Roaring Forties #36 - Mark Worthington's GT40 - Page 4

David York · 01-03-06, 09:49 AM

Hi Mark,

Thanks again for your posts they give folks like me waiting on our cars something to see!
I saw in the RF manual the routing you have taken. I am not sure I like the ideal of a pipe running in the wheelwell. Is there a reason that the overflow pipe cannot be routed through the center tunnel with the other pipework?

Mark Worthington · 01-03-06, 10:23 AM

It sure would be easier to run the coolant bleed line through the tunnel, Dave. I had asked RF about this a while ago and was told that they ran the line as they did to keep it as high in the car as possible, minimizing the amount of pressure needed to move the fluid up to the header tank. They were not sure how well it would work in the tunnel. I believe Pat Barry ran his bleed line through the tunnel.

David Bullock · 01-03-06, 12:30 PM

Mark

On my Tornado, I ran the radiator bleed pipe at floor pan level within the cockpit. This post completion mod resolved the overheating and airlock problems that I had been experiencing. All has now been ok for some years - famous last words!

David

Mark Worthington · 01-13-06, 01:07 AM

Good progress on the fuel system. I got the hard lines installed. They run along a chassis rail beneath the rear bulkhead. Bottom line is supply from the left tank and low pressure pump over to the right side where the swirl pot and high-pressure pump are located. Top line is return to left tank from 3-way valve. Had to be careful to keep them out of the way of the brake, clutch and AC lines.

Here's the right side LP pump, 3-way valve and bulkhead fitting. I'm waiting on some parts from Australia before I can install the HP pump and filters and finish the fuel system plumbing.

So while I'm waiting on the rest of the plumbing, I've started in on the tank fittings and fuel level sender for the left hand tank. When I'm done with that I'll vacuum out any swarf from drilling and tapping holes to mount the sender, test the fittings with water, and thoroughly clean and dry the tank prior to final installation. Same for the right tank, which includes an integral swirl pot into which both LP pumps discharge and from which the HP pump draws fuel.

Hopefully I'll be done with the fuel system and working on the wiring harness in a week or so.

Bill Musarra · 01-13-06, 07:01 AM

Mark,
I noticed that on an earlier post of the twin nostril panel, that it is as supplied from the factory. I would assume you are going with the single nostril when aerodynamics are needed. Do you plan to modify the twin nostril? I believe there were some airpressure issues with the stock twin setup at speed. I personnaly like the twin setup so I modified mine to go to the bottom on the radiator. Are there plans to modify yours. I could supply pics of the final look if needed.
Bill

Mark Worthington · 01-13-06, 12:34 PM

Bill, I have no plans at present to modify my twin-vent nostril. I also recall reading about cooling issues with the twin-vent nostril, but I believe it was with GTDs. I haven't heard of any overheating problems with RF cars.

In the event I take my car on track, I'll simply fit the single-vent nostril. I believe the more critical aspect in cooling airflow is fitting the radiator, front tray and body work so that incoming air doesn't stagnate or bypass the radiator. I have a nice tight seal between the radiator and the upper body-work, the radiator and the front tray, and the front tray and the lower body work.

If I do experience cooling problems, it would be a straightforward project to re-glass and re-spray the twin-vent nostril. Not easy, but straightforward. [img]/ubbthreads/images/graemlins/smile.gif[/img] I have to keep from distracting myself with potential upgrades like this along the way, or else I'll never get my build done. There will be plenty of time after I get the car on the road to upgrade certain components or systems.

**patbarry** · 01-17-06, 09:38 PM

I did run my bleed line through the tunnel. Took three starts and cool-downs, but system is no air-free.

Mark, your assembly looks very tidy and professional!

David York · 01-18-06, 02:32 PM

Thanks for the update Pat. I agree that Marks intsallation is top notch! I look forward to tackling this issues some time in the summer when I should be to that part of the build.

Mark Worthington · 08-06-06, 10:53 PM

Boy, am I past due for an update or what? I've actually made some good progress on the car. I wanted to get the fuel system and AC done and the powertrain installed before I focused on body work and paint prep this summer. Well, here it is, August, with only a couple months of warm weather left, and I'm behind schedule.

