FE Power Forums > The Road to Drag Week 2011

August 14, 2011 - The Road to Drag Week 2011

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jayb:
Things have NOT gone according to plan this week.  I find myself in a bind with the engine, and would appreciate any input from other forum members on some of the questions and issues that I will describe in this week's report.

I spent Monday this week finishing the assembly of the engine and getting it ready to run on the dyno.  This ended up taking me a little longer than expected, so I was not able to run the engine at all until Tuesday.  But Tuesday morning I was out to the shop early, and fired the engine up by 9:00 AM.  The first thing I noticed was that the engine wouldn't idle properly.  Normally this engine idles beautifully at around 800 RPM with the Hilborn setup on the engine, but Tuesday morning I wasn't able to get the engine to idle lower than around 1300 RPM!  I had no immediate explanation for this problem, but it felt like a vacuum leak.  However, the manifold vacuum was around 11 inches at this speed, which was about where I expected it to be.  Setting this issue aside for the moment, I warmed up the engine to make the first pull from 4000 to 6000 RPM.  Before the head gasket replacement I had gotten to about 750 HP at 6000 RPM, while last summer the engine made about 900 HP at this same speed.  I figured that the head gasket and valve repair would solve this problem, and I'd be back at 900 HP at 6000 RPM.

Unfortunately, I figured wrong.  The pull gave the same results as a couple of weeks ago, 750 HP at 6000 RPM!  I was really surprised by this development, and immediately began to suspect a dyno issue.  I hadn't calibrated the dyno in quite some time, so I pulled out the calibration bar and ran through the calibration weights, noting the reading from the torque link.  It was perfect, though, off by less than 1 lb-ft of torque when 830 lb-ft was on the bar.  How could this be?  I ran a couple more pulls just to confirm the original results.  Then I went back to the leakdown checker, and retested each cylinder for leakdown.  I confirmed that I still had no crosstalk between cylinders, and all the leakdown numbers were much lower than they were before I changed head gaskets, mostly less than 10%.

Next I ran through a laundry list of checks, like checking timing, changing spark plugs, adjusting the throttle butterflies on the Hilborn injector setup, etc. etc.  Nothing seemed to help; the engine was just not making the power it should be, or else the dyno was not reporting the power correctly.  The inability of the engine to idle also was a concern, and I wondered if the issues were related somehow. 

I wrestled with the engine's performance all morning and into the early afternoon without any resolution, until finally I noticed the oil in the sight gauge was starting to look goofy.  Sure enough, I still had water in the oil!  I thought this had been an artifact of the head gasket issue, but apparently not.  This engine block, of course, has been the subject of a great deal of non-standard machine work.  It has modified bore spacing to allow for larger bores, and when the block was being bored with the larger bore spacing in a couple of spots casting was so thin that the boring tool broke through.  So, on three of the bores in this block, the sleeves are not "dry"; they are exposed to the water jacket.  After the machine work on the block was finished and the sleeves were installed, I used a special sealing agent to seal up these breaches, to prevent water from leaking down between the aluminum casting and the sleeves and into the oil pan.  It seemed at this point that this sealer had failed, because the head gaskets were new and the intake manifold leaks I'd experienced with the Hilborn intake had been external. 

Draining the oil confirmed that there was water in it.  I had figured at one point or another I would get into this situation with this block.  The preferred solution would be to tear the engine completely down to the bare block and re-do the sealing operation I had done on the block when I'd first built it.  I've also fixed a similar problem on my aluminum Pond block by grooving the OD of the affected sleeve, and reinstalling the sleeve with an O-ring.  Given my Drag Week schedule though, neither of these options was viable.  So I decided to go with the Moroso Ceramic seal that I had on the shelf, and have used successfully in the past.  The problem, of course, was that this water leak probably had nothing to do with the power issues I was seeing with the engine.

