Oh no, broke at the track today.

Mike Puckett

SCCoA Member
I'm hoping it only blew a plug or 2. That's what it feels like anyway. On my last pass, when the clutch engaged as I shifted to 3rd, I was suddenly on maybe 3, maybe 4 cylinders. No smoke, no rattle, no clunking or clanking or ticking noises. The only odd noise is what sounds like a little exhaust leak. It doesn't like to start up either, takes a little coaxing and cranking, but doesn't try to stall out once it's running even though the vacuum's low. No sign of coolant in the tailpipes either. But luck was with me and I was able to drive it the 50 miles home at 55mph with out breaking down. It accelerated up hills and felt fairly smooth going downhill. I could run 65 and it felt the same as 55, it ran cool the whole time, 160 degees, and it doesn't feel like it's picked up any vibrations other the rough running from misfiring. I constantly checked the mirror for smoke out the tailpipes but there was nary a puff. I'll dig into it tomorrow and see what I can find. It's still too hot to work on.
 
Other than a lean deal leading to burned up plugs, it could be spark plug cable going south, or even a coil going bad in the coil pack.

It's great that you got to drive it home. That basically makes it a successful day at the track, regardless... at least in my book.
 
Other than a lean deal leading to burned up plugs, it could be spark plug cable going south, or even a coil going bad in the coil pack.

It's great that you got to drive it home. That basically makes it a successful day at the track, regardless... at least in my book.

i dont care how it runs if my car broke i wouldn't drive it. why cause more damage then what you might have.
 
I've pulled plugs and wires 1, 2, &3 and they look Ok. The resistances of each are all pretty close to each other. #1 plug reads 4.27K while the other 2 read 3.6K & 3.8K and the wires all read close together, too. I'm in the process of doing the the other side and should know this evening. I'm going to pull the power steering/alt bracket out of the way along with the lower IC tube so I can get to everything.
Plugs #5 & 6 are oily so that's not a good sign.
 
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Ok, here's what else I've found. Plugs #5 & 6 are slightly oily and 6 is black. Plug #4 is dry and normal burn look but has a yellowish hue. Plug #5 wasn't tight and #4 was loose. None of the plugs appear to be cracked. The plugs and wires had normal resistance but the plug clips were spread on wire #'s 5 & 6. The head gasket is about 3 years old. I'm going to get a compression tester and check the compression but I wonder if I may have lifted the head.
 
i don't know about the lifting of the head you were pondering. :eek: i'm thinking that to be unusual... especially with arp head studs. i certainly hope you enjoy a good mystery like the BIG E though:D
 
That's what i was thinking. i'd try it just to see what's up. maybe even take it for a spin if it fires up with no smoke.
 
If the compression tests good I'm tempted to just put new plugs and wires on it, fire it up and see how it runs.

If compression tests out o.k. I'd check the PCV valve to make sure you're not building excess crankcase pressure blowing oil by some rings.

Somehow the oil got onto the plugs.
 
BTW, there was a normal amount of oil in the IC tubes and it doesn't smell burnt. My son suggested a cylinder leak down test, too, so I'll try to get a tester for that.
 
Well, I found the problem but not sure of the extent of the damage yet. I ran a compression test and cyl #5 had none, zip, zero. So I pulled the valve cover off and found the retainer on the #5 intake valve broken clean in 2 and one of the keepers and retainer half laying in the head and the other keeper still in place on the broken retainer. The valve is stuck about 3/4" below the top of the spring. I need to pull the rocker and spring and check the valve but I bet it's bent. I've got all the parts so if the head and the piston are Ok I can fix it. Otherwise, time to build a new motor.
 
surprised the valve didn't drop into the bore. That would have been exciting. :eek:. Sounds like an easy fix so far.
 
that'll put some oil into the cylinder. My guess is the retainer broke, the valve dropped down and the hard stock piston hit the valve bending it and driving it up into the valve guide area and it stuck. Since you didn't hear noise I would be surprised if the piston is beat up much. The valve guide area may be pretty messed up. Hoping that it isn't too bad and you can get back to racing this season.

If it's not to bad, it'll be interesting to see how the rest of the retainers look.
 
That'd be my assessment too. I'll take the lower intake, fuel rail, and head off tonight and inspect everything. If the piston's damaged and the head's Ok or repairable, I'll have to transfer everything over to my good short block.
I drove home 50 mi with a dropped valve! Who said these motors weren't tough?:p
I guess I'll be running the Caddy for awhile.
 
That'd be my assessment too. I'll take the lower intake, fuel rail, and head off tonight and inspect everything. If the piston's damaged and the head's Ok or repairable, I'll have to transfer everything over to my good short block.
I drove home 50 mi with a dropped valve! Who said these motors weren't tough?:p
I guess I'll be running the Caddy for awhile.

I did basically the same thing on my 73 Mustang...I thought I just had an intake leak until I did the compression check. I probably only drove about 15 miles though. I never pulled my head to check the total damage though, its just sitting in the garage now. I have forged pistons in that, so I might be ok. I am anxiously waiting to see the extent of the damage on yours.
 
It took a lickin' and kept on tickin'! The guide is cracked but the head itself looks Ok. I've got plenty of valves and hardware pieces. The piston doesn't look cracked and the gouging looks like it can be smoothed off. The valve was stuck but I tapped it and it came right out. I think I lucked out and it's going to fix Ok and I''ll be able to get it going.
 

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It took a lickin' and kept on tickin'! The guide is cracked but the head itself looks Ok. I've got plenty of valves and hardware pieces. The piston doesn't look cracked and the gouging looks like it can be smoothed off. The valve was stuck but I tapped it and it came right out. I think I lucked out and it's going to fix Ok and I''ll be able to get it going.

Make sure you warn whoever is going to try to smooth that piston out that it is likely to be slow going.

How did the retainers still in one piece look?
 
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