Thread spec - inlet manifold port to heater rail (for bung)

[Pupp]

One for the guys who have done the full under manifold plumbing trick - anyone know what size bung is needed to delete the side spout that connects to the heater on the driver's side?

I'm trying to do away with the really tight silicone 'U' bend I currently run and am assuming there is meat enough on the lug below to safely tap in a 1/2BSPT to 15mm compression fitting... sure that's what I have seen used

[Sardonicus]

1/2 BSP Gary

[Pupp]

Thanks Simon

[Pupp]

Right - slight technical hitch on this as have managed to get the new compression spur jammed in the new thread I've cut in the rear of the lower boss; think it galled on going in... it'll either come out with stilsons (yuk - but no flats worth the name left on it), or will be drilled and picked out (carefully) - biggest issue is holding the manifold to use some decent body English on the thread cutting (tapered thread and think I'd not formed enough depth). If anyone is contemplating it, there's certainly loads of meat on the back of the boss to accept the fitting so no worries there (as long as you don't stuff up the install )

Really frustrating as it's a very neat mod and just gets rid of a load of clutter obstructing access to the alternator connections (amongst other benefits).

The corresponding tap into the water pump top went a treat

[Sardonicus]

Hi Gary can you not die gring the center of the barb/boss untill you meet the now weakened threads then just undo are you on about this boss ? ..........................

[Pupp]

Yes Simon... that's the chap... burr grinder inside is a good idea. I is loaded with some good thread sealant 'though

[Sardonicus]

Pupp said:

Yes Simon... that's the chap... burr grinder inside is a good idea. I is loaded with some good thread sealant 'though

Take your time and once the thread break through is wafer this a quick twist and the circumference of the bung/barb will collapse away from the threads even thread locked etc, I also thread locked mine too, under manifold loop one of the best mods I did and soooo easy to bleed the system now all the best with this one funny I would have laid money on your car already having this done for some reason mocking up

Edited by Sardonicus on Monday 17th April 21:05

[Pupp]

I did the heater loop under the inlet but never got round to dropping into the pump or picking up the back of the boss... too busy driving it

[Pupp]

Well, this is proving to be tedious - it's all gone bar literally the male threaded part of the fitting.... which, naturally is still largely sitting tight and secure in its comfy home - have cut a few notches in it, ground it to what must be right on the manifold thread tops and still the bugger will not move. Not even a hint of it giving in....can't be that hard, it's only brass FFS

[ClassicChimaera]

I'm taking a keen interest in my water system lately and very much like these under manifold piping etc. Especially the feed pipe from the back of the heads or manifold ? Back to swirl pot.

Is there any old threads on these improvements especially on the location of any holes needing to be bored rather than ask numpty questions here.

[Pupp]

The only hole in the manifold I have made is the one I am now battling to get the fubarred compression fitting out of... ie in to the back of the same boss the oem gauge sensor goes in. Not difficult to bore as there is plenty of material and it's strong there... not quite so easy to tap for the same reasons (which was my error).

I also opened and threaded a hole into the water pump inlet pipe as shown in Simon's pic above; that one is easy (1/2BSPT male to 16mm barb hosetail is perfect to pop in there)

[ClassicChimaera]

Pupp said:

The only hole in the manifold I have made is the one I am now battling to get the fubarred compression fitting out of... ie in to the back of the same boss the oem gauge sensor goes in. Not difficult to bore as there is plenty of material and it's strong there... not quite so easy to tap for the same reasons (which was my error).

I also opened and threaded a hole into the water pump inlet pipe as shown in Simon's pic above; that one is easy (1/2BSPT male to 16mm barb hosetail is perfect to pop in there)

Considering your having a nightmare I appreciate your reply. Thanks.

[Pupp]

No worries; learned a long time ago to do small sessions at a time and leave it when things are not going well - no harm done and it will come out...

[ClassicChimaera]

Pupp said:

No worries; learned a long time ago to do small sessions at a time and leave it when things are not going well - no harm done and it will come out...

My old ma used to hear me cussing in the garage as a kid, crying over another failed puncture repair probably and would come in and just say leave it half an hour and it will work. She was invariably right but not til id tried another 10 times first.

I spent about 4 days and various attempts to remove a broken drill bit that I heavily handed lay broke after shearing off the seat belt bolt that goes through body into rigger. In all my life I've never bust a bolt that big before, pillock,,, then a frigging drill bit. It took many fked cobolt bits before I'd cleaned it out. Then re tapped it, what a palarva.
It only takes a few years off the tools before you turn into a dummy! For me about 6 weeks.
I dunno mate, I just keep smiling now and fk it, it'll work itself out in the end.

[Pupp]

Well, it fought gamely to the bitter end but after careful reduction to almost nothing with a carbide rotary cutter, it finally came out like a depleted brass helicoil... had belted it from behind with a drift but no way was it shifting even given a vastly compromised structure after grinding away. Literally had to pick it out of the threads (which have survived)...

Next!

[Sardonicus]

Pupp said:

Well, it fought gamely to the bitter end but after careful reduction to almost nothing with a carbide rotary cutter, it finally came out like a depleted brass helicoil... had belted it from behind with a drift but no way was it shifting even given a vastly compromised structure after grinding away. Literally had to pick it out of the threads (which have survived)...

Next!

Well done amazing how a job like this can give so much st

[ClassicChimaera]

Pupp said:

Well, it fought gamely to the bitter end but after careful reduction to almost nothing with a carbide rotary cutter, it finally came out like a depleted brass helicoil... had belted it from behind with a drift but no way was it shifting even given a vastly compromised structure after grinding away. Literally had to pick it out of the threads (which have survived)...

Next!

That took some skill and patience I know.

I've just been looking at Rover water piping arrangements and flow etc

[Pupp]

Thanks - completely avoidable and unnecessary of course save for messing up the thread cutting to start with

Be interested to see any links to discussions of coolant flow etc

[Pupp]

Can I just seek a sanity check on this - now all back together and running with the new arrangement but, for some reason, it seems to be chucking coolant out of the expansion tank cap. Filled it using tried and trusted methods and bled various high points, but does seem to be trapping air where it never used to be particularly problematic.

It's not obviously overheating and no HGF symptoms so I'm just putting it down to an old pressure cap and the fact I was running it fairly hard (more mapping) but...

So, just to check I've not dome something daft, the old heater loop line that tapped into the swan neck on the bottom rad hose now tees off the water pump inlet (the tee on the swan neck supplies the turbo); and the other runs off the rear of the boss on the bottom of the inlet manifold. The old outlet on the top of the manifold is blanked. There's no more to it than that is there?

[Pupp]

Right, this is bizarre... took the caps off cold system this morning. Some pressure still there, expansion tank almost full but swirlpot only half full... has taken a couple of litres and more bleeding to get levels right again.
I am now suspencting a head gasket has just decided to let go... ho hum