Here's my current status. AC system is still in progress. The fuel system is done, but I don't have any decent pictures of it. Imagine three fuel filters, a high-pressure pump, a low-pressure pump, a 2-way solenoid valve, another shut-off solenoid, a bunch of brass fittings, a bunch of carefully routed 5/16 fuel line and hard lines, a trailing link suspension member, and a gear change rod all sharing the space that's equal to about 1.5 Little Igloo lunch box coolers and that's the bulk of my fuel system.

I want to get the powertrain assembled and into the car soon and then go nuts on body prep, so I managed to fund a full summer day to spend on my car. Perfect weather, solitude in the garage, tunes on the radio and cold beer in the fridge - it was blissful. I managed to get a fair amount done today.

I started off by installing the pilot bearing (Brits and Aussies call this a spigot bearing). It consists of a needle bearing which supports the input shaft; the bearing is pressed into a machined steel adapter which is pressed into the rear of the crank. I heated up the adapter in the toaster oven and put the bearing in the freezer, and I still had to use a vice (with wood and aluminum blocks for protection) to press the bearing into the adapter. Then the whole unit went into the freezer again before I tapped it into the bore in the rear of the crank. God have mercy on me if I ever need to remove this thing. Here's the pilot bearing and adapter.

Next I bolted up and torqued my flywheel, which I had surface ground a few weeks ago. It took the better part of 3 weeks to get these damn Ford flywheel bolts. After I had them all in and torqued I realized I forgot the thread locker, so off they came. The FRPP parts are supposed to come with thread locker already installed, but someone at Ford must've figured out how to increase profits by letting the end user do this step, or forget about this step, as the case may be.

Next I installed the clutch disk. I'm told this is a Rover unit retrofitted with a new center spline to fit the Audi input shaft. Note the high-tech clutch alignment tool I used. The manual specified a shaft with an 18.0 mm diameter which steps up to 18.3 mm 30 mm from the bottom. Instead of seeking out a machinist, I just used a socket that was a close fit, and wrapped it with clear tape until the desired diameter was achieved. That's why there's tape hanging off the socket in the middle of the clutch disk. It worked perfectly, and the clutch disk was dead center on the pilot bearing.

Before I installed the pressure plate I test fit the bolts in the flywheel and was concerned that they might bottom out before the pressure plate was good and tight, so I ground a thread or two off the tip of each bolt. This time I didn't forget the red locktite.

Mark Worthington · 08-06-06, 10:54 PM

Next up was the adapter plate. It fit perfectly on the dowels on the block. I need to replace the too-short, cheap-ass fasteners with some Grade 8 stuff. It's not fastened in this picture.

Here's the clutch thrust bearing, custom aluminum carrier, and clutch fork inside the Audi 016 transaxle. This had already been assembled before I bought the car so there was nothing to do other than make sure there was a little grease where needed.

OK, now we're getting somewhere. Time to lug the transaxle up from the basement. I set this up by using a floor jack for the transaxle with plywood plates and shims and eyeballing the height of the input shaft relative to the middle of the pressure plate. When the elevation was close, I used a level to get both the adapter plate and bellhousing face perfectly plumb, them proceded to arrange for some mechanical intercourse. Ms. Ford, meet Mr. Audi.

Ta Da!

That really wasn't too bad. I cheated a bit by using some bolts to pull the transaxle into the adapter plate, but I was careful. I knew I had it when I wiggled the crank and saw the output flanges on the gearbox wiggle.

Feeling all warm and fuzzy, I decided to turn the engine over. It turned a little, then stuck. Damn...maybe it's just compression. Out came the spark plugs (one of which was loose, so it was a good thing to do) and it was still stuck. Damn. And I really hate to turn the crank bolt counterclockwise, so I did so only enough to unstick it. I'm pretty sure I have pressure-plate-to-bellhousing clearance issues. I had inspected the interior of the bellhousing before I assembled the powertrain and it looked as if some light cutting had occurred, creating a couple small but nifty stress risers on some internal reinforcing ribs. I guess it wasn't clearanced enough. Looking through a hole in the bellhousing I think I can see the culprit (note paint rubbed off of pressure plate); I'm just not sure if it's the only culprit.

And so it goes. Three steps forward, one step back.

Mark Worthington · 08-06-06, 10:57 PM

So does anyone have any suggestions how to tell what needs to be ground down inside the bellhousing such that I only have to disassemble and re-assemble once instead of multiple times? Any RF builders have pictures of the inside of their 016 bellhousing that shows the material they had to remove to clear the pressure plate?

