Building Another Stroker Engine for the Track

[inline6]

I worked on mounting the gauges a bit more this weekend.  Some pics showing what I ended up doing for the tachometer: 
 

    

 

Basically, I drilled 4 holes through the outside of the modified gauge pod and into a sliver of a pvc pipe end cap.  I just cut a section off the cap to make a round ring about 1/4" in thickness.  The gauge goes in and seats against the much hacked remainder of the original gauge pod.  Then the pvc ring goes in.  Then the screws go through the housing into the pvc ring.  This locks the gauge in place in the pod. Then the metal frame I made slides on.  Then the trim ring that comes with the Speed Hut gauges gets spun on to lock the metal frame in place.  I welded some M6 x 1.0 studs onto the metal frames.

Backside showing metal frames for the tach and speedometer being secured to the original gauge mounting brackets. 

 

    

 

I also checked the fitment of the pod gauges.  Because the bezels are a little under the size of the dash openings, I decided to buy some 3D printed mounting brackets I found on eBay.  They will add a small ring of black trim around the gauge and facilitate a snug fit in the cut outs.  They should be here in about a week.  

For the three center gauges, I chose water temp, oil pressure, and oil temperature, which I will probably install in that order from left to right.

    

 

I have started looking at the wiring instructions... and comprehending what has to be done to get these functional.  That is where I will pick up when I can.

Edited December 1, 2025 by inline6

[Mitchel0407]

On 11/23/2025 at 3:37 PM, inline6 said:

Pictures from my engine builder when he was making the spray bar and fitting it to the engine:

 

  

 

 

I love the look of the spray bar and the use of the stock fuel pump hole! I believe those are blocked from factory for the L28 engines, did you just cut it open?

[inline6]

The head is an E88 casting which came from a 240z.  So, that opening was there for the stock fuel pump already.  Though not a desirable head as is, this one has been milled quite a bit to get the combustion chambers to be usable for this engine set up.

[inline6]

I purchased some gauge mounts from a seller on eBay for mounting the new Speed Hut gauges in the middle of the dash.  They are 3D printed items.  The design is pretty good.  The plastic seems sturdy.  And they incorporate metal thread inserts.  The screws have a taper head, so they self center, and fit of the various parts is very good.  However, I found that the gauges were loose when fitted to the housings with the backplates (which hold them in the housings) bolted tightly in place.  The gauges rotated easily in the housing as there was no clamp force against the back of the gauge to hold the gauge forward against the "stop" portion that the bezel of the gauge is supposed to fit up against.

After thinking about solutions for a bit, I pulled out some ancient Gore-tex I have.  Basically, it is rubber gasket material with an adhesive on one side.  It comes in handy for a lot of things.  In this case, I cut a strip and ran it around the back of the bezel on the gauge.  I fit the gauge into the housing and then pressed the backplate against the new Gore-tex rubber gasket to seat it into place.  I then briefly removed the gauge from the housing and took this second picture (below) which shows how the new gasket deformed under "crush".  Third pic shows that as well as the metal insert in the gauge housing.

 

    

 

Another issue to overcome though was that the backplate only has two screws to clamp it to the housing, 180 degrees from each other.  After I put the gasket in place and assembled the gauge in the housing, the backplate only pulled tight against the housing where the screws bolt up to the housing.  See the first and second pics just below.  
 

    

 

I realized that I could take the aluminum mounting brackets I had already made during an initial attempt to mount the gauges in the dash, and flip them (back to front) and use the Speed Hut gauge mounting rings to resolve the situation however.  See the third pic (above).

While I thought I wouldn't need them any longer, these aluminum brackets ended up coming in handy.  I simply screwed the Speed Hut mounting rings tight against the aluminum brackets... and this pushed the edges of the aluminum brackets against the plastic backing plate at the points which were not seating against the back of the housing properly.

 

    

 

So, with this distribution of force at the non-secured parts of the backing plate, I was able to resolve the issue.  

