PTV=Bent Push Rod. Is this piston okay? (pics)
07-25-2008, 09:54 AM
#21
I guess reassurance that the mark isn't a problem is more important than preventing the same problem in the future?
Stock cam and over rev causes PTV contact. And whats the answer to this? Lets put in a cam with more lift, more duration, and rely on the new springs to keep it from happening again.
So you put this together with the new parts and didn't check PTV clearance?
I guess the general consensus of LS1tech posts says it's not necessary with that combination of parts?
All I'm saying is check the PTV clearance, thats it. It's not bad advice, it's free.
Take it or leave it but god damn don't ******* cry about someone trying to help.
Last edited by 9000th01ss; 07-25-2008 at 12:29 PM.
07-25-2008, 12:01 PM
#22
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I lost a spring and the valve put a few of those eyebrows into the piston and I planned to just smooth it out and reuse it. I had the chromoly pushrods though and it didn't even put a nick in the pushrod. Instead the piston hit the valve shoving the pushrod down into the lifter shattering the lifter cup haha. But yeah check your valve. My valve was stuck in the head I had to use a hammer and chisel to get the damn thing out!
07-25-2008, 05:12 PM
#24
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I'd rather be "that guy" than one more person commenting about the mark on the piston.
I guess reassurance that the mark isn't a problem is more important than preventing the same problem in the future?
Stock cam and over rev causes PTV contact. And whats the answer to this? Lets put in a cam with more lift, more duration, and rely on the new springs to keep it from happening again.
So you put this together with the new parts and didn't check PTV clearance?
I guess the general consensus of LS1tech posts says it's not necessary with that combination of parts?
All I'm saying is check the PTV clearance, thats it. It's not bad advice, it's free.
Take it or leave it but god damn don't ******* cry about someone trying to help.
I guess reassurance that the mark isn't a problem is more important than preventing the same problem in the future?
Stock cam and over rev causes PTV contact. And whats the answer to this? Lets put in a cam with more lift, more duration, and rely on the new springs to keep it from happening again.
So you put this together with the new parts and didn't check PTV clearance?
I guess the general consensus of LS1tech posts says it's not necessary with that combination of parts?
All I'm saying is check the PTV clearance, thats it. It's not bad advice, it's free.
Take it or leave it but god damn don't ******* cry about someone trying to help.
07-26-2008, 05:28 PM
#25
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Settle down? I'm trying to get through to you how important it is to assemble something properly.
OK now I didn't see anything about this being a stock engine at first. It reads what is going back in then says it was stock. I do see that it's being rebuild with an MS4 cam. Better check it, I bet you're not going to are you.
I'll calm down and let you guys waste more money, sound good? I thought you came here looking for help/advice.
OK now I didn't see anything about this being a stock engine at first. It reads what is going back in then says it was stock. I do see that it's being rebuild with an MS4 cam. Better check it, I bet you're not going to are you.
I'll calm down and let you guys waste more money, sound good? I thought you came here looking for help/advice.
thanks for the advice, don't need to be an *** about it.
07-26-2008, 05:43 PM
#26
Guess who's engine is blown up and who's isn't. Yea yours.
Guess why mine isn't, because I don't over rev stock ****.
07-26-2008, 05:47 PM
#28
07-26-2008, 05:58 PM
#30
I didn't read every post, but MS4 clearance is less than the minimum recommended, even with stock heads. You want to error on the safe side even more with hydraulic lifters, and DEFINATELY install with a degree wheel.. with machining tolerances, dot to dot is not the same for every engine. All these little things add up, and can close clearance down to almost nothing or worse. Flycutting is not a hard thing to do. If you do it, you can run a thinner gasket and mill the heads a bit as well. This will raise compression and get back some of the torque the big cam loses.
07-26-2008, 06:02 PM
#31
And I'd like to point out that I only recommend checking, and they can't even do that, they just throw it back together and bash me for trying to get it through their heads about how important it is to build it right.
07-26-2008, 06:02 PM
#32
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I didn't read every post, but MS4 clearance is less than the minimum recommended, even with stock heads. You want to error on the safe side even more with hydraulic lifters, and DEFINATELY install with a degree wheel.. with machining tolerances, dot to dot is not the same for every engine. All these little things add up, and can close clearance down to almost nothing or worse. Flycutting is not a hard thing to do. If you do it, you can run a thinner gasket and mill the heads a bit as well. This will raise compression and get back some of the torque the big cam loses.
07-26-2008, 06:03 PM
#33
Well, it fits, but by how much? If TSP said it didn't fit safely, they wouldn't sell as many as they do. But the fact is, the clearance is below the industry accepted standard. (iirc it clears by ~ .060 when recommended minimum clearance on the intake side is .080)
I'm not saying don't do it, I am saying flycutting would be recommended and allow you to run a higher compression to make the cam shine. Just make sure to be very very meticulous when dealing with clearances as tight as the MS4 is giving you, or any big cam for that matter.
07-26-2008, 06:07 PM
#34
Fly cutting removes material, removing material lowers compression, milling heads raises compression. You only gain reliability by doing all that, and more compression as well depending on how much is milled and gasket thickness.
07-26-2008, 06:08 PM
#35
You'd be suprised how much clearance is gained with flycutting. Obviously you cut deep enough to offset the increased compression. I'll have to look and find out what the max recommended cut is on a stock piston, but it's enough to run a smaller chamber and .040 gasket and stay on pump gas.
07-26-2008, 06:10 PM
#36
You also gain compression. You don't end up at square 1. You are only flycutting where the valves would press into the piston, but milling down the entire combustion chamber. The overall chamber size is smaller, but where the valves would hit is relieved.
07-26-2008, 06:11 PM
#37
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Im not saying that flycutting doesn allow for more cleareance but u are off setting the clearance u just gained by milling down ur heads and running a thinner gasket....im not saying it cant be done but it puts u back at ur origianl problem....PTV clearance.
07-26-2008, 06:13 PM
#38
Yea thats basically what I just posted isn't it?
07-26-2008, 06:19 PM
#39
**** I give up, some people just need to actually do it on an engine rather than predict what might happen based loosly on thoughts and theories and whatever else.
People will understand when they get into shooting for exactly 11.3:1 static compression, then flycut, measure valve relief volume/dome displacement, measure the combustion chambers, mill accordingly. Until you've done all that you'll never know reading a forum on the internet.
How many people do you see on here selecting a cam based ONLY on not having to flycut, thats not how you build an engine that runs up to it's full potential.
People will understand when they get into shooting for exactly 11.3:1 static compression, then flycut, measure valve relief volume/dome displacement, measure the combustion chambers, mill accordingly. Until you've done all that you'll never know reading a forum on the internet.
How many people do you see on here selecting a cam based ONLY on not having to flycut, thats not how you build an engine that runs up to it's full potential.
