Fox T-Bird/Cougar Forums

Technical => Engine Tech => Topic started by: xjeffs on March 08, 2008, 11:26:50 PM

Title: Cobra engine vs Explorer engine
Post by: xjeffs on March 08, 2008, 11:26:50 PM
So as I'm learning of all the varieties of 302's, it seems as though the best starting point from stock for power is the 94-95 Cobra, followed closely by the late 90's Explorer.  The Cobra realistically makes 260-280hp, while the Explorer is rated at 215hp.  The Explorer intake and heads are equal or better than the Cobras. 

The differences that would effect power are the cam, 1.7 rockers, and the exhaust headers.  Does it account for that much difference?

I understand the injectors, cam, crank sensors and coil packs are different.  None of that would account for the power difference.

Why is it that the Explorer engine is not a hotter pursuit for a drop in for our cars?  It seems that the Explorer engine would be a couple parts from 270hp.  Am I missing something?
Title: Cobra engine vs Explorer engine
Post by: daboss351 on March 08, 2008, 11:33:55 PM
exploder cam is made for low end. someone on the lincoln forum said it was a good drop in for more torque and thats it. I would think the difference in cam and the rockers would defiantly be that big of a difference.
Title: Cobra engine vs Explorer engine
Post by: CougarSE on March 09, 2008, 12:07:06 AM
Well one thing you are missing is the super restrictive stock headers on the Explorer/Mountaineer.  One company makes headers to fit the 5.0 Ex/Mounty.  They provide a 15hp/35ftlb gain... Dyno proven.. at the rear wheels!!!!!!!!  The stock setup is kind of scary too look at.  The Torque Monster headers for the Ex/Mounty also provide a 3mpg gain.  The cam is stupid small in a Ex/Mounty engine.  I have one of those cams in my garage as well as a stock HO cam.  Side by side you can actually see the differences.  The HO cam has a longer duration and a higher lift.  I guess the stock Ex/Mounty cam contributes to my truck idling so smooth you can't really tell its running.
Title: Cobra engine vs Explorer engine
Post by: Sick88Tbird on March 09, 2008, 12:43:28 AM
Quote from: xjeffs;208305
The Explorer intake and heads are equal or better than the Cobras.

Not true...especially when running an HO cam.  Cobra has larger exhaust valve and slightly larger ports.  The intakes are very comparable...on a 320hp engine they are 2-4hp difference in different areas.  The HO cam has 10* more duration on the intake side...and with already restrictive exhaust ports, the Cobra(F3ZE) heads will make a little more power than the "P" heads.  Either way, both are good upgrades...I'll never spend money on "P" heads again, people can say what they will, but my F3ZE's friggin' rock...

Quote from: xjeffs;208305

I understand the injectors, cam, crank sensors and coil packs are different.  None of that would account for the power difference.

Yes, all of that would...the computers are programmed very differently...the Cobra is a performance vehicle...the Exploder is a luxo-suv(where a smooth idle is desired)....cams do make massive differences and that's where most of the power is going away on the Exploder.  Think of it this way...the '86 HO motor is a SO motor with a different cam and it only made 20 or 25hp less than the '87-'88 SD HO's.  SO was rated at 155 vs. the 200hp '86 HO...90% of that power came from the cam.


Claude made an excellent point about the ultra restrictive manifolds...I did a motor on a '96...I don't even know how exhaust makes its way through there...lol.
Title: Cobra engine vs Explorer engine
Post by: xjeffs on March 09, 2008, 12:54:35 PM
Quote from: CougarSE;208317
Well one thing you are missing is the super restrictive stock headers on the Explorer/Mountaineer.

I mentioned exhaust as being a difference.  Any restriction can have a huge impact.


Quote from: Sick88Tbird;208328
Not true...especially when running an HO cam.  Cobra has larger exhaust valve and slightly larger ports.  The intakes are very comparable...on a 320hp engine they are 2-4hp difference in different areas.

http://www.foxtbirdcougarforums.com/showpost.php?p=193552&postcount=7

Valve size is only part of the equation as these flow numbers show.  The P flows better.

