Honestly Selo, you're probably better off just enjoying your car for this driving season and then upgrading to a different Cobra that is more to your liking over the winter months.:cool:

Most Cobra owners want the feel of the engine. That means a lopey noisy smelly old style engine. If you want something that doesn't make any noise or doesn't smell and doesn't need weekly maintenance buy a Toyota. A Cobra is not for you.

I would concur. The cost of your shopping list in parts and labor will probably exceed the cost of finding one already built like that.

I'm not necessarily even asking for myself at this point, just surprised that no one really commented on the coyote as a desirable option.
I think twobjshelby's above is getting to the heart of the issue. That's what I was really asking about. Sounds like most people on this forum don't think the coyote is a pure Cobra engine. By the way, I love the fact that mine is loud and my garage smells like gas. Just wish it had a little more grunt. I'm going to be tweaking a few things within the next week or two that hopefully will improve the drivability, it's a damn nice car, no two ways about it, just needs a little attention.

Drive it for the season, pull the engine out at wintertime and send it to me. I’ll give you more grunt, while using some of the same parts. Easy peasy.

Any small displacement engine (unless supercharged) will make it's horsepower with high engine speeds and low torque. Torque is what makes a car move when you initially push on the accelerator pedal.

If you intend to use a low torque engine and make your power with engine speed you will always be driving around town above 3000 rpm in traffic — and that gets old fast not to mention expensive.

This is a link (click here => Westech Dyno test) of a dyno pull of a 427 Windsor at Westech. Notice the engine has over 500 ft/lbs of torque even down below 4000 rpm. This is what moves a car around town and in traffic when you push on the accelerator.

This is a link (click here =>Hot Rod Coyote Dyno Test) to a Coyote dyno pull writeup by Hot Rod.and here is the Dyno chart for the engine;

https://st.hotrod.com/uploads/sites/...nd%7C596%3A398

Notice how the engine torque falls to 375 ft/lbs at 3000 rpm. When you take the engine down to 1500 / 2000 rpm (which is where you'll be driving it) it has even wimpier torque numbers — it will feel like the engine you have today that you want to replace. The only difference is your wallet will be a lot lighter. BTW FWIW it took E-85 and add ons to get those disappointing numbers.

The only way to fix the wimpy torque problem is displacement, you need to have 427 or more cubic inches of engine displacement, which is exactly what the Westech dyno pull showed.

There is one other fix for the problem and that is supercharging, which is in effect more inches but on demand.. When you supercharge a good basic design like Ford's 4 valve Modular family motors the result is stunning.

This is a series of dyno pulls from Kenne Bell showing what their superchargers are capable of on this engine platform. Notice all the numbers are on bone stock engines except for the KB compressor.

http://www.clubcobra.com/photopost/d..._Dyno_Data.jpg

Even the diminutive 4.6L engine (that I use) produced 500 ft/lbs of torque at 2000 engine rpm and the torque was essentially table flat across the entire engine operating range. The other significant consideration is the figures are rear wheel torque and power figures not flywheel — add another 15% more power for the flywheel figures.

Those diminutive (diaplacement-wise) supercharged 4V Modular engines will slam your eyeballs against the back of your skull, if you hook them up. Ask me how I know. If you are a purist they are not period correct. If you are into eye candy and stunning performance they are just what the doctor ordered but on steroids. They do come from an OEM Cobra so the gene pool is sort of correct ...

Bottom line you are back to needing displacement, either a 427 or bigger n/a engine or a small displacement engine with a screw blower.

You ought to also spend $150 on those books I pointed you at. It is much less expensive than a $15,000 engine mistake but it will require you to actually read and learn the stuff in them.


Ed

This is great info, thank you. I wish there were a way to upload the data from these books directly through my skull. Hopefully in the next few years, I'll be successful in finding a way to shift some of the burden for running this practice with multiple docs and multiple offices to some of the other providers, and I'll have time for other pursuits. Right now family and practice take precedence.

Ed has many great points.
However, it is important to cover the apples to oranges here. The Coyote is a 4 valve variable timing engine that naturally has weak low end torque and big high end horsepower. With a supercharger 690 hp can be SAFELY achieved with pump gas. That said, your personal concern with the Coyote is physical size. The foot boxes in you FFR most likely will need to be modified to accommodate the Coyote.
I personally chose a Craft 427 w/Dart block over the Coyote. RPM Air Gap instead of the Victor jr. 582/572 on their dyno, but the pull started after peak torque. This block can be taken to 465"/468" (465" leaves you 1 refresh on the block). I personally like the big low end grunt. Important note, the cam required has bad low end vacuum, where a carb just doesn't work well below 1800 rpm. I ended up changing to an EFI to work around this.
If I were considering racing, I would consider a Coyote with a dry sump.

