The moral of this story is that you are never too old to learn 

A little background:  Earlier this summer I finally got my 69 Torino Cobra (or Fairlane Cobra, or just Cobra, take your pick) on the road after paint and interior work.  I was planning to drive it as is this summer but after firing the engine, which had not been run for any significant time since 1976, two problems arose.  The lesser problem was that is smoked.  The greater problem was that the rear main seal was gone, and it pumped out a quart of oil every 60 miles. 

After about a week and half I got tired of smoking out all the nearby vehicles at stop lights and stop signs, and decided I needed to get a motor together for this thing.  I had been planning to repurpose the 492" FE used for the dyno testing in my book for this car.  It had been sitting on the engine stand since 2010, and when I uncovered it and pulled the heads and intake, I was really surprised at how good it looked.  I took a couple of rod caps off and the bearings looked like new.  I reviewed the last dyno results from 2010, and oil pressure had looked good, and no notes on problems, so I decided to just leave the short block together as it was, and rebuild it from there.

Joe Craine had ported a set of Edelbrock heads for me a few years ago, and they were sitting on the shelf and ready to go, so I used them.  I also grabbed a Performer RPM intake, since this was going to be a street only car, and had a couple of sets of Comp Cams solid roller lifters with pin oiling available, plus the set of Erson rockers that I had run on the engine previously.  Amazingly, I also located the original pushrods I had used back then, so those went back in the motor also.  Just needed a cam, and unfortunately due to various delays at Comp it took me five weeks to get one.  It finally came about a week and half ago, so I was able to get the engine together.

My good friend "Wild Bill" Conley happened to be in northern Minnesota visiting relatives this week, so he came down for a day to help with the dyno session.  Thursday afternoon we got the engine installed on the dyno and were ready to go by 6:00 PM or so.  Here's a picture of the engine on the dyno:



First thing I always do with a dyno engine is spin the engine with no fuel and use the timing light to set initial timing.  Unfortunately, the timing light didn't blink.   Hmmmmm....

I had been a little concerned about the ignition system on this engine.  The distributor was an MSD that hadn't been used for years.  Same with the wires, cap, rotor, and also the MSD Digital 6 box and the Blaster coil.  I had new Autolite Racing plugs installed, so I wasn't worried about those.  Bill and I started swapping parts.  We tried a different coil, a different MSD box, and new wire between the MSD box and the distributor, and finally we pulled the distributor itself and replaced it with another MSD unit.  Still no spark.

It was pretty close to 8:00 PM and I don't run the dyno after 8:00 in deference to my neighbors, so we called it for the night and took off to have dinner with my wife.  After dinner of course, we were still thinking about this.  Back in the shop, I was wondering about the MSD box.  It has a red LED when it is powered up with the ignition switch, and the LED was on.  Of course, it also has two big wires coming off it, one for 12V power and one for ground.  I decided to check the power there, and low and behold, zero volts!  Surprised the heck out of me; I figured that with the red LED on, the box had to have power.  But apparently, just the ignition power will light the LED, even if the main power wires are not getting voltage.

We figured out that a fuse on the main power line to the MSD box (that was conveniently out of sight under the dyno stand) had blown.  I replaced the fuse, and the engine started.  Too late to run, but at least we could get it going in the morning.

Before firing the engine yesterday morning we set it back up to the original ignition components, started the engine and started testing.  One thing we saw pretty quickly was that the ignition advance wasn't working, so we just locked the timing and ran that way.  A cruise test determined that we were way fat on fuel, which was not a surprise given the 1000 Holley HP carbs jetting (84/84, with 6.5 power valves in both metering blocks).  We jetted down to 76 in the primaries and then ran the first pull from 3000 to 5000 RPM.

The engine missed and pretty much ran like crap.  I had just rebuilt the carb so I wasn't too worried about that, so it appeared we had an ignition problem after all.  Again we went to swapping parts, changing timing, etc. but were not able to solve the problem.  Unfortunately Bill had to leave late morning, so we called the session off without a resolution.

