boss 351

Mustang Australia

Author Topic: boss 351  (Read 3590 times)

Offline snafu

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boss 351
« on: January 18, 2018, 09:58:40 am »
Can anyone help me , did the 71 boss 351 engine have screw in freeze(welsh) plugs or not? i,ve heard the 302 did but not the 351, thanks in advance

Offline GLENN 70

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Re: boss 351
« Reply #1 on: January 18, 2018, 10:12:23 am »
The 71 Boss 351 did not ,but let someone prove me wrong  :grin:

Offline snafu

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Re: boss 351
« Reply #2 on: January 18, 2018, 11:13:33 am »
yes i think your right, all clevelands apart from ford racing ones had pressed  :thumb:

Offline Sundance Kid

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Re: boss 351
« Reply #3 on: January 18, 2018, 03:12:00 pm »
Hi i'll have a look to be sure but from memory only Boss 302 /   unqiue windsor block cleveland had them .cheers
1970 boss 302 mustang

Offline skip70

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Re: boss 351
« Reply #4 on: January 18, 2018, 03:14:58 pm »
No screw in freeze plugs as standard fitment.

Offline mcarnage59

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Re: boss 351
« Reply #5 on: January 18, 2018, 03:38:40 pm »
Hi everyone,

Can I ask why people refer to them as "freeze plugs" aren't they welsh plugs and a product of the sand casting process?
Always dreamed I'd have one!

Offline GEOFF289

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Re: boss 351
« Reply #6 on: January 18, 2018, 05:15:08 pm »
I think they tend to be called freeze plugs in the US because in the absence of correct anti freeze that actually happens in many parts over there and pushing out the plug as the path of least resistance is better than cracking a head or block or something when frozen coolant expands compared to its liquid form. I think welch plugs are just a bit of local idiom.

Either that or I'm completely wrong.

Offline booah

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Re: boss 351
« Reply #7 on: January 18, 2018, 05:55:17 pm »
We used to have to remove the freeze plugs/ frost plugs to install an electric block heater, depending where you lived it could be one or one on each side. Don't miss those days, brrrrr

Offline mcarnage59

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Re: boss 351
« Reply #8 on: January 19, 2018, 08:31:50 am »
I think they tend to be called freeze plugs in the US because in the absence of correct anti freeze that actually happens in many parts over there and pushing out the plug as the path of least resistance is better than cracking a head or block or something when frozen coolant expands compared to its liquid form. I think welch plugs are just a bit of local idiom.

Either that or I'm completely wrong.

Ok I thought they were part of the casting process primarily. Its a wonder they included them in Aussie built cars. Back in the dim dark ages I was returning for Barwon heads after setting up my mum and dads Xmas holiday camp. It was very hot 40C and the old XR did'nt like heat at all.  One of those things where you were frightened to stop as the only thing stopping it from boiling was the air flow at speed. Poor old beast blew one of the little welsh plug's out the side of the head.  :cry: No mobile phones in those days.
Always dreamed I'd have one!

Offline GEOFF289

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Re: boss 351
« Reply #9 on: January 19, 2018, 08:54:27 am »
Maybe we should call them boil plugs or something here?

I guess virtually all Australian engine block casting is using the same tooling as used in other parts of the world. Your old XR Falcon, whether a 6 or 8, was running an engine the same as US Fords of the era.

Exceptions might exist in GM products but even the original Holden grey motor was based on the Chev blue flame 6 pack engine series. I'm not so sure about the red and blue Holden 6's and I guess the 253/308's were entirely indigenous.

Offline D0ZX

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Re: boss 351
« Reply #10 on: February 03, 2018, 09:48:21 am »
No Cleveland ever came with screw in plugs. This includes XE Nascar blocks. They can be fitted, Ford used to stock them. Have installed them in my block that I am using. Thirsty 390 helped with sourcing a tap.

A friend of my dad nearly cooked an engine when it spat a standard welsh plug out. I don't trust press in plugs.