Hot Rods The Belly Button Bucket Build Thread

Glad you didn't get hurt or wreck the T when that bracket tore off! You'd think a big name like Wilwood would make a stronger mounting point for their calipers?
I planned to go to the Cascadia show as I do every year, but both of my buddies couldn't make it so I hit a smaller show close to home. It was nice to meet you last week at PIR cruise.

 

Nice to meet you finally as well! I should clarify- the brake kit is sold by Speedway, with Wilwood components, but I don’t think Wilwood designed or is making the kit. I’m not sure who is making it, but I agree, the caliper mounts need to be improved. I like everything else about it, but I will be making the mounts out of steel, and likely tacking them to the spindle for some extra insurance. The tacks could be cut later if needed, but I do think that would be a safety upgrade and worth the effort.

 

I've used a number of Speedway caliper brackets, but haven't seen any that were aluminum? I buy their rear axle weld on brackets for GM calipers, and then cut and drill them to mate to whatever spindles I need to convert to disc brakes.

 

Tim, could you include a locking device that's removable?
Either safety wire, the folding tabs, or does it require the countersunk fastener?
It's so well detailed I'd hate to see a tack, even though I guess it's hidden behind the disc on the spindle.

 

Small update- daily officially has blown head gaskets- I miraculously got through the summer on a bottle of K Seal, but nothing good lasts forever I guess. So while I delay tearing that apart until the rain will keep me company as I fix it in the driveway, I’ve been driving the T- short trips around town mostly. I felt as though the car runs lean on the primary, so I welded in an O2 bung and connected an air fuel gauge. This morning I had an MRI to get to across town, and my gf had school stuff, so I took the T on its longest trip so far- 20 miles round trip. I figured out pretty quickly that the car does NOT like to run when it’s cold outside- I will need to investigate installing an electric choke. After it warms up, it is wayyyy too lean pretty much everywhere in the primary carb operation. There’s too much going on to figure out secondaries right now- I’ll need an assistant for that.

Anyway, the car more or less drives around somewhere between 16-20:1 AFR. I figured since the idle mixture was ~ 2 turns out and in the low 14s, I’d leave the idle tubes alone and go after the idle air bleeds. I had 0.052”installed and swapped in 0.046”- the theory is this should not only richen up the idle circuit (less air, same amount of fuel), but it should also allow the idle circuit to operate for a longer period of time. Sure enough, idle mixture screws had to go in to achieve same idle ratio, and driving around, I’m in the 14s at light/part throttle, 13s light acceleration, and noticeably a lot happier combo. I’m stoked I went through the trouble of drilling/tapping for screw in air bleeds! Massive success today! We’ve got rain all week, so I plan to fix a couple small issues, then next weekend dial in the main circuit. Photos of car out in the wild:

 

That looks nice out on the street! Bitchin from both angles.

 

It has "the look" doesn't it!

 

The end carbs should be contributing some air and fuel with the idle ports. You don't want the blades jammed shut and you don't want the fuel to get stale.

14 is tough with a rumpy cam, they tend to want to be rich at idle, mainly due to overlap pulling fuel across the valves and the weaker vacuum signal.
I used to adjust using CO and getting under 3 was tough with bigger cams. Just changing from 800 RPM to 1000 RPM would be a big help, but if you want that low choppy idle, it's going to want more fuel.

 

Might need to richen up the high speed air bleeds also. Just doing the idle bleed jets wont help once it's above idle.

 

To clarify, the end carbs have no idle circuits. I started out with primary carb only, then added each end carb one at a time, as mentioned a few posts back. Contrary to what the internet says, it is not possible to completely seal the end carbs. In this particular case, the end carbs will try to suck your hand through the airhorn, no matter how tight you have the throttle shafts held closed. The primary carb was adjusted to compensate for each secondary carb, which was ~ 1/8 turn on the idle mixture screws to bring things back into acceptable range. I believe these are set up pretty decently, because the car will consistently start, idle, cruise, tip in secondaries, and return to idle, cruise etc. Believe me, you KNOW when the secondaries open up. It's like being shot out of a cannon.

This is not a big cam. The guys over on the LT1/LSx forums and the OBS forums have daily driven this cam with excellent results. 218/228 .525/.525 112 LSA. The 112 gives greater vacuum signal/less overlap for the EFI/emissions guys, as that's what this cam was designed for. I can tell you it idles and drives around fantastic in the 14s. I've had it in the 12s and low 13s driving it around and you'll suffocate from fumes (just ask my gf, who has a very sensitive nose). The car has a decent chop about 900rpm, no need to change anything there.

The transition circuit, or transfer slot, or off idle operation as shown in the diagram below, is fed by the idle circuit. Main circuit takes over when there's a great enough pressure drop to pull fuel through the boosters. I haven't got that far in the tuning yet - excited for sunshine this coming weekend to get that dialed in. As you said, I'll be tweaking main jets and main air bleeds to get that circuit happy.

 

It does has the "I'd hit that" look. My roadster be lookin at me like "you're gonna need the rollback".

 

Okay, sounds like you've got a handle on it. I guess that it's a requirement to open those end ones up now and then if there isn't any fuel flow until they are.
Poor Tim, required to stomp on it to keep things happy!

 

LOL