**Chris K** · 08-06-06, 11:14 PM

Mark,

perhaps you could try painting the suspect areas with some machinist blue and grind where it shows being rubbed off, hope that helps.

Chris

Mick · 08-07-06, 10:54 AM

mark i have attached a jpeg of the inside of my 016 with the areas that i had to grind back with a sanding disk to improve clearances, hope this helps.

Mick · 08-07-06, 11:14 AM

Mark cant seem to load the jpeg if you shoot me an email I'll send you the photo

Mick

Mark Worthington · 08-07-06, 11:32 AM

Mick, I'm looking forward to that photo - I think it will help a lot. Your profile is not set up to receive emails so please send me an email with the photo. Send it to: mark(dot)worthington(at)gmail(dot)com. I'll post it up here for all to see.

Thanks, mate.

BTW - I really like some of the stuff you guys are offering for sale over at 40 inches. I'm almost ready to pull the trigger on the easy-off hinges, I know I'll wish I had your control arms when I align my suspension, and I'd love to get my hands on that pedal box. Good stuff, all of it.

Jac Mac · 08-07-06, 09:50 PM

Mark, you may not like this idea as you have to dismantle a few bits ,but here goes.
Remove the T/axle. Remove Clutch cover /plate/flywheel. Assemble Clutch cover and plate onto removed flywheel with plate splines centered as near as possible.( It wont matter if you are slightly off center as this will help create adequate clearance ). Now slide assy onto input shaft splines & rotate gently to check areas that are fouling. Remove material until the assy is approx .125" deeper into the T/Axle Bellhousing than the final installed position. You should now have removed sufficient material to cover any slight size differences in any replacement parts in the future.

Jac Mac

Howard Jones · 08-08-06, 01:15 AM

A message from the wise (this means I FUed this part up and now I know from learning the hard way). Be VERY careful with the spigot bearing. DO NOT allow the input shaft of your gearbox to "hang" or other wise be misaligned in the spigot bearing as you install the gearbox. It takes very little loading to dammage the bearing.

We use 4 long bolts to aline the gearbox with the adapter when you push it forward onto the adapter plate. Simple place the gearbox in a position that is close but not beyond the point that the input shaft of the gearbox enters the clutch. Then screw the 4 long bolts through the gearbox mounting holes and into their respective threaded holes in the adapter plate.

Now you have the gearbox properly aligned with the motor and you can simply slide it forward on the bolts. The input shaft will enter the spigot bearing straight in as it should. When you have the gearbox mated up to the adapter plate, aligned with, and on the dowels you can remove the long bolts and install the proper short ones.

The last thing to remember (that's code for I didn't) is the thrust clearance of the main bearings. The gearbox assemble MUST NOT load the crankshaft so as to reduce the thrust clearance. This could happen if the input shaft is pushing against the spigot bearing assembly or something like that.

You can check this by turning the motor by hand with the rockers loose and the plugs out. Note the resistance or if you like check it with a torque wrench. Now bolt up the gearbox. The effort it takes to turn the motor as configured above with no compression and without opening any valves should not increase very much if at all when you add turning the gearbox. Of course the half-shafts are not connected.

By the way, the thrust bearings will last less that 3 Min's if the motor is run and their clearance is used up by the input shaft pressing on the end of the crank.

Mark Worthington · 08-08-06, 02:08 AM

I disassembled the transaxle and clutch tonight and I can see a couple witness marks inside the bellhousing pressure plate where the cast in bumps for the mounting lugs are. I was going to try to fit an 11.5" piece of sheet aluminum across the clutch disk and use it as a measuring gauge because the maximum width of the pressure plate is 11.375". But the pressure plate is a 3-dimensional pice, and the bellhousing narrows, so I'm going to use Jack's method to find out where all the interference points are. I don't want to do this again if I can help it. But I had to stop shy of taking the flywheel off tonight because it's 1:00 am, the family is asleep, and I need to use an impact wrench.

Howard, I like the idea of a set of extra-long bolts to assiste in assembling (and dis-assembling) the transaxle - I'll pick some up at the hardware store tomorrow. I'm pretty sure there's lots of depth for the input shaft forward of the pilot bearing but I'll take some measurements to make sure.