Lola T91/50 F3000 @ Road America

[mikey]

HU41 moves under its own power for first time since I acquired it from Derek Harling 4 years ago! It has been 6 years since it was on track.

Some of you may recall my many posts as I went thru the car and sorted things that I wanted to improve upon over the last 4 years. I would have had it out much sooner but between COVID and moving across states a couple years ago, and still waiting for a garage build to start at the new house, I was delayed or full of excuses why I couldn't get more done sooner.

But alas, the opportunity to head to Wisconsin for perfect weather and a great track day format (open track all day, no assigned sessions, high caliber drivers) put some emphasis on being ready this past week to get it running again.

Here is some short video:
https://youtu.be/TamScYws5LM

Here's the breakdown of the day:
Started the car up at the trailer. Couldn't get it to free rev past 5500rpm when slowly applying throttle. I didn't recall this behavior during any of the times I had warmed it up in the garage over the last few years, but not sure I ever really tried to get rpm's that high either. Motor didn't sound weird or anything, it just wouldn't rev higher under light to medium throttle. Just acted like it was hitting a wall, something amiss with air/fuel ratio it seemed. Or a very soft rev limiter in play, that I am pretty sure does not exist in the ECU. The only rev limiter I know of is programmed to 7200rpm. If I very quickly stabbed the throttle I could get the rpm's to go higher but couldn't hold them there.
So I decided to try a single lap and see how it behaved. That's in the video link above. Motor was incredibly strong and really wanted to run. No apparent issues and would rev past 5500 under load it seemed.
I brought it back to the trailer and put in 20 gallons of fuel, intent on running 10-15 laps before lunch. This time out, the motor shutdown going into turn 5. I tried to restart it while coasting in 4th gear but it would not fire back up. It coasted in gear without any apparent issues. I went thru the run-off area and then got towed back to my trailer. It started right back up there while on the jump battery and sounded fine. But now it was lunch break.
After lunch, I tried again, but was a bit too anxious and didn't fully warm the car up before heading out. Temps were probably 140F or so.. I have alarm triggers for "too cold" which started going off as soon as I went over the mph threshold for the alarm. I drove slowly around at 60-75mph and pulled into the pits, planning to let it idle a bit longer and ensure the thermostat was open before going back out. As soon as I stopped, smoke was evident and it smelled like oil. I quickly drove back to the trailer and the oil pressure warning came on 100' from parking it!
It seems the LH Cosworth Oil Pump is leaking, badly. So 2.5 laps / 10 miles total time on track this week.
Haven't downloaded data yet, I will this weekend and report what else I find. And I'll start removing things to further diagnose. Perhaps a line came loose. Perhaps o-rings have gone bad. It never leaked in the garage anytime I warmed it up past 200 degrees every 6 months or so. So we'll see.

Hope you enjoy the video, albeit short! I'm miles ahead (literally) of where I was with the car a week ago, so all is not lost. Confident I'll get this thing sorted soon enough and have another attempt at it. It's been 6 years since I drove my last formula car (Pro Formula Mazda) and I've been endurance racing a Corvette in the interim so I have a lot to do to reset my brain! Pretty much even forgot how to shift a dog-ring box! I also think I need taller gears as this one with rev-limit 5th gear @ 156mph. It was immediately apparent that gearing is too short for this much motor!

Cheers,
mikey

[E1pix]

Too cool Mikey, it’ll be great to open that thing up!

Isn’t that the same chassis used in Indy Lights then?

[mikey]

No, Lola designates the Lights chassis with /20. I don't think they made any until 1993.

[E1pix]

I think you’re right about 1993, as relayed to me by Ric Moore when I spent a day with he and Greg at a PIR test in April of ‘93. But I also thought he said the chassis was derived from the F3000 version.

I believe the former Lights chassis were called Wildcats, but built by March.

[tlracer]

Great step forward to get the car on the track! First runs are rarely perfect and better to find snags now than later on.

Thinking about the reluctance to rev fully, do you have a throttle position sensor? These can go bad, also they can be quite voltage-sensitive, which might explain why the engine fired on the jump battery, if the onboard was dropping low?

