Bbt k418 + Chinafold gasket option?

[ADs3]

I've a bbt418 hybrid + Chinafold manifold to fit but have heard of the gasket between the turbo hotside & manifold blowing, I'm trying to avoid this as don't want to be taking the turbo off again.

What causes this? Is it from the heat or poor mating surfaces?

I've read there's a few options. Can run gasketless but what's envolved to do this, is it having both the faces of turbo hotside & manifold skimmed flat by a machine shop?

Standard gasket with nordlock washers or even a copper gasket?

Who's been here & done this & has a definitive answer to what works best?

 

[<tuffty/>]

Gasketless... copper ones are sh*te, assuming your chinafold is ported an OE gasket won't work anyway... if your chinafold isn't ported then best of luck making reliable power... they are known to misfire if left untouched...

Both mating surfaces should be flat... the BBT hotsides should be ok, chinafolds are generally in need of a very very light skim... bear in mind its stainless so its tough as old boots...

<tuffty/>

 

[scotty_24]

Ive learned the hard way and tried a copper gasket. Machine shop for the surfaces to be flat and run gasketles. Use 65mm long M10 1.5 pitch Allen bolts with M10 nord lock washers. Mines never blown or come loose with this set up! Make sure they are m10x65 stainless A2 or A4 grade. All from ebay

 

[ADs3]

Ive learned the hard way and tried a copper gasket. Machine shop for the surfaces to be flat and run gasketles. Use 65mm long M10 1.5 pitch Allen bolts with M10 nord lock washers. Mines never blown or come loose with this set up! Make sure they are m10x65 stainless A2 or A4 grade. All from ebay

Cheers scotty, so with this set up & faces machined flat you didn't use anything between the mating faces at all i.e. No compound of any type? What did you torque the Allen bolts upto?

 

[antwan64og]

At least port the collector if you don’t want a misfire!

 

[scotty_24]

Cheers scotty, so with this set up & faces machined flat you didn't use anything between the mating faces at all i.e. No compound of any type? What did you torque the Allen bolts upto?

Yup. turbo hotside ported by Badger5. Chinafold ported by JNL racing to Badger5 spec.
Chinafold machined flat on the mating surface.
Tried running a copper gasket, lasted one trackday. Binned it and never had a blow yet.
With the bolts and nordlocks, I've NEVER had a loose bolt.
As for how tight, I cant remember I think I torqued them to factory spec that I scoured the internet for and cant remember off hand now. Just make sure they're FT (F'in tight)

 

[ADs3]

Excellent that's exactly what I wanted to hear, I've ordered up the bolts & nordlock washers you mentioned & already spoken to JNL about porting so all should be good to go

 

[ADs3]

Cheers scotty, so with this set up & faces machined flat you didn't use anything between the mating faces at all i.e. No compound of any type? What did you torque the Allen bolts upto?

At least port the collector if you don’t want a misfire!

Thanks, I'm aware of the issues with these manifolds so I've the porting covered

 

[IrishDave]

Yep copper gaskets are *****. Had one on mine and started blowing. Car has been off the road ever since. Nearly 2 yrs.

 

[carbon 20vt]

Thanks, I'm aware of the issues with these manifolds so I've the porting covered

did you manage to port it at JNL at the end? If yes, at what cost?

 

[badger5]

we ensure BOTH mating faces are machine flat.. You cannot assume hotsides are flat, in our experience they're often not.
Gasketless is how we build ours.. Make the fit good, they work fine and reliably.

those who have issues, have missed a trick or two in bolt choice, gasket choice, and not ensuring all faces are flat "to each other"

 

[ADs3]

did you manage to port it at JNL at the end? If yes, at what cost?

No I ended up porting it myself after waiting 3-4 weeks for him to get back to me after initial conversation. From memory JNL's quote was around £250-£300 give or take.
To be honest if your willing to put the time in you can do it yourself & save yourself a fair amount of ££££ and as Bill has mentioned it's best to get both mating faces machined/skimmed flat and run gasketless

 

[carbon 20vt]

Could you maybe share some pics with pointers as in what to watch out for and some no nos?

Found a video too


AliExpress here I come...

 

[badger5]

Pictured are the spec we machine the chinafolds too.... 47mm bore to turbo, to match the k04-380 we use, and 42mm gasket matched on cyl head face, blended to the runners and concentric to the port centres so perfect alignment, and anti reversion step still present. Mating face to turbo machined flat, top edge of manifold flange ground to clear head (varies)
Turbo is port matched to manifold, same template dimensions to ensure perfect alignment

 

[JonnyDerv]

This brings back so many bad memories ******* about with gaskets. Gasketless seems to be the only option but unfortunately, as mentioned, if they’re not machined flat surfaces, you’ll have issues.