I thought about this most of yesterday, and got back out to the shop this morning with a couple of ideas.  First I wanted to see the airflow into the engine recorded by the dyno.  This chart confirmed to me that the issue was ignition, because the engine was continuing to pump air despite the fact that the power was falling off:



Seemed like something was happening around 3900 RPM that was hurting the power production.  I went through the same steps as we had before, swapping coils, swapping MSD boxes, checking everything.  I thought I had found it when I pulled the distributor cap and tried to measure the resistance between the cap terminals and the contacts in the cap, and got very high resistance.  The contacts in the cap were pretty badly corroded, so I shined them up with some sandpaper and ran another pull, but there was no difference.  I checked the resistance of all the plug wires and got 80-110 ohms each, and about 40 ohms on the coil wire.  I looked at all the plugs and they all looked fine, pretty much brand new.  I was about ready to pull the distributor again when I thought it would be easy to just replace all the plugs and try that once too.

The new plugs were Autolite 3923 Racing plugs.  The old plugs I dug out of the coffee can were Autolite 3924s.  I replaced all the new plugs with the old used plugs, and the engine ran like new.  Here's a plot showing the difference, old used plugs vs the new plugs:



The new plugs were junk??  Looking at the graph, obviously, the plug issue was causing problems much earlier than 3900 RPM.  After running some more dyno tests I took the new plugs and measured their resistance.  The plugs in the #2 through #8 cylinders all measured about 5K Ohms.  The plug that had been in #1 measured 72K Ohms.  Obviously, that plug wasn't firing and the engine was running on 7 cylinders.

I'm not through with this engine yet, still have a ways to go tuning wise.  Right now it is making 596 lb-ft of torque @ 4500 and 580 HP @ 6100.  Compared to how it was outfitted in the dyno testing in the book, the heads are down in flow about 15 cfm on the intake compared to the original heads I used, and the cam is smaller, 256/260 @ .050 compared to the cam used previously, which was 266/272 @ .050.  Compression is down about a quarter point also.  I was hoping to get 600/600 out of this engine, but don't know if I will get there or not.  When I get done with it I will post the info in the Dyno Results section. 

Anyway, lessons learned:  The red LED on an MSD Digital Six does not indicate that the main power is connected, and brand new plugs can be faulty.  Go figure...

I'm having a turn signal issue on my 69 Cobra.  I had originally installed new bulbs in the taillights and front turn signal/marker lights, and when I finally got the battery installed last week I checked the operation, and found that the emergency flashers worked fine, but the turn signals did not come on, in either direction.  I swapped the flasher units, and had the same issue; all emergency flasher lights worked, but nothing on the turn signals.  After checking for power and confirming that the turn signal circuit had power (it is on a separate fuse from the emergency flasher circuit), I decided to upgrade the whole mess.

I bought a new turn signal switch (which is where I figured the problem was), new flashers that were LED compatible and also compatible with a combination of LED and incandescent lights, and new LED lights for the taillights, turn signal/marker lights, and the turn signal indicators in the hood.  The only remaining incandescent bulbs are the indicator lights in the dash.  Got it all back together a few days ago, and now the emergency flashers still work fine, and now the turn signal lights turn on, but they still don't flash.  Again I swapped the flashers and got the same thing, again checked the power going to the turn signal switch and confirmed it was good, but still no turn signal operation.

Now normally if you have lights that turn on but don't flash, you have a bulb out.  But all of the bulbs work, with the emergency flashers operating and with the turn signal switch in both positions.  I'm thinking a ground could be a problem, but the lights have always been bright, even with the original incandescent bulbs, and since the emergency flashers work perfectly, it doesn't seem to me that a bad ground is the issue.

I've gone to the trouble of getting a complete wiring diagram for the car, and have traced all the wires, and everything looks to be where it is supposed to be.  Any ideas on this?  Thanks for any comments - Jay

Long story short, I had these made for one of my cylinder head customers but then he got a cancer diagnosis and had to bail on the project.  I kept them for another project for a local friend of mine, but after waiting over a year for a BBM block he finally bailed on that and got a Pond aluminum block.  The Pond aluminum blocks won't go this big on the bore, so these pistons are now available.  They will work on any aftermarket iron block, or a Shelby big bore aluminum block.  They are too big for a factory iron or Pond aluminum block.  They will also work with any FE cylinder head, including the FE Power heads.  A picture of the spec sheet is attached, but basically they are for a 4.25" stroke, 6.700" BBC rod with 0.990" pins, are 11:1 compression, and use 0.9mm steel top ring, 0.9mm Napier second, and 3mm standard tension oil ring.  The pistons, pins, and rings are included.

