Sam's build thread

**simon k** · 16-02-2018, 10:15 AM

Originally Posted by sambb

ha ha sorry didn't mean to sound gruff. No you're right though helicoil is an option. There's no room for a wider banjo so the question would be how much of the area under the washer would be taken away by the helicoil being under it and would that compromise the seal, and how to drill it without crap getting into the bearing journals.

nah, you didn't sound gruff - I know what it's like when you've made up your mind about one thing, and people keep saying "but but but but" and you don't want to know about it...

however! helicoil wouldn't upset the seal, the amount of of material lost is negligible. Normally coat the drill with grease and run it slow, take it out often to clear the swarf. Do the same thing with the tap, coat it with grease and take it out often. If there's anything left in the hole when you're done it's easy to pick out with a bit of MIG wire

What's the upgraded turbo worth? I'm happy with the stock performance of my car, it's my daily and does a 70km round trip. Maintaining *reasonable* fuel economy is important so I don't think I'm going to do anything with tunes or upgrades any time soon. I know what you're talking about with the 6000rpm range though - it really does run out of puff over that... I've no idea where the limiter is, but it certainly doesn't drive like it wants to go bashing against it.

**Sydneykid** · 16-02-2018, 10:56 AM

Originally Posted by simon k

I see.... I guess you're not asking for solutions, but helicoil?

I'm with Simon, I'd heli-coil it, but only if it is beyond liquid thread repair. Keeping in mind that water jacket bangos don't carry a lot of pressure, just a typical cooling systems 20 psi or so. As a result "a couple of threads" may well be enough. But just in case I'd look at something like Loctite Form-A-Thread, I've used it with great success a number of times. If I remember rightly it's now called Loctite PC3967.

Cheers
Gary

**sambb** · 16-02-2018, 11:32 AM

At work they were telling me that Loctite will cook and turn to powder in the turbo. Will that PC3967 work at turbo core temps? I'm starting to calm down now. I'm still going to explore all the costs of K04'ing (or the like) it but I think if I can just get to (and from!) Bathurst and if the car really does feel like a solid jump up on the track too, then I may look at a helicoiling it. Still stressing everywhere I drive - I was only at 20nm (of 35nm) when it let go so there's bugger all torque on there. Hopefully the fact that there's no movement whatsoever on that line/banjo will keep it good. Oh and out of interest - can you/would you Loctite a helicoil thread?

**Stuwey** · 16-02-2018, 02:51 PM

Originally Posted by sambb

At work they were telling me that Loctite will cook and turn to powder in the turbo. Will that PC3967 work at turbo core temps?

Says it's good for 300*F, so probably not.

**sambb** · 16-02-2018, 05:36 PM

Alright alright I've properly calmed down now and have a bit of a last ditch plan. I have no idea where I could source one from but I'm going to try to hunt down a longer banjo bolt. Looking at the threads in the turbo I pulled off the car and looking at the length of the threads on the banjo bolt, there is nearly another 1/3 of unused threads inside the turbo core. I had a head fart before when I was in a bother and now that I think of it its a water jacket (not anything to do with the bearings) so I'll remove the exhaust manifold to reveal the top of the turbo, run a tap into the threads by hand just to clean it out like Simon K said, magnet any crap out that may have fallen in, and bung a longer banjo bolt in with some kind of paste (I'm sure there's something I can use) and the thinnest banjo washers I can find. That way I only need an exhaust to head gasket, exhaust to turbo gasket, a bit of coolant and not such a bad amount of time to achieve it - maybe even feasible to do it before Bathurst on march 3/4. Thanks all for talking me down.

**simon k** · 16-02-2018, 08:18 PM

sounds like an plan Sam

BTW I'll make you a banjo bolt and post it up if you can't find something, or I know a mini guy in Baulkham Hills who would make you one if you were nice to him

**sambb** · 16-02-2018, 09:31 PM

There's an Enzed trader just near me so i'll get down there on monday and see if they can do something. If not though, Baulkham hills is doable. Its sort of on my long way home from work. I could easily drop off a bolt and banjo and beer to him! I'll let you know how I get on.thx

**Sydneykid** · 19-02-2018, 11:51 AM

Originally Posted by Stuwey

Says it's good for 300*F, so probably not.

A couple of things, that's 300 degrees F at 128 ft lbs. Plus it's a water jacket banjo, so it shouldn't get over 200 degrees F. If it does you have somewhat of cooling system overheating problem. I've used it on exhaust header studs in an emergency, more than once, and they get way hotter than a cooling system banjo.

Cheers
Gary

**sambb** · 19-02-2018, 02:25 PM

Spewing - went to beumond trading, Enzed, some engineering shops etc etc and no one had anything on hand. Tilleys a pretty established racing shop near me suggested maybe just threading an AN fitting into that spot (with a longer thread) and replacing the whole hard pipe, but then we couldn't find a fitting that would fit between the exhaust manifold, wastegate actuator rod or the oil banjo. I'll just turn down the head of the banjo bolt ever so slightly and extend the thread on the bolt upwards by the same amount and put it in with the paste that Gary recommended. The guy t Tilleys did point out that there's no sealing benefit from a thread compound as that is all done y the washers but if it gives the threads a bit better strength at the lower torque they'll be bighting at then every bit will help. I'll see how I go.