Modena's progress update

[dhs.buckley]

mine has a little sticker saying that a roof is not to be fitted near the emission sticker,
i have since had a tonneau cover made, also i have put a vent in the foot well if heat is needed for those cool days, works well, you just have to hold the steering wheel at the bottom to keep your hands warm.

[Modena]

An update, I have been making headers!

They are a shorty block-hugger 4-into-1 design, to allow me to put the CATs under the bonnet, nice and close to the engine. The shorty block huggers that are available off the shelf are not short enough and come to close to the chassis, hence I am making my own!

I bought a bunch of mandrel bends and started cutting. The cuts are made mostly with a chop saw, also a couple by hand with a hacksaw. On each side I have one pipe which is one piece, the other three pipes are two or three pieces each. The driver's side front port needs a fair kink in it to clear the steering column, I will add more pics as the headers continue to come together.

I have welded up the pipes with a scratch start TIG setup. The welder is a 140amp DC inverter stick welder, it is tiny! Plugged in a TIG torch to the negative, hooked up a bottle of argon and got TIGging! I have never TIG welded before, so spent a good couple of hours practicing on scrap. It took a couple of hours to get the muscle memory going that you need to remember to turn the gas on at the torch! The hardest part was the scratch start without the electrode sticking, but once you have the knack it is quite easy to start. With this scratch start TIG setup I can weld steel and stainless steel, but no aluminium as that needs AC. I decided to go the scratch start setup as I can't justify $1,000 for a decent hi-frequency AC/DC welder and I have no aluminium welding to do as of now. As you will see from the welds I am no weldmaster, but a flap disc will do wonders!

Below you can see the length of the single piece pipe. I am using 1 & 3/4" pipe. I'm more interested in low and mid-range torque than high-end HP, so from what I have read on these engines this is better suited than 1 & 7/8".



The trolley, big-old MIG on the top, AC stick on the bottom, and the DC stick that I'm using for TIG is hiding in the middle!



This thing is tiny! I have been welding up most of the joins at about 40amps.



The TIG torch cost more than the welder! It's a 17V with the valve for the gas. Also I added a gas lens kit from weldmongerstore.com. I have been using 2.4mm (3/32") ceriated tungsten electrodes and they seem to be working well.







Not too bad, will clean them up with a flap disc. Once complete the headers will get HPC ceramic coated. If you can get the mating surfaces nicely matched then almost no filler metal is needed.

[deano59]

mate well done on taking on such a job .im game to have a shot at most things when building our race cars and stuff but doing headers I always pay as im not confident the job will turn out like I want . kudos for giving it a shot .
cheers dean
ps I have the same trolley but I have a lincon 180 c welder up top and a plasma cutter on the bottom shelf

[guye]

Nice work Ben. I was thinking of giving my own exhaust system a go; I get headers supplied with my kit so I don't need to tackle THAT! As Dean says, good on you.

[DaveW]

Great stuff Ben, I'm not far behind with this job as well and following the same route with the 1-3/4" tube.
Coming along well.

[Aussie Mike]

Very nice work Ben. You would have to be proud of that. I found building the headers on mine to be a very enjoyable job. It's like putting together a jigsaw except you can trim the pieces to fit.

I've got some useful pointers for you that might help when it comes time to weld the pipes into the flange.

Cheers

[Modena]

Thanks all, now's the time Mike, I'm all ears!

[Zedn]

Looks like you may have it a bit too hot. What is the inside like? If its too hot you will get lots of the filler dripping into the inside which won't be good for flow.

[DaveW]

Originally Posted by Modena

Thanks all, now's the time Mike, I'm all ears!

yes, Mike, please share, i'm doing mine as well at the moment.

Dave

[Modena]

Hi Zedn, inside looks ok. You can see penetration, but there's no big goobs of metal.

[Aussie Mike]

One of the biggest things you will be fighting with it heat warping when welding the flanges. I did the final welding of the flanges with them clamped to a large piece of T section steel that kept the whole thing straight.

Welding them in position on the motor is a pain because you will be welding upside down plus you don't want to run the risk of anything disappearing down one of the exhaust ports. Fortunately you have those spare heads sitting there. Once you have the locations of all the pipes sorted on the motor tack everything in place and unbolt the flange and bolt it to the spare head. That way you can flip it around to get the easiest positioning for welding.

Don't worry too much about how the pipe fits into the port. Once welded flip it over and panel beat the pipe out to fit the inside of the opening in the flange. I did this using a steel drift that I ground the end with a dome shape. You can then just run a fusion weld around the port opening if you want. You won't need hardly any filler rod. That will unsure a good gas seal.

You probably still have a little warping after they are all finished it shouldn't be too much of an issue. The manifold bolts will pull a small warp out. Or if you want I can run the fly cutter over the flange on the mill.