My customer originally paid >$1500 for these parts; selling them for $1050 or best offer.

I apologize in advance for this extremely long post, but there is a lot of information I wanted to share here.

It has really taken a long time to get all the intake manifold development and testing finished for my cylinder head project, much longer than originally anticipated.  It all started back in 2020, so it has been over a year and half to get everything finished up.  The scope of the work has changed along the way, to include a complete revamp of the rocker arm system (from aluminum to steel), and the original plan for building three intake manifold options for the cylinder head package has morphed into at least five, and probably six, intake manifolds that will be offered. Nevertheless, at this point I'm pretty happy with where everything stands, and will be going to production tooling on the intakes very soon.

A quick word about the dyno mule.  This engine has been a real trooper.  It has been through tremendous abuse, starting with all the broken aluminum rocker arms and related bent pushrods that showed up in the original test program, followed by a refit using the steel rockers, plus an update to the steel rockers to move from 3/8" adjusters to 7/16", and make a couple of other minor tweaks.  It has endured one major and two minor plastic manifold explosions that ruined the plastic manifolds and in one case blew shards of plastic shrapnel all over the dyno room and into the cylinders of engine itself.  It has seen uncounted hours of running, and a total of 254 dyno pulls, many of them to 7500 RPM.  And it is tired; the right bank looks pretty good with all the cylinders showing 170 to 180 psi of compression, but #5 is down to 140, and #6 is down to 80 psi.  Even so, the engine is still making 885-890 horsepower with the original 8V intake manifold.  It has been a kickass engine.

After multiple redesigns and lots of testing, I've tentatively settled on building two 4V intake manifolds, two 8V intake manifolds, a tunnel ram and the IR crossram intake.  I've put pictures and dyno data for each one below, so that they can be compared.  All the data shown is with the dyno mule fitted with the RE version of the cylinder heads, and 2-1/8" dyno headers.  Based on some back to back testing, the SE version of the heads will be down about 15-20 horsepower from the RE version.

4V Intakes:

The picture below shows the original 4V intake, that was cast at a local foundry.  My dyno junky friend Royce nicknamed this one "Rasputin", because it was tall and terrible!  This one ran originally on the engine with the aluminum rocker arms, and after discontinuing testing to update the rocker arm system it was sent down to Joe Craine for a little porting tune up.  After getting it back it was tested again with the new steel rocker system, and made a little more power than it had originally, so the revised design will be incorporating the changes Joe made.  Also, this intake was originally designed to split in half for easy porting, but Joe didn't think that was necessary due to the easy access to the runners, so for production this one will be a single piece design:





After testing the previous intake I had a couple customers contact me, wondering about hood clearance.  This intake of course was not going to fit under anyone's hood, not even with a CJ or Boss 9 scoop.  So I decided to take a stab at another 4V intake design, with an eye towards making it fit a car with a Mustang shaker scoop.  Because of this the carb mounting point and slant of the carb pad was positioned in the same place as a factory 428CJ intake.  Due to the height of the head ports, this intake was going to be 2" higher than the factory intake no matter what.  However, if a low profile EFI throttle body was used, based on the height calculations the shaker scoop would still fit. 

The 3D printed manifold pictured below is the second version that I designed (Note in the second picture that the manifold plastic has been painted; more on this later).  The first one did poorly on the dyno, making only about 770 HP on the dyno engine.  After revising the runner design, the one pictured made 825 HP, and with a 1" spacer it went all the way to 848 HP at 7100 RPM, which was down only a small amount from the tall 4V intake. I think this manifold would be a really good compromise for someone looking to maintain the stock hoodline of their car.





The graph below shows horsepower and torque from tall 4V, the short 4V with no spacer, and the short 4V with a 1" spacer (3000 to 5000 RPM with the spacer is nearly identical to without, and is not shown in the graph).  All the dyno graphs shown in this post have been standardized with a torque and horsepower range of 300 to 900, in order to make comparisons easier.




