620 Land Speed Record

[sebpv]

Issa joke...right?

Is it legal to keep two guys in the trailer to finish last minute things on the way to the salt ?

[Stoffregen Motorsports]

Jeff, if your bar needs extensive mods, one thing we used to do to help was to cut the end of the bar off (leaving no mounting hole for the end link) then make an end out of slit tubing with a pinch bolt and any style link hole or location you need. This way you can ditch the basic bolt-n-bushing setup in favor of a heim-n-threaded rod setup. It also allows you to adjust the stiffness of the bar by loosening the pinch bolt and sliding the sleeve in or out to lengthen or shorten the bar.

 

Your list sounds manageable. I'll trade you...!

[distributorguy]

LOL - yes, the list is very manageable.  I knocked more of it out this weekend.  Once the suspension is 100%, and I have it back at "stance", I'll build the intake so it sits level.  I may even jump the gun and start it sooner by guessing since the RF suspension is done.  I'm just waiting on a couple pieces for the LF upper control arm.  

 

The list is actually significantly longer than I wrote above, but a lot of it is sourcing parts, making sure we have spares in case we don't pass tech this year, etc...  plus time to go to the only shop in our area that has a road force tire balancer so we know the wheel balance is legit.  Each wheel needs its respective tire mounted in a specific rotational direction to be "land speed" rated, based on which direction the plys are overlapped.  Its a little bit of overkill, but noteworthy to reduce potential failures.  One direction on drive wheels, the other on non-drive.  

 

When I think about the sway bar, my first thought was to forge a new end.  It seems too easy to modify it to accept a rod end.  Especially since we broke a bolt on the driver's side end link last year - no idea how that happened except maybe that it was a stress fracture inherent to the cheap "grade 8" bolts in the kit?  If we stay focused on the list, we'll be on the dyno in no time.  

[distributorguy]

The team got together as usual last night and we punched out more of the list, like getting the truck over to the hoist to finish welding in the new Beebani lower control arms with coil-over shocks to go with the uppers we put in last year for more caster adjustment.  The shocks I bought have 7" long 400 lb springs, and I was afraid they would be too soft, but with roughly 2" between the front crossmember (under the oil pan) and the ground, we could bounce the truck without it bottoming out.  Success!!!!!!  Thank you Jason Pope for making this setup!!!  We now sit nearly 2" lower than last year, which will enormously help reduce air flow under the truck!  

 

When we were pushing the truck back to the shop from the hoist in the other building, the diff locked up - but only going forward.  OH NOOOO!!!!!!   I'm so glad this happened here and now.  It turns out the outer pinion bearing race had not full seated when installed, and the jarring action of turning the truck with a mini-spool in the diff had finally seated it 100%.  Tighten the pinion nut to spec and the rear end now spins better than it ever had with good gear backlash, albeit a tiny bit on the loose side (being picky).  Disaster averted, for now.  

 

We also found out that the brake hoses used with the rear calipers are defective, and leaking.  I may have to source all the parts to hard-line the rear calipers?  Not a big deal but an unexpected problem that'll cost more valuable hours of time.  Another delay from building the intake manifold.  Ugh.  

[Stoffregen Motorsports]

Boy, I don't know if I'd want hard lines to the calipers on a race car. On a solid axle with discs, I do like the OEM's do; hard line on the housing to tabs and then AN lines to the calipers. I'm sure there are enough adapter parts out there to get new lines made in the next couple days. What thread is on the caliper? 10x1.0? Use banjos to make it easier.

 

Sucks to hear about the diff. At least you caught it in time.

[distributorguy]

I currently have banjos on the calipers - yes 10x1.0.   Some quick machining in the mill to make all the clamping surfaces flat and parallel and its now functional.  My power bleeder is still struggling, but we'll get it.  AT least I have fluid pulling through the lines now. 

 

I'm not a good diff guy.  Even worse at transmissions.  With a little beating on the dyno, we'll prove the diff early enough to have time to replace it if I really screwed up, but at this point it appears to be working great! 