In any case, I wanted to fix the leak, so I disconnected the engine from the dyno's cooling tower and hooked it up to the radiator that I had ordered for the car.  After filling it with water and some cheap oil I warmed the engine up and when it reached operating temperature added the ceramic sealer.  I had a floor fan in front of the radiator to provide cooling, but it turned out that wasn't enough, and after 10 more minutes of running the engine was at 220 degrees and I had to shut it off.  This was unfortunate because the directions said to run the engine for at least 15 minutes.  I let the engine cool down and then ran it for an additional 5 minutes.  Next I flushed the engine's cooling system per the directions, and hoped for the best.  I drained the cheap oil and it seemed to be free of any water contamination, so it looked like the sealer worked.  However, the subsequent dyno pulls again showed no change in the power production of the engine.

After all this on Tuesday evening I sent an email to Scott Clark, along with some dyno data and EMS-Pro datalogs asking if he saw anything unusual in the data.  I had to admit I was stumped by the engine's behavior.  Scott emailed back asking for some of the datalogs from the engine from last summer.  He compared them and then we talked on the phone; he pointed out that the engine was using the same amount of fuel from the EFI system as it was last summer, and that the A/F numbers looked pretty much the same as last year.  Scott thought that if the engine was down over 150 horsepower, it would be showing a much richer A/F ratio, or wet plugs, or something.  Scott's conclusion was the dyno was not giving the correct results.  Hmmm....

Later on Tuesday evening I decided to remove the Hilborn intake and look for the potential vacuum leak.  Once it came off, the leak was obvious, along the tops of the 5 through 8 cylinder head ports.  Too thin on the sealer, I guess.

Wednesday morning I gave Ron Quarnstrom, the dyno guy at R&R Performance, a call.  I was wondering if the absorber unit on the dyno could be responsible for the lower than expected torque readings from the engine.  The absorber contains the vanes that transfer torque from the engine to the torque link, and I was thinking that if these vanes had been corroded away or broken somehow, perhaps not all the torque from the engine was being transferred to the torque link.  However, Ron said he'd never heard of a problem like that.  He had me check several other items on the dyno (for example, that the absorber moved freely when the torque link was disconnected), but none of the items he had me check turned out to be a problem.  My conversation with Ron left me less convinced that the dyno was the problem.  I scraped some of the gaskets on the intake in preparation for re-installation until around noon, and then took off with my family for an abbreviated family vacation and camping trip in northern Minnesota.  I spent a lot of time thinking about the problems with the engine during this trip, and probably wasn't the greatest company for my family, but it did dawn on me while I was away that there was one other difference between the engine now and the way it was last summer - the oil pan.  The old pan that fit the Galaxie was a very nice design, with a minimum of three inches of space under the entire crank, and an 8 inch rear sump.  The new pan is much tighter to the block, especially on the rear half of the engine, making evacuation of the oil under the crank more difficult.  But I just couldn't see any way that the differences in the pan could account for a difference of 150 horsepower.

Saturday night after we returned home I got out to the shop long enough to get the intake manifold reinstalled on the engine.  This morning I was out again fairly early, and got the engine ready to run by 10:00 AM or so.  Since I don't run on Sundays until noon in deference to my neighbors, I decided to try to take apart the absorber on the back of the dyno and inspect it for damage.  This turned out to be a big waste of time, because no matter what I did I couldn't crack that thing open.  I took out a dozen bolts around the periphery of the absorber where it appeared it was bolted together, but it was either frozen together with rust, or there was some other connection internally that was preventing it from coming apart.  I removed all the external bolts that I could, but no luck getting the absorber apart. 