8V Intakes:

Similar to the original 4V intake, I designed the original 8V intake and had it cast at my local foundry, then had Joe Craine tweak it for me before I ran it with the revised steel rocker arm system. To date, this manifold has performed better in horsepower production than any other manifold I've tried, and that includes two sheet metal style intakes and two tunnel wedge style intakes.  It is not clear to me why this manifold works so well, because from a pure design standpoint it is a compromise.  One thing I've learned over the years of testing though is that the engine wants what it wants, and sometimes it is not predictable.  Like the tall 4V intake, Joe's changes will be incorporated into the production version.  Also like the tall 4V, this manifold was originally designed as a two piece intake, but will be a single piece in production.  Pictures of this intake are shown below:





In order to make peak power I really wanted to try a sheet metal style intake on this engine.  Long ago when I bought my 3D printer, I had envisioned printing plastic intake manifolds and testing them on an engine, and I did this quite a bit during this intake development.  Of course, there was a learning curve.  The manifolds come off the 3D printer looking beautiful, perfectly formed runners, nice radiuses where they were designed in, etc.  They look and feel solid, but actually the outer layers are only about .060" thick, and the interior portions are a honeycomb-like structure.  One thing I learned the hard way is that despite their appearance, they are not airtight.  Below is a picture of the first sheet metal style intake I printed and tested on the dyno.  Royce nicknamed this one the Red Devil:



The name turned out to be oddly clairvoyant.  When the engine was started with this manifold installed, it didn't seem like it was running right.  Little did I know that there was a massive vacuum leak, right through the plastic of the manifold.  When the throttle was advanced, the engine backfired and blew the manifold to smithereens!  Picture of the aftermath is below:



The explosion caused a loud bang and a blinding flash, and blew both the Dominator carbs over the left valve cover, hanging by the fuel lines and on fire.  We got the fire out quickly so no damage.  Within 20 seconds we were all laughing our butts off over this deal; holy crap, the explosion and resulting fireball was SPECTACULAR!  If there had been a camera running in the dyno room when that manifold exploded, the video would have a million hits on youtube by now.

Anyway, this stopped testing for a bit while the engine was pulled apart looking for problems.  We found shards of plastic in all the cylinders, some of them stuck down between the piston and the top ring, but no other damage.  Put the engine back together with the aluminum 8V intake, and it made the same power as before, so no problems there.  From that point forward, after 3D printing a plastic intake, it was painted it with two coats of garage floor epoxy paint, to make sure that it was sealed before installing it and testing it on the dyno.

Two more sheet metal style intakes were designed, and were tested on the engine.  One had fairly short runners and a fairly large taper in the runners (first picture below), and the other had longer runners and less taper (second picture).  Neither one of them made close to the power of the 8V intake that had been originally designed.  The first one was tested several months ago, and the testing went fine with no issues (I am now extremely cautious when starting the engine with a plastic intake).  The second one was the last intake tested, just on Tuesday this week, and after three dyno pulls it was clear it wasn't going to get close to the 890 HP the original 8V was making; it was only getting to 860 HP at 7000 RPM.  That one looked like it might go a little higher than 860 HP if we ran the engine to 7500 RPM, but inexplicably when starting the engine the last time for that pull to 7500 we had a minor backfire and that broke the sides out of the intake.  The plenum portion of the tunnel ram intake also broke due to a minor backfire when it was tested the first time; the conclusion is that the bigger the plenum, the bigger the volume of air/fuel mixture ready to ignite, and the shorter the lifespan of the plastic intake!






One other intake that I really wanted to do was an 8V intake that looked kind of like a factory tunnel wedge manifold.  Three 3D printed versions of this one were completed.  The first one gave disappointing results, only about 825 HP on the dyno engine.  So back to the drawing board where the runner shapes were redesigned, and also raised a little bit.  After 3D printing that one a mistake was found in the design of how the runners blend into the plenum; sometimes it's hard to see all the potential issues with a design by looking at it on the computer.  Back in one more time to fix up the blending issues, and then that manifold was printed, painted and tested.  The extra effort was rewarded with 875 HP from that one, and still climbing at 7000 RPM.  Pictures of the final tunnel wedge version, in raw plastic and painted, are below:







