Jump to content

A big thank you - 240 LS Conversion

Recommended Posts

Custom fabbed a mounting plate for the external fuel pump.  Added geometery to the plate to make it rigid & a few radii to make it sexy.


The setup worked okay to date - no issues on a maiden 9 day, 4000 mile road trip.  If God built the car he would put the pump in the tank - this is where it's going this winter.  


For you geeks doing risk analysis I rate this as 9 for severity, 6 for occurance, 8 for detection for an RPN of 432.  I'll detect it at the last minute leaving me stranded on the side of the road (and the wife will be with me utimately driving up the severity score).


I've been lucky to date but the setup is not ideal for long term durabilty.  I can tell the pump is working hard sucking fuel and the pump will run cooler inside the tank.  Fuel slosh will be reduced/eliminated if done right too.  I put a different pick-up tube in my factory tank so I didn't experience fuel starvation unless it was below 1/8th of a tank.













Share this post

Link to post
Share on other sites

If the dead rat wasn't exciting, the car was also loaded with Mud Daubers.  According to Wikipedia; The Mud dauber (sometimes called "dirt dauber," "dirt digger," "dirt dobber," "dirt diver", or "mud wasp") is a name commonly applied to a number of wasps from either the family Sphecidae or Crabronidae that build their nests from mud


Many times nests were located in hidden areas making it difficult to remove ultimately requiring creativity such as long picks, scribes, 12Ga. solid core wire, to break into smaller peices and blow out with compressed air.  If not removed the heavy mud nest would rattle around the car.  I could of easily filled a 3 gallon trash can with mud nests (seriously).   











Share this post

Link to post
Share on other sites

I had the tank modified with a larger dia. feed, return and better pickup.  I found a radiator shop willing to mod. the tank and seal it for a fair price.  Scuffed and shot it when I painted/sealed the bottom of the car.


This winter I'll tweak the tank for the in-tank pump.




Share this post

Link to post
Share on other sites

Found some good LS1 wiring references on-line so I built a harness from the Camaro.  It was a good learning opportunity and gave me a reason to invest in a weather pack connector kit, crimp tool etc. 


Integrated the car and PCM harness with a Current Performance relay/fuse module. 


Ran out of space in the garage so I setup a make-shift temporary bench using a piece of law furnature that arrived in the mail only to take up space in the garage until spring. 











Edited by Mikey303LSZ

Share this post

Link to post
Share on other sites

Found a long nose R200 on Craigslist.  The guy was awesome - drove it all the way to my place (~50 miles), and hand delivered it straight to the garage.  I tried to give him a $20 tip for fuel and hand delivery - he wouldn't take it.  Awesome Z guy from CO Springs...


Opened it up, nice and clean, didn't want to drop $ on a high end LSD so I opted for Phantom Grip.  Spent a few evenings at work dusting off the spider gears on a surface grinder (following Phantom Grip instructions).  So far I'm really happy with the setup.  The posi seems to work just fine for my application.


Phantom Grip had mixed feedback from feeds I read on-line but mine works as advertised.  I could see where it wouldn't work well if someone didn't have access to precision equipment (surface grinder or mill) to setup the spider gears.  I would have gone a different route but there's a big $ difference between this and other options.  I figured if it didn't work out I wasn't out much $.  Rear diff & Phantom Grip combined was ~$450 including mustache bar.


Used a TechnoVersions diff. mount.


My neighbors love me. 








Edited by Mikey303LSZ

Share this post

Link to post
Share on other sites

Very well done.  You will have many trials and tribulations once this gets on the road.  Just stick with it and you will have a car that will easily trump your vette any day of the week.

Thanks.  Yes, it's more fun than the Vette.  I put 4500 miles on the Datsun this summer and only 500 on the Vette.

Share this post

Link to post
Share on other sites

Grabbed the cruise control off the Camaro and wired it up (works great - worthy upgrade). 


Bought a Lokar auto shifter - wanted something short to make it look similar to the factory Datsun stick shift.


Sent my tach. to John at JCI for the 8 cyclinder calibration/update - no issues, works great.







Share this post

Link to post
Share on other sites

Replaced the 240 brake booster & master cyclinder with a 280 booster and a 1" bore Wilwood.  Added a proportioning valve too. 


Spent a few minutes ensuring the master c. rod gap was set properly with the booster.  Setup the Wilwood as shown in the photo to work properly with 4 wheel disk brakes.  If I was using drums it would be different.


Found a brake pedal setup from a Datsun with an automatic. 


Didn't want to weld up the clutch master cyc. hole in the firewall so I fabbed a bolt in block off plate.  I change my mind I can easily go back to a 6 speed trans.








Edited by Mikey303LSZ

Share this post

Link to post
Share on other sites

Used the stock Camaro fans.  Modified the plastic shroud to fit the contours of the aluminum radiator.  This radiator and fan setup works excellent.  The car runs really cool even during the last stop on the Hot Rod PowerTour in Lousiana this summer.  We sat in stop/go (mostly stop) traffic trying to get into a venue in Lousiana for over 45 minutes - no overheating.  Most of the time only one fan kicks in to take the edge off the temperature during the summer.


Made a few custom brackets from sheet stock for the condenser.






Edited by Mikey303LSZ

Share this post

Link to post
Share on other sites

I started to run out of time for my deadline of the maiden voyage (Hot Rod PowerTour 2015).  June was approaching quick - lucky for me between my wife, brother-in-law and two friends of mine they knocked out the installation of RAAM Mat (similar to Dynomat).  It took a long time but the end result was worth it. 







