Backdraft Cobra AUS - The search for reliability

[deano59]

thats one awesome car i would love a dedicated cobra track car i will have to stick to the vl race car i have and keep the cobra for road duties when finished i cant see the mrs been too happy if the cobra come home bent from a track day

[spookypt]

I got the accusump relocated and plumbed over Easter and did the 60lbs test overnight to ensure I had no bleed down and all was tight. So that's all done and ready.

I then did a test fit of the GB for clearances and it looks good. I need to fab a different cross member but I'll get the levels right and then make one up. While sitting in there I can finalise my plumbing in/out and breather arrangements ready for install.



Big thumbs up to HGT overnight. I got an email this am to tell me they found a problem with part of the internal assembly on one of their cars so are flying me out and brand new GB all inclusive to now use aka Mark2. I should have it end of April. They are paying all freight in and all freight out.

Not too many companies I know would do that on a $20k GB. Great service and good to know the brand is prepared to back itself. There was no we will send you the parts BS BS yadda yadda. New box coming and Ive not even had a chance to put oil in the Mark1 yet!

[Modena]

Do you get to keep the Mk I box?

keep the updates coming

[SydneyChris]

Spooky.. you are the best kind of nuts.. Loving what you are doing.. Look forward to the updates..

Cheers

Chris

[spookypt]

Did a bit more on the weekend while working out how to best fab a cross member and shift linkage. As I'm getting another box at the end of April it will all come out but at least I have a template to fab everything I need.

Plumbed all the in/out lines.


I had a spare camera on my shelf so I installed it. Should make reversing into pit sheds a bit easier. With hans and seat I cant see anything behind me.


For those of us who remember Ledge, he was the first to build a Harrison with an 8TB LS chevy which he sold to Leroy. Well Paul (Ledge) now runs a RB28 240Z with 800hp and tested the GB at the Mt Alma Hillclimb on Sunday. This is his first run (had a shift cut issue which he rectified) then broke an axle on run 2 so back to the pits and home.

Sure shows some slick potential. Cant wait.

[ame]https://www.youtube.com/watch?v=aih6EqsUUT4&feature=youtu.be[/ame]

Spookypt

[Wazza]

Hey....He's wearing my "Race Gloves"..lol

[spookypt]

Well it has been a while since I updated. That's not to say I haven't been working hard to get the car done. I'll post more pics soon but the updates now are.

- Tail shaft measured and made using 1350 series slip yoke assembly.

- New cross member fabbed with new bushings and crush sleeves.


- Made up my cantilever arms with spherical bearings for the shift leaver.

- Turned a shim down to get the correct TOB throw.

Now all I have to do is linish the above and paint.
Ive ordered all new bolts and will pick them up today.

Ive also pulled the side pipe off, ordered in new flange gaskets and repacked the pipes with fibreglass mat to keep the noise down.



The new Mrk2 GB arrives next week so I'll swap the hose outlets over and then bolt it all in and fill it with oil.

Then the car is off to Chunky's to get the electrical work done, then back to the shed for a systems check, brake bleed and valve lash and its done.

I was hoping to be ready for rd 2 A series tomorrow but Its just impossible with the amount of work needed. Fingers crossed I'll be ready early for round 3.

[albanycobra]

looks very race car.

[spookypt]

More pics added above. I know my welds aren't pretty but Im learning and with a single phase 130amp stick welder they could be worse!!

While I was at it I hand made some exhaust body flanges to cover the edge of the glass where they exit the body. Stuck them in the oven to 100+ degrees and then applied stove paint. They came out pretty good. And the paint is HARD.

[spookypt]

Well first problem. While my snake pit of lines looks pretty I cant get the pumps to prime. Ive installed as per Tilton Spec and these pump drawer up to 8 feet above the primer source so I cant figure out whats wrong yet. Im onto Tilton tech for a solution. They advise to run the pump last i.e. diff out, filter, cooler, pump and diff return. I cant seem to get past inlet cooler.
Somethings up...just not sure yet. Urgh

[dallas_]

Try blowing out the lines from the far end back into the tank.
If you get an air bubble, sometimes the pump can't get good suction.

[SydneyChris]

Exactly.. they can draw up to 8ft of fluid, not air.. . I used a low pressure pump into a swirl pot to ensure the pot was always primed then gravity fed the 044 connected to the reg. It may also help to use a non return valve on the fuel (as I'd expect you already have on the brakes).

Love the updates btw.. is a fantastic machine, will look forward to watching it fly past at Wakefield..

[spookypt]

You know this is oil right? Cold oil in fact. Spoke to tilton and the issue is the cooler outlet being higher than the pump.

I've amended the order to diff filter pump cooler diff and all is good. Tilton prefer pump last due to heat but I won't be doing the 12hr any time ever!

[spookypt]

dbl post

[Aussie Mike]

Originally Posted by spookypt

You know this is oil right? Cold oil in fact. Spoke to tilton and the issue is the cooler outlet being higher than the pump.

I've amended the order to diff filter pump cooler diff and all is good. Tilton prefer pump last due to heat but I won't be doing the 12hr any time ever!

That's the way I have mine set up: Diff - Filter - Pump - Cooler - Diff. My pump is a Genesis which looks identical to the Tilton.

You may want to look at putting a check valve in there to stop the oil draining back to the diff. It'd make getting the system primed and running again quicker. A hinge type is full flow and adds very little restriction to the oil flow. I have a #10 one of these on my engine oil cooler setup.

Hinge Check Valve

Cheers

[spookypt]

Mike I was talking to the Motorsport guys about a couple of flapper valves for this set up. I assume running as close to the source (diff or trans) as possible?

[Aussie Mike]

Yep, I reckon placed below the level of the diff oil so it's always full and then you will have a head of oil sitting on top of it. The pump should be able to draw straight away.

[SVO 050]

Any hydraulic system needs a flooded suction at all times, any cavitation will cause loss of prime and potentially damage the pump.
A trick is to ensure the suction line is larger than the outlet, increases the volume of fluid on the suction side of the pump.
Just my observations after working in the hydraulics industry for ten plus years.
Cheers
SVO

[spookypt]

Well Mk11 arrived yesterday. Looks like I know what I'm doing on the weekend!

[albanycobra]

The smile on your face when you start banging gears for the first time.....priceless.