Quote from: Sick88Tbird;208328
Yes, all of that would...the computers are programmed very differently...the Cobra is a performance vehicle...the Exploder is a luxo-suv(where a smooth idle is desired)....cams do make massive differences and that's where most of the power is going away on the Exploder.  Think of it this way...the '86 HO motor is a SO motor with a different cam and it only made 20 or 25hp less than the '87-'88 SD HO's.  SO was rated at 155 vs. the 200hp '86 HO...90% of that power came from the cam.

No it wouldn't.  Injectors, ECMs, coils and sensors are only control/support devices.  They are chosen based on supporting the engine's ability to efficiently flow air into and out of the combustion chamber, which (outside of increasing compression or boosting) is essential to producing power in an engine.  These are influenced by the cam, I-E manifolds, TB and heads and pipes.

You all have answered my first question and verified my suspicions.  Thanks.

My other question remains, if it is just a cam, headers, rockers and support electronics away, why isn't this a more popular swap?
Title: Cobra engine vs Explorer engine
Post by: HAVI on March 09, 2008, 01:50:58 PM
let's say I have a 94 and up 5.8 roller block in a JY that I'm looking at, and a 302 from a later 90's Explorer in the JY, which is better to get?  Complete engines aside, would it be better to pull the P heads for the 5.8?  Would it be worth the wait to get the F3ZE's?  What cam would be more beneficial?  I'm asking only out of not knowing, not trying to be a smart a$$.  I'm thinking of going a different direction in motors with $4.00 a gallon looming overhead, but still want good power.
Title: Cobra engine vs Explorer engine
Post by: TurboCoupe50 on March 09, 2008, 04:00:44 PM
Quote from: xjeffs;208353

My other question remains, if it is just a cam, headers, rockers and support electronics away, why isn't this a more popular swap?


Ever thought about availability???
Title: Cobra engine vs Explorer engine
Post by: Sick88Tbird on March 09, 2008, 04:04:10 PM
Well, believe what you want...I believe those numbers for the cobra and "P" heads are backwards.

I'll let you know when I get my car set up and run at least half a second faster than similar "P" headed combos.  If you don't like what people have to say, then don't bother asking.

And you VERIFIED my point about the ECM's with your "control/support" devices comment.

Real world experience surpasses letters on paper any day of the week.
Title: Cobra engine vs Explorer engine
Post by: xjeffs on March 09, 2008, 05:38:00 PM
Quote from: TurboCoupe50;208366
Ever thought about availability???

Exactly, the explorer engine is more available than the Cobra.  As are the upgrade parts.

Are the throttle bodies the same size?
Title: Cobra engine vs Explorer engine
Post by: thunderjet302 on March 10, 2008, 06:50:41 PM
Good info on GT40P vs GT40 heads here: http://stangpro.com/html/articles/gt40p_files/gt40p1.htm

A good combo for better than stock HO power for cheap is a GT40P Explorer long block, stock HO cam, Gt40 style intake, 65mm TB, GT40P headers and 2.5" dual exhaust. It should make some where between 260-270 hp. Plus it'll run fine with 19lb/hr injectors and SD if you're so inclined. Throw in a set of 3.73 gears in the back and have some fun :burnout:

If you have any questions about the swap or GT40P heads pm me. I have 'em and I'm very pleased with them :D
Title: Cobra engine vs Explorer engine
Post by: Lightningbird on March 13, 2008, 06:01:55 PM
Explorers have poop exhaust headers, a 90* bend in the intake tract right after the TB and the cam that is made for low end. BTW the explorer engine needs lots of parts swapped off before it can be used in a fox body. Accessory drive system is completely different, oil pan, timing chain cover, EGR system, fuel rail valve covers, ignition system, oil pump and pickup, oil filter adapter, every sensor, motor mounts. Too much work unless you have a new replacement long block with none of the systems, but JY engine will have to be stripped down.
Title: Cobra engine vs Explorer engine
Post by: thundr306 on March 13, 2008, 08:23:07 PM
For what it's worth to anyone, when I first bought my car it had an Explorer long block in it. It had FMS shorties and 65mm TB. Car went 13.9 with 3.55's. Not awfully impressive, but a nice swap to run in the 13's.
Jim
Title: Cobra engine vs Explorer engine
Post by: 1BadBird on March 13, 2008, 09:14:08 PM
Quote from: thunderjet302;208491
If you have any questions about the swap or GT40P heads pm me. I have 'em and I'm very pleased with them :D


