SuperCharger - Belt driven
 

Until recently never gave this option much thought but just might be a very good idea for boosting horsepower. A friend dropped off a magazine that advertised a billet supercharger "TorqStorm" it got the juices flowing.

Any of you go this route the big block Ford kit looks like it just might fit under the hood.

Huffers are 'way cool but you better ensure the bottom end components can handle the extra HP and that you don't start off with too much compression. I'd be leery of even 9:1 to get the greatest benefit. Cam and port flow are also pretty critical.

I'm interested in doing something (would go with procharger, never heard of this manufacturer). I guess the other option is switch to fuel injection and blower.

You want EFI and either a Kenne Bell or Whipple Twin Screw blower.

Don't get crazy with boost on bigger engines. The HP comes stunningly fast and the engine has max torque essentially from the hit. A 427 cubic inch engine with around 10 psi of boost will easily be in the 900 HP range if not higher.

The dangerous element here is the max torque from essentially idle. If you thought a 650 HP FE was difficult to control the blown variant will take your breath away. They get out of control much faster and more violently than a n/a alternative.

You can easily produce 700 to 800 HP out of a 302 cubic inch displacement. With the Twin Screw blower you do not need big displacement or RPM.


Ed

Winter is refusing to let go so have some spare time for leg work. The 460 bottom end was built with all the right stuff, compression is in the 9:5 to 1 area. Heads are Ford MotorSport A429 aluminum with custom built competition headers. My thoughts were to keep the boost in the 5 to 6 lb. area. Looking at the engine bay space is a premium with the big block. These belt driven superchargers can lay off the right or left side may not be enough space. Still have a plenty of leg work thought the forums would be a good place to start.

The other option I'm considering since the top-end is coming off the engine this fall to polish all the aluminum was to install a roller cam.

Just curious are you lacking enough power now? It is the technical challenge?

If you are willing to go with a funky hood, you could always go for the "supersnake" look like Shelby's dual paxton car from back in the day. I thought it was ugly, but I'm sure the scoop wouldn't have been seen from 'way behind.

The v2 Vortech system packaged by Shelby does not need any hood modifications.

Lacking power? depends on the mood usually no but quite often the urge strikes for a hard row through the gears always want an extra 100hp or so then.

Technical challenge? partly, sure feels good with the end results.

The Cobra has been neglected for a long time it's due for an upgrade or two.

I love centrifugal blowers, (I’ve had three myself) they are a great compliment to a late model EFI car or truck. Near stock drivability and 100-200hp increase with a little tuning is not difficult.
I would be curious if that kit (or any factory bbf kit) will fit in the limited confines of a cobras engine bay. Do a search for ByronRACE here on CC. He built a Vortech blown West Coast years ago, it was a quite a fabrication project . Project Ludicrous Speed
I think taking your motor to 545-557ci (4.500 stroke @ 4.390 or 4.440 bore) with a ported SCJ or P51 head @ 10.5-12 to 1, nice solid cam (or a roller), single plane and a bigger carb or EFI rig would be a fun package.

“easily produce 700 to 800 HP out of a 302 cubic inch displacement. With the Twin Screw blower you do not need big displacement or RPM.”
I disagree: 700-800 hp from 302ci requires A LOT of everything! Aftermarket block, Big flowing heads, High dollar rotating assembly, a big blower, race fuel and RPM. Yes it can and has been done, but the motor will be a peaky, high maintenance and temperamental (sounds like my X wife) Not the making of a good street motor.
And that is the beauty of the 385 series BBF. We can make those numbers naturally aspirated on with a stock block, an $800 Chinese forged crank, good alum heads and possibly on pump gas!

Jason

Apologies Jason been away for a while so I did not respond promptly.

You are missing the mark here by a country mile though. The twin screw compressors have an extraordinary track record in the power production department — usually with just a larger set of injectors, MAF upgrade and fuel pump upgrade.

A personal acquaintance of mine, Harold Horton, won the Terminator / GT500 shootout last year. He used an 11 year old showroom stock engine that had never been apart or out of the car! He has raced it almost exclusively for the last eight or so years and not surprisingly won multiple events with it. His upgrades were what I spoke to in the beginning of this post. His final round performance was in the low 8.3x at middle 160's mph-wise at the Shootout.

His car weighs about 3300/3400 lbs and consistently runs 8.3x times in the low to middle 160 mph bracket. The car idles at 800 rpm and when driven on the street gets a little over 20 mpg. Now here is the best part, that is unfortunately really tough. It turns out it is a really big engine at ultra high rpm — it displaces 281 cubic inches and he shifts at between 6300 and 6500 rpm.

The car uses the original OEM ECU. The trick (if there is a trick) is the blower, the fuel supple, the injectors and knowing how to tune your engine and drive your car.

