Stupid coolant LEAK

[Ausydad]

Well, I've just finished a fresh line from the fuel tank to the pump, installed my .454/304 cam, switched to a set of portmatched "L" stamped heads, double roller chain, and Performer intake as well as the March pulley system. I was just about to fire it and break inthe new cam (even though my neighbors won't like it) and filled the radiator only to hear a hissing sound after the rad got halfway. I followed the sound the find a steady stream of coolant coming from the header bolt next to the #8 cylinder. Any ideas on how to fix this without taking off the head again. My wife is already upset about how long I have been driving her Dart.

[dl79]

ausydad, i am far from an expert, and hopefully you get some replies with higher hopes, but that has the sickening sound of a cracked head. if so, i dont know how you could fix it with the head on. hopefully, it is something else, and will be easy to fix. good luck!

[amoparguy]

What kind of sealer did you use on the header bolts?

[Ausydad]

I'm not thinking the head would be cracked as I know it's natural for the last header bolt on each side for a small block to enter the water jacket.My problem I believe is that particular bolt was started crooked. I didn't use sealer on the bolts as I didn't use on the last set of heads and never had a problem. This one is a small but steady stream with no pressure on the system. I can try loosening the header again and see if sealer would help. The only sealer I have is the copper. Would that be acceptable on that amount of heat?

[Secret Agent Toast]

yea, what kinda of sealant did you use? I had a exhaust manifold stud leaking coolant when my car got hot next to cylinder #8. I replaced the stud with a new one & used Teflon tape to seal it, and now it's not given me any more trouble. I don't know if this is a 'permanent' fix, but I'll be replacing the heads in a year and I'll do the research then to see if something better to use as a sealant.

you might already know this, but I didn't, so here goes: the first & last exhaust manifold/header bolts in a small block go into the water passages, and can develop leaks. it's a pisser. It's one of the things I would change about my car if I could.

woops we posted at the same time, and you already know about that. sorry

Toast

[6pakman]

ok aussey dad, heres the deal, just remove the bolt and coat it with rtv sealer, thats the stuff you use on your valve cover gaskets. i use the blue stuff. wait about 1/2 hour then put your coolent back in. that will do it. if it leaks a little bit just warm up the engine . it will seal. i'v done it alot lately because iv' added pwr steering to my challenger and have had to remove the header a couple of times. let me know how it turns out.

[gthomas]

Ausydad, is this the new engine you wrote me about! You going to dyno it? I still haven't got to install my new engine yet.

[dl79]

Guess I learned (once again), better to keep ears open and mouth shut when you don't know what you're talking about. Sorry for that ignorant reply earlier, but I am glad to get that bit of information. No doubt, will come in handy sometime. Just goes to show how us dummies depend on some of you experienced guys.

[Ausydad]

Sorry Gary,
This is not the motor we discussed. This is a few of those parts added with a couple of others to combine this. According to Desktop Dyno, this one should be a good 330 h.p. daily driver. The other motor is still on the stand awaiting new heads (Edelbrock aluminums re-worked), a 360 crank, .060 over pistons, double roller, dry sump with 6qt. reserve, tunnel ram with dual 450 cfm carbs, a .590/312 cam and a 6 lb. nitrous shot. There's a few other tricks to be applied, but we can discuss that through email if you want.

I will try the RTV trick tommorrow when I get home from work.

No problem DL, we all learn from different places. And I'm still pretty ignorant on a lot of stuff, too!

[DAVE JONES]

Hey Ausydad, When I read these posts I got alarmed when you mentioned that the bolt started in crooked. do you think it may be cross threaded or possibly stripped. Did it straighten itself out. My main concern for ya is that you have a real weak thread and a bigger problem about to happen. the only thing I'd like to add to whats been said is that you may want to run a form tap in that bolt hole first. The "form tap" is a special tap that doesnt cut the threads and doesnt leave chips behind. Its the strongest tap made and great for chasing out distorted threads sinces it reforms them back into shape which give them more strength. Just a thought if you think there's a problem with the actual bolt hole.....good luck.....Dave

[Hammer 74]

To add a little more to this post if the threads are damaged a little from cross threading a header bolt you can install a stud with sealant on it. A stud will thread in deeper than a bolt and hopefully fix the leak. Just double nut the stud and screw it in place of the bolt. I have found that header bolts are seldom long enough for a thick flange header and gasket so I try to stud all of them if clearance is there.

[Ausydad]

Thanks again,guys. I've replaced that bolt with a 5/16-18x1 with a lock washer and dipped it in Permatex copper before re-installing it. Got it fired and broke in the new cam. Now I have to re-plug, wire it as well as flush the radiator and change the oil. Hopefully next week, I can atckle the replacement of the oil pan. Any tricks for getting this done quick and easy?

P.S. They really mean what they say when they call the plugs "Splitfires". They fire inside and outside the cylinder!

[70Ted]

On a BB all the header bolts go into the waterjacket.