Dyno data for the 8V High Rise and 8V Tunnel Wedge manifolds is given below.  The 8V high rise makes more top end power than any of the other intakes, and holds in the 885 to 890 HP range from 6800 all the way to 7500, which to me is quite impressive.  There were a couple of pulls with the 8V high rise that netted 894 HP, but the data was a little questionable because the peaks were at one engine speed only, so those pulls weren't included in this data.  We thought with a little tweaking we could get this manifold to 900 HP, but nothing we did seemed to help.  I went so far as to wrap the headers, but got no change in power.  Then I built a whole new set of headers, with 2-1/4" primaries, and actually lost 5 HP on the top end.  I tried different jetting, different valve lash settings, etc., with no change.  I stopped short of actually running the engine at a really cold temperature, and icing down the intake, because I figured that would be cheating    So despite my best efforts I didn't get this engine to 900 HP.  I did not try a higher ratio rocker, which may have gotten it there.  There is also have another cam to try, specified by Chris Padgitt at Bullet Cams, but that one hasn't been installed yet.  This engine needs to be freshened up, before we get back to flogging it with a new cam and springs, higher ratio rockers, and ported versions of the heads; as mentioned before, the heads on this engine are unported.

The 8V tunnel wedge manifold makes better power than the 8V high rise at the lower engine speeds, and appears to still be climbing at 7000 RPM and 875 HP.  Hindsight being 20/20 this one should have probably been run to 7500 RPM too, but the results were satisfactory up to 7000 so it was left at that.  I was putting my bets on the tunnel ram...




Tunnel Ram and IR Crossram Intakes:

These two manifolds are torque monsters, beating the best of the 4V and 8V manifolds by a good 30 foot pounds of torque, which is an amazing 1.5 lb-ft per cubic inch.  I have never had a naturally aspirated engine that makes that kind of torque per cube on my dyno before.  The Individual Runner Crossram manifold had been planned since the very early days of starting the cylinder head project, but for some reason it never dawned on me to build a traditional tunnel ram.  I don't know why; a very large percentage of the people who purchase my intake adapters for their FEs use a Weiand tunnel ram on them.  Seems like FEs and tunnel rams go together. 

Anyway, I finally wised up and designed a tunnel ram intake for the cylinder heads.  Pictures of the intake are below.  I took a lot of the design cues from the Weiand 351C tunnel ram, which works extremely well.  It was 3D printed, then displayed at the FE Power booth at PRI this year.  In March Royce the Dyno Junky drove up, and we tried to test it, along with a couple of other intakes.  As mentioned previously though, a minor backfire cracked the plenum part of the intake, so no testing was possible.  A couple weeks later I had reprinted the plenum area and bolted it back on to the base.  This time the testing went perfectly, and I was blown away by the 763 foot pounds of torque that the tunnel ram made.  But like a lot of tunnel rams, it didn't pull all the way to 7000 RPM.  It peaked in the 6300-6500 RPM range, at about 865 HP, and then fell off.










The IR crossram intake was the most complex intake to get up and running on the dyno.  This one was cast originally as eight individual runner castings, to bolt onto the intake adapter.  However, this arrangement made it nearly impossible to get the fuel injectors, fuel rails, and vacuum taps (which are all under the intake) installed with it assembled on the intake adapter.  After fighting with that for several days I finally concluded that I needed to redesign the intake as a single piece, which would be flipped over for installation of the fuel and vacuum system, and then installed on the intake adapter. 

After redesigning the casting and getting it cast, of course I had to completely rewrite the CNC code to machine the intake.  I also needed a new machining fixture.  After getting all that done, the fuel system and vaccuum system was test assembled under the intake.  The new casting had some bosses on the bottom side of the intake to mount the fuel rails, but one of them turned out to not be in the ideal spot, so that will have to be changed before production tooling is made.  But overall the new setup worked.  The photos below shows how the underside of the intake looks with the fuel and vacuum systems installed:






Next the throttle linkage had to be redesigned to work with the new casting.  The first version did not look robust when it was completed, and it was too high off the top of the intake, so a second version was started from scratch.  This one still has some issues, and it will be tweaked a little before finalizing it for production, but it works well enough to run on the dyno.  The production casting will be changed to add some bosses for attaching a return spring on each bank of the intake, plus an idle screw and an opening stop screw for each bank.  Finally, when it came time to mount the fuel pressure regulator I wanted it up front for easy access, and had neglected to add a boss at the front of the casting for mounting it, so it was just screwed into the front runner.  The production casting will put a boss in that position with a couple of mounting holes, to make it easier and cleaner to mount.