I see now that I didn't take a picture of the other part of the gauge mounts. There is an arm that attached at the top and the bottom of the housing in the same way that was done on the stock 240z gauges.  I hope I won't have any issues with that part bolting up, or with the gauge housings fitting in the dash holes.  I will probably check that out this weekend.

Edited December 15, 2025 by inline6

[inline6]

I found some time to work on the car today.  Where I left off, I tried to fit the arms of the parts I bought, but I found that the parts did not fit well as is.   They were a bit too long and the angle on them was not quite right.  But, I was able to modify one of the 3d printed arms by cutting off the tab, and then drill a hole in the horizontal portion of the arm so that I could bolt it to the original "L" brackets that were utilized with the stock gauges.

 

    

 

    

 

Then, I modified the rest of the brackets to fit the trio of gauges in the center of  the dash.  Though upside down, they look nice.  However, the OD on the bezel portion of that locates the gauge in the dash is also not quite right.  I have been in touch with the seller (maker of the 3d printed brackets) on eBay.  He is going to make some new front portions that have a wider OD and send them to me.  I will still use the modified arms I already have.  Changing projects (3rd pic):
 

    

 

I had need of mounting a 3/8 NPT threaded radiator fan switch.  I came across https://protunerz.com/ while I was shopping on Black Friday - I had never heard of them before.  They make some nice billet parts for Z cars.  I decided to buy this thermostat housing because it has several existing openings for fittings.  In addition to the radiator fan switch, I needed a spot for the water temp gauge sender, and two openings for custom lines that I have on my head to flow coolant from above the #4 and #6 cylinders. 

 

    

 

To fit the 3/8 NPT rad fan switch, I had to drill out the M14 opening.  That was not fun using a vise and drilling freehand with a 37/64" drill bit... and running the tap by hand.  I wish I had a drill press, though I still think it could have been a disaster trying to run the drill bit through the existing threaded hole.  Doing it by hand, the bit "caught" a couple of times nearly wrenched my arms around.

I had to finish the opening with a round file and VERY carefully tap the hole with a 3/8" NPT tap.  It did come out well though.  

Only thing I wonder about is whether the sensor might not work properly without more of an "air gap" between the housing and the body of the sensor.  I am assuming that the gap around the body of the sensor just needs to be large enough for coolant to get in and surround it.  But I wonder... do I need to grind the opening up a little bit more around the sensor (3rd pic above) for proper function?

Edited January 13 by inline6

[inline6]

I think I scored with the purchase of a 240sx transmission.  When talking to the salvage yard, they said the transmission came from a crash test car and it had 28 miles on it.  Well... I was quite dubious, but they only wanted $100 more for it than one with 77,000 miles.  So, I bought it.  Today, I took the gear assembly out of the front and rear housings.

 

The clutch release bearing sleeve has no visible wear marks and is packed with clean grease.  The same grease is present at the clutch fork pivot.  And, the reverse idler gear in this transmission which I have typically seen is chewed up on one side in used transmissions, looks like new (see the third pic)!

    

 

Unfortunately, it has some specs of rust in a few places.  There is one badly rusted spot on the main shaft under the speedometer drive gear (third pic) on about 1/2 of the surface on the diameter there. 

    

 

But, having looked it over pretty good, I think this will be a great transmission for the car.  

I don't need to use the speedometer drive gear because the car will now be equipped with a GPS triggered Speed Hut speedometer.  I think I will just need to replace the rear most bearing (due to some light corrosion there), and give the gear set a thorough cleaning, and it will be good to go!

Edited January 25 by inline6

[inline6]

While working on modifying the engine compartment wiring harness, I bolted up the factory Nissan gear reduction starter that I have been using.  While it cleared the dry sump oil tank, I was not happy with the location of the solenoid.  It was quite close to the oil tank.  I didn't recall it being that far away from the block. 



