engine core plugs

[flimsyboat]

Hello all I am about to replace my engine core plugs but the replacements I have are curved which way do these fit, curve inwards or outwards?
Many thanks
Rob

[mikeyb]

only fit curved ones to places where you removed curved ones - usually behind distributor.

otherwise you need the cup shaped ones

[Paudman]

The curves face out ie the hump is to the outside. If you buy a kit they'll have the correct mix of curved and cupped. Hopefully....

[Casper]

The curved ones are 'Welch' or 'Hubbard expansion' plugs.  See http://www.britishcarweek.org/welch_plug.html
and http://www.google.com/patents/US1058210?dq=1058210

They need 'upsetting' (i.e. deforming by indenting the centre) so as to fit properly.
See http://www.hubbardspring.com/install_reco.php?cid=45
I generally use pretty much any flat drift.

C.

[mikeyb]

490 wrote:

The curves face out ie the hump is to the outside. If you buy a kit they'll have the correct mix of curved and cupped. Hopefully....

oops sorry, I forgot to add that info   :-/

[flimsyboat]

Thank you very much for help the plugs that need replacing are those under the manifolds so I am presuming I have the tright ones as I indeed have a kit

[mikeyb]

ah just done those myself, these were the cup type.  Have a read of my blog and you'll see what I found!

http://triumphandadversity.blogspot.com/

[ferny]

Really early cars had curved ones? I think, anway... Could include 1600 Vitesse?

[Casper]

Quote:

Really early cars had curved ones?

Herald 1200 engines up to GA178101HE - i.e pre 'hot cam'.  This was about Nov '64

AFAIK they were fitted as an engine set (collar and cuffs) but of course heads get changed over time.

Don't know about the Vitesse 1600

C.

[willows40]

when i had my 1600 vitesse that had the curve core plugs

cheers andy

[dave mc]

Instead of starting a new thread, I thought i would ask my question about core plugs on this recent thread.

What is the reason for replacing core plugs? Is it simply to avoid future hassle? My engine hasn't run for about 20 years but I have turned it over on a regular basis. It will be going back into its rolling chassis before too long and is going to get the usual new paint treatment etc but I wonder if i should replace the core plugs.

What is the reason please?

[Nick Jones]

They corrode from the inside and sometimes give way and leak.  Degree of corrosion depends on antifreeze type, concentration and how often changed over the years (good antifreeze contains corrosion inhibitors).  They are cheap and reasonably easy to change and much easier to change when the engine is out apart from a couple which are behind the engine front plate and a pain to change at all times.

Nick

[dave mc]

Thanks Nick, that's a good concise answer. I'll buy a new set.

[garyf]

It's worthwhile having a poke around the waterways with a coat hanger or similar homemade tool to remove the crud!

It should help the Car run Cooler, I was amazed what gunk came out of my Engine ??)

[dave mc]

How did you remove the muck Gary?

[Clive]

Bits of wire, coathanger, and I have used lengths of handbrake cable or similar too as it gets around a few bends. I have also had the jetwash out too, give it a good blast. Don't forget the block drain plug, under the back end of the manifolds. Amazing what collects around there.

[ferny]

Nick_Jones wrote:

They corrode from the inside and sometimes give way and leak.  Degree of corrosion depends on antifreeze type, concentration and how often changed over the years (good antifreeze contains corrosion inhibitors).  They are cheap and reasonably easy to change and much easier to change when the engine is out apart from a couple which are behind the engine front plate and a pain to change at all times.

Nick

Or when you're in a rush in winter and say to yourself when you're working on your car and it's getting late, "I'll just add some water now, drain and refill with anti-freeze later"...
Not that I've ever lost a core plug from the water in the block freezing and I most certainly didn't discover it was gone after a five mile drive!  :B

[willows40]

ferny wrote:

Or when you're in a rush in winter and say to yourself when you're working on your car and it's getting late, "I'll just add some water now, drain and refill with anti-freeze later"...
Not that I've ever lost a core plug from the water in the block freezing and I most certainly didn't discover it was gone after a five mile drive!  :B

glad i`m not the only one to have done that ;D

[Nick Jones]

I once had the core plug pop out of the back of the block on my Herald (original 1200 with dished type at that stage).  Poor seal on g/box tunnel meant that the cabin filled up with funny smelling steam and my shoes filled with very hot water......  Not ideal but did mean I didn't need a temperature gauge to tell me I had a problem!

Nick

[marktheherald]

I once had a core plug on the front end of a Reliant 750 sidevalve blow straight through the radiator....

Fit new ones while the engine is out for peace or mind.

[garyf]

2191 wrote:

How did you remove the muck Gary?

Pretty much the same way as Clives description, I used a Garden Hose to blast some of the Stuff out ??)

You can never get all the Gunge out, but some is better than none!

I reckon my Car had been run without Antifreeze, although it was off the road for 5 years  :-/

[dave mc]

I eventually made a start on the core plugs at the weekend and took the four out that run under the manifolds.

Was amazed at the amount of clogged up rust/silt that was sat behind them.

The drain plug will unscrew quite easily - so what's best - power jet through each hole until its running freely out of the drain plug?

[Paudman]

Backwards, forwards, tilt the engine, turn it upside down if you can - get the water flowing in every conceivable direction until all the grit and crud is out. Get the jet into every plug point and drain from as many directions as possible so that all obstructions get a chance to drain out. If you're going to do it, do the best job you can for peace of mind. Proprietary kettle descaler removes a lot of the solid build-up (depends on the brand), if you can fill the system with a solution and leave it as directed - not so long that it starts eating its' way out tho...

[dave mc]

OK thanks - doesn't sound too difficult and definitely worth doing properly before engine goes back in.

[dave mc]

Front core plug is a bit of a pig isn't it? Timing sprockets and end plate off!!!

To be fair, was going to replace the timing chain and sprockets anyway along with the oil seal.

Hope I can change the sprockets without upsetting the timing. Any tips anybody?