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It's not something that I plan to do right now, so no need to spend too much time on it... But if I were to consider purchasing 600 naturally aspirated HP, I see 2 offers on the web. PIM's Hammer and Summit's 521CUI 580.

Which would be best? PIM's is supposed to be made for the Pantera? Which is the easiest to fit in the Pantera?

Has anybody bought any of these 2 engines and installed? And lived with it for a while?
burn rubber
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The Summit engine is a big block Ford (= more weight & less room), the PIM Hammer is a stroked Windsor block.

BOTH will need a lot of new parts to fit in a Pantera.

Mounts...headers...water hoses/pipes...etc.

Big block will require relocating the a/c condenser due to its length.

On the other hand, 500 HP is pretty easy from your Cleveland, and if you turbo it, your 600HP is a piece of cake.

Or check out Ford Racing Part's Boss 427 in long and short-block form. I like the 4" stroke and 4.125" bore in a beefier block. FRPP also sells a 9.2" deck height block (however it's a windsor-based block with cleveland mains, etc.) Just get a short-block and use some good alloy cleveland heads with a good manifold & cam. I agree- save the weight and the big-block custom installation hassles.
Originally posted by LF - TP 2511:
big-block custom installation hassles.

You will have just about the same hassles with a Windsor-based small block.


Agreed, except one part:

I understand that you need a new bellhousing, custom headers, motor mounts, and you may need to slide the ZF back just to fit that big-block motor & have room for the front-of-engine stuff, not to mention the usual stuff as on the windsor. It seems like a 460-based motor is more work than a windsor to me, but I'm not an expert by any stretch of the imagination.

In the "Ford stroker with all Ford parts" thread, I likened the 400 to the windsor swap (in a way), so I am agreeing with you there.

If you want something impressive in your engine bay that will improve the performance of your car in a "smart" way, consider building a 351 cubic inch motor using an aluminum block, heads and intake manifold. You could use one of the currently available after market Windsor blocks with a 9.2 inch deck height, or the new Tod Buttermore Cleveland block, which I expect to become commercially available sometime this year. This will remove about 200 pounds from your car. Use an alloy radiator and a few other lightweight parts, with a target of lowering your Pantera's weight to 2900 pounds. A 2900 pound car with a 440 BHP motor has 6.5 pounds per horsepower, that's Z06 Corvette & Ford GT territory. Those cars accelerate 0 to 60 in 3.5 seconds, they do the quarter mile in 11.5 seconds.

It's very easy to build a 400+ BHP street motor with the Cleveland, peaking at 6000 RPM, and retaining reliability and drivability. Dan Jones hit 440 BHP with his dyno motor. No major expense in stroker kits, roller cams or aftermarket cylinder heads is needed. And 400 to 440 BHP will put a smile on your face all day long. Of course, if you build an all aluminum motor you will be buying some aftermarket parts, but I would consider reducing the weight of the car spending your money more wisely.

If you install the widest street tires that will fit in your Pantera you can spin them all day long with 400 BHP, 500 BHP will simply overwhelm any commercially available street tire, and 600 BHP is even more over-kill . And lets not forget the Pantera's coach has a propensity for cracking, even with the stock motor.

One thing to consider, the ZF is good to about 550 ft/lbs of toruque. The radiator's foot print is good for about 500 BHP. The 351C was designed by Ford to produce about 520 BHP at 7000 RPM as an endurance racing motor; like Larry wrote, its pretty easy to make 520 BHP with a Cleveland. Increase the displacement and the engine speed where peak horsepower occurs will decrease and the powerband becomes more driver friendly. With the Pantera the stars align to make 500 to 550 BHP a reasonable limit. A 2900 pound car with 500 BHP has 5.8 pounds per horsepower.

If you go through the trouble and expense to build or purchase a 600 BHP motor and shoe horn it into your Pantera, there shall be broken parts, a cracking chassis, loosing control on the road and hitting something, finding the car is too difficult to drive and no longer any fun. Eventually you will regret the choice. I've seen people regret even having a 500 BHP motor.

If you gotta have 600 BHP we'll help you do it, but as a friend, 2900 pounds & 440 BHP is my up front advice.

I agree with George. My older brother, Ryan, has a modified 2007 Shelby Mustang with the bigger supercharger and over 600 hp. It is a riot to drive, but can go sideways at speed if you're not careful. Given the weight of the car, it comes in at 6.3 lbs/hp. Too bad he wants a Lambo- yes, I'm trying to convince him to get a Pantera, but he likes the Gallardo a bit too much.
Last edited by coreyprice
I second Georges advice. I was always a proponent of you can’t have enough horsepower until recently. I’m just finishing up a cobra replica that will weigh about 2200 pounds wet but without a driver. I was planning on building a Dart based 9.5 in Windsor block stroked to 454 cubic inches, putting out about 650 horse power and 600 ft/lb’s of torque. Recently I ran into Bob Bondurant at Infineon raceway (formerly Sears Point) before doing the engine build and told him of my plans. I expected Bob to applaud my plans as those of you who know him know he is a wild man whether it is in his helicopter, his various motorcycles or a car.