I looked for other versions of the gear reduction online, specifically hoping to find one with the solenoid located closer to the block.  However, I was not able to find a factory one that was different.  I was able to find this one however: 

https://www.classiccarperformance.com/products/datsun-240z-260z-280z-high-torque-starter?srsltid=AfmBOopbvBP16wSs5tvniJbqMb9CK2Kds63KS8RAjuCAWd7ZupU4Lbwm

 

Because it features the ability to change the "clocking", I went ahead with buying one. 

After receiving it, I compared it to the one I already had:

 

 

As you can see, the solenoid is in a very different location.  In fact, out of the box, the solenoid bumped up against the block and the starter would not bolt up as it was delivered.  I moved the mounting plate one hole location counter clockwise (referencing the picture above).  In this position, the solenoid no longer interfered with the block.  However, one of the mounting bolts had to be placed into position before re-attaching the mounting plate, as there was not clearance to put the bolt in after clocking to this position.

 

That made installing the starter to the transmission MUCH more difficult.  It was possible, however.

 

    

 

Another issue that isn't great is that the positive terminal, where you bolt the positive battery cable, as well as some of the other items that have to be powered by this terminal (radiator fans), is on the underside of the solenoid, quite close to the engine block.  It is just another inconvenience.

So, I was able to achieve the overall objective - improving the clearance between the starter and the oil tank, but it was with some sacrifice of convenience in mounting and bolting up main power cables.

In other news, I received the real oil lines that I had made.  These are XRP Pro Plus hoses.  I spent a lot of time and effort figuring out the routing, making "mock up" lines from pool hose, and waiting for them to be crimped and sent back to me.  Yesterday and today, I worked on routing the two that cross just at the front of the engine.  I have fabricated a plate out of 6061 T6 that mounts with some spacers at the front of the cylinder head.  I have drilled holes and bolted rubber insulated P clamps to locate the lines precisely so that they do not rub against each other or anything else.

 

    

The tank return line runs quite close to the water pump pulley.  But, it is well located to eliminate interference.  

I also have little clearance between the studs in the water pump (holding the fan pulley one) and the Spal electric fans.  Today, I removed the studs, and switched to the use of bolts instead to gain a bit more clearance there.

 

It was super cold here on Saturday, and I wasn't feeling 100%, so not much time in the garage this weekend.  In coming weeks, I plan to do some floor pan repairs.  I will likely be pulling out the engine and transmission and differential... and mounting the car body on a rotisserie to facilitate that effort.  I have a couple of patch panels (due to prior rust) that I'd like to redo, and I need to install mounts or anti-submarine straps (for the 6 point safety harnesses).  Plus, I need to finish welding in the custom brackets I made to mount the Tillet carbon fiber seats.  

 

 

 

Edited February 2 by inline6

[flatout]

I sat in those tillet seats at PRI this year and was very impressed with the hold and comfort despite not looking like it would be either. 

[inline6]

Here is the plate I made to assist with routing the dry sump hoses across the front of the engine:

 

 

 

Here is the -16 AN hose that runs from the outlet of the tank to the inlet of the pump.  It has a heat shield sleeve over it to protect it from getting overly hot from its proximity to the header.

 

    

 

I put the intake manifold and carbs in place so I can determine how to route the coolant hoses from above the #4 and #6 exhaust ports to the thermostat housing.  

 

[inline6]

I started stripping the car today so I can put it on my rotisserie for few unibody sheet metal repairs... mostly the floor and the rear portion of the frame rails.  I removed the heater core box, the engine and transmission, the front struts and the rear axles.  I still need to remove the rear differential and the gas tank.  

 

I have a 2006 Chevrolet Corvette Z06, and one day I was looking at the brake vents and thought they would be good for the 240Z.  And so they are!  I installed these before I went to Road Atlanta in 2016 (I think)... this car has been off of the road for so dang long now!  Anyway, they worked very nicely to cool my brakes.  I made a custom fiberglass piece to adapt from the Xenon front spoiler to the round inlet of the Z06 vent, and used one screw and washer to secure the back of the vent to the inner wheel house sheet metal. 

