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8/22/2016 8:42 PM  #1


New engine combo in my Cougar

I am about to install my old 306 into my 69 Cougar. Concerning the GT40 heads, I've heard about how low performance they are several times, but I have a set of 96 Explorer non P heads which I did just a little port matching, Crane springs and roller pedestal rockers.  This is on a flat top piston 306, with a TFS stg II cam and GT40 EFI with 19lb inj. It ran consistant low 13's at 103 in a 3100lb Ranger with a T5.  Would it really be worth while to dump them in favor of aluminum ones, like inexpensive one's not AFR 205's or something?

 

8/22/2016 8:49 PM  #2


Re: New engine combo in my Cougar

Welllll......what are your plans for the Cougar?! Just a fun "street piece" I(personally) would leave the GT-40 heads on it.  Low 13's ain't 2 shabby for a street ride.
ME........I would play with the cam and the ignition timing first. If it still don't "toot-your-whistle" like you want it
then look at heads.
6s6
Welcome to the board,BTW!


Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8
 

8/23/2016 4:27 AM  #3


Re: New engine combo in my Cougar

Its not a case of the GT40s being "low performance".  Anyone who said that doesn't know what they are talking about.  The GT40 was THE factory performance head for two decades.  They went on the '93-'95 Cobras and Lightnings, plus were available from Ford Racing.  In an effort to continue to make more power as vehicles got heavier Ford eventually started putting the GT40s and later GT40Ps on the Explorers and Mountaineers on the last iteration of the 5.0.  For a stock head the GT40 flows very well, particularly at low lift, where torque is made in a street engine.

Where people likely get confused and call the GT40 "low performance" is that the stock valvesprings were not really up to the task of a reasonable performance cam.  Its especially confusing because Ford Racing GT40s came with different valvesprings that would tolerate more lift.  But basically, change the valvesprings and they are good to go.

The other issue is that when buying a used set of GT40s they can take considerable work and expense to get back into shape.  High mileage heads need to be checked for cracks, they may need to be decked, they need a vavlejob, obviously springs, etc.  The costs start to add up to where you could basically buy an entry level set of aluminum heads for the same money, and aftermarket heads are going to outperform the GT40s.

Why?  Simple, the GT40s are still a production head and had to meet guidelines by which aftermarket heads are not bound.  Aftermarket heads are not concerned with meeting emissions typically.  They are not as concerned about production costs.  They are not concerned with fuel mileage.  Aftermarket heads are designed to make power.

If you have a good combo I say why mess with success?   Could you make more power with aluminum heads?  Yes, BUT, and its a big BUT, if the rest of the engine is matched to those heads.  Right now the engine seems well matched to the GT40s.  Change the heads and now its a question of is the cam right for these new heads?  Intake, etc.  Its hard to leave well enough alone, but over the years I've ruined enough good combinations in the quest for more that I've learned the hard way that sometimes its best to leave what works alone.

 

8/23/2016 7:00 AM  #4


Re: New engine combo in my Cougar

TKOPerformance wrote:

Its not a case of the GT40s being "low performance".  Anyone who said that doesn't know what they are talking about.  The GT40 was THE factory performance head for two decades.  They went on the '93-'95 Cobras and Lightnings, plus were available from Ford Racing.  In an effort to continue to make more power as vehicles got heavier Ford eventually started putting the GT40s and later GT40Ps on the Explorers and Mountaineers on the last iteration of the 5.0.  For a stock head the GT40 flows very well, particularly at low lift, where torque is made in a street engine.

Where people likely get confused and call the GT40 "low performance" is that the stock valvesprings were not really up to the task of a reasonable performance cam.  Its especially confusing because Ford Racing GT40s came with different valvesprings that would tolerate more lift.  But basically, change the valvesprings and they are good to go.

The other issue is that when buying a used set of GT40s they can take considerable work and expense to get back into shape.  High mileage heads need to be checked for cracks, they may need to be decked, they need a vavlejob, obviously springs, etc.  The costs start to add up to where you could basically buy an entry level set of aluminum heads for the same money, and aftermarket heads are going to outperform the GT40s.

