Cyl Head coolant plug - ZR-1 Net Registry Forums

tpepmeie · 09-14-2016

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.

#attentiontodetails LOL.

GOLDCYLON · 09-14-2016

Don't forget the crank plugs as well.

tpepmeie · 09-14-2016

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

GOLDCYLON · 09-14-2016

Quote:

Originally Posted by tpepmeie

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

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

Paul Workman · 09-14-2016

Quote:

Originally Posted by GOLDCYLON

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 · 09-14-2016

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 · 09-14-2016

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

secondchance · 09-14-2016

Quote:

Originally Posted by efnfast

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 · 09-14-2016

Quote:

Originally Posted by GOLDCYLON

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

Twice the fun!

efnfast · 09-15-2016

Quote:

Originally Posted by secondchance

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.

09-14-2016	#1
tpepmeie Join Date: Aug 2005 Location: Fishers, IN Posts: 814	Cyl Head coolant plug 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. #attentiontodetails LOL. __________________ Todd ____________________________________ *** our email address has changed! info@pepmeierengines.com pepmeierengines.com Friend us on Facebook too: www.facebook.com/profile.php?id=100011443683384 Pepmeier Engine Development

09-14-2016	#3
tpepmeie Join Date: Aug 2005 Location: Fishers, IN Posts: 814	Re: Cyl Head coolant plug That's been done already, spot welded in place. __________________ Todd ____________________________________ *** our email address has changed! info@pepmeierengines.com pepmeierengines.com Friend us on Facebook too: www.facebook.com/profile.php?id=100011443683384 Pepmeier Engine Development

09-14-2016	#6
FU Join Date: Mar 2004 Location: Found Member Posts: 4,346	Re: Cyl Head coolant plug 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. __________________ Frank Urbo. NCM Lifetime member # 982 Registry Founding # 237

09-14-2016	#7
efnfast Join Date: Nov 2011 Location: Dunbarton NH Posts: 7,451	Re: Cyl Head coolant plug But, if you stake the freeze plugs in place, aren't you defeating their purpose?

09-14-2016	#2
GOLDCYLON Join Date: May 2007 Location: Peoria, AZ Posts: 9,155	Re: Cyl Head coolant plug Don't forget the crank plugs as well. __________________ GOLDCYLON - 91 ZR-1 #2014 GOLDCYLON - 90 ZR-1 #2794, 4L60e (Formerly Schrade's) GOLDCYLON - 11 CTS-V Arizona State Director 91 WHITE/BLACK #2014. 380 P&P&PCed,Ported Heads, Jeal Long tubes, Corsa Exhaust/FIKSE FM-5s /LED TLs, LED Headlights, Front Wilwood 6 piston narrowlite calipers and rear Wilwood caliper street shop mod,CNCed Coolant Pipes,TPI Cvr,Filter cover,Stainless Bolts, DRM/DOM PROM /ZFDOC mod build #102,DRLs,BMAD with stainless Debris Screen,Coplan Air Blaster, Pioneer APP Radio 4,Brey-Krause HB,Sub Bar,Fire extinguisher seat mount,DRM Coilovers,LEDs everywhere,Compass mirror (orange),V1 DIC hidden display, Homelink sun visor, Carbon Fiber top x3 and APSIS Carbon Fiber interior, APSIS CF Steering Wheel/NAPA Leather, Banski trailing arms, Guldstrand front suspension,urethane bushings from Prothane (total suspension) ZFDoc drive shaft safety loop, raptor shift light (orange),AO engineering louver front plate, Console seat cushion, 96CE seats with black custom Sheepskins, ss billet catch can,Viper remote entry/alarm,Cragar Rear Louvers,LED side louver lights, Dewitts Radiator with SPAL fans and a Woods 160 T-Stat 90 RED/BLACK #2794. 4L60e Automatic Stage V by RPM Transmission, TCI Dedicated TCM, OBX Stainless Headers, Corsa Exhaust, SAN Secondaries and Haibeck PROM, Exotic Muscle Coil overs, LED Interior Lights, LED Tail Lights, LED Headlights, 94 Sport seats with black custom Sheepskins , Cragar rear louvers, GS Front calipers, Banski Trailing arms, APSIS Carbon Fiber steering wheel, Front and Rear Baer Eradispeeds, DRLs, Guldstrand front suspension,urethane bushings from Prothane (total suspension), Dewitt's Raditor with Dual SPAL fans and a Haibeck 170 T-Stat 11 RED/GREY CTS-V