Here is a video of the car in action click here ⬇︎Stock Cobra

It looks like he might break into the sevens this year with a freshened engine and some hot rod cams. He has already been a whisker short of 170 mph.

Not bad for an 11 year old, off the show room floor, untouched stock everything in the engine compartment except for blower injectors and fuel supply, 281 cubic inch midget motor.

Positive displacement screw blowers and people who know how to use and tune them make a BIG difference.


Ed


p.s. Imagine what an engine like that, in a car like ours, that weighed 1000 lbs less might be like :D ...

You are comparing one of the strongest factory stock shortblocks ever in production to "bolt this thing on your 302 and get 800hp". Speaking specifically of the 302 block, 600hp WILL require an aftermarket block or you can count your blessings every time you don't crack the block (been there done that at under 450rwhp, not to say it HASN'T been done though, just not reliably). I have also had an 03 Cobra at over 700rwhp, no problems what so ever. You are making two completely different comparisons, and you are BOTH right in regards to the particular engines that you are discussing.

Besides, twin screws/roots/rotors are notoriously HARD on engines, quite contrary to your statement.

While I hear what you are saying, we do not have agreement with respect to the issues.

MDross1, the OP, originally inquired about supercharging as it might apply to a big block Ford engine. The discussion covered a wide ranging group of suggestions and possibilities.

I entered the discussion and suggested the supercharged big block would be overpowering in terms of its power even at relatively low boost levels. I suggested the power would allow you to get out of control more rapidly and more violently than a n/a equivalent.

I went on to suggest a supercharged small displacement engine (302 cubic inches) would still be capable of significant power (700 to 800). I implied this would be less dangerous than the supercharged big block alternative.

Jason went on to say,

As you can now see from my original posts and commentary I made no references to the block, heads, rotating assembly, blower size (although somewhat implied with Whipple), race fuel or rpm.


Jason believed the engine would be,

In actual fact as we can see from Harold's performance nothing could be further from the truth assuming the engine was built correctly and the tuner knew what he was doing..

The Internet is capable spreading misinformation at a mind boggling rate. Truth and fact are always better. It allows readers to make informed decisions in their own build's component selection and build process avoiding costly mistakes and misspent funds which are always in short supply.

While we are talking about misinformation your own representation that the modular block was
is also misleading. The engine was a force fit into the rear wheel drive product line because another engine had become cost prohibitive in the early 90's. Its original home was a transverse front wheel drive application in a Lincoln — which is how the bore centers got squeezed to 100mm. That tight bore spacing was necessary to transversely fit between the shock towers.

The block in terms of strength is probably several pages back from the leaders Detroit has offered over the years. When you look at the main caps, their fasteners and main web dimensions the engine pales in comparison to blocks like the FE, the 427 Chevy or the 426 Chrysler.

Shucks, a Modmotor even pales when compared to a stock 302 block. The fasteners, main caps, wrist pins pistons, connecting rods, and crankshaft all look like toys compared to a 302. The Modmotor's 10mm main stud is marginally larger than 3/8 inch. The 289 uses 7/16 main studs, the 302R uses 1/2 main studs and the 351's use 1/2" main studs. The "little" Ford Windsor blocks are massive compared to a Modmotor engine.

The Modmotor pistons are so small they do not look real. This is a picture of an intake valve from a Chrysler and a Modmotor piston;

http://www.clubcobra.com/photopost/d..._Stuff_004.jpg

Mod motor pieces are diminutive in size compared to any performance engine part we normally handle — including 302 components.

It is worth noting the width between the fenders on those early 90's FWD Lincolns that forced the 100mm bore centers also forced very narrow main webbing and main web anchors to the block structure — making the block a dicey choice at best as a performance engine.

It is a foregone conclusion in any engine build that the higher you target the engine's specific power output the stronger you are going to have to make the stressed components when you build the engine. Considering the age and casting technology of the time it is probably a prudent decision to use a block built with modern casting technology and benefiting from the decades of continuing product development done for the small block Ford engine.

You don't have to buy DART, you can also buy Ford. More to the point however, blocks rarely if ever crack because of horsepower. They will crack because of torque, they will crack because of detonation, they will crack from cyclic failure as in a 24 hr endurance test on a dyno or in a car on a race track but they will not crack because of horsepower. When most builders experienced an engine failure, they look at what they used and simply use better/stronger parts rather than attempting to discover the real reason for the failure and then address that.

For decades engines were built, sold and or put into cars for immediate use. Infrequently were they ever evaluated on a dynamometer and tested for fueling let alone fuel distribution, spark mapping or lean spots in the power band. My suspicion is you have built one perhaps two 302s that failed and you can not explain the origin or mechanics of the failure — other than to say an aftermarket block will not fail.

The 700 RWHP threshold you have achieved in your Cobra was a direct result of the Ford calibration team's building the logic that was employed in your 03/04 PCM to manage the engine. The monies they spent on the engine management system for that one engine alone dwarf anything the aftermarket can even begin to approach — or you can do when you attempt to build a high specific output 302.

