+boost ...No likey. I blew two of em up.

The v10 is an unbalanced low revving POS. Yes it has a cool factor as I did much research into it. Just a bad design. basically a poorly balanced 5.4 with two extra cylinders.

If you want a supra or a GM..I suggest ay just buy one!@

My quick thoughts..Gotta jet

Weve been through this topic many times and teh cheap and easy way into the 300rwhp range is stick with the 3.8..If you want 400 plus...then I say go look for a v8..PArts to make our lil v6 make 400 plus are out there but not readily available and custom made to say the least....

Or if you o turbo on teh 3.8......Yah Id do that
 
the 4v bottom ends were not forged. the cobras got the forged crank but the mark 8s got the cast crank. either crank is fine under 600hp however both the cobras and mark bottom ends got the same weak crack capped rods and weak hyperucraptic pistons. the only modulars that have forged internals from factory and ones that had a supercharger strapped on top.
 
Possible future

Okay, let's say I decide to get another 3.8SC engine and build it PROPERLY. I mean Super Six forged rotator kit, Morana stud girdle and windage tray, bored/align honed/decked, MLS gaskets, and a nice ported top end.

HOW HARD CAN I LEAN ON THIS THING?

Had-a-bad-day-at-work hard?

Can't-afford-to-get-another-ticket hard?

Hey-y'all-watch-this hard?

How close to indestructible are we talking about here?
 
You're right Booster. I rechecked my source material. The early Mark VIII had the Teksid BLOCK, but unfortunately stuffed with the cast crank. Still a good foundation for a build.
 
The other point that has to be considered for the engine is tuning it properly when you mod it.

There's alot of folks around here that will tell you that slapping in a big MAF, putting in some 42# injectors, big TB and other mods on the car doesn't require a tune because the computer will compensate. It can only compensate so far and 42# injectors will push over that limit, and thats only when the car runs in close loop NOT at WOT etc. Spark is also totally wacked out and will lead to detonation. Those folks are just asking for trouble and eventual engine failure.

There's alot of folks like Dave Dalke and others that have alot of experience with these cars and if you do the job right you'll have a good solid motor. Don't short cut on things like tuning etc.

Of course this applies to any other motor as well.

Frit
 
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