Coolant In The Exhaust

On the '65 Rubicon rig, 225 oddfire. I've noticed since this motor was first assembled that there was an intermitent coolant smell from the exhaust. So much so, that just after it first ran, I pulled the heads to check for head gasket issues and found nothing. It runs great, and there is no water in the oil, or any pressure visible in the radiator. We have lived with it, and I only notice it after it has sat for a few weeks, and only until it is up to temperature. It still is nagging at me, and recently when I went to move it, and the unmistaken smell was coming out the tailpipe, I decided the time is now to dig deeper. I noticed a drip under the number 3 cylinder exhaust port, (so I guess the exhaust gasket is leaking, or has blown out there), pulled the header off, and I've got a little Artesian spring going there.

I pulled the intake and head, and it's hard to tell because I got coolant everywhere when the head came off, but I don't see any rust in the chamber, so I don't think it's getting into the chamber.

So what say everyone? Cracked head?

 

Yep.....Me thinks so. Besides the coolant smell, do you get the tell-tale white smoke ? I'm curious......What's downstream of your headers ? However, on Cold start , My 231 Turbo with a straight exhaust pipe, will produce & even drip Condensation outta the tail. Just Say'n

 

Hopefully it is not a crack. Have it magnafluxed.

 

Symptoms do seem like a cracked head.

 

White smoke (really steam) and condensation, but that's normal when cold. It's the smell of coolant.

 

I think that's where this is going.

 

...... Sorry Tim. Cracked heads can make one

 

Is that a casting parting line about 1/3 from the top of the port in the first picture? Seems too irregular of a line...

 

Hmm, now that I zoom in, don't know. Now that it's off, it's not going back on without being checked professionally.

 

It doesn’t look like any coolant is getting into the combustion chamber, but you could till have a crack from the water jacket into the exhaust port. Most shops can magnaflux the head to check for cracks. It pretty reliable.
You didn’t do any porting in there? Did you have hardened seats installed?
-Donny

 

My 3 cents ( Inflation, Ya Know ) is like Donny has diagnosed . Have you had any extreme ( Cold ) temp's out your way ? . Likely not the cause , as that would hopefully blow a freeze plug first, but I'm always .
Any Hoo , if a crack in that area is found, most likely it's been a weak spot from when it was made....... A long time ago, Eh ? Good Luck to you , Tim, you'll get to the bottom of it, + you've caught it early enough .

 

I am thinking if it's cracked, yes, from the water jacket to the exhaust port. And yes, it does have hardened seats. That's a thought.

 

I have a KwikWay headshop (machine for most cylinder head rebuilding) and have done a lot of hardened seat work in the past. When cutting the seat area down to accept hardened seats, a cutter is sized for the seats to be installed. With wear on the cutter, or “different” brand seats, there can be a tighter interference fit. Also, I have come across heads that were cast with a “core shift” where the water jacket is offset from ideal. Either of these factors can cause the head to crack when driving the hardened seats in the head. I have seen this a time or two. The replaced seat is likely the source of your crack/leak.
-Donny

 

......Thanks Donny.
It's cool to always learn things from Y'all.

 

Danny from DB Heads in Carson Valley not only answered the phone, he said get it down to him. Don't have to tell me twice, so I ran it (and another spare head I have) down to him. First thing he said was what Donny said. Probably the seat got into the water jacket. But we'll see after he magnafluxes it. I took the other head to hopefully save me a trip if it's cracked. And actually the valve seat scenario probably isn't worth fixing either, so he has another head to machine for me.

 

X2. Thanks Donny, I think you are correct.

 

I firmly believe in having an expert inspect and measure before I rebuild any engine. Many of us can put it back together and save some money but don't have the proper tools and experience to inspect the components. We had a machine shop locally that would do just that and it really wasn't a lot of money. He did all the reconditioning, and he would also order the rebuild kit for you and answer a few questions while you assembled at home. I miss that place.

 

Well, Danny called and said it's not cracked, but the hardened seat on the number 3 exhaust valve got into the water jacket. So he (and @Keys5a ) were right. My dad had the heads done somewhere back in about 2006, so that's when that happened. My machinist said it's common with hardened seats. Is that because they are deeper? I didn't get a chance to ask. He said I could pick up the replacement head this weekend. That is if the monster 10 foot storm all blown up by the media doesn't crush me first.

 

Not a machinist but they probably cut the pocket for the seat and that brought it very close to the water jacket. Probably close enough that it wore through by erosion or it didn't show up as a leak initially because the seat sealed it. That's a shame it can't be fixed. It's probably just a pin hole under the seat. I'm glad I found this thread in case I have to go this route in the future.

 

I‘ve got.a nice set of oval port big block Chevy heads I put larger valves/seats in about 10 years ago. When blending the ports to the valve seat, I went through to the water jacket on a port. I then started probing with a pick, and poked through 3 more into the water jacket. Thats when I learned about a “core shift” in the casting process. The water jacket wasn’t perfectly centered where it was supposed to be around the valves and runners. With mine, one side was thicker, and the other side thinner. Apparently not uncommon. It doesn’t cause a problem until you start cutting into the iron for things like seat pockets or larger valves.
I still have those heads on a shelf. I may take them to a shop that can weld up my thin spots, but its expensive!
-Donny