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Oldsquirt
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Posted: May 01 2005,10:38 am |
Post # 2 |
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That really sucks!!!!!!!
From the pics it appears that all the intake valves have made contact with the pistons. Do the pistons all have marks on them? Got any pics of them?
Edited by Oldsquirt on May 01 2005,10:39 am
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Oldsquirt
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Posted: May 01 2005,11:13 am |
Post # 5 |
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It was seeing the pics on HotBoatpics.com that sent me over here.
Here's a cropped and expanded pic of the piston. You can clearly see where the intake valve has hit the piston at the left side of the "eyebrow".
I'd be looking at the things that could cause this in ALL cylinders....cam timing, too much lift for the parts combination, intake valves that are a larger diameter than the pistons were designed for.
Edited by Oldsquirt on May 01 2005,11:14 am
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shueman
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Posted: May 01 2005,12:32 pm |
Post # 8 |
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| Quote (AZKC @ May 01 2005,10:14 am) | ...Guess I'll be buying a motor from someone the next time or at least let somebody else build one out of my pieces. I surrender  Â  ... |
Sorry to hear this news....   
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shueman
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Posted: May 01 2005,1:00 pm |
Post # 10 |
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| Quote (AZKC @ May 01 2005,12:45 pm) | | The Yami's are looking better all the time. Â Â |
Don't flake now for OP6....I'll give ya a ride...  ....or is that asking for  
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Oldsquirt
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Posted: May 02 2005,8:47 am |
Post # 17 |
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| Quote (AZKC @ May 01 2005,11:53 am) | If you had about a week I could tell you the whole story. Â  This is the 3rd valve I've broke with 2 different sets of pistons and 2 different cams. and its allways #7. The cam in this motor is about .505 lift. We degree'd the cam and it was right on. We're going to reck the cam timing and ck piston to valve clearance later. But with that small of a cam I doubt its a clearence prob. |
It sounds like the only constant here is the block? I'd be wondering about that #7 lifter bore if I kept bending/breaking that valve. Hell, I'd be looking for another block just because that one sounds jinxed 
I agree that .505" lift is not much, but that is no reason NOT to check the piston to valve clearance. If it was me, and I saw all those pistons had been tagged, it's one of the fiirst things I'd do. Pulling the timing cover and checking chain/gears and cam timing would be the other. Leave the bottom end together until after youve done that. How about a pic of the timing chain and gears BEFORE disassembly.
Is this the same scenario as the previous failures? Did they also have piston to valve contact? Any pics of those?
Edited by Oldsquirt on May 02 2005,8:59 am
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Oldsquirt
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Posted: May 02 2005,10:36 am |
Post # 21 |
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I do believe that pic identifies your problem. Your gears are not lined up correctly. The keyway is not what you line the cam gear "dot" up with. There should be a "dot" on the crank gear. If you cant see it, you probably have that gear on backwards. When the dots are lined up on the two gears, the keyshould be pointing in line with the #1 cylinder .
Your cam looks to be about two teeth advanced.
Edited by Oldsquirt on May 02 2005,10:38 am
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Oldsquirt
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Posted: May 02 2005,11:03 am |
Post # 23 |
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When you use that crank gear, you have to match the keyway in the gear to the dot on the gear. That is, if you use the "O" dot you must also use the "O" keyway. If you use the "A" mark on the gear, the "A" keyway must be used.
Any choice you go with, when the gear marks are lined up, the keyway WILL line up #1 cylinder.
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11-13-2024 Three Word Post.....The Next Generation.... (Rep.#19,415) from: GoFastRacer
Sleek and Brother Drew came over and helped get the boat running and it sounded pretty good 
 
when the intake rocker stud backed out and the intake wouldn't open, the exhaust opened and hydrauliced the cylinder causing everything to stop bending the push rods and smacking the valves into the pistons. But I'm totally gueesing cause I have no idea. 
That bites. Sorry to hear I thought youl'd have it this time. 