He has also had a fair amount of experience in Cobras, both the originals and replicas so I highly regarded his opinion. He knows my driving abilities as well as I received my pro racing license from his school and he was one of the sponsors of our old racing team. His response surprised me. He suggested that the engine produce no more that about 400 rear wheel horsepower max. Most of his reasoning was similar to Georges regarding controllability and drivability issues as unlike the Pantera, the Cobra drive train was going to be upgraded to handle the additional horsepower which is difficult and expensive to do with the Pantera. Or maybe he just thinks I’m a lousy driver. In any event I’m now putting a 347 cubic inch stroker in the Cobra.

For what its worth, I’m just finishing a 408 stroker for the Pantera and in keeping with Bob and Georges thoughts its set up to keep the horsepower and torque in the 500 to 550 range and the rpm’s below 6500. Otherwise you’re just going to be constantly fixing the weakest link, which, if it’s the ZF, is a rather expensive proposition.
George is right about controlability. The 67 fastback in my avatar once had a 347 w/ alum heads etc. car ran well and had good grip. Now it has a 432 windsor stroker 550 hp. car is very fun but is a bit dangerous for the inexpeienced. The rear tires have very little grip now and can easily be put in to a slide. Really Fun. I would never give the keys to my son.
I installed the 427 cu in Windsor-based PI Hammer in my GT5 a few years ago. At that time, it was only rated at 538 hp at the crank, if I recall correctly.

I bought the engine for three reasons. First, my car originally came with a Windsor from the factory (it was built in 1988, by which time De Tomaso had run out of 351Cs), so it was a straight swap. The second reason was price; I did not think it possible to build the engine for the same cost and, except for the Ford Racing/SVO crate engines, the PI motor offered the best bang for the buck. The third reason was that the engine had been designed from the outset to run in a Pantera and so I expected fewer hassles getting it to work.

I bought it with the PI Motorsports ready to run kit, which gives you most of the accessories, and the PI headers. In hindsight, the headers were a mistake, because I went to a full 3" exhaust to avoid choking the motor, but the PI headers are designed for a smaller diameter pipe. This meant I had to cut up the collectors to weld on a bigger flange, and then re-do the ceramic coating. If I were to do it again, I would go with Pat Mical's headers & 3" exhaust kit.

My experience with the motor has been, by and large, positive. It is much lighter than my stock engine, by virtue of all the aluminum. Despite my unchanged stock cooling system, it runs much cooler because the aluminum sheds heat faster. It pulls as you would expect, although, in my personal opinion, another 100 hp would still be useable and reasonably safe (the go-pedal has more settings than just "on" and "off", after all).

My gripes with the motor are as follows:

1. There is no choke on the Demon carb. This may be fine if you live in California, but can be a real problem if you live anywhere north of that.

2. There was no crank case vent recirculation system on the motor, and the supplied valve cover vents just spewed oil all over my engine compartment to the point of creating a fire hazard. PI Motorsports did not sell anything to fix the problem (or even acknowledge it, for that matter) so I had to risk evisceration and go to Hall for one of their (admittedly very attractive) kits.

3. I suspect the recommended 6,000 rpm redline on the engine is given more in the interest of avoiding warranty claims than anything else. The motor is just starting to pull at that rpm, and will happily go to 6,500 rpm.

4. The chrome moly rings never seated properly, so the motor has burned a little oil from day one.

5. My experience (and, for all I know, it could have been the exception rather than the rule) was that I received very little support or information after I bought the motor.

All in all, these are relatively minor issues in the greater scheme of things. The bottom line is that I do not baby my motor, and it has held up well for almost 10,000 km and four years. It's very good value, it's proven to work in the Pantera (although most of you would have to modify your engine mounts to accept a Windsor block), runs cooler than the stock motor, and weighs much less. And, yes, I would buy another one.
Last edited by peterh
Sorry for my late reply...this is my first time posting.

I chose to put a Ford Racing Big Block Ford into my '74 Pantera because it takes much of what I like about the car-- large displacement American V8, pushrod, 2-valve-- and multiplies it. The sound of a Big Block is awesome, and it really fills the engine bay! The Big Block can generally make 600hp with more durability than a similar-powered, high strung Cleveland or Windsor. Admittedly, this is not the light-weight approach, but with aluminum heads and intake it is not too bad.

I am in the middle of my Big Block conversion now. I have a replica block in place, with the engine getting dropped into the vehicle in a couple weeks. I have been able to keep the engine in the "stock" location, not needing to move the transaxle back any amount; no modification to the chassis metal has been required. I was able to accomplish this by using a Compu-tronix distributorless ignition and electric water pump. The headers are from Precision Proformance. The bellhousing is from Quicktime, with a Centerforce dual-friction 11" clutch, and McCleod hydraulic throwout bearing. The Canton road racing oil pan has needed modification to squeeze between the frame rails and clear the emergency brake bracket.