:evilgrin:  Runs and sounds good toooo!!!  :evilgrin:

:burnout:                                      :burnout:
Title: Cobra engine vs Explorer engine
Post by: xjeffs on March 13, 2008, 11:31:43 PM
That's all good info, but why don't you just run on the Explorer ECM, MAF with a 5 speed?  Then you can leave the ignition system and sensors alone.  Is it the compatibility with the dash?
Title: Cobra engine vs Explorer engine
Post by: vinnietbird on March 14, 2008, 09:22:49 AM
The Explorer has the EEC-V system.We use EEC IV.
Title: Cobra engine vs Explorer engine
Post by: V8Demon on March 14, 2008, 11:14:35 AM
Cleaned up and pretty right here:

http://www.tristatecylinderhead.com/catalog/product_info.php?cPath=41&products_id=40

As far as which flows better?  The P's
Quote
I'll let you know when I get my car set up and run at least half a second faster than similar "P" headed combos


Without port work? ......If you say so.....http://sbftech.com/index.php/topic,171.0.html
Quote from: Thumper460

Actually... there are a LOT of 302/306 in the 12s with GT40s and the GT40Ps and Ported E7s!!  Add port work to the 40s and the power is greater.. install the 1.55 40 exhaust valve in the better flowing P's ( stock is 1.46 in the P's) and pull more power!!


In case you don't know who Thumper is:

http://www.thumperoforangepark.com/

This guy's been porting heads forever.  I have no reason to doubt what he says.  When he posts, you should pay attention to it.

BTW Tmoss of http://www.tmossporting.com/ says the same thing about the P's vs non P's...

Quote
A good combo for better than stock HO power for cheap is a GT40P Explorer long block, stock HO cam, Gt40 style intake, 65mm TB
and a set of 1.7 rockers....
Title: Cobra engine vs Explorer engine
Post by: thunderjet302 on March 14, 2008, 01:41:42 PM
Quote from: 1BadBird;209020
:evilgrin:  Runs and sounds good toooo!!!  :evilgrin:

:burnout:                                      :burnout:


Thanks. You've heard it and even with the py 2.25" tubing aft of the 2.5 H pipe it sounds mean:evilgrin:

Quote from: V8Demon;209124
and a set of 1.7 rockers....


Yeah forgot about that. I use 1.6 roller rockers because with my cam I'd be smacking valves :hick:
Title: Cobra engine vs Explorer engine
Post by: V8Demon on March 14, 2008, 01:48:26 PM
Not necessarily....

Where is the piston when the valve --either one-- is Fully open?;)

http://www.fordmuscle.com/fundamentals/pistontovalve/index.shtml
Title: Cobra engine vs Explorer engine
Post by: Sick88Tbird on March 14, 2008, 07:51:19 PM
V8Demon...I understand what you're saying, but I still haven't seen the flow bench set-up. 

And it's not all about just the heads, it's about the rest of the set up....I didn't see anybody else running 14.30's into a 20mph head-wind with just an HO swap, exhaust and 3.73's with a stock AOD/convertor.  I'm still a few months away from even thinking about building my next motor, so things may change...the one thing that'll remain the same is the iron GT-40's.  If everybody has a hard-on for the "P" heads, good, more iron GT-40's for me...lol.

If I could afford to get a valve job and port work done...then I'd run the "P" heads, but that just isn't in the budget for me.  I'm not, by any means, saying that the "P" heads are no good...I just prefer the regular GT-40's.