Cheers

[Modena]

Thanks Mike, that was what I had planned, welding while on the heads, although I'm going to MIG them, there is a bit of a gap around the pipe and flange port and I'm more comfortable MIGging it than TIGging up that gap.

The 1 & 3/4 pipe is still bigger than the exhaust port, so matching is not a problem.

It was actually very handy having those spare heads, as it allowed me to mock up both in the car (also have a dummy block in there) and also mock up on the LS3 on the engine stand in relative comfort, this made it a lot easier because the body is on.

[DaveW]

Thanks Mike, good info

[Modena]

Another long weekend has come and gone and I got a few things done. First, I tackled the disaster that has been sitting under the car for a year. While assembling the left rear suspension I put the driveshaft in the outer knuckle and wound on the driveshaft nut to pull through the spline, but the nut cross-threaded, argh! It would not come off - I had a 4 foot pipe on there and I could see the 1/2" Snap-On breaker bar visibly flexing, I'm sure it almost broke. I tried heat, no go, it was stuck fast. This happened a year ago or more, and I threw the knuckle and driveshaft under the Cobra in disgust and forgot about it for a while.

I had assembled the drivers side knuckle and driveshaft the same way it came through ok. So.... I went to a wrecker and got a replacement knuckle and driveshaft. I had already spent time and money reco'ing the original knuckle, blast, paint, all new handbrake mechanism, nolathane bushes, new upper heim joint, so I wanted to keep it rather than retro all that to another knuckle, so if I could get the shaft out, all I needed from the wrecker was a new outer CV. So, grinders at 10 paces, that nut is coming off!









The real pain with this is that the nut has a tubular section that goes down into the hub and a captive washer, so splitting it is NOT an easy task - I never want to have to do this again, it took about 2.5 hours.





Who's your daddy



Once the nut is off, a small pressure with the press and the CV is out.



The outer CV (VE Commodore) is held together with a snap ring, so TUG and it comes apart



Then flip it, press out the drive flange (which destroys the bearing) and then the other half of the bearing



A quick trip down to Holden and I have a new drive flange and nut, waiting on a new bearing from Ebay and the original knuckle will go back together with the CV from the wrecker - this time I am going to press the outer CV half in to the knuckle before assembly to the driveshaft, this way I won't be using the nut to pull the shaft through the drive flange. You cannot press the splined CV into the drive flange by hand as it's a bit of an interference fit, but on the press it does not take a lot of force. It will be good to close this nightmare chapter in my build.

Next, was to continue work on the headers. First to clean all the mill scale off the flanges with a flap disc



Then welded up the headers to the 4-into-1, 2.5" outlet collectors. They will then get a 2.5" 90 degree turn towards the sides of the car, then the cats, then out into sidepipes.

Yes, my welds need some clean-up, but hey, I work at a keyboard all day!



















Finally, it's amazing how you can work in the shed for days, using all manner of dangerous and even lethal equipment and come out unscathed, then cut your finger on the foil on the whisky bottle

[gjkrv8]

Looks great Ben. I admire you for having a go. A bit of grinding and finishing etc and some paint/ceramic coating and it will be a work of art :-) Cheers Gregg

[DaveW]

WOW Ben, Marathon effort on that Knuckle, I can understand the frustration, That disassembly then rebuild is quite a job on the VE rears. Hope I never have to re do mine.

Great job on the headers, They will come up great after coating.
You deserve a drink after that effort.

[Aussie Mike]

Excellent update Ben. The headers look great. Should come up a treat once they are ceramic coated.

On the rear upright I've seen on Ebay you can get rear wheel bearing kits that include the wheel hub. Might be a cheaper option. Then you only need the CV jount.

[url=http://www.ebay.com.au/itm/ONE-REAR-WHEEL-BEARING-KIT-INC-HUB-HOLDEN-COMMODORE-VE-8-2006-4-2013-5235-/201074614021?pt=AU_Car_Parts_Accessories&hash=item 2ed0fb1f05[/url]

Or how about this complete assembly?

If it's not the right side you can still use the hub and drive shaft.

http://www.ebay.com.au/itm/HOLDEN-CO...item4adae1806c

Cheers

[Modena]

thanks, yes a bit of a clean-up and coating and they should look ok.

Mike, already got a flange from Holden ($100), those "kits" are actually just the bearing, I got mine for $84 instead of $290 from Holden, and if the bearing price isn't enough of a ripoff, the drive shaft nut is $34....

[Modena]

oh, and I forgot to say, the flanges had a very slight bow at the start, but after welding them up while bolted down they're all good and flat. Cheers for that.

[Aussie Mike]

I just realized that and fixed the link. There it a hub and bearing kit for $130

Cheers