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Ranger wrote:
[quote]bdigel wrote:
Is that an unusual result for a coolant loss situation? Since it’s the first valve I’ve ever had stuck in my head, I don’t know much about it. Both wife and Gasman have mentioned wanting to stick things in my head before, so I wasn’t all that surprised.
What are valve guides made of anyhow…brass or something?[/quote]
Honestly , yes a stuck valve is an unusual result for a coolant loss situation, never in 20 years seen that!
bdigel wrote:
[quote]Ranger wrote:
[quote]bdigel wrote:
Is that an unusual result for a coolant loss situation? Since it’s the first valve I’ve ever had stuck in my head, I don’t know much about it. Both wife and Gasman have mentioned wanting to stick things in my head before, so I wasn’t all that surprised.
What are valve guides made of anyhow…brass or something?[/quote]
Honestly , yes a stuck valve is an unusual result for a coolant loss situation, never in 20 years seen that![/quote]
Anyone have a theory?
IndyJim wrote:
[quote]Low Oil Pressure?
Sorry couldn’t resist.[/quote]
I was figuring low coolant pressure .
Scott, I suspect the valve stuck when you guys shut down the motor and the ambient temperature continued to rise. What is really surprising to me is that you didn’t find other damage…especially to the cam. Based on what I have read previously, the engine was started after adding coolant and shutdown when you guys heard a horrible noise. It is impossible to hear a “horrible noise” in a motor without damage being done somewhere, maybe small but probably not. A valve doesn’t make noise as it sticks, it is everything else rotating and the valve not moving that makes the noise. I think if you look closer you will indeed find damage to the camshaft.
Steve, welcome to my world. 
Gasman wrote:
[quote]Scott, I suspect the valve stuck when you guys shut down the motor and the ambient temperature continued to rise. What is really surprising to me is that you didn’t find other damage…especially to the cam. Based on what I have read previously, the engine was started after adding coolant and shutdown when you guys heard a horrible noise. It is impossible to hear a “horrible noise” in a motor without damage being done somewhere, maybe small but probably not. A valve doesn’t make noise as it sticks, it is everything else rotating and the valve not moving that makes the noise. I think if you look closer you will indeed find damage to the camshaft.
[/quote]
That’s pretty much how I see it too. I think that the noise was the cam lobe whacking the sticky valve. I inspected the cam closely but didn’t see any damage. Which may just mean that I didn’t spot the damage. The fact that the cam had to have taken a beating is one of the reasons I chose Chuck to help me fix it. Chuck’s had a lot of experience with making worn cams right.
The cam lobe only got in about a dozen whacks. We shut the motor off in a couple seconds.
If I’d a been smarter I’d have set aside the rocker arm on the stuck valve. That rocker arm may have gotten stressed.
Chuck: Pls check to see if a rocker looks like it took some hard wacks.
Someone start something new as the resident mathematicians are obviously bored.
Indy Jim, care to do a rant or two?
RP
shaunatl wrote:
[quote]Gasman wrote:
That would be 78,000 RPM, not 800.[/quote]
And on Gasman’s cheater motor, that’d be about right. :laugh: :laugh: :laugh: :laugh:
PS - I am ashamed to admit I started to do the math on Ranger’s first post about the number of whacks… Under the theory that it is better to keep your mouth closed and let people wonder if you’re an idiot (rather than open it and confirm you are), I didn’t say nuthin’.
If you got the head hot enough to make a valve stick( still never heard of that) I be worried about the head it’s self. In My professional opinion I would at get a density test done on the head, before doing anything else!
Gasman wrote:
If that’s the case I’m gonna hang around with Brendan more. A motor builder with chicks in every bar. Ooh Rah!
Seriously tho, so maybe I should go ahead and send the head to someone who really knows M20 heads, like Chuck Baader?
1st off I hate golf! haha
Who ever you send the head to make sure they can do a density test, and do that first before you waste any time or money! Alluminum can only hold up so well, I have seen several heads fail that test! After that I would get them to do pressure test, make sur there aren’t any crack’s wraped surface etc?? , I don’t mean to get you worried But I have been down this road before.
Ranger’s stuck valve…is not stuck anymore. It is amazing what you can do with a 2# brass hammer and drift.
Actually, the stuck valve was caused by insufficient clearance within the valve guides. All of the valves had to be pushed out of the guides. Not enough clearance does a couple of things. First it prohibits oil from lubricating the stem. Second, as the motor warms, clearances change, and in this case, changed enough to stick the exhaust valve. The guides will be bored and sleeved for proper clearance.
Head is being pressure tested but I think the head is fine, except for the .003-4" sway in the center:woohoo: Chuck