All this took a lot of time to accomplish; the intake probably came apart and went back together six or eight times before it was ready for the dyno.  But finally this week the time arrived.  Here are some pictures of this intake mounted on the engine:










The dyno mule has been using the MS3-Pro EFI system to control the engine's timing, with the crank and cam sensors and no distributor, so it was easy to just add the fuel system from the MS3-Pro to run the injectors.  This setup is low compared to all the other intakes, and uses long runners, so it was expected to make a lot of low and midrange torque, but not as much top end horsepower as some of the other intakes.  Also, as an individual runner intake, it was going to be peaky (In fact the power and torque curves from this intake look very similar to the Hilborn setup I ran on my SOHC years ago).  But it started right up on the dyno, with only real issues being getting the throttle linkage adjusted correctly.  This intake idles with the butterflies almost completely closed; if they are cracked open even a little, like maybe .040", the engine is right up at 2500 RPM.  Hilborn used to recommend setting the idle so that a strip of newspaper would barely slide out of the gap between the throttle bore and the throttle plate, and that is probably just about right for this setup.

The dyno curves for the tunnel ram and the IR intake are shown below.  The peaky nature of the IR intake is evident, especially below 4500 RPM.  But it is making huge torque down there, almost 600 foot pounds at 3000 RPM and nearly 700 foot pounds at 3800.  During the dyno pull, as the peak at 3800 approached, the sound from the engine was unbelievable!  You could really tell the power was increasing.  The IR intake actually made the most torque of any of the intakes, edging the tunnel ram at 767 foot pounds.  As expected it flattened out after about 5500 RPM, but to my surprise it started gaining again at the higher engine speeds, and actually surpassed the tunnel ram's power at 7000 RPM.  It looks like it's headed for another peak at a higher engine speed.

In contrast the tunnel ram made smooth power up to peak in the 6300-6500 RPM range.  It made a remarkable 763 foot pounds of torque, and 865 HP, before it started falling off.  The manifold behaved nicely on the dyno, no special tuning or adjustments necessary.  It would be a great bracket race manifold, for someone who wants to lauch at 5000 RPM and shift at 6500-7000, to go through the lights at 7000+.




So, FINALLY after a year and a half of concerted effort, I'm ready to go to production tooling with these intakes.  I will be sending out a summary to my customers and asking for their input on which intake manifolds they may be interested in.  If there is little or no interest in one of them, I will probably just produce five instead of all six.  We'll see what everybody says.  I'm currently building a 390 stroker engine that will use a set of my SE heads, and I will be putting the IR intake on that engine.  I may go to the low 4V intake for my Mach 1, so that I can put the original hood and shaker scoop back on it.  And I want to use that tunnel ram on something, just not sure what yet...

This topic has been moved to Private Classifieds.

http://fepower.net/simplemachinesforum/index.php?topic=10578.0

A friend of mine is looking for one of these.  If you have one, or have a set you want to sell for a reasonable price, please let me know.  Thanks, Jay

I've been doing a little more testing on the dyno mule with my cylinder heads on it this week (up to 894 HP now).  After the last go around a few weeks ago I had some conversations with a couple of my head customers, and John S (oldiron.fe on the forum) mentioned putting a window in the oil pan to see what was happening.  Ever since I started with this engine on the dyno last September, I've noticed that at the higher RPM pulls I have a significant decrease in oil pressure, typically starting around 65 psi at 5000 RPM and dropping to about 50 psi at 7000 RPM, with the oil temperature around 180 degrees, using 10W-30 VR1 Valvoline oil.  Higher oil temps of around 200 degrees make it a few psi lower, and I really wasn't too comfortable with those levels.  I've seen this oil pressure issue before with vacuum pumps, so I figured that was a contributing factor, but I thought it would be interesting to see exactly what the oil in the pan was doing.

Since I was planning on pulling the pan to check the bearings, I decided to go ahead with the window, potentially wrecking the oil pan but hopefully learning a few things in the process.  After checking all the bearings (which looked almost new), I cut a big rectangular window out of the Milodon 7 quart oil pan and bolted a piece of 3/8" thick clear polycarbonate to the side, using a bunch of The Right Stuff to seal it.  The engine is using a Moroso windage tray between the block and the pan, and a Precision Oil Pumps high volume pump using the small spacer between the spring and the cup plug.  I've also installed a new vacuum pump from Star Machine to replace the GZ Motorsports pump that I had been running previously.  This pump gave me a few more inches of vacuum, and probably contributed to the latest HP numbers.