    

 

The front brake rotors are Z31 vented units.  I still have the unmodified backing plates on them, which is a mistake.  It prevents air from getting to the back side of the rotors.  Something else to address added to my list!

 

 

Rear rotors are Z31 units.  Calipers are 240SX.  Axles are Z31 (with custom shafts).  I bought parts from Ross back in the day (Modern Motorsports) for the brake and axle conversions.  I bought the R200 differential from an eBay seller probably about 20 years ago.  It was a NOS 200SX unit with a 4.11 ring and pinion.  I removed the factory carrier and replaced it with a Nismo clutch type limited slip.

 

    

 

I bought a high capacity finned differential rear cover and a billet transverse link from Protunerz.com during the recent Black Friday sale.  So, I will be installing those when I put the differential back in the car.

For now though, everything has to come off the car so I can make it light enough to put on the rotisserie for the floor repairs.
 

Edited February 10 by inline6

[inline6]

I removed the rest of the list of items so I could mount the car on the rotisserie.  With the glass still in the car, the center of gravity is quite a bit higher than the other Z I restored.  When I went to rotate the car body, it got away from me and flipped upside down even with me trying to hold it.  Luckily there was no harm done, and after adjusting the height a bit, the rotation of the car is easy to control now. 

As you can see, the floors are bare metal.  They have been like this for about 15 years, but the car mostly has just been stored inside, not driven.  It has been a major item on my to do list for this car to address a few rust though areas on the floors and to repair the dented up frame rails and floor.  I will also be installing some plates for the safety harness belts.  It will be very nice to get the floor fixed up and get the floor protected from the elements again, finally.

 

 

The original frame rails are pretty bashed in.  And the right side one is missing several inches of length at the rear because it rusted and I cut it off years ago and did a partial repair on the floor panel at that same location.

 

 

I am using both a spot weld cutter tool and a die grinder to cut through the spot welds.  The die grinder bit I am using works quite well.  Same for the spot weld cutter.  

 

 

I worked on removal of the right "back half" of the frame rail yesterday for about 2 hours.  I am only about 20 minutes from finishing the removal of it.  Then I will remove the driver side one.  

[inline6]

My efforts to get this other Z back running have expanded quite a bit beyond the rebuild of the 3.0 stroker motor. At the moment, I am working on repairing some rust in the floor panels. I have been watching a number of "Make It Kustom" videos on Youtube by Carl Fisher. In one of them, he creates some forms out of 3/8" plate to create a "hammer formed" part. Additionally, he uses a hydraulic press to "stamp" a recess into the battery tray he is making in the video.

The rust in my floors on this car is not extensive. It is generally in the area of the large oval depression in the floor panel (on both sides of the car). Yesterday, I spent a few hours cutting out and grinding/filing on part of the form I plan to use to replicate the depression. On the right side floor, I only need a small portion of it. On the left side, I will attempt to make a full piece to replace the depression.

I've never done anything with forms likes this, so we'll see how it goes. I will be using my 12 ton press because it is what I have to attempt to make the replacement part. But, I have been watching facebook for a suitable upgrade, perhaps a 30 to 45 ton press.

 

[inline6]

Unable to find a hydraulic press on Facebook or Craig's list that was 1) adequate in size, and 2) reasonably priced, I found my way to the grizzly.com website while they were having a free shipping promotion. After much thought, I decided to buy a 50 ton press. Yes, it is a bit overkill.

My 12 ton harbor freight press has served me well. I rebuilt a couple of transmissions with it, and a differential. And I used it for some bumper straightening as well as pressing studs into hubs, etc. Oh, and I was able to replace rear control arm bushings with it too. It really is sufficient for most automotive hobbyist needs.

I also took advantage of the free shipping promotion and bought a drill press. I had considered buying one many times over the now more than three decades I have been doing hobby work on my cars. All things considered, at this later point in my life, I figure I will buy some of these things while I am still active with my hobby.

