Jump to content
HybridZ

78 280Z LS3 Project


Recommended Posts

  • 1 month later...
  • 2 months later...

I knew I had an issue with my fiberglass hood mounting flange (where it bolts to the hinge) hitting the cold air intake. The mounting flange is super thick in comparison to the stock hood and it hits the intake. Some say why not redo the cold air intake but I just like the way it came out so that's not an option for me. I have been trying to come up with solutions and still use the same hood since I like the scoop. The scoop is not massive plus I don't see this type of hood on a lot of S30's which is a big plus for me. Nothing worse than hearing, I know someone that has one just like it after you spend tons of money trying to make your car unique. 

 

So I decided to purchase an used stock steel hood and have it modified to look just like the fiberglass hood. This is the progress so far. 

IMG_7851.jpeg

IMG_7839.jpeg

IMG_7831.jpeg

IMG_7820.jpeg

IMG_7803.jpeg

IMG_7797.jpeg

IMG_7799.jpeg

Edited by alainburon
Link to comment
Share on other sites

  • 4 months later...

After looking for months for Inner Fender Liners I was able to find a complete set. However they were cracked in multiple places and some of the mounting holes were 2 sizes too big due to damage. That seems to be the norm with these parts since they are old and brittle. Finding a complete set it's a task all on its own. Finding a perfect set it's just about impossible. 

 

I found a place that has a plastic welder and sent them the parts. They had a hard time welding the plastic but were able to get the job done and you can't see where they welded these parts. Now to finish to body work on this car and repaint it so I can get it on the road sometime this millennium. 

Front Fender Liners-2.jpg

Front Fender Liners.jpg

Link to comment
Share on other sites

  • 1 month later...

Finally my car has paint again and this time the body work is done right. All that's left to do now is wetsand, buff the car and assembly. If you are in Texas DO NOT take your car to Richey Collision for any work. They were known to do great custom body work but after what they did to my car I would not spend a dime there. 

New Paint Job 2.jpg

New Piant Job.jpg

Link to comment
Share on other sites

  • 2 months later...
  • 2 months later...

The car finally made it home a couple of week ago from a long trip at the body shop. Very happy with the work they did. Now the fun begins, sorting out all the issues. The car is getting a bit hot, gets to about 230 degrees. The transmission rear seal is leaking and the front tires are rubbing the fender. It never ends with this car. At least its home and I can work on it when I have time. 

IMG_0373.jpg

IMG_0374.jpg

Link to comment
Share on other sites

Thanks for the compliments.

 

Well I have learned a lot about thermostats in the last 2 weeks and I wanted to share it in case someone runs into this problem. I also learned how so many people know so little about them, even the so called experts. Most people think the lower the temperature rating on the thermostat the cooler your car will run and that’s not actually true. Then you have others that think taking out the thermostat will overheat the car or cause it to run too cool, not true either. I was finally able to talk to a GM Engineer who was involved in designing thermostats and he set it straight once and for all. The purpose of the thermostat is to set a minimum operating temperature for an engine. In other words no matter what you do the temperature of the motor will not be lower than the thermostat rated temperature. It also helps in getting the car up to that temperature faster. Your cooling system is what sets the temperature your engine will operate at not your thermostat unless of course the thermostat is not working properly. LS engines were not designed to operate at 160 degrees, therefore he told me for starters replace the thermostat with the GM unit set at 187 degrees.

 

What happens next proves his point. I removed the thermostat to replace it with the one he suggested. The one in the left is the Ligenfelter thermostat I had in the car. It’s a 160 degree thermostat, the one of the right is the AC Delco GM unit for a 2002 Camaro SS. This is a 187 degree unit. You can see the difference is quality between the 2 thermostats. I replaced the Ligenfelter unit with the GM unit and my temperature went down from 230 to between 215 and 220. Still not perfect but a big improvement. So I put a higher rated thermostat and the operating temperature went down. Why? Design, you can see the clear differences between the 2 thermostats. The Ligenfelter creates more of a restriction that the GM unit so even though it opens at 160 degrees the flow is reduced therefore not allowing the cooling system to do its job. Also the rear part of the thermostat has holes on one and not on the other as well as the spring tension. Now to see if I can lower the temperature even more.

 

IMG_0405.jpg

IMG_0406.jpg

IMG_0407.jpg

Link to comment
Share on other sites

  • 1 month later...

After researching countless hours and talking to everyone and their sister I decided to follow what LOJ Conversions suggested since it made a lot of sense to me. Not to mention some of the suggestions I was getting were just way out there. Like, remove the heads to check for blown head gasket etc..  According to LOJ the heater circuits on Chevy LS powered vehicles utilize a heater control valve that has an internal bypass. When the heat is off in a Chevy LS powered vehicle, coolant still flows through the heater hoses. You are not supposed to block the heater ports on your LS water pump, they must be looped to always allow flow. If flow is blocked in these ports, you will cause a pressure differential on your water pump impeller creating cavitation, resulting in aeration of your coolant and an overheating condition. The Datsun 280Z  system works a lot different than an LS power vehicle, it has 2 heater control valves that block the flow of coolant into the heater core, it has no bypass valve. One valve is operated by the heat/cool level and the other is operated via vacuum. So when you turn the system to heat both valves open and allow coolant to flow through the heater core and back to the water pump. When the heat is off then the path is blocked and creating the exact same problem LOJ is describing.

 

So I did a little test, I ran the car until it got to its operating temperature which was between 215 and 220. Then I turned on the heater at the lowest fan setting this way the fan does not aid much in the cooling process and to my surprise the temperature dropped 10 degrees to 205 to 210. So I decided to purchase their LS Swap Heater Bypass Block since I’m not driving my car with the heat on all the time specially in Texas. I removed the hose barbs it came with, drilled it and tapped it to ½” NPT and fitted AN10 fittings. I installed it on the car and sure enough overheating is now gone completely. Car runs at 195 to 200 steadily. By the way I’m running a factory heater and A/C on this car. The A/C was always super cold before the swap and the heater worked well so I left it stock. No point trying to fix something that works well already.

Heater Bypass Block 4.jpg

Heater Bypass Block 3.jpg

Heater Bypass Block 2.jpg

Heater Bypass Block.jpg

Link to comment
Share on other sites

This is good information.  I Installed a heater (well, defroster really) in my car and when it is turned off I would have this same problem....flow between the heater hose ports would be blocked.

 

Would it accomplish the same thing to plumb an "H" with AN fittings between the water pump and heater core, or does the LOJ part have other design features I am missing?

Link to comment
Share on other sites

Yes, an "H" with AN fittings is exactly what the LOJ unit is, well I added the AN fittings to it. I put it between the water pump and the heater core. The only feature the LOJ unit offers is a port on the side for a Nissan water temperature sending unit which I'm not using anyways, I blocked mine with the plug they provided. Here are some pictures of some others that are available as well. The metal one is a Vintage Air unit and the other looks like something home made but it worked. 

3kJRP1y.jpg

vintage-air-vintage-air-5-8-heater-hose-h-pipe-cro.jpg

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...