I set up a camera to take videos of the window in the oil pan while the engine was running, and during a dyno pull.  I also rigged up a tach so that you could see the engine speed in the video, but unfortunately the tach I used didn't work, or else it didn't like the tach signal from the MS3-Pro.  Regardless, I started testing the engine and then watching the videos.  I was really surprised at what I saw.  The first video link is below; this is with a total of 8 quarts of oil in the engine.  It takes a while in the video to get to the actual dyno pull, which happens starting around 1 minute and 45 seconds in.  The oil levels are marked on the pan in the video:

https://youtu.be/ZPL_05cKRKY


Wow, the amount of air entrained in the oil during the actual dyno pull is shocking!  Lots of big bubbles circulating in the oil, certainly contributing to aeration of the oil coming out of the pump.  As my dyno junkie friend Royce said, it looks like you are spraying a garden hose into a bucket of water.  There appears to be about 6 quarts of oil in the pan during idle, and it drops to about 4 quarts during the pull.  A while back on the Engine Masters show on Motor Trend on Demand, they did an experiment where they saw oil pressure drop as engine speed increased, attributed it to foaming of the oil, and solved the problem by taking some oil out of the pan.  I thought I would try the same thing, so we pulled 2 quarts out of the pan, and ran the test again.  Here is the video:

https://youtu.be/cQRGg-nI8m0


Well, that didn't work, we still had the same drop in oil pressure as before up at 7000 RPM, we seemed to have the same amount, or even a bit more, of foaming and bubbles in the oil, and we didn't make any extra power.  The oil level in the pan looked like 4-1/2 quarts during idle, and about 3 quarts at peak RPM. 

The obvious next test was to remove the vacuum pump and see how it looked without the pump on the engine.  We went back to 8 quarts of oil in the engine, and ran without the vacuum pump.  Here is the video:

https://youtu.be/sd29Ye2E0Q4


Unfortunately for this video I had decided to remove the tach (which wasn't working), and apparently after repositioning, the camera position was off a little compared to the last two videos, and we got some glare from the window that kind of obscured the oil.  However, if you look closely you can see that the oil level in the pan drops quite a bit farther in this video than in the first one, and there still seems to be a whole bunch of foaming and air bubbles in the oil.  BUT, the oil pressure stayed stable throughout the dyno pull.  Unfortunately the oil pressure win was offset by a large HP loss.

Based on the fact that the engine has been behaving like this (oil pressure wise) for several dyno sessions, and that the bearings looked very good when I inspected them, I'm not overly concerned about the oil pressure issue when the vacuum pump is running.  However, it seems like there ought to be some oiling system modifications that could mitigate this problem.  One thing I tried with this new vacuum pump setup was a second vacuum port lower in the engine; this was recommended by Star Machine, and also Andy Miller at Olds Performance.  I actually put a hole through the side of the block right across from the #3 main cap, and then milled a slot in the main cap to allow air from the crankcase into the slot, through the hole, and out to the vacuum pump.  The hope was that since the hole in the block was shielded by the cap, it wouldn't draw in too much oil, but that didn't work, so I went back to a single line from the valve cover to the vacuum pump.  I might try that again next time around with a baffle over the slot in the cap; Lykins also suggested going through the fuel pump opening in the timing cover, so I could try that too.

Another thing is the windage tray.  The Moroso tray has louvers that strip oil off the crank, and several of those louvers point straight down at the oil level in the pan.  You can see this in the videos when the engine is idling, one of those louvers is right above the window and oil is coming straight down.  It seems like using the Ford windage tray, which has louvers only on the right side of the engine and shoots the oil horizontally through the louvers, rather than vertically, would be a better design.  Also it seems like a kickout on the right side of the oil pan, designed to catch that oil and give it a chance to slow down before it hits the rest of the oil in the pan, would be good.  It's also possible that a screen on the windage tray, like the Canton pan has, would lead to less foaming in the oil.  Maybe no windage tray at all would work best? 

Maybe the standard volume pump would yield an improvement.  And of course if you ran a really, really deep pan, that also might help.  The list goes on...

I'm sure there will be a million theories on the best approach to this issue, but the problem is there is very little data to back up the theories, and getting data requires changing up oil pans, windage trays, oil pumps, etc., which of course is a huge pain.    But if I go forward with any modifications I will certainly post them here for general interest.  I'm not sure if there is really HP to be had with a better oil pan setup, but an improvement in the stability of the oil pressure would be a worthwhile goal.