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"Swamp thing" JBC 510 racecar


Icehouse

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So much to say!  A lot has happened in a week.  Hopefully I can bring everyone up to speed here...

 

As well as getting the car running much better (Thanks Sam for tackling the fueling issues) we were scrambling to get the last few parts for the car, set aside what we planned to bring to the race, apply mandatory race stickers, finish wiring gages, etc.  The week before the race was such a blur and frankly, we were all exhausted and just plain tired of working on the car!

 

Grabbed a front valance from my front clip.

 

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Jeff said he needed a light for the alternator - the auto parts stores didn't have anything suitable besides trailer lights, then I remembered my spare 620 dash.  Perfect!

 

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Stickers and more stickers.

 

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It was nice to hit the pillows Thursday night..  We earned it.

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Friday we loaded up at lunch.  Fortunately, my Z-therapy spares arrived in the mail just in time!

 

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Of course, this means we probably won't have any carb issues now.

 

Sam and I picked up my son from school and drove down to Shelton from there.  How many of you were picked up by your dad towing a racecar?  All we knew was that we had to be at the track by 7pm for a mandatory drivers meeting for new drivers - That's us!

 

It was a long trip to Shelton in Friday traffic but we made it there, what, just before 6pm maybe?  We found another Lucky Dog racer on the way down and pretty much drove together on the freeway from Fort Lewis on down.  What are the chances?  I figured we'd spend a lot of time looking at the back of racecars this weekend so I might as well start now.  : )

 

It was a bit chaotic when we arrived.  There was a well attended track day that was just getting out of the track and most of the other Lucky Dog participants were already there and set up.  We couldn't park next to our pit stall so we got as close as we could, unloaded the car, and started setting up the pit.  It  looked like most people were putting their cars thought tech at this point.  Sam found some staff and explained that we had to go to the 7pm meeting.  They told us to park our car at the end of pit lane and they would take care of us after the meeting.  We had just enough time at that point to go through equipment check (making sure helmets and race suits are up to snuff) and to the meeting.

 

Afterwards we met the inspector in pit lane and he passed our car with flying colors!

 

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And we have the first (hopefully of many) inspection tags on the roll cage.  Cool!

 

We rolled the car back to the pit stall and covered everything up for the night as it started to rain.

 

Here is a little video Corey took as he left the track with my Dad earlier in the evening.

 

http://datsun510.com/index.php?/gallery/image/38977-04202018-swamp-thingmov/

 

Allows you to see some of the competition. All the cars on the other side of the wall are lined up for tech inspection.  We would have 72 cars in the race the next day!

 

On the way to my parents that night, I grabbed a few gallons of premium for the race.

 

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The next morning we arrived bright and early to get the car ready and dump the water out of our tool boxes.  (dang rain)  But it looked like a beautiful day was ahead.

 

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These guys are ready to go racing!!!

 

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There was a driver's meeting at 8 or 8:30, I don't remember which.  It was lead by Kathy, the event organizer and owner of Lucky Dog Racing.  She has done an amazing job with this series.  Everyone has positive comments.  She had a special announcement - there would be a crew filming the race weekend for a TV show focusing on two of the race teams.  Hopefully you will see a 510 racecar in your living room soon. 

 

There was a 40 minute qualifying session at 9am and our understanding was that all three of us were supposed to lap the car.  I heard laps were under 2 1/2 minutes so I figured if we each took 4 laps, with driver changes, that would be just about right.  We agreed that the last qualifier should start the race since they'd be all suited up and ready to go.

 

We then proceeded to make last minute equipment/fluid/safety checks and then Sam got in the car and did 3 laps before coming back in.  I repeated his lead and then brought the car in for Jeff.  He was just about to head out for his laps when the officials announced that qualifying was over.

 

Hmmm....  Must have gotten a late start.

 

No biggie.  They said in the meeting the night before that in this series, qualifying is really just to help them figure out what group the car will be running in (A, B or C).  They don't actually grid the cars based on qualifying "position".  It's first come first served to the starting line and there would be a minimum of two pace laps before the green flag drops on a rolling start.  That would  allow Jeff to see the track before racing.  Something Sam and I didn't get to do actually.  We had to qualify on a hot track with nothing more than a track map in our heads and a view out the windshield and mirrors.  Exciting stuff!

