Bullitt v2.0 Gets New Heads, Stage II Cams, More

Although the Bullitt put down good power, the recently-rebuilt engine needed some sorting. The engine had been detonating at high rpms, since I first bought the car. Changing the tune didn't fix the detonation, so the engine problem was likely internal.

Fortunately, Piedmont Custom Motorsports is just down the road from me. I hadn't had a chance to work with PCM previously, but I'm fortunate that they know Mustangs of all years and were eager to help me.

PCM found that the power level was actually low—for the surprisingly high 19psi of boost. Reinstalling a stock larger blower pulley for a more reasonable 13psi resulted in a big drop in power. And a leak down test showed poor engine sealing. At this point, the motor came out to have a closer look.

The heads showed previous detonation damage/repair around the spark plug holes.

A new threaded insert on one spark plug hole could be introducing a hot spot into the combustion chamber.

In addition, not all the valves were sealing properly.

PCM dropped the engine/crossmember/trans out from below.

PCM hooked me up with a set of stock replacement heads in great shape for only $300. The machine shop properly cut the oversize valves from the original heads and installed them. At this point, I figured the upgrade to Stage II cams was worthwhile... :)

While the Bullitt was in surgery, I figured I'd clean up the intake. I spent a few hours disassembling, cleaning, and painting...

And I ended up with this. The end-of-day lighting is harsh in this photo...

Here's the intake on top of the motor at PCM. They also installed a Centerforce clutch and adjustable quadrant for me.

Here's a video of the dyno, showing 533hp at only 13psi.




Mentioned in this post:

Cleaner Air with an RX Catch Can

First up, apologies for the lack of posts. I have a handful of new posts ready to go though, so more info coming soon. Today I'm posting about a product that I picked up for the supercharged Bullitt. However, this product should work just as well on a normally aspirated engine as well.

The RX Catch Can by Rev Xtreme is a unique catch can design that uses engine vacuum to operate a check valve to control the flow of air into the can before sending it into the intake. The dual-valve design is for supercharged cars, and uses a second identical check valve controlled by vacuum from the supercharger intake. This is a very clever unit that reduces the oil contamination in the intake charge, which is important for all cars especially with forced induction. And the unit appears well made too.

It took me a while to figure out how to install this unit on my car, but the manufacturer is very helpful and responsive to inquiries, so I was up and running soon enough. I'm posting an overview of the installation on my Vortech-supercharged 2001 Mustang GT Bullitt, since it seems that most installations happen on GM vehicles — so installation guidance for Fords is difficult to find online. (But the unit works great on any engine.)

One item I had noticed on my particular car before installing the catch can was a rattle at higher rpms. A local shop used a laptop during tuning to verify that the rattle was not detonation. I later discovered that the rattle was actually the stock PCV valve fluttering under boost. This was remedied with this catch can since I removed the stock PCV valve for this install (replacing it with two valves on the can).

I decided to modify my catch can to make it serviceable with replacement check valves and rubber grommets. This is optional of course, but for the extra $15 in valves and grommets at the local parts store, it seemed like a good idea. This modification, which now allows the valves to swivel, also helped since the original check valves can't be twisted to ease in installation of the can into the engine bay.

I don't have any photos of what was in the kit I received so I'm borrowing this photo above from the manufacturer's website. In addition to the catch can with dual valves, a drain hose (for emptying the can), and a mounting bracket (with hardware), I also bought a breather for the oil fill cap. I chose a black can with a blue breather element.

I bought a pair of replacement check valves and a pair of rubber grommets. (Assembled new valve and grommet on lower left; old removed valve on lower right.) The part numbers are on the PCV boxes, but the grommets are Help brand part number 42058. (Both are available at AutoZone, but AdvanceAuto and CarQuest sell the grommets.) The old valves can be removed from the can by twisting them out, which is made easier by pulling off the plastic elbow on the middle port temporarily.

The top of the can with the stock valves removed... The hole on the right is now larger, since I hogged it out with a stepped drill bit. There's not much more room to go as you can see. After this photo was shot, I did the left hole too.