Engine failures are most often the result of poor engine management rather than ultimate strength failures in individual components. This is especially true in high performance aftermarket pieces which can frequently be overbuilt. You can however mitigate the failure due to poor engine management issues by using a Ford engine management system — vastly superior to aftermarket.

Your statement that,
could not be farther from the truth either. When supercharged engines fail, in almost every case, it is a fueling or lubrication failure that precipitates the engine failure. The fueling failure is invariably traceable to error(s) in judgement made in the build and/or tuning process or a tuner that did not either appreciate or more likely understand the intricacies and nuances of the Ford calibration lab's engine management system logic.

Properly tuned and intercooled, the twin screw supercharged engine is as reliable as it n/a cousins. Your own 700 RWHP Cobra was in effect an 820 FWHP engine performing at 2.93 hp/cu in. A 3hp/cu in. engine is normally not looked upon as a reliable daily driver. Yours was because of the work the Ford engine calibration lab did to make it reliable.

The traditional roots style compressors (even intercooled) have a substantially increased downstream air temperature if the compressor is over sped. The attendant reduced engine reliability is directly attributable to that increased down stream air temperature (intercooler not withstanding), what Ford calls IAT2 or downstream air temp.

When you increase the downstream air temps the tendency to detonate increases which requires the spark map to be flattened out and the AFR richened to mitigate the conditions necessary for detonation. The higher the down stream air temperature the higher the temperature throughout the entire power cycle and the more likely detonation.

Additionally as that temperature rises, the greater the heat losses to the internals of the engine. As those heat energy losses increase the engine's thermal and volumetric efficiency is reduced with each increment of air temperature.

In all cases the roots style compressor will enter this destructive phase much, much sooner than the intercooled twin screw. Moreover, proper engine management logic/models can push out the twin screw detonation threshold even more.

For the inexperienced builder / tuner the tendency to push the spark map and push the manifold boost to recover the lost power quickly sends the engine into detonation with attendant massive destruction of pistons and cylinders. The old adage 'lean is mean' should be lean is destructive.

Again with proper engine management the twin screw compressors can deliver engine reliability performances equivalent to their n/a brothers but at substantially elevated power levels without the detonation issues of a roots style compressor.

The reliability issues you attributed to the twin screw compressor are in fact the very issues the roots style compressors experience but the properly designed twin screw system does not.

I have built supercharged engines for just shy of 50 years now. Properly architected and with a correctly designed engine management system, very high specific power output twin screw engines can be easily had without bad street manners, with excellent throttle response and fuel consumption. If you adhere to a regular maintenance schedule, as the owner you will wear out your supercharged engine instead of blow it up.

BTW I think it is always good when we consciously choose not to buy low priced Chinese knock off goods. We have talented design teams and engineers over here that can produce great product. When we buy Chinese knock off product we are cutting our own throats and most likely buying inferior product.

A for profit Capitalist economy ceases to sell what people cease to buy. Do it long enough and the only ones we will hurt will be ourselves.


Ed

Thank you all for the input there is certainly some serious talent carousing the pages on this forum. That huffed mod engine mustang is certainly is impressive. As it turns out my car with the 385 engine armed with belt driven dimensions without removing inner fender liners supercharging is out.
Honestly this engine is close to what I'm looking for now a roller cam should/will be the answer. For now going to enjoy the car and loosen up the all new drive train before tearing into it.
Mike

That's pretty slick, and not that expensive.

Good show Mike and congrats on your decision. That will be a very enjoyable ride.

Ed

Probably other options but Chris Alston has a pretty cool gear drive system that drives a Procharger right off the end of the crank:
https://www.cachassisworks.com/cac_p...ger-drive.html

Just what I need Mark a little more fodder to whet the whistle. For now plan is to polish all the engine aluminum and roller cam change. If not quite enough then by all means will look into the Chris Alston drive system that looks as if it could be made to work. Might even call for dimensions.
Thank you all again.

Mike

My current car has a 427.....I will probably stick with a small block but give it a bit more punch next go around. Speaking of the 385 series I think that it would be an awesome motor punched out to 550+ or whatever size. For a street car running a big hydraulic roller it would be a great street cruiser but I still think it would be insane on tires and just trying to remotely hook it up without some super sticky rears and the right suspension. I just got rid of a gem of an 03 cobra with a stock motor with a KB2.6 twin screw running just 16lb making 575hp/575tq at the wheels. The torque was literally at 500+rwtq at 2000rpm and up. It sounds really fun but I think it would be pretty treacherous. When I was thinking of my first cobra I kept thinking I would go the coyote route but now after I've had the 427 I really enjoy it. In the future I could see having a second cobra with a mod setup.....they are easy to modify and produce insane power if that's what your into.