Dyno'd the Car, Please Critique.

FWIW, you get a long-winded reply! 300 bhp at the rear wheels usually equates to about 400 at a Pantera's flywheel; not bad IMHO. You are maxed out on compression with pump gas, so your only choice is a bigger cam- either flat-tappet or roller, or use $6.50-per-gallon race gas and jack up the compression. Expect to lose about 2 miles per gallon of fuel economy with each increment of cam duration beyond your 268. I sugest calling ALL the cam grinders and telling them your plans- and budget. They are the real experts on camshafts. I always recommend a matched set of springs AND valve lifters with any aftermarket cam. Be aware that all cam grinders get their blanks from one of only 3 manufacturers in the U.S, and the last 10 yrs or so, there have been a rash of poorly-machined integral drive gears and improperly hardened lobes on 351-C cams. Since the 351-C is a low-production engine, aftermarket cams don't sell fast so there may still be some bad blanks out there. The gear problem has shown up in as little as 5 miles, failing a stock cast iron distributor drive gear, so check the gear within the first 50 or so miles. Be SURE you can return the whole mess if you get a bummer. The guarantee will not reimburse you for cleaning the shavings out of your engine or the rebuild costs.
A tuner carb will help somewhat but there will not be a huge power increase. I added a 700 tuner double-pump (jetted for a 351C at 4700 ft altitude) and picked up about 15 bhp PLUS 2 extra miles per gallon with our very similar combination of parts (A-3 heads & Ford/SVO hydraulic cam). I originally had a 600 Holley.
I recommend adding a 10-qt fully baffled oil pan to any Pantera. Aviaid and Armando both make acceptible units. Otherwise, you WILL lose the rod bearings sooner or later. Do not use anything but a stock oil pump; high-pressure or high-volume assemblies are not needed this side of a full-race engine. Melling makes a good one.
A stock crank will take around 600 bhp before giving trouble. A stock block, much the same. Your fuel line out of a stock Pantera gas tank will not support more power than what you've already got (400 at the flywheel) before running lean at high rpms. There is a 0.205" ID restriction in all the steel lines wherever the line is 'beaded' for a rubber hose. For much more power, a 3/8" or 1/2" ID line everywhere from the tank bottom up to the carb will be needed for high-rpm road work, regardless of what fuel pump you select.
Add-on vacuum pumps for drag racing (or Weber carbs) can be used, but a cleaner solution is a small vacuum surge tank that stores vacuum for panic-braking use.
Any 351-C waterpump should be able to move at least 50 gallons of water per minute, or you're limited in the cruise distance- and rpms- you can use. The best today is the $350 Meziere which is marginal for your present power level. One L.A owner with a nearly stock engine drove his Mezeire-equipped Pantera the 250 miles 1-way to 'Vegas a few years ago, and saw 220 degree water temps at certain points on the trip. He also had to cut some of the bulkhead support away to fit it in. I'd personally recommend a much cheaper, bolt-on Weiand 8209 aluminum mechanical waterpump, that is half the weight of the iron stocker. Mine is 17 years old and has not had an easy life.
The pump is not the problem in hot-running Panteras; flow restrictions (including any brass radiator) are. Over the nearly 30 yrs we've owned our '72, I've altered every single thing in the cooling system, and nothing changed engine temps except an aluminum radiator. Fluidyne makes a nice bolt-in unit that solved a cooling problem in Pat Hals' factory Gr-4 racer at last year's '08 Classic LeMans race in France. It is not a 'racing' radiator, either. Flexilite makes a fully shrouded dual-sucker fan assembly that bolts onto the backside of any Pantera radiator and keeps the engine acceptably cool around town, with shut-off thermostats for highway use. I use both these trouble-free assemblies.

I've included details on two 351C engine builds that seem to work well, just for comparison. Maybe the cam info will prove useful. Note that I believe all quoted horsepower and torque figures are at the flywheel, not the rear wheels:

Paul Rimov's 393hp/425ft 351C
Dan Jones helped Paul Rimov me set up his mildly built Cleveland with Aussi 2V heads, Performer intake and 725 Demon carb and it makes 393hp/425ft at 5700 rpm and 3800 rpm respectively. The Aussi 2v heads with a two plane manifold like a Performer lack the 4000rpm kick the 4v heads have but have a really long flat torque and horsepower curve right of idle. His engine is done at 5700 but that is due to his cam, exhaust and intake choice.