MKS 427 made an excellent point that I had forgotten to mention — size. The Coyote while about an inch narrower than my Modmotor is still huge. It is right on sizewise with a 427 SOHC engine which is impressively big.

My generation of SPF was among the first to be built to accept these huge engines. It is always challenging to keep from chipping the entry to the engine compartment when you install any of the usual engine picks. When you install a 427 SOHC, Coyote or a Modmotor (even worse) it takes three or four sets of hands to do it w/o incurring some damage to the car. Additionally things like the steering column need to be moved leftward on left hand drive cars to clear the engine and accessories.

Don't get me wrong I love the engine and its power but looking back in hindsight the primo pick (IMO) for these cars from a fun and ease of assembly standpoint is a big inch Windsor based engine. The primo pick if you want best resale, best authenticity etc. is the big block FE. The primo pick if you want easily achieved displacement and massive low speed torque is one of the big displacement 385 series engines.

Keep in mind the bigger the block and head casting the more weight you put on the nose of the car — unless you go aluminum block and heads which you could also do with a Windsor based engine and get a very nicely balanced car.

BTW a few thoughts in closing about Coyote's and supercharging. The standard Coyote bore size is 92.2 mm and the bores are on 100 mm centers. That leaves 7.8 mm of block webbing between bores. 7.8 mm is equal to 0.31 inches or just a whisker short of 5/16 of an inch and that includes the cast iron liner.

This sort of design will let you get by with a n/a engines but is tender, in the extreme, for supercharged engines. When you push out a head gasket on a blown motor, under power (where else do you do it?), it will torch the head and block. The appearance will be just as if you took an acetylene cutting torch to the metal. Neither the block or the head can be economically brought back to their as manufactured condition.

When you weld aluminum you produce a large soft spot in and around the area of the weld. This defines the weak spot where the head will next fail under power. You could, of course, remove the seats and guides from the head, anneal it and then re-heat treat it.

Once out of heat treat you can install new guides, new seats do a new valve job and you're good to go, sort of. Once you think you are all done don't forget you still have to re-align hone the cam bores in the heads — try to find a shop to do that! This is all a lot of work and money. It is cheaper to buy a new head.

Supercharged Coyotes will use up a lot of your money faster than you can imagin unless they make no power or you can't hook up the power. Once you hook up and load a supercharged version of that engine it is on borrowed time.


Ed


p.s. Something for anyone reading this post to be informed about is that you can not re-heat treat aluminum. Heat treatment is a one time event with aluminum. I misspoke when I suggested re-heat treatment of the casting. It is not possible.

You can look at them on Ford racing website.
https://performanceparts.ford.com/engines/#modular

The maximum Hp coyote is 5.2 ltr 580 Hp @ 7800 rpm 440 torque @ 4500 rpm and it is not street legal in a modern car. It costs $20K. I do believe you would have to get a wire harness and a new ECU which could set you back another $3K unless you could source used from a salvage yard.

The more typical coyote is 5.0 ltr 435 Hp @ 6500 rpm 400torque @ 4250 rpm. It costs $8K plus the CPU and wire harness.

The dyno chart I saw on a newer Mustang hit about 300 torque at 3000 rpm peaks at 350 and is back down to 300 at 7000 rpm, on a chassis dyno (power read from the wheels to the ground). From everything I have read these engine produce good low rpm torque and have a very flat torque curve. They can do that with the variable timing cam shafts, which also allows the torque to be produced to very high rpm numbers, which is the reason for the high Hp at high rpm. Also contributing to that is the very well designed 4 valve per cylinder heads. The heads make the engine and these are some of the best head designs out there.

They purr like a kitty cat at idle. They are smooth superb running engines everywhere. This is not what people expect to hear out of a Cobra, at least the old school guys. That said a Backdraft dealer has been putting Modulars and Coyotes in his Cobra's for years and he is a member on this site. Drawing a blank on his name.

400 Torque is not too shabby and it is flatter over a longer rpm range than a push rod engine. The size of the Coyote is huge. As big as a 460 in most directions, but shorter front to back. It is very wide and tall. The block is small, but the heads are massive. They house two camshaft per head.

They are a great engine, and if that floats your boat, so be it. Be prepared for smart ass, know it all, can't control their mouth, people talk to you and about you as if you stuck a Chevy engine in it. If you have thick skin and it doesn't bother you, or if you can kick the whole worlds ass, then go for it and be happy.