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Here's Jeff ready to go.  We elected to sit on pit lane and fill in at the back of the grid.  We are not here to win.  Plus, that would give Jeff 4-5 laps before the fast cars started filling his mirrors.

 

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Cars behind (we would file in after them)

 

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Cars ahead

 

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Go Jeff Go!!!

 

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Corey captured the roll off...

 

http://datsun510.com/index.php?/gallery/image/38980-04212018-swamp-thing-42mov/

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We agreed to take ~1hr shifts to "guarantee" that we'd each get a chance to drive the car - since we were still pretty unsure of the potential longevity.

 

Here are some shots of Jeff in the car and some more video from Corey.

 

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Look at all the cars!

 

http://datsun510.com/index.php?/gallery/image/38979-04212018-swamp-thing-40mov/

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Oh yeah, forgot...  While watching Sam qualify, we could see quite a bit of smoke trailing his car (oh no, not that again) but it seemed to run really strong.  When I was doing my laps I noted the same.  It seemed like maybe it was tire smoke from rubbing the front fenders?  I rolled out the fenders a little more with a pipe before Jeff got in the car - hopefully to fix the issue. 

 

Well, when Jeff was racing, the smoke had definitely subsided but it was still there.  Especially on the 3-4 shift down the straight.  It seemed to be decreasing as the laps ticked by though.

 

When he came in, I think we pretty much put Sam in the car and straight out onto the course since the car was running well.  Sam cranked out lap after lap and had about the same smoke situation in the same place as Jeff.  And just like that, another hour was up and it was my turn in the drivers seat.  Jeff and Sam will have to tell you about their own race experiences later.

 

We determined by the fuel gage that we could keep going so I got strapped in and headed down the pit lane and was waved onto the track.  I pushed the gas pedal down and something didn't feel right.  The car started to sputter so I feathered the gas to keep it running but it was obvious the motor wanted to stop running so I found the edge of the track just after the left kink at the end of the straight and pulled onto the dirt/grass.  It seemed like it had run out of gas.  That's just not right!

 

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I waved to the marshals that I needed help. (In case that wasn't obvious)   A truck came and the crew hopped out to make sure I was okay.  They asked if I needed a flat bed or if I could be towed.  Nothing was broken or seized so they hooked up a tow strap and set out for the pits, so my very first racing lap was spent 20 feet behind a pickup on a nylon strap.  Awesome!

 

When we got back to the pits, we took off the hood and started looking at possible causes.  Fortunately, we are now all experts at identifying all the ways to prevent fuel from getting in the motor.  This time, it would be the fuel filter.  It was basically orange.  Jeff grabbed my wallet out of the tool box and took off into the paddock to find a replacement fuel filter while Sam started shaking and cleaning what we had just in case.  Jeff found one pretty quick.  Sam installed, car started after some cranking and we were back in business.  I'm pretty sure we then elected to fuel the car before I went out just in case. 

 

Back down pit lane I want and onto the track and the fun began... 

 

What an amazing experience!  The car was so much fun to drive.  After a lap or two, I found myself behind a silver sirocco.  One of the guys on that team is a fellow autocrosser at Monroe and I thought Jeff said the car and skills were pretty evenly matched so I figured I'd do well to follow him around the track.  Well, it was way easier than I though to keep up with him so I was able to get passed and move on down the track.  The car was a total joy to drive.  So much traction!  But you could feel the limit very clearly.  Try to build speed too soon exiting the carousel and the rear would step out but in a nice easy progressive manor.  You'd really have to work to lose control in this car I think.  The front is stuck solid to the track but everything is communicated so well.  Not bad for a first stab at this!

 

A few laps later and building confidence and speed and I found myself behind a newer V6 mustang.  I spent the next few laps riding his bumper all around the track 'till we got to the straight where he would pull out a few car lengths on me.  I'd be back on his bumper by turn 3.  Contact is strictly forbidden and we have a long weekend and a lot of driving left so I resigned myself to hold this position and wait for him to make a mistake or take advantage of traffic or something.  Then with about 15 minutes left in my session, there was a full course yellow to clear a couple cars that had found their way off track.

 

It stayed like this 'till my hour was up so I pulled into the pits and we put Jeff back in the car and the track soon went back to green.

 

Sam and I were sharing our driving experiences with each other and after about 10-15 minutes, we noticed the track went yellow again. 

