Nope, the tach never saw the high side of 3500....
http://youtu.be/YwVrnQUoea8
Nope, the tach never saw the high side of 3500....
http://youtu.be/YwVrnQUoea8
“If the people of the nation understood our banking and monetary system, I believe there would be a revolution before tomorrow morning.” -Henry Ford
I took another look under the valve cover today and it looks like the valve is stuck open where the rocker came out. The retainer and keepers are still there at least. Not really sure what to do now. The rocker arm was just lying there loose, but somehow the valve is just stuck open causing no compression.
Maybe tap it with a small hammer to see if it will let loose? Curious as to why it's stuck open too, especially if it isn't a bent valve. But I'm thinking a bent valve. :\
[SIZE="3"] [B]Jon Trotter[/B][/SIZE] [B]1985[/B] Dodge Shelby Charger, Currently decommissioned [B]1987[/B] Shelby GLHS, #937 [B]1987[/B] Shelby Lancer, #628 [QUOTE=Reeves;587010]I can be ready. Please send pics of wife. _____DodgeZ add comments here______[/QUOTE]
I will try that Jon. The cylinder head only has about 100 miles on it since it had a valve job done. It was originally out of an '85 Shelby Charger turbo with about 80k miles IIRC.
Probably seized in the guide if it got hot
I tried tapping the valve in the hopes it would pop back a closed position but it did not work. Looking at couple other valves that were closed (on cam base circle), the valve is stuck open approximately 1/4". I was able to pry it a bit but it is stuck pretty bad. Looks like I'll have to pull the head next and either replace it or have it serviced/valves replaced/checked for flat deck.
My guess is a seat fell out.
Thanks
Randy
There is no logical reason to call an Engine a motor.
Randy Hicks
86 GLHS60
86 GLHS 373 : SOLD, but never forgotten
89 Turbo Minivan
83 Turbo Rampage : SOLD
Edmonton,Alberta,Canada
Randy if that was the case, would the piston likely be toast? The spark plug looked good, just black from all the unburnt fuel. I really hope the shortblock is OK because the pistons only have 100 miles since installed new.
Piston should be good. I've had a few where the valve seat falls out of place, but gets jammed between the valve and cylinder head, as it's smaller than the valve head. I have a couple of heads on the shelf like this, and had it happened to me personally once. The seats are just an interference fit so there not a lot holding them in place.
Thanks
Randy
There is no logical reason to call an Engine a motor.
Randy Hicks
86 GLHS60
86 GLHS 373 : SOLD, but never forgotten
89 Turbo Minivan
83 Turbo Rampage : SOLD
Edmonton,Alberta,Canada
The AL expanded quicker than the harder seat when it overheated and it dropped down enough to allow compression to escape.
I've had exhaust valves seize in the guide before and hang open. Did you have the exhaust valve guides replaced when the head was done? When it happened to me, guides were new, head had about 20 miles on it and it hung one open. My issue was guide to valve clearance too tight.
Does your valve push open further or is it stuck? If it pushes open further, it's likely a seat. If it's stuck and doesn't open further or close, it's likely a guide/valve issue.
Just as a quick update..
I got the top 1/2 of the motor pulled off today. No signs of oil or coolant contamination and the Felpro headgasket was just fine as well thankfully. Kinda surprised given that it overheated so bad and this is still a 10mm headbolt motor ('85).
I was wrong about what valve it was. It was actually the #2 intake valve. The valve seats are all fine so I've determined that it's a valve guide and/or bent valve issue. Piston looks fine too....really I have not been able to find anything else wrong at this point. I did take a hammer and *lightly* tapped on the intake valve face and it popped back shut.
Thanks for all the help/suggestions. Doesn't look like this will be too bad to fix other than some elbow grease and new gaskets and head bolts in addition to a replacement valve/guide.
Pat what do you recommend for valve to guide clearance?
Originally Posted by GLHNSLHT2
I don't know...I took my machinist's advice. If I recall, we went the loose side of spec.
At what point with a bad overheat should you replace rings?
I've heard rings can lose tension from overheat but never know to tell.
If it got hot enough to seize a valve you need to check and see how bad the head and possibly the block warped.
At this point I now have the entire top end completely taken apart. After removing the camshaft, rocker arms, and lifters, I reinstalled the camshaft. It turns smoothly by hand with no binding as car as I could tell.
I have the bare head ready to drop off at the machine shop tomorrow morning and will most definitely have them check the deck for flatness while they are at it.
I really can't say for sure how bad the car overheated since I was not there. All I know is that my brother said it started running like crap and had to have it towed home. When I got to have a look at it, the alternator/water pump belt was long gone and it was running on three cylinders due to the valve problem.
After a very thorough tear down today, I could not find any other issues. Everything still looks 'new' for whatever it's worth.
Also, I did do a compression check on all cylinders. The engine was completely cold, spark plugs removed, HEP unplugged, and throttle held open. Cylinders 1, 3 and 4 pumped up to 120 psi within 3-4 revolutions. Cylinder 2 was absolute zero.
That may sound low to you guys but here I am at near 5000 ft elevation.
120 cold does not sound low to me.
Oh good. I suppose it might show higher at sea level but just a guess.
IIRC, I did set the ring gap up on the tight side of the spec because it's just a log TI motor that will probably never make more than 160 whp. The pistons are new cast Sealed Power +.030. Rings are Sealed Power moly E453K.
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