LQ4 into a 3rd Gen/1972 Nova by frojoe

10 minute(s) of a 891 minute read

More progress on the exhaust tailpipes/tips. I didn't get much exhaust work done this weekend as I spent far more time rewiring and pinning the Holley ECU than I anticipated, but in preperation for this weekend during this past week I made a mockup support to hold the tips in place while I connect the dots between the mufflers and the bumper.

Because the tips are notched up into the bumper more than halfway (2.75" upwards on a 4.5" round notch), I needed to trim back some of the bumper bracket support sheetmetal on the trunk floor. It was pretty thin and easy to deal with...

I'm still not sure exactly how I'll semi-rigidly affix the tips to the trunk or bumper, but when I was winging this mockup bracket I figure this won't be too far from what I end up doing.. likely eventually mounting the tips to the bumper, and isolated by some stiff rubber or silicone bushings...

Cut some angle iron to ziptie the tips to, to make sure they're in the same spot while I make the connecting tubing from the rear axle area. There is a 1/4" gap all round the tips which I aim to maintain....

Tack welded some square tube to keep the angle iron in the right place...

And bingo, rear bumper re-attached to the car with the tips mockup-ziptied in place! I'm suuuuuper happy with how it's shaping up... the proportions are exactly how I was envisioning in my head....

Here's an update a while in the making... the trans pump. I got a Tilton unit just because.. I could spend time attempting external fuel pumps and other stuff for half the price or just get the right thing the first time.

I made a little test fixture when I first got it, to see what the transfer rate was like. HOLY CRAP.. this thing hauls ***. I originally thought the restriction of a -4AN line would be enough to load it up a bit.. nope not at all. Then tried -3AN hose.. still crazy flow. Just cycled some engine oil into a pan and thought I'd measure the distance the fluid would shoot out of a 1/4" hose with a adapter restriction on the end...

Here's the pump flow with a -4AN fitting on the end...

Here's the pump flow with a -3AN fitting on the end...

I ended up using the front gear cluster inspection port (??) plug as my fitting, into which I drilled I believe a 0.070" hole.. about the smallest hole I was comfortable drilling and not snapping the drill bit. I test fired it on the pump fixture and it finally had enough restriction to slow the pump flow down some, so should work well enough...

I then blind threaded the plug with 1/8" NPT, to accept a -3AN adapter fitting in it...

And here it is installed....

Next up was where to put the pump? Things are pretty tight under the floor with the exhaust placement and my low ride height, so I knew I'd have to slam the pump as close to the trans as I could. I came up with a mild steel bracket that mounts to the two thru-hole machined tabs on the trans case (I tapped the holes to M10x1.5); the bracket is oriented at 45* to slam the pump as close as possible to the casing.

For mockup I used M8 thru-bolts on my old T56 for since the tabs on it weren't threaded....

The fabricated steel plate is 1/4", and has M6x1.0 threads on it to mount the pump's stamped steel baseplate to...

This is the original orientation I was thinking of. With the floorpan and trans tunnel constraints it was pretty difficult to raise the pump up at all.. obviously the -8AN feed fitting was far from ideal in how low it was...

Here is the pump in the above configuration, showing how tightly it fits once assembled under the car...

Here is the -8AN 90* adapter fitting as a pickup that threads into the trans drain plug NPT threads. The 90* adapter was helpful in quickly kicking the feed hose up and over the trans x-member....

There is about a 1.5" gap between the pump and the exhaust tube. I'll be adding a formed metal heatshield to the pump to heat protect from the heat...

This is arrangement 2.0.... I rotated the pump around 180* to get the lower-profile -3AN fitting on the bottom, but in order to fit the -8AN feed fitting up top I had to flip the pump again front-to-back. I'm not sure why this orientation hadn't come to mind when looking at the trans on the bench, but I think this will work much better overall...

Significantly better clearance, not to mention it's a steel fitting on the bottom and not an aluminum one.

Some more mundane stuff from the weekend like radiator hose routing. Got the radiator and shroud final-welded which is nice... I think I lugged the pair to-from work a good dozen times as I was making the fan shroud and checking fitment in the car...

The hole in the middle-upper part of the fan shroud is a 1/8" NPT threaded port, to install...... a pressure sensor. I'm curious to see at speed how much pressure buildup is present underneath the shroud. I plan to measure the under-shroud pressure it at a handful of points (and measure corresponding coolant temps if any change is present):

1) fans on, at idle
2) fans on, at various speeds, core support holes not filled
3) core support holes filled
4) core support holes filled, chin spoiler added under bumper
5) no inner fenders
6) yes inner fenders
7) vent holes cut into the hood (eventually)
8) rubber flaps added (if necessary)

The bottom outlet is a hard mandrel bend as it gives better subframe clearance than a straight outlet with a rubber rad hose 90* bend attached...

I added two 1/8" NPT ports to the top inlet port to allow a place to attach the front and rear head vents independently. I looked at joining the front+rear vents together and going into a single fitting on the rad, but this was just easier to route two 1/4" hoses.

And here is the routing in the car... spaces are getting filled up pretty quickly!!