The Road to Bonneville and back

[Plechtan]

I didn't mean to confuse anybody, these events happened in August, I was admitted to the Hospital on Aug 9th, A Sunday. My Wife and son remained with me for a little while, but it was getting late and they still had a 2 hour ride back to the hotel.

They left, and as i was lying there with the IV in my arm i started thinking about the opening scene in the "Worlds Fastest Indian" There was a sign on a wall that said "Offerings to the god of Speed" and underneath was a shelf with broken pistons, valves, rods, etc. Perhaps you were required to make some amount of offerings before the god would permit you some success. Things were definetly not going as planned.

On Monday My wife and son arrived at the hospital around 1pm. We talked a while then My son left to go get the oil filter adapter at the hotel, which was about a half hour away from the hospital. He returned about 3pm, picked up my wife and headed back to the salt.

By Tuesday Morning i was getting better and i convinced the doctors to release me. Speed week ended on Friday, so we still had a chance to run the car. It was about 2:30 by the time i got released , and about 4:30 by the time we got back to Wendover. We decided not to work on the car that day , we would only have had about an hour and a half before we would have had to pack up anyway. The salt closes at Sunset.

[Plechtan]

On wendsday we arrived around 9 AM We set up the Pits, Got the car out of the trailer. My son had already installed the new oil filter adapter. we were ready to go through tech. We found the paperwork we would need, and i asked my son to go buy a Vehicle log book. He said he bought one the day before.

Each vehicle has to have a log book with a serial number. it comes with a serial number stricker that has to be attached to the frame or roll bar of the car. We attched the stocker to the roll bar on the passenger side.
We hooked up the tow strap and pulled the car over to the tech lanes. We were the only car there, and since the 3 inspectors were bored, they all came over to go through the car. If you do Tech at the start of the event the inspecotrs are under pressure to get all the cars through. So it is probably eaiser to go through tech then. We had 3 inspectors with all the time in the world on their hands.

We passed on most things, but there was some debate on the roll cage. Our design complied with the rule book, but did not have bracing on the rear into the bed of the truck. They called in a 4th inspector to see what he thought. When it was all said and done they did approve us to run but limited our top speed to 150mph.

It was impoprtant that we pass tech this year. Some rule changes come into effect next year and if we had not passed tech we would have had to go back next year as an new car and comply with all tbe new rules. The biggest one is that the new cars roll cage must accomidate a Hans Device.

So we got our tech sticker, and a sticker with a big "R" (Rookie) on it for my son's helmet. we were cleared to run.

[yuppiexj]

We wait with bated breath for the next installment.

[Plechtan]

We hooked up the tow strap and pulled the truck into the pits through the tech lane. This was the way we should have entered the pits 5 days earlier.
We brought the truck back to our area and broke out the laptop. The fuel injector injection time was controlled strictly by the throttle position. This is common on race cars. A street vehicle uses a MAP (manifold Absolute pressure) sensor to control fuel. The TPS ( Throttle Position Sensor) method assumes a specific volume of air coming in for a specific throttle position and engine RPM. The problem with this assumption is that as air pressure changes, the volume of air changes. We tuned the car at about 300ft above sea level. Bonneville is at about 4,000 ft above sea level. The ECU does have a barometric compensation table, but you have to fill in the values.

We had not run the car since the adapter blew off the block on the dyno, and the Dyno used it's own wide band O2 sensor. We had 2 wide band sensors on the ECU, but they were removed to all the Dyno sensor to be installed. We now had the sensors back in, it shouldn't be a problem to compensate for the difference in barometric pressure.

We started the engine to let it warm up, we checked the oil pressure, it was about 30 LBS. It was 30 pounds at idle before the adapter blew off, but it still seemed low to me . the external pump should be able to put out 70 lbs at idle with no problem. The engine ran a few minutes and i checked the Air/fuel mixture. The rear O2 sensor was reading way lean. when we ran on the Dyno they ran only 1 O2 sensor that looked at the front 3 cylinders. I was having problems with the sensor that looked at the rear 3 cylinders.

We turned it off and did some checking, swapped thing around, then started it up again. Same thing. The engine was up to temp not and it started popping on the #4 throttle body ( the engine has 1 throttle body per cylinder). Popping out the intake is usually a sign of running lean. Very strange . Could the Number 4 fuel injector be plugged? I guess it could. We did not have a spare injector and It did not see to be running right anyway. We made the decision not to run. A lean cylinder could burn the valves and cause other engine damage.