With the new tools set up in the garage, I have picked back up on attempting to make the floor panel replacement section. I had to resized the length of the form a bit - I had to make the opening longer. Cutting the .250" plate with a jigsaw didn't go as planned. The cutting blade wouldn't quite make the desired cut radius. So, I had to make some adjustments. The part that I cut out of the plate will be used to push the new repair piece into the outer form. I also had to build up the length of the former by welding along one of the curved edges. I built up additional material with weld beads and then ground that new material to shape. The first hole with my new drill press:

This is also the location of the factory drain hole. I will bolt the replacement panel to this oval form using this 5/16" hole. That will keep the form from shifting on the part. Additionally, I will clamp the outer form (the one that is a rectangle) to the oval form along all of the edges. The idea is to clamp the sheet in place all around the forms so when I use the hydraulic press to push the oval into the other form, it will make the large oval depression in the sheet.

I have many hours into the measuring, cutting, grinding, hand filing, etc. of the forms. I have a bit more grinding and filing to do before I will attempt to "stamp" the part. I am thinking it will not come out as desired on the first try, but I hope I can get it to be a nice replication of the factory shape with a couple of tries.

[inline6]

As I got closer to wrapping up the two plates pictured above, I realized I needed a third. In order to press (or stamp) the floor panel section, I not only have to use the big oval plate to press against the thin sheet against the large rectangular form, I also need another rectangular plate to sit on top of the lower rectangular form and get clamped securely to it. Only by sandwiching the thin panel between these two plates and pressing downward with the oval plate can I replicate the shape of the original floor panel.

So, what I have done here is drill a hole in the center of the oval plate that the hydraulic press will push on. And, I have drilled the same size ( 5/16") diameter hole in the replacement floor panel section which is 22 gauge thick (.299"). Then, I bolted the oval plate to the panel section. I moved the other plate (with the oval cut out) to the other side of the panel section.

To align the plate with the oval cut out properly, I drilled two holes, both at opposite corners of the replacement section. By drilling these before moving the plate with the oval cutout to the backside of the panel, I was able to establish the correct location for the plate with the oval cutout. In the picture above, after drilling the holes, I moved the plate with the oval cutout to the other side of the repair panel section, and then I ran some bolts through the repair panel section and that plate. This effectively locates the plate with the oval cut out in the correct orientation so that the oval plate will be able to push down through properly. I got to this point when I realized I would have to make another plate.

With the remaining scraps I had on hand, I made another plate to surround the oval plate. This new plate then has to be clamped tight to the original plate with the oval cut out to create a rigid structure to hold all sides of the repair panel tightly.

With the entire periphery of the repair panel held tightly in place, the operation of the press against the oval plate will be effective in pushing the repair panel downward only where the oval plate is contacting it.

 

I manually operated the press to push down on the oval plate to test how everything would react. The good news is that in the area directly below the ram, the oval plate pushed down on the repair panel section and it definitely performed as expected, depressing the unclamped portion of the panel. I can feel the depressed area of the panel when I reach up under the assembly and touch the backside of the repair panel in the center of this form assembly. However, the oval plate bent very noticeably such that only the center of the oval panel pushed the repair panel downward. At the far ends of the oval plate, there was little to no movement downward.

Given the large size of this repair panel, I do not have enough room in the press to shift the assembly to the left or right to apply pressure directly to all parts of the oval plate. Instead, I will need to make the oval plate more rigid and attempt to make depression in the repair panel again. That shouldn't be too difficult. I just need to weld some support to the top side of the oval plate to give it more strength to resist bending when the pressure is applied to the center area of the plate. Stay tuned!

[inline6]

I tried using a rather thick walled round tube I had on hand to press down across the long side of the oval, without welding to the oval plate. It did better as it was able to distribute more of the load towards the ends of the oval plate, but it still didn't work as well as direct force below the ram. Perhaps it was flexing as well. I'll probably visit my local metal supermarket and look for some suitable drops to add to the plate to make it more rigid. I am thinking about adding some two solid square bars about 1/2" thick lengthwise on the oval from end to end. Then using another plate under the ram to push down equally on those.