PS

You will note that the torque on the Coyote is pretty much what you can get out of a 347 stroker, actually a little less. The 347 stroker below 6000 will be similar but the Coyote will pull away in the top end. However a 347 stroker will pretty much bolt right in for a lot less total cost. You can build a lot stronger windsor stroker for about the same total money, most likely quite a bit less all said and done. It would still be a much easier to fit engine.

If you are set on a Coyote, I would look up the Backdraft dealer I mentioned.

I agree. Modern engine, so then of course it will have a modern gearbox behind it as well. It’s a Cobra replica, and the more modern mechanical bits and other creature comforts are fitted, the more modern is the driving experience. Even using electric instruments on the dash takes away some more of the vintage feel of a Cobra replica. There’s something about the cool-down ticking noises (OK, yes, vintage engine or new) of a car, accompanied by the sight of the "mechanical” (ie Bourdon tube) water and oil temperature gauges slowly dropping as the 'beast' cools down. The period correct bits on a Cobra are the things that help give it that ‘alive’ feel.

That said, building or speccing your own Cobra replica is a very personal thing, and there should be no criticism of a particular approach or choices, IMO.


Cheers!
Glen

Here is a pic to help visualize the difference in size between a Modmotor and a Windsor. The coyote is only about an inch or so narrower than the Modmotor.

https://www.rx7club.com/attachments/...t-img_5356.jpg

I'm not saying don't do it because after all, I did. What I am saying is that it is more challenging than you might at first anticipate although, the supercharged versions are stunningly impressive in the power and torque departments. In the n/a space a 427 inch or bigger Windsor is a much better, more cost effective and dare I say, smarter choice.


Ed

Actually that's torque argument and low RPM is he weak one. Why? You have a car that weighs 2200 to 2400 lb it doesn't take much to make it move. Your gear multiplication. Typically for starting line ratios you're looking around at 2500 lb of a ratio of 8.75 (first gear + rear gear)

First gear x rear gear.
That said, it is very subjective based on what each individual prefers. You must consider trans gearing, tire height, and what you are willing to tolerate for cruising RPM.
I run a 3.08, 17" tires, TKO 600 w/.64 OD, 1600 RPM at 60 mph.

All right, so picking up where I left off, car is really coming along. With the help of a killer mechanic and hot rod guy, I've now got the steering and alignment where it should be, and the car tuned for high altitude. These changes alone have made it much more fun to drive. Now thinking about upgrading from 3.31 to either 3.55 or 3.73. (Modified 302 with 300-325 hp) Also looking for recs on which LSD , currently has Ford TracLoc.

You should be able to find a mile per hour calculator online that will give the best information for rear gear selection.
If you are considering rear diff replacement, I have a Torsen T2R-race version. It works great. However, it is not recommended to drag race with.
Glad you got your carb worked out. If you are going through multiple altitudes, like we do in Arizona, you may consider and EFI. When we get up to 7000' from 1200', everybody with an EFI doesn't have issues. It will take away a few top end HP, but the low end driveability is so much better.

I have a Fast EFI, but parameters were for sea level and I'm at 5000 ft. We reset parameters and it's made a huge difference.

You may want to ask the tuner about this:

If the EFI is using a MAP sensor and is speed density strategy, which fast used to do, they typically could get by with one MAP sensor. They did this by saving the MAP reading before the engine was started. That told the ECU what the atmospheric pressure was. If you don't change elevation too much and no huge storm front blew, in you were good.

If you drive up a mountain and see a 7000 FT change, that strategy doesn't know this happened. If you shut the engine off and then restart it, it resets the atmospheric pressure to the new elevation. If your ECU uses this strategy, this little trick is worth knowing. If not, there is no point in doing it.

Ford Mass Flow EFI systems starting around 1990 measure the mass of the air flow into the engine and use a MAP sensor not connected to the engine and all this was compensated for. Earlier speed density systems were as described above.

Is there something you do not like about the Ford Tracloc? If it isn't causing a problem, leave it alone. Assuming it has clutches in it, measure how much torque it takes to make it slip. It may need new friction discs.

What are your transmission gear ratios? How many gears? Typically a 4th gear in a 5 speed is 1:1 and 5th is 0.8:1 or 0.65:1. 1st gear ratio is handy to know also. The answers matter when changing rear end ratio. Assuming 4th is a 1:1 ratio how many rpm is the engine turning at 60 mph.

If all this was answered in an earlier post, point us to that post. I gotta run.