[Stoffregen Motorsports]

Which bearing do you think moved? If the front pinion bearing (the one closest to the flange), then your pinion depth won't change. If the larger pinion bearing moved, then so will your pinion depth. I'd at least pull the cover and re-check the pattern.

[distributorguy]

It was definitely the front bearing, because the driveshaft now had "extra room" to get it back into place from the pinion flange now sitting deeper in the housing.  It was a comforting feeling to see that, and to feel that the backlash was the same as before.   After the first assembly, I thought I was feeling the additional drag from the C-clip eliminator kit which has pretty tight bearings.  Of course we have an issue develop right after filling the diff with $80 worth of high tech diff oil.  

 

You guys were right.  I started building the intake this weekend - cutting and welding tubes.  I had time to make 3 of the 4 runners, and tacked them in place.  I'm really hoping to get it ready for final welding by Thursday evening's gathering here, but its going to take some hours to pull that off.  Ugh.  I can't wait for this particular project to be done.   

[distributorguy]

Huge progress on our weekly Thursday night team gathering!  The punch list is getting SHORT!

Finished the suspension 100% - thanks Beebani for the new steel upper control arm adjusters!!!!

Got a couple more hours of work completed on the intake manifold.  1/2 a tube left to finish, and a little fitting before getting it TIG welded.  

The new rear disc brakes work beautifully, and the rear calipers are clearanced to fit the new rear wheels.  

This year's wheels and tires are now installed to verify fit, next we're off to get an alignment and balance the wheels.  Need to fix the trailer brakes first.  

We started reworking ballast placement.  Less ballast in a more ideal position.  

Lots of little jobs were also completed - like adjusting hood pins, replacing damaged hardware on tow hooks, packing wheel bearings, etc...  

 

7 weeks to go, and the salt reports are the best in years.  Let's hope the weather holds out!!!

[distributorguy]

Alright.  The damn manifold's almost done.  Lots of TIG welding to do after final fitment of the "roughed in" carb plate at the correct angle.  More shaping to do to blend the 2" ovalized tube into the spliced pipes, and get the angle correct.  The runner lengths are close enough to what I wanted, diameters are good.  Hopefully after this week we'll be working on tuning.  7 weeks to racing.  

 

Hopefully this pic works via photofuckett.  If not can one of you help get it posted?  Crappy pic, but definitely not something you'll see on any street engine.  

 

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[Stoffregen Motorsports]

That's going to be one crazy intake.

 

Be sure to brace it so it doesn't crack.

[distributorguy]

Yep,  I left extra material on the flanges to weld a support up to the tubes.  It should enhance torque, and at high velocity/rpm it'll be a wild card.  May be just what we needed - or the kiss of death.  We'll see.  

[distributorguy]

The new coil-over shocks in place.  None of the parts are new, except for the lower control arms from Beebani.  Shocks are 20+ years old adjustable Spax with 7" 400 lb. springs.  The rest was 100% restored before we went to Bonneville last year.  Anyone who believes that Rustoleum can stave off rust is kidding themselves.  Not for long, anyway.  

 

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[Stoffregen Motorsports]

I personally have never seen an L intake that long, so I am curious how it works.

 

Rust Oleum sucks. I grew up with it as a name brand (my dad loved the stuff) but I stopped using it about 15 years ago. But then, you're driving on salt... That's this truck's main job...

 

I wouldn't powder coat it, as the coating just hides cracks and encapsulates the rust that may form, making it hard to see. Maybe next year when you get a chance to tear it down, you can do a solid cleaning and spray it with a primer and a chassis paint. I know, not on your list of priorities, but rust bothers me too.

[distributorguy]

The goal is to strip the truck when we get back.  Literally disassemble the whole damn thing and clean, paint.  The trip gets pretty exhausting though, and no one has the energy to do it when we get back.  This year we'll spray a rust preventive on it before we arrive.  Forgot last year - too many bigger fish to fry.  

