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Unread 08-21-2015, 05:30 PM
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Fair! Fair! is offline
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Join Date: Jul 2004
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Default Re: Vorshlag Budget TT Build: Project DANGER ZONE

continued from above

Engine Bay Power Wash + Seat Swap + Firewall Re-seal

Having the drivetrain out sure makes for a perfect time to clean two+ decades of crud out of an engine bay. This one had it all - oil, dirt, funk, and grease. Brad rolled the car out back and fired up the pressure washer in 105F heat and got it blasted clean under there.

Once inside I used my "WD40 all the things" trick to shine up the old painted surfaces and rubber. Let that soak then wiped it down.

After the cage tube removal mess we cleaned the glass inside and out with Windex and newsprint, to polish the glass. First time I've been able to see out of the glass in all directions without looking through some film of decades-old funk.

Today Olof installed the new Cobra seat (the red one went away) and then re-sealed the firewall. There is an aluminum panel where the old factory blower motor/heater core box was in the engine bay, and it leaked a bit of oil into the passenger foot well when the motor smokified. That's finally water tight and should be leak free.

Now we just need a motor...

Aluminum Griffin Radiator Upgrade

One of the things I had hoped to do at VIR was take a lot of laps. I have never driven that track and it has a LOT of turns, so I was hoping to make every session from Friday-Sunday, to learn the line and hopefully put in a good time. I was going to take 2 or 3 sets of tires on 2 sets of wheels, too.

Originally Posted by 2015 NASA TT rules
8.3.I.c.3) Radiator upgrade/shrouding/fascia modification (drilled or cut holes/slots) that only provides increased airflow to the radiator or oil/transmission coolers (without aerodynamic or engine air intake improvement), and/or radiator core support modification/replacement
To ensure that the car ran smoothly for longer stints on track at VIR, I wanted to upgrade the radiator. This is FREE in TT-letter class, by the way, for all of you rules Nazis looking at this build (see the "No Points Mod" rule above, which is from page 35 of the 2015 NASA TT rules).

The stock radiator is already pretty sketchy design, with a tiny aluminum core and glued plastic end tanks. They fail over time at the tank to core junction. This looks like the original piece, too. So I looked at direct fit C4 radiators that were all aluminum and beefed up in size. $545 for one, $625 for another, and all of them would take 6-8 weeks to be built. Nope!

The OEM radiator is bundled with the A/C condenser (already removed) in this fiberglass, factory duct box. It has no filler neck, as the car has a remote coolant reservoir tank higher in the engine bay. The two fans and shroud look sufficient, and don't do anything at speed anyway. I measured the radiator core size and did some searches...

We used the generic Griffin aluminum radiator for a mockup in the 69 Camaro (left), which fit that frame spacing well

Summit Racing catalog has 2,312 different aluminum radiator listings just from Griffin. So I picked a NASCAR style Griffin radiator of the same basic height and width, with the same inlet/outlet layout, but with a massive 3" thick dual core. This was a $175 retail part, now we just had to modify it to fit this car...

Olof then modified the "generic" radiator to fit inside the C4 shroud and frame layout. The lower radiator hose was angled, so that was cut off and the hole plugged. It needed to move upwards a few inches to clear the front cross beam (see below), so he drilled a new hole and moved it there. Then he modified the fiberglass radiator shroud/housing/mount to clear the inlet on the top left corner. The radiator neck was cut off and capped, then a matching "steam line" was added. This was done with a weld bung and re-using the fitting that came with the Griffin, which was threaded into the water neck for the overflow port.

It worked out great and took a total of 4.05 hours in total for Olof to: remove the OEM radiator assembly, modify the radiator (cutting and TIG welding), pressure test the modified Griffin unit, modify the brackets/mounts inside the fiberglass shroud, and reinstall everything. In the end we got a LARGER capacity Griffin radiator that fits better and is bigger than anything we could have bought that was a direct "bolt in" for the old C4.

During that 4 hours of work Olof also made an aluminum cover for the gaping hole in the side of the fiberglass box where the A/C bits passed through (visible above left). The new radiator was bigger in every dimension just enough so that it barely fit in the fiberglass enclosure, and there wasn't even room for rivets to hold this panel on - so it was bonded with epoxy and held in place while it dried with the green tape. There were also weather-strip seals added next to the new radiator to better seal it to the inlet/outlet sections of the fiberglass duct - that should be better than the factory airflow management in the radiator box.

We're really ready for the motor....

What's Next?

I just heard back from my engine builder minutes ago, and he says the last "hard to find OEM LT1 engine parts" are finally there. He's supposed to be wrapping up the motor this weekend, then bring it personally to our shop since its so late (no time for pallet shipment). So I'm hoping he's right, and we might, just might, get this car together in time to make VIR in 2 weeks. They need my entry for TTC to "make a class" at Nationals, so others are counting on us to be there, too.

We had a lot of other plans we would have implemented if this car was put together 2-3 months ago, like we had hoped for. Things that are small incremental improvements in weight balance, airflow, safety, etc. But with virtually no time left to test even if the motor showed up tomorrow we're holding off on more changes to the car. Too many changes means too many risks of something done that fails - and I cannot afford for any failure if we make it to VIR in 2 weeks. I need an uneventful weekend with lots of track time, some good lap times, and no trivial protests.

Now we just need a motor...

More soon,

Last edited by Fair!; 08-21-2015 at 05:45 PM.
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