In the meantime, I turned the assembly 90 degrees and slid it fore and aft on the press bed to get different areas directly under the ram. All of my various sized C clamps made for an obstacle course, making it difficult to maneuver the assembly where I needed it to be. It would be better to bolt the plates together instead of using clamps. If I had to do it again, I'd to make the forms larger on the outer periphery and drill through them and use bolts. This would make a better finished panel and give me the additional material I need beyond the over depression. I could just cut the part of the panel where the bolts held it.

Pictures of the finished "prototype" - where I removed one of the C clamps to allow maneuverability in the press I got a large wrinkle. And I got a few more wrinkles around the outside of the panel outside of the form. But I think I'll be able to straighten those without much effort with a hammer and dolly.
  

  

I am quite pleased with this first attempt! However, I am going to address a couple of small issues and try again. I hope to make an improved version, and then a second one for the other side of the floor of my track car.

[inline6]

So, after the above effort, I needed to address three things:

1. The edge on the pressing side of the oval plate is a bit sharper than it should be.
2. One side of my form - the one with the oval cut out of it is 1/8" wider at the opening than the others side.
3. I want to strengthen the oval plate so it will not flex in the press

I was able to quickly address the first item by using an air powered 90 degree die grinder to soften the radius on the oval plate. I use 3" Cubitron 3M sanding discs (36 grit) for a first pass at contouring. Then I follow that with a course hand file for final shaping.

 

For the second item, luckily the side that is too wide is the side that has another plate tack welded to it. Tonight, in a matter of seconds, I broke this plate free from the larger part of the form. Then I pushed one of the "fingers" toward the other just 1/8", and then welded the plate back on.

With the form moved 1/8" on this one side, I now have a consistent opening for the length of the form. It'll only take a few minutes of grinding and filing on one side of the form to restore the proper shape.

And finally, I will weld a couple of angle iron pieces (cut to the full length of the oval plate) in the orientation shown here so that I will be able to make the next panel with a lot less fuss with moving the clamped assembly around in the press.

With those welded in place, pressing with the hydraulic ram just one time in the center should transfer the load equally across the span of the part because the oval plate will no longer deflect at the ends.

[inline6]

I was able to find the time recently to make the above mentioned mods. And I made three more panels. I messed up on the second one, but the third and the fourth came out nice. This is the fourth. For this one, I didn't need as much extra material around the outside of the depression. This one will be going on the left floor panel. The third one with some extra material outside the depression will be going on the right floor panel.

  

  

My attempts to weld supporting material to the back of the oval plate was not successful in making it rigid enough not to bend. I ended up determining that it was easiest to press the part by moving the assembly fore and aft in the press. I applied pressure to the middle, and then to each end. There were some tricks I employed to align the oval plate in the ideal position to push down through the plate with the oval cut-out properly. Mainly, I ran some bolts through to locate everything, and then unbolted and re-bolted the thin sheet in the exact location to ensure the oval plate pushed precisely where it needed to. There is some slop in the two forming plates, so you have to get things aligned properly in a way where you can't get it wrong. I got it wrong on the second piece. So I used bolts and holes in the forms for proper alignment in the final pieces.

Next, will be sectioning these in the floor panels of the track car.

[inline6]

Back out in the garage this past weekend. I made some progress sectioning in one of the repair panels:

  

 

 

I used the new drill press and a hole saw to cut the drain hole in the replacement section. It is a tiny bit undersize, so I will use a die grinder to open it up the last bit to get to the correct diameter. I also used the "shrinker" die that I got from Mittler Bros back before the holidays They were running a Black Friday special. I also used the sheet metal brake I got from them at the same time. I am pleased to be getting some use out of these new tools.

I should be able to finish welding this repair section into the right side floor soon. After welding and grinding down the welds, I will be doing some shrinking with an oxy acetylene torch to get the floor panel flat and eliminate any "oil canning".

[flatout]

very cool. new tool are always fun. Love seeing how people process a challenge and overcome it.