Around noon my pal JC showed up to help, and as I put the absorber back together he taped up the inlet air box to the top of the injector stacks.  Another idea I'd had was to check the air requirements of the engine, and back the power output of the engine out of that.  The calculation goes something like this:  Each pound of air that an engine uses per minute will generate about 10 horsepower.  Each standard cubic foot of air weighs about 0.075 pounds.  So, assuming that the correct ratio of fuel is mixed with the air, if we know the cubic feet per minute of air that the engine is ingesting, we can calculate the horsepower that the engine is making.  Unfortunately it is difficult to get a good seal to all the injector stacks up to the airflow turbines in the ceiling of the dyno room.  However, JC did a pretty good job, I think.  We ran the first pull, and at 6000 RPM the engine was using about 1000 cfm.  This worked out to just about 750 horsepower, which is what the dyno recorded.  This result tended to support the idea that the engine was the problem, not the dyno.

I had just two more tests that I wanted to run today.  First, I wanted to replace all the plugs with some standard 3924 Autolites.  I did this and the engine didn't really like it, but it made about the same peak power as the Autolite Racing 3923 plugs I had been using.  Scott Clark had also sent me a second EMS-Pro to test, to make sure that it wasn't the EFI box.  I got the new EMS-Pro hooked up and the engine started with no trouble, but it missed during the pull.  Looking at the datalog there was a lot of dropouts in the crank trigger signal, and there is a pot on the EMS-Pro board that needs to be adjusted to try to compensate for this.  Unfortunately, I didn't get the chance to try to adjust this pot, because a look at the oil sight tube showed water in the oil again.  Damn!  I had thought that problem was solved.  Just in case it was coming from a poorly sealed intake manifold (which I'd re-installed last night) I drained the water from the engine and pressurized the cooling system to 10 psi, then stuck a tube into the valley of the engine through the plug in the rear of the intake, listening for an air leak.  It was dead quiet in there, so probably what happened was the ceramic sealer I used on Tuesday didn't set long enough to seal permanently before I ran the engine again, and I still have a leak between the block and one or more of the cylinder sleeves.  Last thing I did was to run the leakdown checks on the cylinders one more time, just to make sure I hadn't missed anything.  Again, they all looked good.

I called it quits for the day at this point, and I have some serious issues to resolve with this engine, and very soon.  One option I'm considering is to just put the engine as it is into the car, run the ceramic sealer in the water system, and see what happens.  I'm also considering sealing the engine up on the dyno again, and changing the oil pan to at least rule out the pan as the reason for the lower than expected power production.  I'm still very confused by the engine's performance.  I'm also thinking about other options for Drag Week this year, including just taking my GT and running in Daily Driver again.  Things are not coming together for this engine/car at this point, and I have to be in Topeka in exactly four weeks.  To get the Shelby clone there at this point is seeming less and less likely, and while I haven't given up yet, with no solution in sight for the engine problems its a risky bet to show up with this car.  We'll see what happens next week...

Joe-jdc:
Jay, can you drain 1 quart of oil and run the engine?  Drain another quart and run again?  If it picks up HP, then you will know quickly if the pan is the problem.  I saw an 18 hp increase, each time on a BBC I was testing on the dyno.  Finally dropped 4 quarts and it stopped gaining.  Just an idea.  Joe-JDC.

RLander:
I know that you have had the engine apart, could it be something with the valvetraing/cam phasing being slightly off from previous set point? Could the water have toasted the rings and be causing ring flutter? 
Hoping to help
Rlander

mmason:
This may not be any help to you but I will tell you anyway. A couple of weeks ago I put a new cam in my engine. It was a bigger cam so I was expecting it to run a little differently but turned out to be quit a bit worse. I could not get the Idle below 1100 and when I increase the rpm over 3000 it would smooth out but it seemed to be lacking power. I checked everything and could not find anything wrong. finally when I went to pull the plugs I found that the plug cables on 7 and 8 were on but not all the way. I think they were firing but not all the time. Plugged the cables all the way on and everything was fine. My point is that it might be electrical.

Michael

country63sedan:
I'm with Joe - start draining the oil a quart at a time. I remember about 20 years ago one of the magazines was running a puick on the dyno and kept gaining power until they had like three quarts in the pan. I don't think that will account for 150 horses, but you'll know if it's part of the problem.
Good luck, Travis.

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