Rusty exhaust valves??

[PeteyDaMan]

Hey all,
I've been noticing a change in the exhaust note on my 512 and some blow-by over 3000rpm.

I built the engine myself a few years ago and have around 1500 miles on it. Some of it full tilt boogie on the back roads.

I did a leak down test and found cylinders 7 and 8 really bad (like 45-60% blow by) and a lot of it is coming out the exhaust ports.

I stuck a camera in the cylinder and found rust on the exhaust valve3 on #8

The heads were new in the box Eddy Perfomer RPMs when I built it along with cometic head gaskets.
Head bolts (ARP) are tight to spec (70ft/lbs as per Eddy)

The car is always stored indoors, never sees rain or snow.

Lastly, I have noticed the coolant looks muddy. I checked and there's no oil in it nor coolant in my oil.
I also check for combustion gasses in the radiator and it passed that as well, but I'm beginning to doubt the validity of that test.

I'm going to have to tear it apart but wondering how to check for cracks in the block or heads.
Should I leave it together ad take in to an engine builder for diagnosis?

I'm pretty knowledgeable on engines and have built a number of them over the years but this was my first, full-on, Hi-Po build (est 600+ hp)
(forged Eagle rotating assy, Mahle coated pistons 10:5-1, aluminum heads, roller billet cam, etc)

Love to hear your thoughts

 

[69Bee]

Stainless steel valves do not rust. Post some pics to be able to ascertain the problem better. Also, ARP head bolts are torqued to 80 ft/ls, not 70ft/lbs.

 

[PeteyDaMan]

Stainless steel valves do not rust. Post some pics to be able to ascertain the problem better. Also, ARP head bolts are torqued to 80 ft/ls, not 70ft/lbs.

Yep, my bad, the valve seat is rusty, not the valve.
As for the head torque, I'll have to double check what I did. I checked with the torque wrench and they didn't move up to 70, but didn't try to 80.
I'll see if I can get some pics

 

[pnora]

Cant see rust with aluminum heads and SS valves. Blow-by and combustion leaking past the exhaust valves together does not seem right. Unless your valves were not closed completely.

 

[69Bee]

Yep, my bad, the valve seat is rusty, not the valve.
As for the head torque, I'll have to double check what I did. I checked with the torque wrench and they didn't move up to 70, but didn't try to 80.
I'll see if I can get some pics

Yes, Edelbrock states 70ft/lb, but that is with stock or Edelbrock bolts. You used ARP head bolts and must then follow their installation procedure on their instruction sheet. It states 80 ft/lb and to use their assembly lube for that torque. On a personal note, I would never use OEM bolts on aluminum heads because you will tear up the head bolt seat. The OEM bolts have a thin shoulder used to clamp the head (for cast iron), and will easily tear up an aluminum head. That is why ARP includes hardened washers for their bolts or studs as it provides more surface area for the clamp force, and won't tear up the head bolt holes

 

[4speed68rt]

Ring seal issue, possibly. Not even broke in yet. Maybe you have real hard rings and one or two of the cylinders are a little off or scratched. Aluminum or SS doesn't rust.

 

[PeteyDaMan]

Here's a couple pics of the valve seat

Also found the installation card for the head bolts and it specifies 70 ft/lbs

 

[69Bee]

You are good on the bolt torque. I looked up a Pro series kit. If you take the heads off (recommended), you will need some more ARP assy lube. You could have a coolant leak from an exhaust manifold fastener, and it is going into the exhaust port. Head are going to have to come off for a valve job and mill (done properly for aluminum!!) as a minimum.

 

[pnora]

Its most likely from condensation. However that exhaust valve looks to be burnt.

 

[RemCharger]

I've seen mysterious condensation from cylinder walls before

 

[PeteyDaMan]

Its most likely from condensation. However that exhaust valve looks to be burnt.

Yea, I was wondering if it was burnt.
Well off with the heads!!!

 

[RemCharger]

Yea, I was wondering if it was burnt.
Well off with the heads!!!

What better time for some bowl cleanup!!

 

[BSB67]

What do the plugs look like? Is there white smoke at start up? Did you do a cranking cylinder pressure test?

You have conflicting info. Just guessing, you have a coolant leak or two from either the exhaust port or head gasket. The rust is from the block iron in the coolant.

 

[PeteyDaMan]

I didn't do a cranking test. I may do it tomorrow.
The plugs look a little crusty as well around the end of the threads but the electrode and insulator look fine. I post some pics of those as well.

Never had any white smoke from the exhaust that I noted but there was a bit more rust that came out of the exhaust system on disassembly than I would expect for a fairly new build

I don't think I have an exhaust port coolant leak as the header bolt holes are blind and do not go into the water jacket on the Eddy RPM heads, although the head gasket could be compromised.

 

[BSB67]

I didn't do a cranking test. I may do it tomorrow.
The plugs look a little crusty as well around the end of the threads but the electrode and insulator look fine. I post some pics of those as well.

Never had any white smoke from the exhaust that I noted but there was a bit more rust that came out of the exhaust system on disassembly than I would expect for a fairly new build

I don't think I have an exhaust port coolant leak as the header bolt holes are blind and do not go into the water jacket on the Eddy RPM heads, although the head gasket could be compromised.

Crack in exhaust port. I have seen this. However, seem unlikely in both heads.

 

[PeteyDaMan]

Here's a look at the plug from #8
Looks to have the same rust/deposits on it

 

[BSB67]

Here's a look at the plug from #8
Looks to have the same rust/deposits on it

View attachment 1508342

Right. But what do the rest look like?

 

[PeteyDaMan]

Heads off. Gaskets look good but is this detination damage? It's not pitted, just marked up

 

[PeteyDaMan]

This is the #8 cylinder from the earlier pics

 

[PeteyDaMan]

And the 2468 cylinder bank