Edelbrock RPM 5.0 Intake Installation - Part 1

I started the replacement of the upper and lower intake this weekend.  Since I removed the upper before, I'm familiar with the process and had some extra time to order a few things that would make the installation as nice as possible.  I don't expect to rush but also expect this shouldn't be too difficult.  

The upper intake, EGR spacer, throttle body, and throttle bracket all came off easily as a complete unit.  Without the 5.0 decorative plate on top, the entire package weighed 26 lbs. and 2 oz.  The decorative plate weighs 8 oz by itself so the entire package is 26 lbs. and 10 oz.

While I wasn't ready to install it, I took the time to assemble the new Edelbrock upper intake (EGR spacer, throttle body, and throttle bracket) to match what I'd just removed.  The point was to ensure all the parts mounted up as expected and to compare the weight.  The Edelbrock setup came in at 23 lbs. and 4 oz.  While that is 3 lbs. and 6 oz lighter, I expect to ultimately find the Edelbrock lower intake weighs far more than the stock piece.

With the two side by side, I also compared the size of the intake runners.  The stock upper has oval ports that measure 1.57" x 1.2" as compared to 1.8" x 1.1" rectangular ports on the Edelbrock.  This should be about 30% more cross sectional area than the stock upper.  This matches well to the 70mm Accufab throttle body, EGR spacer, and matched 70mm Edelbrock intake opening which are all about 34% over the stock 60mm pieces.     

I started pulling the injectors and they were incredibly hard to remove.  They are very dirty and the O-rings are about as hard as rubber can get.  Once out, I could tell it wasn't just dirt on the exterior as there was plenty or grime around the O-ring and even residue on the hat around the spray nozzle.  I'd originally planned to just clean them up and reuse them but I'm second guessing that direction now.

I removed the water temperature sensor (bottom in picture below) which looks good and should be fine to reuse.  However, the Air Charge Temperature (ACT), which mounts in the intake runner for the #5 cylinder, was so covered in soot I don't know how it worked (top in picture below).  Researching it a little, I expect it would get hot early and tend to think the air going through the engine was a little hotter than it was perhaps changing ignition timing.  I luckily found an original Motorcraft replacement (E1AZ-12A697-A / DY-674) on eBay for $15 so that is now on the way. 

I set the engine to top dead center and made a few reference marks on the distributor position.  I then removed the distributor from the car.  My mark was just to the left of the hold down bracket and then I found there is already a notch in the distributor there originally.  The distributor O-ring on it is also about as hard as rubber can get so I'm glad the FelPro gasket set I purchased included a new one. 

I removed the upper radiator hose, coolant lines from the top of the intake and the fuel rails.  With those all removed, I was able to remove the stock lower intake.  The lifter valley is clean just like under the valve covers.  However, there is quite a bit of soot in the intake runners going down into the head.  All the runners look about the same so I imagine this is just miles, EGR running exhaust through the intake, and the PCV working as expected for years.

I took the thermostat housing off the stock intake and it weighed 15 lbs. and 8.5 oz.  The Edelbrock intake with nothing mounted to it was 19 lbs. and 10 oz.  The lower Edelbrock weighs 4 lbs. and 1.5 oz more than the stock intake.  If we combine that with the difference in the weight of the upper intakes, we find the total Edelbrock package is about 9 oz. more than the stock setup.  That isn't much at all.  I'd hoped to drop some weight but everything stock was already aluminum.

I set the upper intake on top of the lower with both the stock and Edelbrock setups.  The Edelbrock is 10.5" from bottom to top.  The stock one is a little more challenging to measure as it isn't as flat across the top.  On the lower edge where it curves under, is about 9 1/4".  However, once you near the throttle body area, it matches the 10.5" height of the Edelbrock setup.  I don't expect this will make much difference in under hood clearance.

I now have everything torn down as far as needed to replace the intake.  I need to do quite a bit of cleaning of the lifter valley and head surfaces.  I'm not installing all new components so I'll also need to clean the coolant lines, fuel rails, thermostat housing, valve covers, EGR, and IAC.  I'll probably end up going just a little slow through all of the work but I'll get it done and prioritize doing it right more than fast.  

Next Projects

Next Projects List...