I had bought these drill bits at Harbor Freight recently for about $10 or so. Use the fat one on the left, which cuts the larger hole without drilling too far into the can (and piercing the baffle). Also, keep the can on its side or even upside down to avoid aluminum shavings getting into the can. Clean the can thoroughly when you are done drilling

Here are the new valves and grommets installed. I hadn't popped the plastic elbow back onto the middle port yet. (When I did I used a little RTV around the inside edge of the elbow to help seal it on the port.)

Here's the can installed onto the bracket that comes in the kit. (I painted the bracket satin black.) The can is installed on the plastic radiator tank in front of the engine and looks almost factory.

Here's the optional breather on the left. Rev Xtreme modified my stock oil fill cap with a check valve and this breather element. A stock cap is on the right for comparison.

Here's the whole install... In this photo, I had left off the rubber pieces of the intake tract so you can see where the oil vapor hoses are routed. The supercharger intake pipe on my car actually had an unused port on it at the A2 location, so I removed the cap and installed the catch can hose there. The vacuum signal should be strong enough there hopefully. Also, this particular install requires more vacuum hose than what comes in the kit normally. When you buy additional hose, find hose that can handle oil.

Here's the passenger side of the engine. Notice the brass "T" which I bought at Amazon is used in place of the stock PCV valve.

The driver's valve cover uses the stock plastic elbow, but I inserted a brass fitting and attached the new hose, clamping it with nylon ties for a clean appearance.

 I had wanted a catch can or oil separator for the Bullitt for a while now, and am happy with this one. The others on the market, while very simple to install, just didn't seem as capable as this one—and I really like the dual-valve design here, too.



Mentioned in this post:

Dyno Day!

I visited Fastlane Motorsports in Benson, NC. The Bullitt spent a couple hours on the dyno getting tuned this afternoon, and the second and final tune was good for a stout 494HP/466TQ. This was with an outside temperature of about 80 degrees. (In fact, just the "house tune" for my car's particular combo, which we started off with, was already good for 453HP.) Base timing is at 14 degrees, which is safe for 93 and even 91 octane. I wanted to not have to worry about using 91 octane if needed on a trip or something.

I learned a lot about how the car's onboard computer works, and it's way more advanced than I realized. For instance, the computer can pull timing if the Inlet Air Temp gets too high, so there's a margin for safety there even with a supercharged car (if the probe has been installed in the correct location.)

I've decided I'm bringing in the '66 for a pull or two next week! :-)

Here's a video of the 494 pull:

Steady Sweeper

I have an Auto Meter 3363 Sport-Compact Fuel Pressure Gauge on the Bullitt. Most recently the gauge had been sweeping from 20-100psi for no apparent reason and with no drivability problems, which tells me the sending unit is probably bad. Before that, at idle the gauge was fluctuating between 30-32psi so it seemed like it was on the way out anyway.

Because the gauge is at least 5 years old, the previous sending unit (#4590-0008-22 P158-5190-2) was no longer available. Auto Meter has a new and improved replacement for these 0-100psi electric full-sweep gauges, but it's not obvious when calling the mail order places. It is Auto Meter #2246 Replacement Sender (#4590-0023-12). Besides the subtle differences in the photos, the port on the new replacement is quite a bit larger than the old one. With the new sending unit, idle is rock steady at 30psi and the gauge now sweeps correctly.


Mentioned in this post:

Nothing Like a Little Stainless...

The Vortech supercharger on the Bullitt has a Vortech Aftercooler kit. Over the years, the anodized hardware around the stainless trim ring on top of the plastic tank got really rusty, looked lousy, and dropped crust into the coolant below. Also coolant would weep from around the gasket after using the car.




The hardware was so far gone, it couldn't be tightened. So I bought a gasket from Vortech for about $8, and since they wanted about $60 for the anodized hardware, I bought stainless hardware from the local hardware store. Spent about $14 or so on replacement allen head bolts with two washers and a lock nut for each.





It was definitely a hassle installing these bits with my big hands. I didn't drain the tank, and there are a pair of semi-circle trim rings inside the tank that is held on by the lock-nuts. Took a good hour to fiddle with this stuff. Looks great now though and should look that way for a long time. The stainless does not rest in the coolant, and the trim ring is stainless anyway so I can't see a downside at this time. We'll see!