I am very happy with how the swap has gone so far.


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Welcome! to the Forum, New Guy (whatever your name is Wink)

Could you be Craig...?

I am very happy with how the swap has gone so far.

Nice. Especially the lack of rearward movement of the block.

I too have a hydraulic throwout. NICE looking, PAIN to work on when things go wrong. Be as nitpicky as you can be when setting it up. Real PITA to have to pull things apart when adjustments are needed. Don't ask how I know.

I noticed you still have stock rear rotors - and stock calipers?

You plan on improving brakes any?

...I built My engine in My Garage using parts from all over the US. That's Right! I did My 'HomeWork' and I know what I'am Doing! I stayed with the Iron heads because I wanted to keep the Larger Valves. There was 'some' Polishing Work done to them (Heads).

351 Cleveland .030 Over, 10.6 CR, Dual 450 CFM Holleys (Vac Sec's), and Much More! 530 BHP @ FlyWheel...
I know Craig, he doesn't live far from me, here in Wauwatosa. My name is Matt.

Thanks for the advise on the hydraulic throwout. I can see were they can be a major headache if they need to be worked on after the engine's in. Because of the Quicktime bellhousing I would need to make up new brackets for a push or pull slave cylinder. I decided on the hydraulic unit just to simplify things-- we'll see if I pay for it later.

The brakes are the original units. They are very "piccolo". I hope to replace them in the future. For now, my family-friendly budget will only allow for the car to get on the road, with some upgrades coming later.

The remote electric water pump and controller are from EWP DAVIES CRAIG, out of Australia.

Here another picture of my project. This car was a complete teardown and acid-dip. The car hasn't been driven for over 30 years.


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Hi Matt,

here in Wauwatosa

Wow, Two of you in a town I sure have never heard of.
complete teardown and acid-dip

Interesting color - what is it?
Were you able to bake the car dry prior to paint work? Acid dip can sometimes have a sneaky habit of weeping out years later - not nice to the paint when that happens.
car hasn't been driven for over 30 years.

Well then, thank you for giving a re-birth to this car. FAR too many of them are like yours, having been put away and left for decades.

I always wonder - WHY!??

After acid dipping the car went through several stages of neutralizing washes prior to being shipped to Detroit, washed again, and E-coated with an epoxy primer, in an attempt to get into all the boxed and welded-in sections.

I am embarrased to say that work was done nine years ago. Two daughters later I have now found the time to really begin the project in earnest. I have been seriously working on the car for only the past two years. It will be on the road this year, even if it kills me!

The picture is deceiving; the car is more silver than blue. The color is late model Ford.

Below is picture of the Ford Big Block header clearance to the A-arms, fuel tank and shock. Things are tight, especially up front.


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Another thing to consider about Pantera engine swaps: As mentioned by an earlier post, the expensive weak link is the ZF. Its durability is a function of torque and torque generation is largely a function of engine displacement. For this reason I chose the Ford Racing 460 Cobra Jet SVO engine. It makes almost as much power as the much more expensive 514/521 engines, but with less torque and cost. I was able to find a new 460 engine, built by Ford, for almost 1/3 the list price of the 521. The 521 also comes with some heavy duty components to improve durability at sustained peak power, but this engine is not going into a cigarette boat. The 460 is still a hairy engine, making 576hp and 548ft-lbs.

Precision Proformance used to do Big Block conversions, but they told me that they have since stopped due to customers having ZF failures. My solution is to use the smaller 460 and not use ultra-wide rear tires.
Originally posted by Pantera L #7341:
My solution is to use the smaller 460 and not use ultra-wide rear tires.

A thing which does suprise me as well... Many of the owners go for big wheels - 17' is way too little already - and therefore use low tires. The tire is the damper, the damper which is supposed to keep your drivetrain alive! It has its reasons why drag machines use that high tires...
In reply to the "440 BHP motor has 6.5 pounds per horsepower " line of thought, I offer the following.

I have recently taken to classifying cars thus:
peppy (my V8 Miata)
performance = 440 BHP motor has 6.5 pounds per horsepower
brutal = a 2200lb Kirkham w/ 550hp
stupid fast [1] = Gallardo w/ 1800 wheel hp

One should NOT be exercising anything peppy or above on public roads, its just isn't safe.

butt, in rebuttal to the "440 BHP motor has 6.5 pounds per horsepower " line of thought I say this, the throttle works both ways. Don't drive like you don't have relatives and friends.

all the best,

[1] When at the Texas Mile event I saw a guy w/ a hat that said "stupid fast" on the back - wtf? Now I know. that car would peg the tach on boost in every gear.
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