Measured compression is 10.25:1.

Cam is a custom grind made by Comp Cams:
Gross Lift .531/.531
Duration at .006 268/276
Valve Timing: Open Closed
Int 28 BTDC 60 ABDC
Ex 72 BBDC 24 ATDC

Installed at 106 ICL
Duration at 0.50 222 226
Lift 0.3060/0.3060
Lope Sep: 110

Chuck Engles 483hp/436tq 351C
I've also attached a build/dyno sheet from Chuck Engles which details his combination which seems to work quite well.

Great info you guys, thank you! the pan looks like an aftermarket baffled pan, of course no way of knowing whether it is baffled or not from the outside, but its definitely an aftermarket aluminum piece and not a factory piece. It looks like my limit at this point would be the fuel line diameter, so I will have to investigate this more with a flashlight.

I think tonight I am going to duplicate what I have setup in desktop dyno and play around with some different cam specs I can find on the net just to get an idea of what might change. I've seen a few engine builders/cam designers make fun of this software, but honestly it was pretty damn close on my last motor build once I had everything spec'd out correctly. I let an engine builder spec the cam for my last motor and then just plugged it into my build on desktop dyno. I really wouldn't mind a solid roller in the mid .600 lift range. My a4 based 308 runs one with .670.

Aside from a cup motor, do you guys know of any 35x builds on here in some drivers that are pushing 500bhp? What do you guys think of pushing the cleveland into the 6500-7000 rpm range? I've read a few sites talking about not overboring anymore than .040 at risk of having to thin of a wall. I suspect only being at .030 there is enough material to support my turning the motor this hard?

The compression is right where I would like to have a naturally aspirated motor, I run 92 all the time and don't want to go through the mixing octane fun again. It just seems like there is a lot more power left in the motor when I look at some of the milder 302 based 347 builds I've read about over the years.

Hustler, are you running stock or aftermarket headers & exhaust? Just wondering ...

Like yourself, I am curious re: the HP I am running and, as such, have scheduled some dyno time on Jun 22nd. Any advice you wish to provide re: set up, expectations, etc. would be appreciated.

The headers are aftermarket, I'm not sure where they were sourced from though. The exhaust is an Ansa unit, looks just like the exhaust setup on this webpage.

http://www.panteraplace.com/page4.html

If you plan on doing some tuning obviously you might want to undo the passenger seat etc. so that you aren't being charged dyno time taking your stuff apart to access the bulkhead. They usually charge by the hour, so you want them to charge you for tuning not taking stuff apart. They should have a timing light etc.

We didn't mess with my timing because it was a group dyno session and obviously we didn't have time for me to take everything a part. Check your plugs obviously and make sure they are showing the right tan color. Make sure all your fluids are good and oil is right on since you will be pushing it. Make sure they aim the fans directly at the radiator inlet so that you don't have overheating. Shutoff the engine when its not making a pull so that it doesn't heat soak. Its hard to see changes in tune if the engine is just getting warmer and warmer negating any actual finds from timing changes, carb adjustments etc.

You have to have reasonable expectations because you have to factor in drivetrain loss on a chassis dyno. A dyno operator can skew the numbers by some settings they input on the dyno also, and of course factors like whether the dyno adjusts for SAE correction and if it has a weather station to factor in humidity, ambient temperature, how many feet the dyno is above sea level etc. Some of these features are only available on certain dynos. Really the dyno is a tool to compare changes to your own motor and tuning, and not a tool to bench race engines. There are so many factors involved. Even then, if you go back to the dyno on a cooler day you may see a considerable increase in power with just that alone.

A mustang dyno is load bearing, so it can simulate actual driving conditions. You will see higher numbers on a Dynojet chassis dyno because it doesn't put a load on rollers. Last I recall the typically difference is about 15%? Hope this answers a few questions. If you take your car to a dyno, the foremost question is whether they specialize in carburetor tuning or newer EFI programmable computers. Obviously if you know how to tune a carb yourself that probably wouldn't matter. They should also put a wideband o2 sensor on the tailpipe to read your A/F ratio throughout the pulls. Without this it will be hard to tell if the car is running too rich or lean.

