New motor gone...

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Shitttt that sucks.

It's easy to forgot all the **** that goes on in an engine when it's running. Even at idle RPM things can go wrong in a hurry. Did pieces get elsewhere in the engine? It's hard to tell with the wet, but that bore looks ok to me? Hopefully not much damage.
 
Lustle said:
Shitttt that sucks.

It's easy to forgot all the **** that goes on in an engine when it's running. Even at idle RPM things can go wrong in a hurry. Did pieces get elsewhere in the engine? It's hard to tell with the wet, but that bore looks ok to me? Hopefully not much damage.
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Not sure if the damage goes any further. The cylinder did take some hits so it will need to be sleeved. I'm going to just let this sit for a while and enjoy the holiday. It'll be back.
 
famous bob said:
I knew that`s what it was, been there , done that. feel for ya ! better check valve to piston clearance on rebuild. could also be a faulty valve to start with. what brand of valves are they ?
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The valves are the ones that come with the built Eddy RPM heads. I had Comp Cams build my grind to match my spring rate and max lift. Looks like they didn't quite match.
 
chargd72 said:
The valves are the ones that come with the built Eddy RPM heads. I had Comp Cams build my grind to match my spring rate and max lift. Looks like they didn't quite match.
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did u check the valve to piston clearance ?
 
O
famous bob said:
did u check the valve to piston clearance ?
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Absolutely. The valve likely overheated and stuck. It's hard to have contact by a "floating" intake valve as it is closing while the piston is deep in the whole.
 
chargd72 said:
O


Absolutely. The valve likely overheated and stuck. It's hard to have contact by a "floating" intake valve as it is closing while the piston is deep in the whole.
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didn`t check guide clearance? just because their edelbrocks, don`t mean u don`t need to check them, or have them checked by a head guru. I`ve got a good friend that`s ahead expert that checks mine for me. not related but, being a plumber, I takes care of his hacienda too !---LOL
 
chargd72 said:
O


Absolutely. The valve likely overheated and stuck. It's hard to have contact by a "floating" intake valve as it is closing while the piston is deep in the whole.
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Floating maybe;stuck no.
Typically the intake is supposed to be closed at somewhere between 66 and 86 degrees ABDC.At that time the piston is somewhere between 1/3 and nearly 1/2 way back to the top, on the compression stroke.
But if the intake is hung open;
Now,I'm having trouble with math today,but lets say at cruising speed, you are doing 2400 rpm; that's about 40 revolutions per second. So say 2/3 (from say around 66*ABDC) of a revolution might be .0167 second. So if it sticks for just .0167 second.... BAM! that valve done been kissed!,assuming it was hung far enough open, I guess.
 
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MiradaMegaCab said:
Based on your post and recommendation to the OP, I'm wondering what total timing you'd run...
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Depending on camshaft and some other things,on 8lbs I'd start at 32-33 not pulling any and read the plug from there. I've seen some sb stroker stuff make more power with more(35+) and some with less (30-34). This being said, if the intercooler isn't efficient, maybe start a tad lower. Also, non projected plugs are a must.


Most people wait till 8-10psi on turbo cars to pull timing to aid with spooling as well.
 
pull the valve stem out and see if there are signs of the stem to guide being too tight. any other cylinders showing signs of valves kissing pistons? what is the cam and what are your measured installed spring loads?
 
Marcohotrod said:
pull the valve stem out and see if there are signs of the stem to guide being too tight. any other cylinders showing signs of valves kissing pistons? what is the cam and what are your measured installed spring loads?
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This is a copy of my cam specs. Spring pressure is 120 lbs with .575 max lift. Taking heads in this week to get the valve guides checked. I'm pretty sure that's where I dropped the ball.

IMG_2752.PNG
 
Your seat pressure is way light. You should have your advance locked out. I didn't see that mentioned. Id pull timing running pump fuel regardless what others think. Ive melted pistons. I don't know anything about the Mallory ignition. I run MSD digi 7 with a map sensor. My first motor was 9-1 on pump at 8 psi. Cheapo china map sensor failed and melted the tops off the pistons sent aluminum through the turbo and bent the shaft. I had the total timing at 36*. Ive since upgraded the whole ignition system and gave up on pump gas. its much easier to be conservative and sneak up on the tune than to be replacing pistons and turbos.
 
HOTMOPR said:
Your seat pressure is way light. You should have your advance locked out. I didn't see that mentioned. Id pull timing running pump fuel regardless what others think. Ive melted pistons. I don't know anything about the Mallory ignition. I run MSD digi 7 with a map sensor. My first motor was 9-1 on pump at 8 psi. Cheapo china map sensor failed and melted the tops off the pistons sent aluminum through the turbo and bent the shaft. I had the total timing at 36*. Ive since upgraded the whole ignition system and gave up on pump gas. its much easier to be conservative and sneak up on the tune than to be replacing pistons and turbos.
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Timing is locked out at 35* and pulling 1.5* per psi so that is very conservative. My heads are getting looked at now but it is definitely not detonation.

What seat pressure are you suggesting? 140#? These springs were supposed to match the cam.
 
chargd72 said:
Timing is locked out at 35* and pulling 1.5* per psi so that is very conservative. My heads are getting looked at now but it is definitely not detonation.

What seat pressure are you suggesting? 140#? These springs were supposed to match the cam.
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I run 250 lbs with a 640" solid roller
 
HOTMOPR said:
Did they know it was a boosted motor when they specd the springs?
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Yes. Comp cams knew it was a boosted motor. That was the reason for the custom grind cam. So are you thinking the valves were floating due to weak spring pressure? It looks like all intake valves were kissing the pistons.
 
chargd72 said:
Yes. Comp cams knew it was a boosted motor. That was the reason for the custom grind cam. So are you thinking the valves were floating due to weak spring pressure? It looks like all intake valves were kissing the pistons.
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Boost will try to hold the valve open. Could be the reason.
 
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Need more spring psi because the damn turbo is gonna put serious pressure on the back of the intake like never before.
 
Curious what Spark Plugs you chose to use......
 
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