Inlet manifold leak

[Gio]

I'm trying to decide which way to go re a damaged inlet manifold - the thread on the left side balance port is stripped. The options I'm considering are :

 

1) replace with new or used manifold (if I can find one)

2) drill and re-tap the port (would need new balance nipples with larger thread)

3) drill and heli-coil the port (to orig thread)

4) JB weld balance nipple(s) in place and either plug or connect together when not in use

 

Option 1) might be $$$ and I would prefer not to have to remove the manifold and/or drill the port ... so leaning toward option 4)

 

Question - what would be likely result of an air leak (eg if the JB welded nipple became loose)? I realise that this would imbalance the "carburation" and also lean out the mixture on the leaking side ... but is there any danger of say burning a valve or ???

[luhbo]

You probably know, that you are downhill on the bodging route, don't you?

This said I say that I once went for option 3, having the tools and inserts, without removing the manifold. Put a little grease on the drill and cutter and you'll catch most of the flakes. The rest will go straight through.

In case I had to buy this expensive Helicoils I'd probably go for option 4, using slow (8h min.) curing epoxy stuff (UHU Plus it's called over here f/i).

 

If it comes loose not very much will happen. You'll notice it quite directly at idle or transition. If not (noticing) nothing bad will happen either, should things become really bad the engine will start to ping before any failure. You'd check this point from time to time anyway. In my eyes the 'Oh my God, it's running lean, the piston's melting' approach is a rather theoretical approach, maybe based on 2-stroke racetrack stories. You have an EFI engine, used most of the time at 25% of its full potential only.

 

The real bodger tries things out first and asks for absolution afterwards, btw.

 

Hubert

[guzzimeister]

You probably know, that you are downhill on the bodging route, don't you?

This said I say that I once went for option 3, having the tools and inserts, without removing the manifold. Put a little grease on the drill and cutter and you'll catch most of the flakes. The rest will go straight through.

In case I had to buy this expensive Helicoils I'd probably go for option 4, using slow (8h min.) curing epoxy stuff (UHU Plus it's called over here f/i).

 

If it comes loose not very much will happen. You'll notice it quite directly at idle or transition. If not (noticing) nothing bad will happen either, should things become really bad the engine will start to ping before any failure. You'd check this point from time to time anyway. In my eyes the 'Oh my God, it's running lean, the piston's melting' approach is a rather theoretical approach, maybe based on 2-stroke racetrack stories. You have an EFI engine, used most of the time at 25% of its full potential only.

 

The real bodger tries things out first and asks for absolution afterwards, btw.

 

Hubert

[Gio]

You probably know, that you are downhill on the bodging route, don't you?

This said I say that I once went for option 3, having the tools and inserts, without removing the manifold. Put a little grease on the drill and cutter and you'll catch most of the flakes. The rest will go straight through.

In case I had to buy this expensive Helicoils I'd probably go for option 4, using slow (8h min.) curing epoxy stuff (UHU Plus it's called over here f/i).

 

If it comes loose not very much will happen. You'll notice it quite directly at idle or transition. If not (noticing) nothing bad will happen either, should things become really bad the engine will start to ping before any failure. You'd check this point from time to time anyway. In my eyes the 'Oh my God, it's running lean, the piston's melting' approach is a rather theoretical approach, maybe based on 2-stroke racetrack stories. You have an EFI engine, used most of the time at 25% of its full potential only.

 

The real bodger tries things out first and asks for absolution afterwards, btw.

 

Hubert

 

Always nice to compare notes with a fellow bodger ... it is the drill flakes that I would be concerned about with options 2 or 3 (unless manifold removed for drilling) and as I do not have the heli-coil stuff I think I will go for option 4. Thanks for putting my mind at ease. Bodge first - ask later. I like that!

 

See you further down the slope then.

 

Gio

[guzzimeister]

You probably know, that you are downhill on the bodging route, don't you?

This said I say that I once went for option 3, having the tools and inserts, without removing the manifold. Put a little grease on the drill and cutter and you'll catch most of the flakes. The rest will go straight through.

In case I had to buy this expensive Helicoils I'd probably go for option 4, using slow (8h min.) curing epoxy stuff (UHU Plus it's called over here f/i).