[mikey]

Didn't find anything obvious in the data on the 1/2 lap where it shut down before T5. TPS seems to be functioning normally. Voltage average 12.6-12.8, never fell below 12.0VDC (onboard alternator). Fuel pressure never dropped. Appears ECU just suddenly dropped out because at the point the motor quit I was not getting any more ECU CAN bus data, only AIM sensor data. External voltage was still 13.3VDC at that time and throughout coasting thru the runoff area. I'll have to check the power connection to the ECU, but whatever that was, it was intermittent only as I mentioned it fired back up 5 minutes later at the trailer on the jump battery.

On the Coswoth pump failure lap, oil pressure steady up until pump started sucking air in the paddock almost to the trailer. Rapidly varied oil psi for last 200 feet, between 70psi and 20psi, but nothing lower than that. I pulled 2 qts of oil out of it just now in the garage, so I lost about 5-6 qts. Must have been flowing or squirting straight down because there wasn't much on the car or on top of the floor.

I removed the rear floor and diffuser, not certain where the main leak was yet, but I do have a curious small stream coming from a small area that has a dried mustard yellow substance on it. My thought is the yellow is some sort of torque seal mark, but not sure. See photos below. The 4th photo shows where a small stream free flows down from the yellow spot - this amount of oil appears within 60 seconds of cleaning.



Bottom view:


Last note, when I removed the oil cap from the tower on the transaxle, there was a frothiness at the top lip. The oil that came out did not appear milky though.



At any rate, it now appears I have to pull the motor to get the pumps off and re-seal. I don't have the space to do that in my current garage without evicting another car which I don't want to do, so it may be a while before I can go any further here.

[tlracer]

Froth on the filler cap isn't an issue, most likely just residual moisture that didn't get flashed off due to the unfortunately limited running time.

Hopefully the pump will be a failed o-ring seal. Be sure to replace with a suitable oil and temperature resistant material, eg. Viton.

[teamwisconsin]

I’d reach out to Frank Guerrini @ Phil Reilly Indy or Forrest Teran @ Teran Motorsports. Both of them are very knowledgeable on DFV’s. The oil pumps have a clutch that drives them. The clutch can slip or stop turning which can cause a loss of oil pressure. On the dual pump setups, one side was scavenge and one side was pressure so if your scavenge failed it would blow oil out the breather on the leading edge of the left bank when the sump filled up. However, that looks like a slimline pump setup (single side pump).

Both Frank and Forrest would have the o-ring kits in stock as well as filters. They are easy engines to service but if I were you I wouldn’t run the car again until you had the engine looked at. You might spend 20k+ on a rebuild but if you run it with little to no oil pressure and it goes south you can easily be heading towards the six figure mark to replace it. I don’t know much about the differences between the F3000 DFV and the GP DFV, but I’ve worked on a lot of the GP DFV’s and I have always deferred to one of the DFV experts rather than taking a chance. Ounce of prevention/pound of cure sort of scenario.

Take all that I say with a grain of salt though, Cosworth used to have these mileage cards that went on the top of the ignition boxes, at the bottom of the card, it said something like “it is better to be underinformed than illinformed”. Hopefully I’m not providing ill-information but a phone call to an expert would certainly be a worthwhile venture at this point.

Phil Reilly Indy - (317)484-8240
Teran Motorsports - (707)658-2489
Best of luck-

[mikey]

Thanks for the POCs The pressure pump LHS is the one that leaked. The scavenge pump RHS is not leaking. Note this is a Buick Indy Lights motor.

[teamwisconsin]

Thanks for the POCs The pressure pump LHS is the one that leaked. The scavenge pump RHS is not leaking. Note this is a Buick Indy Lights motor.

Well there I go giving wrong info! Sorry, I saw the oil pump and F3000 in the title and assumed it was a DFV.

best of luck with the issue-

[johnhafkenschiel]

Too cool Mikey, it’ll be great to open that thing up!

Isn’t that the same chassis used in Indy Lights then?

Mikey: There are people who are experts on the Buick V6 for Indy Lights. Now might be the time to consult with them.
George Montgomery, Gregg Montgomery, Dayton, Ohio