For me the group dyno day worked out to be the best option because of the discounted rate and not knowing anything about how the motor is running or in what shape its in. The next time I go back I will be ready to pay for a complete tuning session for a few hours. It really would have been a waste of time for me to pay to tune the car further anyway since I have no plans to not rev it past 5200. The motor needs new springs or a new cam if I want more. If I think of anything else I will repost. I've included a link to a video of the dyno pull.

http://stangnation.com/index.p...lery;sa=item;id=7862

You sound like the ideal candidate for one of the new Buttermore blocks.

I love the original look of the ANSA's but they are rather restrictive. I had mine gutted and noticed an immediate improvement --- and yes, they are a little louder but I don't mind the extra noise for a little extra horsepower...

Just something else for you to consider

Billy
#3382

Before...

After...

I was wondering what the inside of the mufflers looked like, did you also gut out the rubber like inner baffling in the tailpipes? I'm torn because I love the look of the Ansa pipes, but I look at the whole exhaust system on the car and it appears so restrictive. I know I'm looking at over a grand to have someone fabricate the 180 headers, so that will have to wait. Has anyone done testing between the stock 2.0", big bore 2.5", and a 3.0" collector on a standard routed header? Will a 3" exhaust even fit past the u-joints and does it overscavenge?

Are the buttermore blocks the blocks I was reading about that someone is trying to cast right now? I would be interested in one of those once I can compile a little more money. I have been keeping my eye open for a used 9.2 deck SVO block like a G351 with the cleveland mains. Till then, I'll see what the R/Q code can do.

Tod Buttermore actually has cast both iron and aluminum blocks. He has already taken orders. I haven't seen an updated post on this BB for about a month or so. The design corrects weaknesses in the orignal design which have been recognized through the years.
Pat Mical makes an excellent header with a 3" collector. You might contact him for details.

I will do that, another member mentioned purchasing his headers in another thread for his yates headed car, so I will wait to hear back from him to get an idea of pricing. Then I'll give Pat a call. My budget will dictate that this happens in stages.

Hustler,

I am running big bore headers and gts Ansa's. I left the inner baffling in my tail pipes. I've never had my car dyno-ed so I can't help there.

Good luck and please keep us posted...

Billy
#3382

Here's a shot of the tailpipes with the inner baffling. I've since painted the mufflers black...

Thanks for the pics Plankton, I would be really curious to see the gains since gutting the mufflers, is that why you did it? But I'm thinking you'd have to gut the tailpipes as well, that inner diameter is small and would block off flow. I found a max effort 35x cam and he's running stepped longtube headers on it with a 3.5 inch collector lol. I've monkeyed around on my desktop dyno with the cam and it estimates that there is around 50 horsepower plus in the last 2k of power going from a longtube header with mufflers to a stepped race header. I'm not a fan of the 180 header look from the back and like the ANSA look, so maybe I'll have a local header builder weld a 3" setup back to the tailpipes, and either gut the ansas, or find another stainless set with the twin tailpipes that fits with the same look. I'll do some measurements between the rear a-arms when I get home, not sure this can even be done. Maybe if I flipped the u-joints?

I'm guessing the vendors never made this setup because all the money was in a tuned header like the 180 headers, or because it was impractical to get anything larger than a 2.5 inch diameter pipe around the suspension in the rear. I guess I'll do some more searching on here.

You can flip the half-shafts if thats not already done, so the thicker section is out of the way. Gains a little space.

Hustler, you may wish to consider a Mind Train exhaust. I am running with Hall's ceramic big bore headers and the gutted Mind Trains absolutely scream to life north of 2400 RPM. I've been told this setup provides an additional 40-50hp, but I am not an expert. They do sound gnarly, though - like an entire pack of Harleys!

Have a look ...

Hey Erik,

Have you ever tried revving the engine up and dropping the clutch in first and seeing how far back you can shoot those ramps? I'm guessing they would go at least 50 feet...

Just an idea...

Mark

That definitely looks good, the problem with all the vendor muffler setups is they still use stock size piping. Do you guys know of anyone who has put 3" or larger exhaust through the stock routing?

I am in the process of putting in a new engine, hopefully this weekend. I had some time to work on the exhaust by putting in a 3" collector and exhaust pipe to the muffler. It can be done though it is tight. I have seen Pat Miacal's system and he has a small dimple in the system where it crosses the sway bar. Hopefully I have eliminated it. I also am putting a flange connection right before the muffler so that I can attach a straight pipe for track days. I'm learning to weld so its functional.

