Getting Greedy - Getting Closer to Our Goals

Last month was a very hectic time for my latest project car, a '91 LX with a stock engine and an AOD transmission. As mentioned in my previous articles, I made the purchase with the intention of modifying it, but I still want to keep the fun level high. Super-fast, 9-second race cars are just awesome to watch and/or drive, but racing at that level can get very expensive very quickly. This '91 LX may not be the fastest thing on four wheels, but it's affordable, reliable and a blast to drive. I purchased it from a friend for $3,200 and swore that my total spending limit would not exceed $10,000. With a BBK exhaust system and a Maximum Motorsports suspension kit, I am just now creeping over the $5,000 mark. With a tick under $5,000 still to play with, I knew tackling the engine would be a wise next move.

I ran the car with the engine in stock form, save for a K&N air filter and 15 degrees of timing. With a set of drag radials and 4.10 gears, it clicked off a strong 13.86 at 97.11 mph. We accomplished this feat with the transmission in "D." We tried manually shifting it, but to no avail. Although a 13.86 from a high mileage stocker is impressive, like most gearheads we want more. This is where an aftermarket set of heads and an improved intake manifold come into play.

Most high performance engine builders will admit that the cylinder heads are where the power is made. True, custom cams and headers, among other things, help but high performance cylinder heads are everything. If you're racing with out of the box stock heads, you're not running anywhere near as well as you could. To remedy this, we contacted Power Heads in Fullerton, Calif., and wanted to find out about its ported stock iron E7TE castings. There are a host of aftermarket companies offering high performance aluminum heads for 5.0s, but the Power Heads versions are quite affordable and that sparked our interest. The Power Heads units are heavily ported on a CNC-machine and are fitted with bigger valves and matching seats.

"Our 5-liter heads are stock E7TE castings that we take and CNC-port in-house," explained Ralph Pici of Power Heads. "We port them, stuff them with bigger 1.94-intake and 1.60-exhaust valves (1.78 and 1.46 are stock) and mill the deck surfaces to add compression and restore the flat deck finish. We also replace the weak, stock valve guides with bronze racing guides, helping to reduce the overall wear of the valve stems. Our heads are very affordable and can be completed in no time at all." The Power Heads castings have very smooth intake and exhaust ports and that should pick up our performance level considerably.

"Our CNC-ported heads flow 215-cfm on the intake and 175-cfm on the exhaust side," explained Pici. "To give you an example of how good those numbers are, stock heads flow 160-cfm on the intake and 110-cfm on the exhaust side, a ton more airflow than stock. These numbers were generated on a SuperFlow flow bench with a 28-inch reading."

The heads bolt onto the engine in the same manner as the stock versions, but the fun didn't stop there. To complement our new castings, we scrapped the factory intake manifold for a Trick Flow Street 5.0 intake, a BBK Performance 70mm throttle body and spacer, Crane Cams 1.6-ratio roller rocker arms and an Anderson Ford Motorsport B-21 hydraulic-roller camshaft. As mentioned, we ran the 13.86 with the engine mostly stock and couldn't wait to get to the track to retest the car with the new engine components. By the end of the day, with the engine work completed, we were able to generate a best time of 13.55 at 102.88 mph. You may be surprised that the car didn't run better, but let us say that we have a major problem that's hurting our on-track performance and it goes by the name of AOD (more specifically, the stock torque converter). When Rick Anderson of AFM shipped us out the B-21 cam, he mentioned that the true potential of it would never be achieved with the stock torque converter in place. "This cam needs a 2800- to 3000-stall converter," stated Anderson. "Our B-21 cam is designed to operate up to 6000 rpm but the stock converter will never let that happen, even with 4.10 gears out back. The car will be dead off of the line with the tight converter and that will kill your elapsed time." Ralph of Power Heads agreed. "Our CNC-ported heads are so much better than stock. They need to be revved to at least 5800 rpm to generate the results that they're capable of. With the stock converter and unmodified transmission still in use the performance of the engine combination will be severely hampered." Our converter struggles to stall to 1200 rpm on the line and, because of this and the fact that our AOD is shifting at 4600 rpm, we can't get off the starting pad to save our lives. The stock engine could turn 2.00 60-ft. times all day long but with the bigger Trick Flow intake and improved heads we lost torque below 3000 rpm and could do no better than a 2.07 60-ft. This is why a looser converter is so important. It will allow the engine to reach its higher rpm range sooner and should also help get the LX off the line much quicker, reducing our elapsed times quite a bit. Even though the stock converter and abused tranny are killing us on the track, they should have no bearing on the chassis dyno. With that in mind, we cruised over to Crazy Horse Racing in South Amboy, N.J., and strapped the car down to the rollers. With the stock engine combo we came in at 197.2 hp and 256.6 lbs.-ft. torque at the wheels. On the first pull with the new hardware in place, we jumped to 238.4 hp and 273.4 lbs.-ft. torque--a gain of 41.2 hp and 16.8 lbs.-ft. torque. If you read our BBK Performance story last month you are aware of the fact that we still have the stock mufflers in place.

One of our old projects, the Stone Pony, made 255 hp with Edelbrock aluminum heads and a matching intake and cam but it had a set of aftermarket mufflers strapped underneath it. We figure that the stock mufflers are hurting us by approximately 15 hp. If you add that 15 hp to our total of 238.4, we come in at 253.4 hp, right where the Stone Pony was. This tells us that the engine is solid and is making power. The transmission is now the culprit. All in all, our white '91 LX is making the steam but as expected, our stock AOD transmission and way-tight converter are holding us back big time. These are some of the prices you pay when real-world testing takes place. We could lie to you about the results but that is not what die-hard MM&FF tech is all about. We'll do it the right way and address the worn out trans.

Next month we plan on taking care of that with the installation of an Art Carr Performance Products Extreme AOD and matching 2800-3000 stall, 10-inch converter. This will allow us to use more engine rpm to get off the line and should keep the engine in a higher rpm band, right where it needs to be in order to run at its best.

Hopefully, after our AOD nightmare is addressed, our first 12-second timeslip will become a reality.

Counting My Pennies
Our goal is to construct a simple, 12-second street machine that can be driven to and from the track with no trouble, one that the average racer can afford. We set out to accomplish this with a budget of approximately $10,000 and have already spent $5,519.27 on a Maximum Motorsports suspension kit, a BBK Performance exhaust system and, of course, the Mustang itself (which cost $3,200). With $4,480.73 left to play with we addressed the engine and installed the following components:

1. Power Heads ported stock iron cylinder heads $881.64 (with shipping)
2. Trick Flow intake $395 (Summit Racing)
3. AFM B-21 cam $269
4. BBK throttle body $189.95
5. C&L mass air sensor $229
6. Engine gaskets and oil/filter approx. $100

*These prices do not include tax and shipping.

So with the engine components totaled up they come in at $2,064.59. After adding that to our old total of $5,519.27 we arrive at a new total of $7,583.86. We are on a budget of around $10,000 and are still left with $2,416.14.