Unknown piston matching with cam
Unknown piston matching with cam I am wanting to make more power out of my modified by previous owner and sitting on deployment i keep thinking of best options to make this happen.
Its a LS1 with 2.5 prc heads 13/4 exhaust makes 360rwhp with ls6 cam. When getting it tuned I have been told twice it has unnaturally high compression. Making the car not like adding timing and boost. it however likes nitrous.
I was told the heads are probably milled but after measuring them(on the car) multiple times they read out to be stock or unmilled height.
I bring this up because when i get home I am looking to put a cam in and intake. Can I find max lift possibility without taking the heads off? I love rough idling choppy cars and dont mind dailying something like that. The goal is 400-450rwhp and id prefer closer to 450 heck even 475 would be awesome. anyways any suggestions to be able to be lazy and not take the heads off?
thanks for supporting my being a dirtbag
Its a LS1 with 2.5 prc heads 13/4 exhaust makes 360rwhp with ls6 cam. When getting it tuned I have been told twice it has unnaturally high compression. Making the car not like adding timing and boost. it however likes nitrous.
I was told the heads are probably milled but after measuring them(on the car) multiple times they read out to be stock or unmilled height.
I bring this up because when i get home I am looking to put a cam in and intake. Can I find max lift possibility without taking the heads off? I love rough idling choppy cars and dont mind dailying something like that. The goal is 400-450rwhp and id prefer closer to 450 heck even 475 would be awesome. anyways any suggestions to be able to be lazy and not take the heads off?
thanks for supporting my being a dirtbag
Max lift has nothing to do with PTV clearance if that's what you're aluring about.
You can run a .700 lift cam that will fit fine and you can run a .500 lift cam that will smash into the pistons everytime.
You can run a .700 lift cam that will fit fine and you can run a .500 lift cam that will smash into the pistons everytime.
so if i have to take the head off to measure just say it, or dont I guess. You know what I am asking I mean usuuuuuuuuuually cams are designed around a specific goal the larger the lift the durations follow or smaller. So I mean im sure somewhere there is a super huge lift cam ground with itty bitty durations and just the opposite. You can whip your big ole engine knowledge dick out elsewhere I wont bother stroking it.
You can whip your big ole engine knowledge dick out elsewhere I wont bother stroking it.
Take care and good luck with your build.
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trying to help and being a real subtle douche is different when i ask max lift possible and you have to beat around the bush how duration is the real ptv killer and act like it isnt directly related to the max lift or just simply assume im stupid well im not inclined to be all nice. Also navy has rubbed off a bit on me and i forget how uptight civilians are when youre not overly sweet to them.
Im asking a question steming from me being a lazy *** if it isnt possible well oh well. I was under the assumption i would have to pull them heads off. But figured id reach out because I def dont know everything. However just because im lazy doesnt mean im clueless to engines and their operation.
Im asking a question steming from me being a lazy *** if it isnt possible well oh well. I was under the assumption i would have to pull them heads off. But figured id reach out because I def dont know everything. However just because im lazy doesnt mean im clueless to engines and their operation.
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TECH Addict
Joined: Aug 2005
Posts: 2,305
Likes: 126
From: Monroe,NY
well i bought an already built car and there are up and down sides to that, yes it alot cheaper than if i built it myself, but you dont know all the details and one that i didnt know was compression ratio. i was told it had 13.5:1. a local engine builder a few days ago happend to get a new tool that measures youre compression ratio without pulling apart the engine, or even getting the car off the trailer for that matter!!! the way it works is it screws into the spark plug hole and pulses air in/out of the cylinder and you turn the engine with wrench in slow very small increments. basically it measures the largest volume and the smallest volume. the only thing you need to know is the cubic inchs of the engine(in my case i didnt even truly know that i was told it was a 427, the block is a 454 and the crank is a 427 but i didnt know the bore of the block i figure at least 030). this tool is supposed to be DEAD ON accurate being that its what the track officials use to regulate the compression limited classes with. anyway my 13.5 ended up being 11.3 my figuring is that it probably has 13.5 pistons in there but it does have open chamber heads. anyway the test costed $100 but it saved me a day of work, $50 worth of gaskets and math with alot of variables that i may not have known(i dont know if the heads have been milled, gasket thickness...). in my case it was money well spent, i was just hoping it wasnt going to end up being a 10:1 engine, now all i need are some small chamber aluminum heads.
trying to help and being a real subtle douche is different when i ask max lift possible and you have to beat around the bush how duration is the real ptv killer and act like it isnt directly related to the max lift or just simply assume im stupid well im not inclined to be all nice. Also navy has rubbed off a bit on me and i forget how uptight civilians are when youre not overly sweet to them.
Im asking a question steming from me being a lazy *** if it isnt possible well oh well. I was under the assumption i would have to pull them heads off. But figured id reach out because I def dont know everything. However just because im lazy doesnt mean im clueless to engines and their operation.
Im asking a question steming from me being a lazy *** if it isnt possible well oh well. I was under the assumption i would have to pull them heads off. But figured id reach out because I def dont know everything. However just because im lazy doesnt mean im clueless to engines and their operation.