Share this post

Link to post
Share on other sites

Somewhere around this point I fired the car and put a few hundred miles on it (no issues, no problems except for a turn signal switch, a bad ground on the horn and a little leak at the water pump).  What a BLAST to drive.  It ran good but felt like it could use more power. 


Since I was getting ready to do a 4K, 9 day road trip I was going to have to replace the water pump.  About that time a buddy of mine was upgrading his LS2 heads on a Corvette to AFR ported heads so I grabbed them for this car.  The heads had 25k miles & were the right price so why not?  


During the water pump R&R "while I was at it" I installed a TexasSpeed 224 cam, LS7 lifters, LS2 heads, matching springs, retainers, push rods and updated the problimatic LS1 oil pump with a Melling.  My intent was to do my own tuning but ran out of time.  I took it in for a dyno tune - ~340HP at the wheel.  Not too bad for a cobbled car/engine.  I suspect the cam/heads added 60 to 75HP making it a wanna be an LS6 with a slightly larger cam.











Share this post

Link to post
Share on other sites

Thanks for the kind comments.  The build took awhile and WELL worth it in the end. 


The HybridZ posts kept me inspired and up to date on options for the car. 


In a few of my posted pictures you will see pictures of cars taped to the side of the blue two post lift (next to my car).  Each day as I walked through the garage to go to work, take out the trash etc. it reminded me of the hard work you folks put into your cars and the outcome I would have if I just stuck with it.  It was equivilent to the skinny bikini girl posted on the refrigerator door as a reminder to stick with the program.


I hope my photos inspire your builds as they progress and hopefully inspire to keep plowing ahead in times of low motivation.  I'll try to finish the post this weekend.

Share this post

Link to post
Share on other sites

Along the way I bought a few different tire sizes, brought them home, checked measurements and made the commitment.


Along the way I took the car to a friend's shop for a 4 wheel alignment.  Even with the rear camber plates I was not able to set the camber up for a street setting.  It works for now and it's great for the track - ultimately not the way I would like it.  I'll looking at some adjustable rear control arms as an upgrade at some point. 







Edited by Mikey303LSZ

Share this post

Link to post
Share on other sites

When I first started driving the car I started out using stock rear axle shafts.  I never had a problem with them but from a risk perspective they can be problimatic.  I swapped them for a set of Wolf Creek Racing axles prior to the Power Tour.  The new axles feel smoother on the highway and I'm sure they're a little stronger.  :-)


Upgraded the headlights to Truck Lite brand LEDs.  Wanted to take the current load off the old wire harness/switch - they are really nice and bright.  Investigated the wire harness/relay setup but figured I'd put the money into LED technology vs a wire harness/relays.


Along the way I took the car in for Colorado pre '81 emissions testing.  Passed with flying colors (these results were pre heads and cam).  MUCH cleaner than a stock '73 240.








Edited by Mikey303LSZ

Share this post

Link to post
Share on other sites

Had about 500 miles on the car, upgraded heads/cam put another 75 miles on it and decided it was ready for the 2015 PowerTour.  We were on the road 9 days and logged 4000 miles.  As part of the event I ran it a few times at Memphis Speedway.  Just wanted to get a feel for what it would run in the 1/4 mile.  It was a ~95 degree day.  It ran a 12.6.  I was pretty happy considering I had about 150 lbs. of misc. luggage, tools, cooler of water, 33PSI in the tires etc.  In comparison there were 2 Hellcats running (12.4-ish) and a few new Corvette C7s running 12.8's & 12.9s.  The car made it back home unscathed to the exception of a blown A/C fitting (didn't crimp it tight enough) and a REALLY leaky windsheild gasket.  I had to bail out what seemed like 1/2" of water on the floor boards one morning after a full night of rain.  I pulled up the front carpet and set it on top of my luggage to dry for a few days while driving with the window down.  NOTE:  For those of you with old windshield rubber you may want to replace it before you experience rain. 


The car draws a lot of interest and lots of folks talking about their old 240 or someone they knew who had a 240. 


A few friends including HybridZ member 75280z got me excited about taking the car to a 2.5mile track for a little road racing.  One main point in terms of preparation for the first time racing was to upgrade the brake fluid to something better than standard DOT4 to reduce brake fade. My intention was to upgrade the fluid prior to a local Datsun club day and I ran out of time.  I spend the better half of a week trying to find a local store where I could buy a helmet for the event and didn't get to the fluid.  The day was AWESOME.  What a blast.  On the back stretch the car hit ~115MPH (per GPS) and surprisingly zero brake fade with regular DOT4 fluid.  I'm really happy with the Silvermine brakes and the coil over/suspension upgrades.


Next year I'll try a set of sticky tires install the rear sway bar that never got installed and see how the car performs. 


I also owe my dog a ride.  She was patient during those long days in the garage...








Edited by Mikey303LSZ

Share this post

Link to post
Share on other sites

SunnyZ inspired me on the winter turbo project.  


Picked up a set of used truck exhaust manifolds last weekend.  Keeping the A/C - hoping to sneak the left bank hot side between the F-body alternator and the A/C compressor.  Time will tell.  6psi should wake it up and keep it reliable.


Wife says, "why do you need to make it so fast?"  Reply - I enjoy fabrication and learning something new.


Edited by Mikey303LSZ

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now