 

We watched the cars coming down the straight and kept waiting to see Jeff.  Then we think we started seeing cars twice but no Jeff yet.  Uh oh.  About 5-10 minutes later our fears were realized when the flat bed comes down corkscrew with a Datsun 510 on the back. 

 

Accident?  Mechanical?  At first, we thought it might be missing a door skin but it was just the window net down.

 

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Then I could see fluid on the windshield and I figured something blew.  Jeff confirmed...  Engine was toast.

 

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Unfortunate timing as his family had just arrived to watch.

 

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We roll the car to the pits and remove the hood to find a Valdez sized oil spill in the engine bay.

 

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Turns out piston rod #2 got tired of going up and down and wanted to go sideways instead.

 

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Well.  I guess that's that.  Someone floated the idea of calling around to see if we could find another motor but I don't think any of us had enough fire left to install motor #3 in the span of two weeks...

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We decided to pack it up at this point so Jeff and Sam could head back up north. 

 

On the way out, I snapped some picks of the two Datsun Z cars that were also competing.

 

I would like to have raced against this one.  I think we were turning similar lap times.  ???

 

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This one blew its motor during the Friday track day.  They had a spare however which they built up and installed while everyone else was taking their cars through tech on Friday night.  That makes two less L motors in the world.  : (

 

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Pretty car!

 

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All packed up and nowhere to go...

 

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As disappointing as it was to face an early end to the race weekend, there was a silver lining...

 

My dad made us pizza in the barbecue for dinner! 

 

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I definitely see a pizza stone in my future.  Yum!!!!

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Only 5 weeks 'till the next race at Pacific Raceways in Kent.  (was SIR) 

 

We have a plan!

 

We spent Turbo Tuesday cleaning Jeff's garage and taking a look at the car.  Jeff and Sam had removed the head Monday night...

 

Dang rod even dented the motor mount!

 

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We think the smoke we were experiencing was from crank case oil being sucked out the crank vent and into the valve in the intake.  None of us remember if we saw a crank vent baffle/filter when we put the motor together so we were likely asking for it.  The decrease in smoke would then have been linked to the oil level which was getting lower each lap as we vacuumed it out of the sump. 

 

We think the destruction was caused by over revving the motor.  I thought we were setting the rev limiter at 6,500rpm but I found myself at 7,000-7,200 at the end of the straight lap after lap.  Jeff and Sam said they saw even higher numbers.  Not sure if in 4th or in 3rd before shifting...  Either way, that's just too hard on a basically stock L20B - or so it would seem. 

 

If only Nissan made a more modern 2 liter motor that could withstand higher revs for days...   Maybe one with dual cams and EFI?

 

Hmm...

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7,000 is the theoretical red line for an 86mm stroke (L20B) engine. This is sustained RPM. I don't see evidence of blueing on the rod or crank so maybe the bearing didn't fail from lack of oil...maybe the rod bolts failed from revving?

 

 

On the next engine maybe a windage tray / crank scraper to reduce the oil fog around the crank. The block vent should be closed off and only the valve cover vent used directed into a catch can. (which you probably have to use on a trck) That'll save a lot of oil and keep it in the engine sump.

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At 7K...

 

The crank is spinning fast enough to be rolling along the ground at over 140 MPH!!

The L20B piston is traveling up and down a distance of 3,953 feet per minute or on average 44 MPH.

The piston has to accelerated and decelerate 14,000 time per minute or 233 times per second, and this does not start at the half way point and end at TDC. Maximum speed is when the rod and the crank throw are at 90 degrees to each other or around 60-70% of the way up the cylinder. The piston and rods are subjected to brutal compression and stretch in the top 1/3 of the piston travel.

 

I seem to remember an L20B rod being around 775gr. Pistons around 40gr? Lets round to 800 gr. Using some on line calculators I get a deceleration rate of over 942g. So those rods are being stretched by over 1,600 pounds then compressed by this amount 233 times a second... the mind boggles.

 

Hey, I could be wrong.

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No warning needed.  We built up speed as we went.  Fun getting the car unweighted over the rise.  Easy to step the rear end out if you're too early on the gas going to 4.  I realize we've only driven one track but it's hard to imagine a better one.

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  • Icehouse changed the title to "Swamp thing" JBC 510 racecar

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