Core Plug - Fiat Twin Cam

[jon_cox]

I am looking for some advice please. Due to a house move and subsequent extensive renovation my Marlin Roadster has been sat in my parents garage for the last 2 years. I am now ready to move it home and get it ready for the road again. It started first time which is great but it had no water in the cooling system. On closer inspection it looks like the core plug has been pushed out. Probably due to the coolant having no antifreeze and the cold weather causing it to freeze and expand. My question is this..... Can I put the old core plug back in or does it require a new one. If so does anybody have one for a 1800 Fiat TC. Any advice around this subject is gratefully received.

[h_m_cumming]

Re: Core Plug - Fiat Twin Cam

Hi Jon, if it's like the 2l I've got it is 40mm and there are 5 of them, 4 under the ex. and 1 at the rear.
I would have thought that a main Fiat dealer should be able to get them as the block was used extensively in several guises. Some main motor factors may also carry stocks of core plugs. If one has popped I would consider replaceing them all as if it's frozen there's a good chance the others will have been strained. They should sit just under flush, (about a mm.) with the surface of the block. They are a slight taper fit so should not be re-used, although as a last resort I suppose you could with some Loctite.
Hope this has been helpful. Hugh

[stevejgreen]

Re: Core Plug - Fiat Twin Cam

Core plugs only have to resist the water pressure in the galleries. Normally no more than 15psi.
It's quite common when fitting new ones to use a bit of silicon sealant around them before pressing them in.
Much as Hugh says, I would not personally trust a core plug that has been pushed out by ice and others could be suspect. Replacing all of them would be advisable.

Also as Hugh says, main dealers, but it might be worth talking to www.guy-croft.com probably the best fiat engine tuner around.
Check out his forums.

[h_m_cumming]

Re: Core Plug - Fiat Twin Cam

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=150275862488&ru=http%3 A%2F%2Fshop.ebay.co.uk%3A80%2F%3F_from%3DR40%26_np mv%3D3%26_trksid%3Dm570%26_nkw%3D150275862488%26_f vi%3D1&_rdc=1

Have a look at this. I've delt with him and he's very helpful.

[djj_engineer]

Re: Core Plug - Fiat Twin Cam

Might be worth doing a compression test on the cylinders. I lost a MGA engine that had been frosted. Took me a sledge-hammer to get the 2 pistons out of the block

[James]

Re: Core Plug - Fiat Twin Cam

Thanks Hugh for my moment of mirth. The first time I've heard of someone having four core plugs under the ex. ;-)

[jon_cox]

Re: Core Plug - Fiat Twin Cam

Thanks guys for all your help. Hugh, the core plug that has popped is on the carb side of the engine, just above the starter, there is only one.
Derek, hopefully no further damage. The engine started first time and I could see no evidence of water in the oil but until I get a chance to repair the core plug and run it up to temperature I guess I won't know for sure.

[h_m_cumming]

Re: Core Plug - Fiat Twin Cam

****** forgot about that one. Have you managed to source a new one yet? Engine looks nice-is it a GC tuned one or have you just used the pic?

[jon_cox]

Re: Core Plug - Fiat Twin Cam

It used to look like that many years ago. But sadly not now. I stole this picture from GC's forum to use as the example. I bought my engine from a place in Street, somerset called Avanti Motorsport back in 1990. Fully rebuilt and blueprinted but nothing more. It runs twin IDF's which gets the power up to around 120bhp. Not bad for the 1800.