If someone is going to do this they will need 2 180 U bends and a couple of feet of straight pipe. I don't think you could go more than 3" OD. The other alternative is to use some oval tubing under the axle. Just a bit more complicated to do.

Mark

Search up Goran Malmbergs Hemipanter site.

His car runs 3" pipes, among many other features.

Lots of great engineering and photos.

There is room to run them over the suspension; but there are issues:

I'm pretty sure I have the big bore headers, what is the primary size on these headers? I'm thinking about just having an exhaust fabricator cutoff the collector and re-work on a bigger collector and then run the 3" from there instead buying another header. This may very well be my best and most affordable option. I'm pretty sure I would gain a significant amount of power as the motor sits now and would see even more after I did the cam swap. But with all that would need to be done I may have to pull the motor making that a better winter project.

Here is another article I found on gutting the Ansa exhaust, so I will probably do this and have the 3 inch piple mated to it if I can cutout the old pipe.

http://www.spacecitypanteras.c..._the_GTS_Exhaust.htm

If you are going to go through the trouble of modifying your headers to add a 3" collector, I would also add 3" ball flanges instead of the standard 3-bolt flange for a leak-free seal without a gasket that blows out. The other advantage is you can reposition the exhaust pipe to center them on the cutout easily. I never liked the Hall Big Bore exhaust because what they called the 'Venturi Effect' collectors which choked their 2.5" collector to a 2" flange. Look at them and you'll see what I mean.

Here's a pic of the ball flange. These are from Flowmaster.



FYI - I have considered 'engineering' a tuned exhaust myself and I gave up after reading up on the theories and applications from better men than I. The best read I have had on exhaust theory were those written by David Vizard.

I made up an exhaust for fun using Flowmaster 40 mufflers (3" single in/ 3" dual out) and they sound great with solid cams. I can really feel them working when I am going through the gears. But, they are loud. I only put them on when I go to the local cruise ins. Attached are pictures of the Flowmasters on my car:




Good luck with your build.

I went home for lunch and did some measuring. The primaries are 1 3/4" and I think you are right as it tapers from a 2.5 into a 2.25" pipe back to the mufflers. I've also decided that hacking into the stock muffler and doing all that work will be for little gains. Thinking about getting the mufflers from PIM with the 2.5 inlet and cutting it out to accept a 3" inlet. The tips are 3.xx so that should provide way better flow than th stock units.

I'm just not excited about doing a mechanical or electric cutout, they go south quickly and I don't want to wire some goofy setup or run a cable for them.

I like those flowmasters, always have had a great sound to them, but I think personally I want the polished stainless look since my car still has the chromed bumperettes. Think they would compliment the car.

here's two pictures of 180s that exit traditionally. I personally like the ansa look and thought this might be something to do, maybe capturing the best of both worlds. I would think that with that setup you'd be able to keep the A/C too. I do also like the hexagon Lambo exhaust too, decisions decisions.
http://p400sv.at.infoseek.co.jp/GT5.13-06.jpg
and
http://p400sv.at.infoseek.co.jp/GT5.13-04.jpg
and
http://p400sv.at.infoseek.co.jp/GT5.19-06.jpg

A little update, I got a call back about doing the Pantera exhaust from a guy whos done a few local Panteras and he seemed doubtful a 3" exhaust could be routed through the factory path.

As far as the camshaft, I plan on doing either a hydro or solid roller swap this winter since I'll probably be pulling the motor to change out the springs etc.

A 2.5" exhaust pipe will route fine thru the factory path but requires you flip the halfshafts to gain some clearance. A 3" pipe will definitely have a clearance problem unless you use 3" oval pipes inbetween the halfshafts and lower A-arms. Even then, you need to check your clearances to verify interference with the rear suspension travel.

Have fun


Aloha

I talked to the guy this afternoon and he was willing to take a look at it to see what we could do. I may just take it down there and talk about either getting an oval piece, but the problem is I need to get the lowering springs on before we do anything because that will change how high the a-arm sits in relation to the halfshafts as well.

Does anyone have any real world gains doing back to back dyno testing going from a 2.25 or 2.50 to 3" exhaust with a cleveland? Chassis or Engine Dyno?