Second, the question you asked could be answered several ways but because you are a clueless self-admitted dirtbag, you think he's talking down to you when he is offering information and correcting something you're misinformed about.
You're asking how big of a cam you can use without jamming the valves into the pistons, which you can calculate without pulling the heads but it would be more accurate if you just pull the heads and take some measurements. The confusion here is because you're asking about "max lift". Since the piston is nowhere near the valves when they are fully open @ max lift, it doesn't really matter. That's the point he's trying to help you with.
However, if you were actually asking how much lift you can run, then that's a different problem since it would have less to do with the valves hitting the pistons and more to do with the clearance between the retainers and guides/seals. Again, this is something that probably could be measured without pulling the heads, but it would be better to pull them and measure on a bench.
E
well i bought an already built car and there are up and down sides to that, yes it alot cheaper than if i built it myself, but you dont know all the details and one that i didnt know was compression ratio. i was told it had 13.5:1. a local engine builder a few days ago happend to get a new tool that measures youre compression ratio without pulling apart the engine, or even getting the car off the trailer for that matter!!! the way it works is it screws into the spark plug hole and pulses air in/out of the cylinder and you turn the engine with wrench in slow very small increments. basically it measures the largest volume and the smallest volume. the only thing you need to know is the cubic inchs of the engine(in my case i didnt even truly know that i was told it was a 427, the block is a 454 and the crank is a 427 but i didnt know the bore of the block i figure at least 030). this tool is supposed to be DEAD ON accurate being that its what the track officials use to regulate the compression limited classes with. anyway my 13.5 ended up being 11.3 my figuring is that it probably has 13.5 pistons in there but it does have open chamber heads. anyway the test costed $100 but it saved me a day of work, $50 worth of gaskets and math with alot of variables that i may not have known(i dont know if the heads have been milled, gasket thickness...). in my case it was money well spent, i was just hoping it wasnt going to end up being a 10:1 engine, now all i need are some small chamber aluminum heads.
Ok first of all, quit with that veteran/civilian bullshit. He is genuinely trying to help you and you're the one that's uptight about the response. I don't know what military life was like for you seamen, but you should have learned to keep your mouth shut and say thank you sir when you don't exactly like what someone is saying. That is a valuable skill in the civilian world as well, which I think you should utilize.
Second, the question you asked could be answered several ways but because you are a clueless self-admitted dirtbag, you think he's talking down to you when he is offering information and correcting something you're misinformed about.
You're asking how big of a cam you can use without jamming the valves into the pistons, which you can calculate without pulling the heads but it would be more accurate if you just pull the heads and take some measurements. The confusion here is because you're asking about "max lift". Since the piston is nowhere near the valves when they are fully open @ max lift, it doesn't really matter. That's the point he's trying to help you with.
However, if you were actually asking how much lift you can run, then that's a different problem since it would have less to do with the valves hitting the pistons and more to do with the clearance between the retainers and guides/seals. Again, this is something that probably could be measured without pulling the heads, but it would be better to pull them and measure on a bench.
E
Second, the question you asked could be answered several ways but because you are a clueless self-admitted dirtbag, you think he's talking down to you when he is offering information and correcting something you're misinformed about.
You're asking how big of a cam you can use without jamming the valves into the pistons, which you can calculate without pulling the heads but it would be more accurate if you just pull the heads and take some measurements. The confusion here is because you're asking about "max lift". Since the piston is nowhere near the valves when they are fully open @ max lift, it doesn't really matter. That's the point he's trying to help you with.
However, if you were actually asking how much lift you can run, then that's a different problem since it would have less to do with the valves hitting the pistons and more to do with the clearance between the retainers and guides/seals. Again, this is something that probably could be measured without pulling the heads, but it would be better to pull them and measure on a bench.
E
Check that post above you oh snap he was helpful didnt get his panties in a bunch over it either. Knew what i was asking and weird didnt have to try and be a tightwad about perfect explanations. We can play the game lift and duration are seperate and completely unrelated. However assuming a person has half a brain the larger the lift the larger the duration and the bigger the concern for being clear of the piston. Sure as said ignorantly above you can have massive lift and itty bitty duration but lets be real, oh I sure gosh darn hope that was sweet enough to not upset you
Calling me uptight thats cute, sorry Im not all hugs and kisses with sillyvilans :/
Check that post above you oh snap he was helpful didnt get his panties in a bunch over it either. Knew what i was asking and weird didnt have to try and be a tightwad about perfect explanations. We can play the game lift and duration are seperate and completely unrelated. However assuming a person has half a brain the larger the lift the larger the duration and the bigger the concern for being clear of the piston. Sure as said ignorantly above you can have massive lift and itty bitty duration but lets be real, oh I sure gosh darn hope that was sweet enough to not upset you
Check that post above you oh snap he was helpful didnt get his panties in a bunch over it either. Knew what i was asking and weird didnt have to try and be a tightwad about perfect explanations. We can play the game lift and duration are seperate and completely unrelated. However assuming a person has half a brain the larger the lift the larger the duration and the bigger the concern for being clear of the piston. Sure as said ignorantly above you can have massive lift and itty bitty duration but lets be real, oh I sure gosh darn hope that was sweet enough to not upset you
What redtan told you was accurate, and it's not just duration. There are several variables to consider. That's why I said you have to calculate it. There is a spreadsheet out there where you can put in your variables (valve drop, ICL, ECL, etc.) and it can give you a pretty close calculation of your PTV clearance for a given cam, but as the old saying goes, "garbage in, garbage out".