Fix Power Steering Leak

Install Coil Cover

Determine TDC

Edelbrock Intake

Final Header Bolt

Install Passenger Door Speakers

Sound Deadening in Door

Create and Mount Passenger Tweeter

Create Mount for Crossover Network

Touch Up Driver Speaker Grill

Fix Rear Speaker Fitment

New Transmission & Driveshaft

Rear Gear Installation

Rear Upper Control Arm

Rear Brake Hose

- Need Axles and Studs

Splash Shield Retainers

Reverse Lights

Brake Lights Different Brightness (Don't Get LED)

Radio Microphone

Sound Deadening

Luxury Liner

Seat Foam and Fabric Repairs
Install Luxury Liner
Plastic Panel Rattles

Headliner Repair

Paintless Dent Repair

Touch Up Pen

Reinstalling Upper Intake & Valve Covers

Due to an unfortunate timing, I need to have the Mustang driving again so I can have some repairs done to the epoxy coating on the garage floor.  I have a new intake to install but time doesn't allow for it now.  That is for the best as removing the stock intake pointed out a few things I would need to do the new intake install perfectly.  This allows me some time to get those things together so the intake install goes much more smoothly when the time comes.

Putting it back together is rather straight forward.  This gave me the opportunity to clean up the spark plugs and confirm they were gapped to .054".  They a new Motorcraft plugs but since I didn't install them originally, you always have that doubt something could be off.  This put that to rest as they are all now perfect.  Before cleaning them, I inspected them all and there was no sign of oil or other trouble with the engine.  

While installing the spark plugs, I wiped off all the header tubes and swapped out the header bolts one at a time.  I'm using stainless ARP 400-1102 bolts which look great.  I was able to swap them all in except for one on the passenger side.  That bolt will not come out unless I completely remove the header.  Since I don't have a gasket on hand, I'm installing all the bolts except for that one and will come back to it later.

I spent a good amount of time wiping down the mating surfaces of the valve covers and tops of the heads to get a good seal.  I used Fel Pro VS 13264T gaskets and the stock bolts.  They don't look any better than they did before removal but they work. I purchased a set of nice ARP valve cover bolts but I'm saving them until I put on a set of nicer valve covers.  

I mounted the original intake using the stock bolts and a Fel Pro MS 94555 gasket.  I torqued it down to 18 ft/lbs. per the manual and even reconnected the strange support bracket at the back of the intake.  With it mounted, I then meticulously reconnected the coolant hoses, vacuum hoses, throttle cable, cruise control cable, PCV value, and cold air intake.  The only thing that I question is that the connection to the vacuum tee now seems a little more loose in the back of the intake as it will twist slightly.  However, it didn't impact driving when I went for a test drive.

I have a good list of items that I would want to get for the new intake installation.  This isn't a complete list as I've been collecting a few items already.  The items I need include:

• Injector O-Rings (LRS-SK1-K or Fel-Pro ES 70599 @ Summit) 
• New Throttle Cable (LRS-9758A-K)
• PVC Grommet & Filter Screen (LRS-66631 & LRS-6892-A)
• 1/8" NPT to 1/4" Barb Fitting (Charcoal System)
• 3/8" NPT to 3/8" Barb
• 3/8" Barb T Adapter
• Thermostat
• Throttle Body

I'll ultimately want to swap out the two long bolts for the intake with some ARP bolts (ARP 651-4750) but they are custom order and probably wouldn't be here in time so I'll order them a bit later.  

Compression Test

This evening, I performed a compression test on the engine.  I did the test with the engine cold without an intake installed so there was no air restriction.  The results were as follows:

1 - 160 

2 - 143

3 - 156

4 - 162

5 - 160

6 - 145

7 - 158

8 - 150

The best is number 4 with 162 psi and the worse was number 2 with 143.  That is a difference of 19 psi which is a 11.7% difference between the best and worst performing cylinder.  Ideally, you would have a 10% difference between them.  The average of the one side is 155.3 vs 153.3 on the other so the two sides of the engine are very similar in compression.

I decided to test the number 2 and 6 cylinders again a little later.  They tested as follows:

2 - 145

6 - 143

After researching a little, I decided to put some oil in a few cylinders and test again.  When I did number 2, it went to 180 psi.  When I did number 1, it went to 180 psi.  When I did 6, I must have put a little more oil in because it went to 225.  I cranked it over without the tester in number 6 and tried again and it went to 210.  I suspect the oil is raising compression due to displacing oil.  It would have been better to add oil with a syringe to know you are adding the exact amount to each cylinder but this test has essentially told me well enough the condition of the engine.