Not much to do now but to pack up the trailer and load the camper into the pickup bed. It was late in the day by the time we got everything packed up and we decided to leave early the next morning. We took the whole rig back to the hotel and parked it in the RV lot. I was not Happy.

[Plechtan]

We were on the road about 6:30 am, Scott was driving again. Nothing much to look at as you head east on I80. Plants don't seem to grow too good in the salt. Most of the area from Wendover to Salt lake is flat. Dried mud is all you can see and the mud has such a high salt content that nothing will grow.
We planned to stop about 20 miles west of Salt lake at a truck stop to get some breakfast and get the Salt off the truck and trailer. Look at the picture below, thats not snow, it's SALT. It cost $100 at the Truck wash to clean everying off.

My wife was suspose th fly back home on Wendsday, but decided to drive home with us. My plan was originally to sleep in the Camper in a campground on the way home, but thought it migh be eaiser to just stay in a hotel.

We drive across Utah, Wyoming, and into Nebraska. we got off at Exit 126, "Ogallala" Found a Holiday inn express and called it a night.

bonneville small 299.jpg

[seanyb505]

Murphy's Law sucks...Is there more to this story or has everything started working toward next year already? There will be a next year, right?

[Plechtan]

Friday Morning Aug 14th, we left Ogallala about 8:00 am, The GPS said 820 miles to home. It was a long ride. I was still not fully recovered. We would go from Mountain time to Central time about the middle of Nebraska and lose an hour. the construction was non stop. On the way out we went through Nebraska at night and didn't have any construction backups.

We Finally arrived back in Woodstock Il about 7:30 pm Friday night. We decided to take the weekend off, we had been going non stop for the last month.

The following week I was back at work, but it was really bugging me what was going on with the truck. I found a company in Oregon wthat would test and clean the fuel injectors. On Wendsday (Aug 19) I pulled the injectors and sent them out. I was hoping one or two was plugged so i would have a root cause for the lean condition. My son was off work on Thursday and i asked him to check the compression. While we were running the engine on the dyno @ 6,500rpm prior to going to Bonneville, the oil filler cap blew out of the valve cover. It was a new engine and a 13.5 Cr , but i thought that it should not have built up so much pressure.

My son called me back, Cylinders 1-5 were about 270# but cylinder 6 was only 160#. Not good. I was hoping that the head gaskes had blown out on the passenger sideon #6 and that was how the cylinder pressure was leaking down . We decided to pull the motor and bring it back to the engine builder.

On august 27th the InJectors came back, I reviewed the reports. Nothing wrong with the injectors. I was stumpted. How could i have a lean condition on one or two cylinders if the injectors were working properly? Maybe somthing else was going on.

We pulled the motor on labor day weekend. We removed the intake and the headers. Looking at the intake and the head, it seemed that their may have been a leak between the intake and the head. I had a independent throttle body setup, so a manifold leak would only effect that one cylinder. I checked the Clifford manifold flange with a straight edge. It was warped by .060 ( 1.5mm). What a piece of crap. This explained the lean condition but not the high crankcase pressure and the so-so oil pressure.

On the Tuesday after labor day we dropped the engine at the builder. I was not in a bigh rush, but when i had not heard from him in 2 weeks, i gave him a call. I asked if he had a chance to look at it, and he said he did. The Rod bearings were all shot, the mains maybe could just be replaced. The #6 rod was the worst and had so much clearance that the piston had actually contacted the head and the top ring was pinched in the grove. I was only running a .040 Quench.

The rod could probably be saved, but i would need a new piston.

OK, but what caused it? looks like low oil pressure. We are running an external pump using a setup similar to the one below. The one below is a dry sump setup. We are running a wet sump setup with a single stage pump. I Called Peterson and talked to tech support. The pump was rated at 6.8cc per rev. The pump turns at about 50% engine speed, so at 1,000 (engine) rpm the pump would flow ( 6.8cc x 500rpm = 3,400cc or .9 gpm) I don't know the specs on the stock pump, but i would think it would be about half of that. @ 6000 rpm we would be flowing 5.4 gpm. The oil system holds 2 gallons.

Hesco_drive.gif

[Plechtan]

Looks like the oil pump has plenty of volume. The oil system must have a large leak. The oil system on the Jeep I6 is pretty simple, the oil comes from the pan, up to the pump, then through a hole in the block up to the oil filter. The oil goes from the outside of the oil filter to the the center, then up a hole into the main oil galley. The main Oil Galley runs from the front to the back of the engine. It is about a 1/2" hole that is plugged on either end. If you have a bare block, you can see one of the plugs next to the cam bore in the front. The oil comes into the side of the galley through an intersecting hole from the oil filter housing. Holes are drilled in the Main bearings supports that intersect the galley. Holes are also drilled from the cam bearing housings into the galley. Now for the lifters. The hole that is drilled from the front to the back of the block and is positioned so that it intersects the side of the lifter bores. This provides the oil for the lifters.