Any more questions you were too lazy to research and figure out for yourself?
Hey, I get it. If I were called seamen all day, I'd be a little uptight too so I guess I can overlook your sarcasm and poor attitude for a little bit. The disdain towards civilians is patheic though, even for a Navy seaman.
What redtan told you was accurate, and it's not just duration. There are several variables to consider. That's why I said you have to calculate it. There is a spreadsheet out there where you can put in your variables (valve drop, ICL, ECL, etc.) and it can give you a pretty close calculation of your PTV clearance for a given cam, but as the old saying goes, "garbage in, garbage out".
Any more questions you were too lazy to research and figure out for yourself?
What redtan told you was accurate, and it's not just duration. There are several variables to consider. That's why I said you have to calculate it. There is a spreadsheet out there where you can put in your variables (valve drop, ICL, ECL, etc.) and it can give you a pretty close calculation of your PTV clearance for a given cam, but as the old saying goes, "garbage in, garbage out".
Any more questions you were too lazy to research and figure out for yourself?
TECH Senior Member
Joined: Apr 2002
Posts: 6,080
Likes: 17
From: So.Cal.
Unknown piston matching with cam LOL... this thread is interesting...
First, don't you forget it that you work for those civilians (taxpayers, screwed royally by the IRS). Civies don't hate you, they understand you may get shot at, and they know you get orders barked at you... they're not against you.
Second, are you proud of being Navy (you should be, the greatest Navy in all history, you chose to enlist in it)...? I don't know why you refer to yourself as lazy or dirtbag (or are you just repeating your Chief's terminology)...? You already defeated your ownself all by yourself. Come across with more self-respect, people (civilian and military) will show you more respect.
Third, I reread your thread opener post and it does sound a lot like a valve retainer/seal clearance question... there are so many max lift vs ptv questions on this forum that we all have to make sure what the poster is asking... while a PhD is not required, some preciseness helps (max lift vs dur vs ptv)... same as "juice" can refer to gasoline, nitrous, electric current/voltage, IV fluid or blood.
Fourth, while the CR measuring tool mentioned above may allow heads to stay on, it does not give a sufficiently accurate ptv measurement... you wiuld have to remove heads anyway to upgrade lifters (which you should given your goals).
First, don't you forget it that you work for those civilians (taxpayers, screwed royally by the IRS). Civies don't hate you, they understand you may get shot at, and they know you get orders barked at you... they're not against you.
Second, are you proud of being Navy (you should be, the greatest Navy in all history, you chose to enlist in it)...? I don't know why you refer to yourself as lazy or dirtbag (or are you just repeating your Chief's terminology)...? You already defeated your ownself all by yourself. Come across with more self-respect, people (civilian and military) will show you more respect.
Third, I reread your thread opener post and it does sound a lot like a valve retainer/seal clearance question... there are so many max lift vs ptv questions on this forum that we all have to make sure what the poster is asking... while a PhD is not required, some preciseness helps (max lift vs dur vs ptv)... same as "juice" can refer to gasoline, nitrous, electric current/voltage, IV fluid or blood.
Fourth, while the CR measuring tool mentioned above may allow heads to stay on, it does not give a sufficiently accurate ptv measurement... you wiuld have to remove heads anyway to upgrade lifters (which you should given your goals).
Last edited by joecar; Sep 27, 2015 at 04:12 AM.
but lets be real you knew what I was asking.
Let's be real doe, you asked it this way just so you can start **** with us civilians.
The disdain for civilians comes in when you two know what i am asking but have to play like it takes a college level of education to spec a cam for a motor. I bet youre just mad nobody appreciates your level of "knowledge" like you want so when you can go high and right with being super unneededly technical you do it to show people you know what your talking about. I am working long hours and didnt think I needed to write a thesis paper level of correctness description on what we all know I was looking for. I get that being a moderator means you need the last word and that you need to be right. So yes there is much more to be thought out in the way of a cam swap other than lift........but lets be real you knew what I was asking. You can respond to this as you see fit with correcting me
Do you have any more questions, or is this thread going to continue with you bellyaching over how we respond to your vague questions?
Let me correct you on something. I enlisted in the Army in 2002 at 17 years old, I deployed to Iraq in 2004, made Sergeant and reclassed as OPFOR in 2008, got out in 2010. You're problem isn't that you have a disdain for civilians, you're just a dick.
Do you have any more questions, or is this thread going to continue with you bellyaching over how we respond to your vague questions?
Do you have any more questions, or is this thread going to continue with you bellyaching over how we respond to your vague questions?