Valve Replacement

I'm about to pull the block apart to replace all my valves. I'll be swapping the thermostat while I'm in there, and I have roller-rockers on the way. A machinist is going to port match the heads and the IM for me.

... is there anything else I should do while I have it disassmbled like Johnny 5?

Are you doing a full rebuild? I would if I had the block apart. And are you getting the head machined? Replacing seats? seals? etc...

Stupid question, why are you replacing the valves instead of just a valve grind? Don't forget the valve guides. NEVER allow the machine shop to knurl the valve guides, only allow them to sleave the guides. Knurling will last 10-15k miles then they will be worse than before.

Blown exhaust valve. Had some overheating take place one night. Couple hundred miles after the radiator was replaced an exhaust valve blew.

Replacing IM/Ex head gasket, head gasket, thermostat, ALL valves.

I was thinking about doing the piston rings while I was there... anyone got any reason NOT to. ?? I just want to break them in and get full compression. I read an article that WOT new piston rings is the BEST way to make them seat and it makes a huge difference, but you only have the first 20 miles worth of break in period to get that done. Mine were being broke in while the cam was being broke in so it's needless to say that didn't happen. I also hadn't read the article at that time.

This is the article here: http://www.mototuneusa.com/break_in_secrets.htm

old_man said:

Stupid question, why are you replacing the valves instead of just a valve grind? Don't forget the valve guides. NEVER allow the machine shop to knurl the valve guides, only allow them to sleave the guides. Knurling will last 10-15k miles then they will be worse than before.

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What is a valve grind?
What is "knurling" the valve guides vs. sleaving?

I just woke up. I'm about to leave to go take the engine apart at the shop and see if any other damage was done after the exhaust valve blew.

Wayne P.~

(edit: I was informed that it actually cracked because when you put a piece of paper up to the exhaust it gets vacuumed in between exhaust puffs)

Are there any SPECIFIC gaskets that come recommended?

HttpWayne said:

Are there any SPECIFIC gaskets that come recommended?

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When doing a head swap I like the Felpro gasket set. Everything you need and it comes in one box. Mopar has a few head gaskets as well.

The questions you ask indicate your already "in over your head".Also dont do a "upper" end job without rebuilding the lower,its a formula for disaster.

I'm doing this at a shop where professionals help new guys like myself so we don't f*$k anything up. I should be safe. But thanks for contributing positively (I think?) to my post.

I was just looking at felpro and victor reinz. I know Felpro was good so I was going to go with that, I was just wondering if anyone knew anything about Victor Reinz?

Define lower end build. I'm just changing the valves because one (or more) burned out. I figured while it was apart a head porting was in order. This engine was already "rebuilt" as a stroker 8 months ago. What on the bottom end absolutely has to be rebuilt WITH the upper head or disaster occurs?

If you just rebuilt the motor 8 months ago why would you need new rings? Why the valvetrain issues? All of these issues should have been addressed in the original build,makes me wonder about your "professionals"!More details of how you went about putting together your stroker might help.

A burned exhaust valve is a sign of running lean. It it is a stroker and the injectors weren't change to larger or a MAP adjuster added, that is the reason.

I've been building engines for over 40 years and I built one of the first strokers a long time ago. I have over 100k on it.

Writeup on valve stem issues

RCP Phx said:

If you just rebuilt the motor 8 months ago why would you need new rings? Why the valvetrain issues? All of these issues should have been addressed in the original build,makes me wonder about your "professionals"!More details of how you went about putting together your stroker might help.

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Need new rings? I just said I would LIKE to (not need) to break them in WOT per the article I read, which was never done before.

Why the valve train issues? I already covered that. Read the posts.

I paid Titan Engines to build it, that's how I went about it.

old_man said:

A burned exhaust valve is a sign of running lean. It it is a stroker and the injectors weren't change to larger or a MAP adjuster added, that is the reason.

I've been building engines for over 40 years and I built one of the first strokers a long time ago. I have over 100k on it.

Writeup on valve stem issues

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I ran the stock injectors for a couple of months then changed over to 24lb, but still never tuned it. I will be as soon as this thing gets put back together.

I pulled the plugs and found that number 4 was covered in oil. Is that the sign of a cracked exhaust valve?

Number one looked whiter on one side than the other. On the whiter side the metal portion looked as though it had very little of the "carbon" that you see in the Haynes manual in the back where it shows the different pictures of spark plugs. But other than that the others all showed normal wear.

(according to the manual carbon means running lean.. ?? If that's the case then #4 plug was really white before it got oiled up??)

