Cyl Head coolant plug

[tpepmeie]

I know of at least two high-rpm engines which have had the rear coolant freeze plug blow out of the cylinder head. Once was about 10 years ago on a chassis dyno at BG. That was a 415 engine. And just recently a race car suffered the same fate, at speed. There may well be other examples of these plugs blowing out. I think it is usually the driver side.

Not going to take that chance with the new 427 build. 3x #2 drive screws on each head.

http://i1036.photobucket.com/albums/a441/tpepmeie/IMG_0591.jpg (http://s1036.photobucket.com/user/tpepmeie/media/IMG_0591.jpg.html)

#attentiontodetails LOL.

[GOLDCYLON]

Don't forget the crank plugs as well.

[tpepmeie]

That's been done already, spot welded in place.

[GOLDCYLON]

That's been done already, spot welded in place.

Yep. Better safe than sorry. Secondchance and I found out the hard way

[Paul Workman]

Yep. Better safe than sorry. Secondchance and I found out the hard way

I'm a believer! Missed a gear in a 1/4 mile drag race. That's when I discovered how much coolant pressure could spike, in spite of the pressure cap. Coolant blew through a thin spot as result of recent porting. I wouldn't have thought that would happen. But, it did. So, staking the freeze plugs really makes good sense.:)

[FU]

Blew out my D/S head rear freeze out plug on the LPE 385 on a 6.8K shift at BG one year. Coolant on the track at 110 mph can make for a bad hair day.

It's more common that you'd think.

[efnfast]

But, if you stake the freeze plugs in place, aren't you defeating their purpose?

[secondchance]

But, if you stake the freeze plugs in place, aren't you defeating their purpose?

Yes. But very few ZR-1 owner would let the car sit outside in freezing temperature with only water in the cooling system. Don't you think?

[secondchance]

Yep. Better safe than sorry. Secondchance and I found out the hard way

Twice the fun!

[efnfast]

Yes. But very few ZR-1 owner would let the car sit outside in freezing temperature with only water in the cooling system. Don't you think?
And then there's that.

[BigJohn]

Yes. But very few ZR-1 owner would let the car sit outside in freezing temperature with only water in the cooling system. Don't you think?

There is always that one unforeseen time!!!

:(

[efnfast]

There is always that one unforeseen time!!!

:(
Agreed!

[DRM500RUBYZR-1]

There is always that one unforeseen time!!!

:(

Unforeseen will quickly lead to Unforgettable, for all of the wrong reasons.:cry:
Yet, it likely should be done for the stated reasons.

:cheers:
Marty

[tpepmeie]

Just for clarity, there is no chance in #$%^ i'm going to leave a $50k engine out in the cold to freeze, and without any antifreeze at that. Not going to happen. I don't want to spew water all over the dyno room at 7500 rpm, which has been known to happen with these particular plugs.

[Jagdpanzer]

That little core plug at the end of the head won't do squat to protect the engine from freeze damage. Its main purpose is for emptying core sand from that end of the head after the head is cast. In the inprobable event an LT5 should ever experience serious coolant freezing the block and heads will be total scrap afterwards.

[BigJohn]

Up here in the backwoods of New England; we have times when there is no power for weeks at a time !
Is that not correct Steve?

[GOLDCYLON]

That little core plug at the end of the head won't do squat to protect the engine from freeze damage. Its main purpose is for emptying core sand from that end of the head after the head is cast. In the inprobable event an LT5 should ever experience serious coolant freezing the block and heads will be total scrap afterwards.

100% correct. It's a sand casting hole and an expansion plug. The procedure done by the OP is a great way of prevent disaster down the road. Especially if you modify any engine beyond its original and predictable engineering design.

[efnfast]

Up here in the backwoods of New England; we have times when there is no power for weeks at a time !
Is that not correct Steve?
Oh yes it is, and there are days we leave the house at 50 or 60 degrees and come home in sub freezing temps. All that being said, I've always wondered how much good those small holes would do for an engine that froze.

[Mystic ZR-1]

Steve
What about those solar panels?
:)

[BigJohn]

Steve
What about those solar panels?
:)

Solar Panels!

:neutral:

[efnfast]

Those solar panels are great for the house, but do little for the car.

[Mystic ZR-1]

Those solar panels are great for the house, but do little for the car.

Unless you have a Tesla