LQ4 into a 3rd Gen/1972 Nova by frojoe

8 minute(s) of a 891 minute read

This weekend was semi-productive, but a bit disappointing to be honest.  

I first started cleaning and deburring the edges of the new GM CNC'd LS9 heads, and found that the "wall" at the bottom of the rocker mounting threads was poking thru the intake chambers. This wasn't a surprise since GM highlighted this area in their accompanying instruction sheet... however on most cyclinders there was a very large thin "flap" of aluminum at the bottom of the hole just waiting to be broken off under boost/vacuum and sucked into the cylinder. I was hoping that an assembled head from a maker like GM would've taken care of this by some form of tumbling/finished or QC, but just goes to show that you should always inspect brand new parts before install.. always.

Here is the poke-thru hole, this cylinder didn't have the worst/biggest flap.. I never took pics of the HUGE flake of aluminum slag that I peeled off..

After flake removal....

Just a couple of the deburring tools I used to try and snake into the intake port and smooth out the edges of the thru-tapped hole..

Then I tried to do some Friday post-work head assembly to get ready to slap these on the short block this weekend and confirm the pushrod length is the same. The new springs I got are Brian Tooley 0.660" lift "Platinum" dual springs with Ti retainers.. seem to be one of the best around, good price and supposedly no reported breakages. 150lb seat pressure @ 1.800" and something like 405lbs at 0.660" lift...

...buuuut one cylinder had an exhaust valve with a HUGE gouge in it. It was at ~0.600" from the Brian Tooley valve seal... unfortunately my cam is 0.620" lift and I can only imagine this would end up leaking. Thanks GM.. brand new high-performance assembled head with a **** valve. I'm REALLY curious if this passed some sort of QC because the imperfection was technically above the valve seal "as the head is assembled" (max rated valve lift of 0.570" with the LS9 springs that came with the heads), or if this was simply a **** up on GM's behalf and slipped thru the QC. Ohhh well. I have a single exhaust valve on the way, hopefully here for next weekend.

I then proceeded to take off the flywheel and the modified truck oil pan. I was a little mystified (pun intended) why there was so much oily grime on the inside of the bellhousing.. the clutch slave looked minty clean, and the backside of the flywheel was clean. Well one of the 6 flywheel bolts allowed a dribble of oil past when I removed it, which was weird. Then I yanked the flywheel off and turns out there's a nice pool of oil at the bottom of the rear main seal.. sweet.  

Good thing to catch now, while everything is out and apart. I know I replaced the front main seal when I rebuilt the engine, but I don't particularly remember replacing the rear main seal, not to mention when I poked at the seal and deformed it, the seal liked to stay deformed and not spring back. So, now have to try and find a rear main seal before next weekend. Essentially that stopped me from final-installing the new Holley oil pan, new flywheel and new clutch, as well as the transmission today (if we're getting real optimistic).

I pressed on, and started the new Holley pan install to see if there'd be any hiccups. The Holley instructions are exceptionally good, and provided detailed schematics of a bunch of things including where to trim the full-length (truck, etc) windage tray to fit their pan.

The pickup tube was close to the windage tray, but didn't need any clearancing, which was nice.

I'm not sure about other engines, but my original truck pickup tube mount flange was only one-bolt at the oil pump, which I never liked. When removing the truck oil pickup tube, I noticed the o-ring and tube where floppy as hell inside the pump the instant I cracked the single retaining bolt loose.. so I'm hoping maybe that was an area of introducing the slightest bit of air and thus slightly lower oil pressure, once up to operating temps.

Either way, the Holley pickup tube and supplied GM o-ring was a VERY snug fit to the oil pump, which I liked. The Holley instructions say to install the pickup tube entirely into the oil pump before using the two retaining bolts to final tighten it down. Well the o-ring was such a tight fit (even with fresh oil on pickup tube, o-ring, and oil pump) that I could only push the pickup tube maybe 80% into the oil pump. The o-ring was probably 2mm past being visible on the pump, so I'm quite certain that the o-ring migrated past the lead-in chamfer on the oil pump, and isn't pinched. In fact I did an oiled test-fit first before final install and the o-ring wasn't pinched at all... it was just a tighter fit than described in the instructions.. but I'll take it.

I'm also a HUGE fan of the two-bolt securing flange on the pickup tube at the pump, complete with brazing for rigidity.. I have a good feeling about the security and sealing of the tube in the pump...

The pan installed nicely, only mocked in there until I re-seal the rear main cover.

If Toddoky is following along, this may be useful to him... the new Holley pan came with 2 X M6x30 flange head hex cap screws for the standard GM F-body oil cooler bypass plate above the oil filter. Unfortunately the flange OD on these screws is too large to fit inside the counter-bore on the Earl's oil cooler CNC'd adapter I'm using. I measured the thickness of the oil cooler adapter where the M6 screws pass thru as 10mm, and the maximum thread depth on the Holley pan for these M6 screws was 20.5mm. So even if the Earl's adapter was counter-bored with a larger diameter to share the 30mm long flange head cap screws, with production tolerances they might bottom out in the pan before fully tightening the adapter down.

The other thing, which I think is the real issue, is that the Earl's adapter doesn't come with any mounting screws, which is a bit disappointing. I work with metric M5/M6/M8 fasteners every day, so supply of socket head screws isn't an issue for me.. but I have a feeling this may be an issue for some people in various parts of the states. So I ended up cutting down some M6 socket head screws to 25mm UHL to provide 15mm of thread engagement, which is 2.5x the thread diameter, which should be plenty...