 

If it comes loose not very much will happen. You'll notice it quite directly at idle or transition. If not (noticing) nothing bad will happen either, should things become really bad the engine will start to ping before any failure. You'd check this point from time to time anyway. In my eyes the 'Oh my God, it's running lean, the piston's melting' approach is a rather theoretical approach, maybe based on 2-stroke racetrack stories. You have an EFI engine, used most of the time at 25% of its full potential only.

 

The real bodger tries things out first and asks for absolution afterwards, btw.

 

Hubert

Hi

 

think I just posted an empty reply, apologies. To answer your question, I would take the inlet manifold off and heliciol it. Do not do it in situ becuae it will take only one loose flake of metal to destroy your cylinder liner - this is an almost certain outcome. Also if you do not feel confident doing a heliciol you can take it to your local engineering who won't charge you much.

 

Consequences of a leak depend on how much of a leak. Connecting the two nipples together with a rubber tube will work for a while until the rubber gets hard. As Hubert says, intila signs will be an erratic surging idle which should be warning enough. If you ignore this you will get to the stage where the beat will spit back through its injector and blow the inlet rubber off - that should get your attention. Very unlikely to seize a motor through lean running, although I have met a guy who fitted Mistrals and K&N cones to a nion lambda sensored V11 without a Power Commander and had a nip which cracked the cylinder - so it CAN happen, but you'd have to screw it to do so.

 

My advice - go with a helicoil, the kit is £20, job including takeing the inlet manifold off is about two hours. Make sure you apply Hermetite or similarto the inlet manifold agsket and make sure all your rubbers are done up tight. V11s are very sensitive to leaks in the engine to injector rubber. Airbox rubbers do affect the bike but to a lesser extent.

 

Hope it all helps.

 

Guzz

[68C]

As we always said in the Army, 'It is easier to beg forgiveness than seek to permission'. Just bodge it.

[Gio]

Thanks again for all the advice. I share your concern re the risk of flakes guzzimeister (I guess we are not as brave as Hubert!). Just waiting on another possible option (a used manifold) ... but otherwise the urge to bodge will be hard to resist.

 

Cheers,

 

Gio

 

PS - do we still award bodge points ... and if so can they be converted to airmiles or ?

[luhbo]

It's in fact not a big thing to remove the manifolds and bore them 'offline'. The idea of adding a bit of grease to catch most or hopefully all of the resulting flakes is not one of my ideas but more or less common practice when it comes to repair torn plug threads.

You better stay on the safe side, it's your engine.

 

Hubert

[jrt]

Geez, it's too easy to remove the manifold(s) to worry about it. 3 bolts and you're done. Then you don't worry about metal flakes. If you don't have the money for a helical, then drill and tap it oversize.

FWIW, I have mine set up with a balance tube running across both sides all the time. Seems to run just fine.

 

 

Now, if you really want to bodge it, then buy a very small rubber cork and stick that in the existing hole. Carry spares in your pocket, that'll be good for a laugh. Or better yet, wrap the intake manifold in saran wrap.

Sorry, too much wine.

[Gio]

Geez, it's too easy to remove the manifold(s) to worry about it. 3 bolts and you're done. Then you don't worry about metal flakes. If you don't have the money for a helical, then drill and tap it oversize.

FWIW, I have mine set up with a balance tube running across both sides all the time. Seems to run just fine.

 

 

Now, if you really want to bodge it, then buy a very small rubber cork and stick that in the existing hole. Carry spares in your pocket, that'll be good for a laugh. Or better yet, wrap the intake manifold in saran wrap.

Sorry, too much wine.

 

I'm not so sure it would be as easy as 3 bolts jrt ... I suspect the main problem would be removing the original (12+ year old) throttle body rubbers (which are now nice and hard) and possibly getting the manifold gasket to re-seal. Then I would need to replace the balance nipple with another size etc etc

 

I think the balance tube solution is perhaps the easiest ... and even if this hardens or leaks, tube is easy to replace. And yes - little Chianti corks would be cool!