 

The goal with the manifold is to get up to speed faster (torque) with the dreadful 2.72 gears.  Might work, might be an epic fail.  No one will ever know without trying.  Had most of it welded yesterday, but it warped enough to merit a quick reshape before welding the final flange in place.  We plan to fit carbs tonight to start working on linkages and fuel lines.  

[Stoffregen Motorsports]

Ok, the logic is sound, and there's only one way to find out. Too bad there are so many moths in between race seasons.

 

Could you bring your old intake setup just in case this is an epic fail? Would you have time to swap it all over in between runs?

 

I know you like the mechanical linkage, but a simple cable linkage would probably be just fine. Sooooooo many cars and trucks came with cable linkage, and so many race cars run cable linkage without problems. Use a quality heavy duty cable with a good cable housing (modified OEM maybe?) and then run redundant return springs. Should be fine.

 

If you're worried about throttle sticking, you've got a couple miles to figure out what to do before it's a problem, and then you could always just shut it down if it remains stuck.

 

Is TC driving this year?

[distributorguy]

TC and Steve are both driving, buts its TC's ride until there's time allows.  We may even get a 3rd driver licensed this year?  Depends on how things play out.  

We can run a cable if its a solid cable with a metal housing - no plastics allowed.  Rules.  They were drooling over my solid linkage last year in tech however.   :thumbup:

 

Yes, the DCOE setup will come with us.  We WILL dyno tune before we leave, so we'll know in advance if it it'll work or not.  Mostly.  Should be able to get it running some time next week.  7 weeks from today we hit the road, so there's time.  We may even get it out on the road for a test???

[distributorguy]

The manifold is back off for final welding today.  Here's a glimpse of how it looks with the carbs in place.  We have a game plan for linkage and fuel lines, albeit convoluted.  The hood scoop will get completely rebuilt to accommodate. 

 

Last night's build night was full of stuff you'll never see.  Cleaning, modifying and shifting ballast weight, painting, rebuilding the tow bar, etc...   

 

 

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[datzenmike]

Would there be any benefit running the intake runners 1,2 and 3,4? (edit 14 and 23) Rather the same as the firing order 1,3 and 4,2? So the intake pulses are separated back and forth between carbs? This would reduce scavenging pulses going down the adjacent runner.

 

Could carbs be facing forwards to take advantage of air pressure at speed? Or is there an enclosed hood scoop?

 

Velocity stacks? To smooth the transition where air enters?

[DanielC]

I would think you would want to join intake runners 1 and 4 to the same carb, and  2 and 3 to the other carb.  That way each carb gets an intake pulse every 360 degrees of crankshaft rotation.   The way it is now, each carb gets an intake pulse, and 180 degrees later a second one.  Then each of the carbs waits through 540 degrees of rotation before it gets an intake pulse again.

 

That is all assuming you are using the standard firing order of 1,3,4,2.

[datzenmike]

Daniel I think you said it better than me. Yes 14 and 23 same as the L16 exhaust 4 into 2 pairing.

[G-Duax]

That makes perfect sense to me.....

[captain720]

I just read through this whole thread......

Wow

[distributorguy]

Have you ever built a part from scratch, and you realized after you're done that you were so close to the project that you didn't step back and take a look at the big picture?   After building the flanges, I had it stuck in my head that I could build the front and rear runners and cross the center 2 to get the front and rear carb pulses alternating.  I was trying to get away from what happens when you pair 1-2, 3-4 as in a factory setup, and I just replicated it the hard way by going 1-3, 4-2.   :poke:

 

My welder buddy is not going to be amused when I hack this thing up to correct it.  1-4, 2-3, but it opens up a new idea to get the runner lengths closer to correct, and maybe I won't have to modify the hood scoop as much.  Its going to be a LONG week.  Crap.  Crap.  Crap.   :poop:     Thanks for the heads-up guys.  At least I hadn't built the linkages and fuel lines yet.  

[G-Duax]

Have you ever built a part from scratch, and you realized after you're done that you were so close to the project that you didn't step back and take a look at the big picture?   

 

Only a few hundred times....