Why?  Simple, the GT40s are still a production head and had to meet guidelines by which aftermarket heads are not bound.  Aftermarket heads are not concerned with meeting emissions typically.  They are not as concerned about production costs.  They are not concerned with fuel mileage.  Aftermarket heads are designed to make power.

If you have a good combo I say why mess with success?   Could you make more power with aluminum heads?  Yes, BUT, and its a big BUT, if the rest of the engine is matched to those heads.  Right now the engine seems well matched to the GT40s.  Change the heads and now its a question of is the cam right for these new heads?  Intake, etc.  Its hard to leave well enough alone, but over the years I've ruined enough good combinations in the quest for more that I've learned the hard way that sometimes its best to leave what works alone.

sounds like my Dad, "If it work's, don't mess with it."  Course I knew more than he did when I was 17.  It's amazin how much smarter he got the older I got.  Jerry
 


"when I drop something, it always goes to center of the car"
 

8/24/2016 6:14 AM  #5


Re: New engine combo in my Cougar

I guess the best thing to do is leave it as is for now, I was toying with putting a single or dual quad setup on it, but that too would probably just mess things up.  I'm considering using a Ron Francis EFI wiring kit to wire the EFI and upgrade the injectors to 24 or 30lbs and the MAS to something closer to 65MM which is what the throttle body is. And having a custom chip burned for the 9AL computer I'm using. Hopefully this will push the hp up closer to 400 and offset the additional 400+lb weight of the Cougar. Now the difficult part..submitting this to the finance manager/wife.

     Thread Starter
 

8/24/2016 6:41 AM  #6


Re: New engine combo in my Cougar

If you already have EFI, keep the EFI.  More torque, almost certainly better mileage, and much less fuss than even a single carb, let alone two.  Multi carb setups on most engines are for show anyway.  My neighbor was a very influential Pontiac racer & mechanic back in the day, and much to guys chagrin he would rip those 3x2 setups off those 389s and put a single quad on them and make more power and be more reliable.  Multi carbs were basically a marketing ploy falling under the bigger is better mentality. 

You're not going to make 400HP with that combo.  Not trying to rain on your parade, but 400HP from a 306 is a tall order and can only be done without nitrous or forced induction at very high RPM (7,500+).  This is also where I can say with confidence that the GT40s just won't flow enough to support that kind of power at any RPM.  The valves are too small and so are the ports.  You would need AFRs or worked Edlebrock or TFS heads to even consider hitting that number, and you'd need a thumper of a cam. 

350 is a realistic goal, but you'll be at or even beyond the limit of the GT40s.  Keep mind that the GT40s were designed to boost power on an engine that made 225HP.  So you might see 275, or 300 with the right cam, intake, headers, etc., but I find even 350 is going to be tough.

Injector wise, if you're serious about more power then you need 24s.  30s are too big.  Injectors have a sweet spot in the 85-90% duty cycle, and that's right where 24s are making 350HP.  You could probably crutch the 19s with decent programming and higher fuel pressure, but you'd  be safer with 24s. 

On the MAF I would run a Pro-M 75mm.  The mass air in effect can't really be too big.  We used to run these all the time on stock engines, or one with mild modifications.  The stock MAF is a restriction, even on a stock size throttle body. 

If you want to really wring it out you need to be able to tune the car on a dyno.  The TwEECer is by far the best setup for tuning the EECIV.  Chips only get you so far, because the programming isn't created in a dynamic environment and all cars react a little differently. 

 

8/24/2016 9:12 PM  #7


Re: New engine combo in my Cougar

http://www.mustangandfords.com/how-to/engine/28898-400-hp-302-small-block/

Joe Sherman is definitely one of my engine builder heroes!
Whether you can get 400HP out of a 289 is up to you but "according to Joe..."
Regardless a great  read.
6sal6


Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8
 

8/25/2016 5:17 AM  #8


Re: New engine combo in my Cougar

I never said it wasn't possible.  I said it wasn't possible with his combination.