 

PS - why exactly are you sorry about too much wine ..? Send some my way if it becomes intolerable

[jrt]

 

I'm not so sure it would be as easy as 3 bolts jrt ... I suspect the main problem would be removing the original (12+ year old) throttle body rubbers (which are now nice and hard) and possibly getting the manifold gasket to re-seal. Then I would need to replace the balance nipple with another size etc etc

 

I think the balance tube solution is perhaps the easiest ... and even if this hardens or leaks, tube is easy to replace. And yes - little Chianti corks would be cool!

 

PS - why exactly are you sorry about too much wine ..? Send some my way if it becomes intolerable

 

I'll have to look at mine...I've been thinking about my Eldorado recently, so I have that on the brain. It really shouldn't be too hard to take the intakes apart though. Are new gaskets available?

 

I'll pack that wine up post-haste and get it right out to you!

[Gio]

 

I'll have to look at mine...I've been thinking about my Eldorado recently, so I have that on the brain. It really shouldn't be too hard to take the intakes apart though. Are new gaskets available?

 

I'll pack that wine up post-haste and get it right out to you!

 

I'm sure that new gaskets are available, as would new intake rubbers should the hardened one crack during removal (!) ... but this is how these things go sometimes - one thing leads to another. So if I start to add up the cost of the helicoil kit and possibly gasket and rubber ... a small dab of JB weld starts to look way easier/cheaper. Plus I get a bodge point!

[jrt]

OK, I just looked at my bike. The manifold is still 3 bolts (on mine). Loosen the rubber intake boots on both sides (after you remove the gas tank) and it really shouldn't be much trouble to remove both injectors (just pull them back). Then removal of the intake is a piece of cake.

I have to admit that I'm biased- I wouldn't ever drill and tap a part without removing it. The possibility of swarf in something that matters is too much for my weak constitution.

JB weld I view as a 'side of the road' fix. Well, except that one time on one of my old BMW. There it seemed to last. JB weld is basically a usable, but inelegant fix. Yes, it's cheaper. But it looks cheap. If you go that route, then make sure to clamp the balance nipple in so it's a good seal. And use rubber-toothed wood clamps, so you don't mar the intake or other metal surfaces. Just saying'....not like I've ever done that.

Or, pop the manifolds off, send them to me, and I'll drill and tap them out to the next thread (M5?, I'd have to look).

[Gio]

OK, I just looked at my bike. The manifold is still 3 bolts (on mine). Loosen the rubber intake boots on both sides (after you remove the gas tank) and it really shouldn't be much trouble to remove both injectors (just pull them back). Then removal of the intake is a piece of cake.

I have to admit that I'm biased- I wouldn't ever drill and tap a part without removing it. The possibility of swarf in something that matters is too much for my weak constitution.

JB weld I view as a 'side of the road' fix. Well, except that one time on one of my old BMW. There it seemed to last. JB weld is basically a usable, but inelegant fix. Yes, it's cheaper. But it looks cheap. If you go that route, then make sure to clamp the balance nipple in so it's a good seal. And use rubber-toothed wood clamps, so you don't mar the intake or other metal surfaces. Just saying'....not like I've ever done that.

Or, pop the manifolds off, send them to me, and I'll drill and tap them out to the next thread (M5?, I'd have to look).

 

Thanks for the kind offer jrt - but already went the JB weld route ... carefully cleaned up the remaining thread with a tap and some brake cleaner / cotton bud - then used just a small amount of JB on the threads and either side of the alu washer on the damaged (left) side, and regular loctite blue on the other.

 

Gio

 

(PS - thread is 6.0 x 1.00 with a 5mm hex on the original plug)

[jrt]

Thanks for the kind offer jrt - but already went the JB weld route ... carefully cleaned up the remaining thread with a tap and some brake cleaner / cotton bud - then used just a small amount of JB on the threads and either side of the alu washer on the damaged (left) side, and regular loctite blue on the other.

 

Gio

 

(PS - thread is 6.0 x 1.00 with a 5mm hex on the original plug)

 

Good to know- and I'm happy to hear you have it fixed. Now you can get out there and have fun.

We've been having unbelievably nice weather hear in St. Louis. I'm sad that I missed a chance to ride today (25 C and sunny!!!). Damn work.