I was just reading about lifter removal and installation on I6 engines. I came across this and wondered if crankshaft position had any bearing on removal of lifters, or just the re-installation.
"With the lifter on the base circle of the camshaft (valve closed), tighten the rocker arm nut to 20 ft. lbs. (27 Nm). Do not over torque. You will have to rotate the crankshaft to do the individual valves."
This was after the lifters was replaced (installed). It didn't mention anything about crankshaft position before removing it originally though...

Here's the link: http://arrc.epnet.com/autoapp/8977/8977CH03_Valve_Lifters.htm

Please sir do not take this the wrong way...but your posts are a bit confusing. You are asking questions but not including the proper information. To start from your original question....why would you replace a bad or broken valve and not check to see why this happened on a engine that was rebuilt 8 months ago? There is a reason it happened, it was prob not due to overheating. By blown if you mean broken, I would be checking into the guides for straightness and concentricity.

If you had this engine built by someone else and are now trying to fix it and for some reason, you can not return to the builder, you need to get ALL the info on what was done to it. This one problem can cause a domino effect and cause a bunch of other problems.

Skreed said:

Please sir do not take this the wrong way...but your posts are a bit confusing. You are asking questions but not including the proper information. To start from your original question....why would you replace a bad or broken valve and not check to see why this happened on a engine that was rebuilt 8 months ago? There is a reason it happened, it was prob not due to overheating. By blown if you mean broken, I would be checking into the guides for straightness and concentricity.

If you had this engine built by someone else and are now trying to fix it and for some reason, you can not return to the builder, you need to get ALL the info on what was done to it. This one problem can cause a domino effect and cause a bunch of other problems.

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You read my posts and the other posts right? You would have notice that I ran stock injectors in for for about 5 months after it was built in one of the more recent posts. I also didn't have it tuned.

THEN on a 600 mile trip up north the rad. was leaking. I stopped after 120 miles because it jumped to 260. I filled up with 1.5 gallons of water. went 60 miles and repeated. Went 25 miles and repeated. Went 10 miles and repeated. The next morning went 3 miles and repeated.

Why? I HAD to be up north the next day for work. I had to leave it in SC with a dealer to fix.

So it wasn't just one over heat. I picked it up and drove it maybe a couple of hours over the next few days, then embarked on that same 600 mile trip. Right near the end it started shaking, like it does now, while I was driving.

So you say the overheating I did that night and the exhaust have absolutely no correlation even though it was in perfect working order for the previous 8-9 months? I would call that a coincidence.

In all my automotive troubles of the past nothing has ever been coincidence. This would be a first.

HttpWayne said:

You read my posts and the other posts right?

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Here's the thing: there's information about this spread across multiple threads from a timeframe that spans several months, but none of it is in one location that gives the full picture. It's difficult to know what's really going on when there's no way to refer to one place that has all of the key information - and it seems like more information is being added as the thread continues that possibly should have been there to start with.

If you want to more effectively receive help with this, I would strongly suggest gathering all of the relevant details into one post. It really isn't terribly clear which direction replies should be going in when it's difficult to comprehensively understand the circumstances of the situation.

True.

Yeah really, now that I go back and read about the injectors I noticed it but like I said a bit confusing. Old man gave good advice that I would follow. I would also check the head and deck surface for warpage after all that over heating.

The head is off. It's getting resurfaced. The valve guide in the #4 cylinder was worn. The piston and valves were covered in burned oil.

The #1 cylinder valve faces were white. I was told that is from coolant. The gasket was pristine though, so I don't see how that's possible. Can anyone shed some light on that?

The exhaust lifter in cylinder 4 was a bit hard to get out unlike all the others. The magnet took all the others out, but I had to use needle nose to get it out.

There was a very small amount of play in the #4 exhaust valve. So little that it seemed like it was a 10th of an 8th of an inch. It's hard to believe that little bit can make such a huge difference.

The machine shop is going to replace all the valve guides. The valves themselves were just fine. He won't be done with the guide replacement until the end of next week however.

So there you have it. All that vehicular shaking was from what felt like a hundreth of an inch in play in one exhaust valve.

FYI, when I did the stroker rebuild the IM had a ton of gunk in it. The Sears IM/Fuel Injection cleaning stuff REALLY works because it's ALL gone now. I'm amazed at how well that worked.

FYI 2, talking to the machinist about porting our heads. Price to HP output = worthless. They can only port so little due to the head bolds and coolant runners. It comes out to nothing according to them without running dangerously close to screwing up the head completely.



Wayne P.~