Let's look at that engine built by Joe Sherman for this article.  First, this is not a street engine.  Peak torque at 5,200RPM.  Using a single plan intake on a 302, a 750cfm carb, and heads with 210cfm intake ports.  I don't get the cam to be honest; its a peanut, and I find it hard to believe they made that kind of power with such a small cam, but I suppose if everything else is huge the cam only needs to open those giant valves into those giant ports so far and for so long.  BUT, I guarantee low RPM performance is lazy. 

Second, its Joe Sherman.  He's won the Hot Rod Engine Masters Challenge numerous times, and is one of the best engine builders in the world.  I wouldn't think I could equal his recipe.  BUT, let's also examine that for a minute.  Joe has shown he's very capable of making big power on a dyno, but a dyno is NOT a street car.  I'm not saying he couldn't build a killer street engine, but that was not the goal of this article.  The goal was to have a cover blurb that reads "400HP from only 302 CID!"  You have to take everything you see in a magazine with the appropriate grain of salt. 

So, let's call this 400HP 302 what it really is: an engine best suited to the track where peak power is really all that matters.  On the street this thing has no bottom end, and is not going to be fun to drive.  The car it goes in is going to need a high stall converter or a stick shift, and some deep rear gears.  Its a strip engine you could run on the street, but that's all about what you're willing to give up and live with.  As I get older I'm willing to compromise less and less.  If its really a street car I want it to drive like a street car.  I want it to be fast for sure, but I'll pass on the masquerading a race car as a street car thing at this point in my life because there's something I figured out along the way: street cars make slow race cars and race cars make poor street cars.  If you want to run stellar numbers at the track buy yourself a trailer and a tow vehicle and build a race car.  If like me you hit the strip maybe once a year, build a fast street car that you can see what its capable of once in a while.  But this engine isn't going in that car.  If you want a 400HP street car build yourself a 331 or 347.  Cubes make torque and you can do it with less radical parts, yet it will still idle and not be cantankerous. 

 

8/25/2016 8:00 AM  #9


Re: New engine combo in my Cougar

360 HP seems to me to be a good running 306. Still able to cruise around town and depending on hardsare and gearing a lot of fun to run at the upper mid range. I have a 306 in my racecar that is around 430 HP and I wouldn't have any problems with it in a street car. BUT, I would have 4.30:1 gears in it and I like to shift gears. Most people would not like it for "normal" driving. 

 

8/25/2016 10:41 AM  #10


Re: New engine combo in my Cougar

THIS is the "cool" thing about this site.....what some of US call acceptable ....others call radical. Who sez we can't all be right? As far as that goes.
Pretty sure that "bullet" Joe Sherman put together would get old (even for Me and DC!) after a few weeks.
The same (or more) power could be built with more cubic inches...better heads....dual plane intake..less aggressive(can't believe I actually typed that!!!) camshaft...and so on.
IF I was looking for a "upper 375-ish HP" SBF I would go with the 347 kit...maybe 10:1 CR...nice flowing heads... still have the snotty camshaft(because I refuse to grow up) ...one of the after market port fuel injection systems... with maybe  3.89:1 gears in a Detroit Locker (same"growing up issue" as before) and a 6-speed tranny with cruise to make it to all the MSBB get-together.
Guarantee THAT would get you in "upper 375HP" territory and still be "streetable" IMHO&DC's opinion.
ONLY thing missing is the money to make it happen!?!
6s6

Last edited by 6sally6 (8/25/2016 10:43 AM)


Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8
 

8/25/2016 2:40 PM  #11


Re: New engine combo in my Cougar

I'm building a 347 now that I'm targeting in the 400-415HP range and it will use AFR 185s, a hydraulic roller I got from Crane (after a discussion with one of their tech guys), and I'm still working on the intake and carb I'm going to use.  Eventually it'll run EFI.  It should be a good street engine, a bit or rumpity rump, but not over the top. 

 

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