-Don
Title: Cobra engine vs Explorer engine
Post by: V8Demon on March 14, 2008, 11:14:40 PM
Quote
And it's not all about just the heads, it's about the rest of the set up


Thanks.:rolleyes: I knew that already.

12's are possible in stock head/cam fox Mustangs BTW...

You said .5 sec faster than similar "P" headed combos...

Guess my idea of "similar" differs from yours. 

Quote
I didn't see anybody else running 14.30's into a 20mph head-wind with just an HO swap, exhaust and 3.73's with a stock AOD/convertor.


Weight? Suspension?  I do believe Kingcars is in 14 land with 3.27's IIRC...Fish around SBFtech.com as well. Plenty of stock head/cam Birds and cats over there running good #'s.  If you want cold hard proof of the "P Vs. Non" head flow question ask over there and more than one person will give you the proof you require.

**Edit**  Your specs 
Quote
Ride:
1988 T-Bird
Engine type and displacement:
302
Induction:
N/A
Major modifications:
HO conversion, f/l headers, full exhaust-dumped, 3.73's, shift kit,electric fan, U/D pulley
Tranny type:
Automatic
Tires:
Street Radials
Race weight:
3250
Horsepower:
0.0
60 foot time:
2.110
1/8 Mile ET:
9.304
1/8 Mile MPH:
76.38
1/4 Mile ET:
14.382
1/4 Mile MPH:
96.78
Track Name:
Atco Raceway

As far as times are concerned in a quarter.  I have no basis myself as I've never run a stock HO cam even in my old E7 setup.  The old cam I had was a phenominal fit with my ported heads.  You could squeeze a 14.1-14.2 if you can get that 60 foot down though.  You're right on track for a race weight of 3250...
Title: Cobra engine vs Explorer engine
Post by: Sick88Tbird on March 17, 2008, 08:00:56 PM
Quote from: V8Demon;209224
  You could squeeze a 14.1-14.2 if you can get that 60 foot down though.  You're right on track for a race weight of 3250...


14.38 into a 20mph constant head wind with gusts of 30-35mph that night...and it was a little squirrelly through the '60.  And my 225lb butt wasn't figured into the weight equation either.

Not too bad for a 300k mile J/Y engine.
Title: Cobra engine vs Explorer engine
Post by: xjeffs on April 19, 2008, 12:21:53 AM
So how many engine HP you think you can get out of an explorer engine with an HO cam, 1.7 rockers, good headers, and maybe better valve springs?
Title: Cobra engine vs Explorer engine
Post by: Sick88Tbird on April 19, 2008, 09:55:33 PM
I don't really do HP numbers because they're pretty useless to me...the 'strip is my dyno...lol.

But, if I had to guesstimate, I would think 240-260 flywheel horsepower could be had....according to my MPH, the old dragstrip dyno calculator put my old 300k mile HO at 240 flywheel horsepower...but we all know that's just a pretty round-about method for figuring hp.
Title: Cobra engine vs Explorer engine
Post by: xjeffs on April 20, 2008, 12:20:58 PM
I was hearing the Cobra was more realistically around 260-270 hp at the FW with a milder cam, so I was thinking more than that.

I did just read that the compression is down on the GT40P engine compared to others.  Anyone confirm that?

I found my own answer.  Compression is actually up. Good read.  http://www.mustang50magazine.com/techarticles/4379_gt_40p_heads/index.html
Title: Cobra engine vs Explorer engine
Post by: thunderjet302 on April 21, 2008, 11:50:07 AM
By the SOTP meter I'm guessing mine makes ~270-280 fwhp but I'm using a slightly better than stock HO cam.
Title: Cobra engine vs Explorer engine
Post by: xjeffs on April 21, 2008, 11:39:20 PM
Did some more research and found that GT40, GT40P, and HO engines were all 9:1 comp ratio.

That's not to say that if you put GT40P heads on an HO you don't increase that ratio.
Title: Cobra engine vs Explorer engine
Post by: Sick88Tbird on April 23, 2008, 01:41:01 PM
"P" heads on an HO supposedly raise compression slightly and the old standard GT-40's drop compression slightly.