We were feeding oil directly into the side hole that intersets the main oil galley. The clearences on the rods, Cam bearings and mains were the same as stock, so the oil was not ( or should not) leaking there. That leaves 2 possibilites, the lifters, and the engine shop had run a line up to the gear drive for additional lubrication. The new line was attached where the oil pressure sending unit normally would be screwed into the block, right by #6 cylinder. I think this was the main cause of the failure, The orifice in the line is .125" I was inaware of the oricice size until i started checking. The engine shop decided on the size. I am replacing it with a .022 orifice and moving the line to take it's pressure from the oil filter adapter rather then the end of the oil galley.

We are using solid roller lifters. The lifters have an oil feed hole that is inline with the roller and located near the top of the lifter. This is to feed oil up the pushrod to lube the rocker arms. It could be that the hole is being exposed to the oil galley at some time during the stroke of the lifter. The lifters are back at Isky now having the hole that might intersect the oil galley plugged.

With these 2 modifications the oil pressure issue should be resolved. We plan to run the oil pump with a drill, with the oil pan off to check for excessive leakage prior to buttoning up the motor.

[Plechtan]

We have a long winter ahead in Illinois, we plan to reassemble the motor and make the roll cage modifications that the Tech guys at Bonneville said we had to make. The goal is to get everything together by Feburary, then take it down to Hesco for some dyno tuning ( who Better?) It will be nice to visit Alabama in the middle of the winter.

We should then be more than ready to go to Maxton NC on April 10-11 for the first ECTA meet of the year. They only have a 2 mile course, but it will let us get some bugs out of the car before we go to Bonneville in August. If we have problems in April, they also run in May and June. Next year we will be ready.

Looking back, it looks like we bit off a little more than we could chew. The biggest problem was not having the engine far enough ahead of time. Everything just got too rushed at the end.

Was it worth it? I think it was, I learned allot, and i think my son did too. Perhaps it is more the journey than the destination.

Should we have held off? No i don' think so, it is always easy to post pone things. Not so easy to meet a deadline. We ended up not running, but we did make it through tech, and we know what to do for next year. Our goal is to go 185MPH. The record in my class is currently 170mph, up from 144 the year before.

Maybe we won't break the record next year but i guarantee you we will run, and run fast



To be Continued.......

[TurboTom]

Great read Pete.
Sorry to hear the dyno shop stuck you with an Alpha/N tune instead of Speed/Density.
I am a big fan of Speed/Density, of course with my turbo engine Alpha/N just would not work.
Good luck next year,I may be able to get to Maxton to take it all in.

[amcinstaller]

yes, good luck for next year!! at least now you know exactly what youre up against!

[donnie]

Been watching this thread, been looking for an update, yall going to make to Maxton in April?
Whats the record at Maxton?

[Plechtan]

Sorry, i didn't get back to this thread until now, but to answer your questions, we did not make it to Maxton in april, but we will be there in May (22-23) We could use a hand or at least a cheering section if you are in the area. The current record in Maxton is 160 mph set this april The previous record was 155 set last fall. Both of the records were set by a truck called the HVAC express. it's an S10 with a 4.3 stroked to 5.0L

Over the winter we repaired the motor and this weekend we did a dyno run at Hesco ( see the project thread) Everything is going much better than last year. We have to make some more changes to the car to comply with rule changes and things the inspectors did not like. The goal is to have it ready for Maxton in May.

One thing that I suspected before is more than clear to me now. The Jeep head does not flow worth a damn. If you look at the sim's that 1bolt did, you can see the difference between my head and a head that would flow 300 CFM ( 50hp) His sims were on the money for my engine, and i suspect that they would be correct for a different cylinder head.

So for right now, no drama, just hard work and persistance.

[Plechtan]

I put up a facebook page, if you are interisted, just search "Comanche LSR 3" and it will come up.

[Plechtan]

We did go to Maxton in May, but didn't get it much past 90mph. The front end began to shake violently. We have since replaced the steering linkage, steering box and installed adjustable lower control arms that use rod ends instead of rubber bushings. It seems to be good now. we will be taking it to the drag strip on Wendsday to see how it does. If everything looks good, then we will be at Maxton on June 26th and 27th,