Second head removed...more pics...and a total # of bent valves.
#1
928 Engine Re-Re-Rebuild Specialist
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Second head removed...more pics...and a total # of bent valves.
Spent some more time in the garage tonight and got the other (driver's side) head removed. It looks like I bent a total of 6 valves: 4 exhaust and 2 intake. The location of the bent valves corresponds to the cylinders that produced 0 compression when I tested them. I guess I should be thankful there weren't more bent valves.
Time to take a moment for some personal satisfaction. Roughly speaking, this is my 1/2 way point in the rebuild. Now it's time to clean up and put everytying back together.
Anyway...here's the pictures:
Time to take a moment for some personal satisfaction. Roughly speaking, this is my 1/2 way point in the rebuild. Now it's time to clean up and put everytying back together.
Anyway...here's the pictures:
#4
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Nice... that thing is going to sing sooooo sweet when you get done. Whenever it gets too cold your hands too numb... just relax and feel the BWWWAAAHHH.... it's calling to you...
#5
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Anyone else as surprised as I am about how minor the damage to the valves looks? I know it's serious damage, I just always thought the carnage would be...well....more graphic. You've really got to look closely to see the damage.
#6
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Detecting bent valves is more complicated that looking to see where there's light passing through. To get a good read, pull the valves and set them up in a lathe (preferable) or a good drill press (second choice). With the end of the stem in the chuck, rotate the chuck by hand and do an eyeball for bent. Those that pass the eyeball test get another check with a dial indicator, looking at the ground face that contacts the seat when the valve is closed. Runout on that face is what you are concerned about.
If you have the valves ground and reseated in the heads, the shop that does the work will tell you right away if there are more bent. Keep in mind that the valve needs to seat securely all the way around, not just to seal the gases in the chamber, but also so that heat in the valves can be sinked to the heads through the seats. A valve that doesn't seat perfectly is a valve that will burn fairly quickly. In my experience, this is a very worthwhile check.
Plus, while the heads are off getting some reconditioning, you'll have a chance to sanitize the rest of the block and the engine bay. You'll never have this kind of access to all those bits that are normally hidden/buried when the engine is back in place.
If you have the valves ground and reseated in the heads, the shop that does the work will tell you right away if there are more bent. Keep in mind that the valve needs to seat securely all the way around, not just to seal the gases in the chamber, but also so that heat in the valves can be sinked to the heads through the seats. A valve that doesn't seat perfectly is a valve that will burn fairly quickly. In my experience, this is a very worthwhile check.
Plus, while the heads are off getting some reconditioning, you'll have a chance to sanitize the rest of the block and the engine bay. You'll never have this kind of access to all those bits that are normally hidden/buried when the engine is back in place.
#7
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Originally Posted by dr bob
Plus, while the heads are off getting some reconditioning, you'll have a chance to sanitize the rest of the block and the engine bay. You'll never have this kind of access to all those bits that are normally hidden/buried when the engine is back in place.
I know that more valves may be bent...I'm just pointing out the most obvious ones. As far as the heads go, I've got new ones waiting already. Everything else will get a complete cleaning as I re-assemble. I want this engine to be C-L-E-A-N.
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#8
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In several photos I see clear impact damage on the valves that have contacted the piston. Don't forget the seats on those valves too. If they can be saved with a grind, that's fine. They may need to be replaced. You're not reusing the old heads, so it's not really your problem. Inspect the lobes and lifters from the bent valves too, they come in for a lot of stress when the contact was made.
I've seen much, much worse carnage. Broken valve heads through the piston, pounded into the heads, cracks, etc. You're gonna be out of this job pretty cheap, considering the catastophic failure.
As for being half way on the job --- hahahahahhahaha! Just kidding, keep the spirits up, thanks for the update.
I've seen much, much worse carnage. Broken valve heads through the piston, pounded into the heads, cracks, etc. You're gonna be out of this job pretty cheap, considering the catastophic failure.
As for being half way on the job --- hahahahahhahaha! Just kidding, keep the spirits up, thanks for the update.
#9
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As the builder of Dave's new heads, the old heads are mine to rebuild. I think the damage to the seats themselves should be limited. If not, I guess I'll have to adjust them. I have access to the tools to do that.
#10
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Originally Posted by 86_5Tiburon
As the builder of Dave's new heads, the old heads are mine to rebuild. I think the damage to the seats themselves should be limited. If not, I guess I'll have to adjust them. I have access to the tools to do that.
Kevin, you've made this a manageable project for me. Thanks again!