How do i know what all haset been done to my car?
08-14-2016, 12:08 AM
#1
How do i know what all haset been done to my car? Hey guys, so I'm finally about to the point of all the little things with my new car being finished, and it's come time to begin modding.
I'm sorry if any of this sounds ignorant, but I'm trying to learn the right way sooner rather than later:
My question is, how can I find out what's been done? For example, has it been rebuilt, is my intake just painted or is it an lt4 piece, did someone send the heads out to get ported, do I have 1.6rr's, or what kind of cam is in it?
As far as I know, I should try to pull off the oil pan to look for tooling marks to see if it's been rebuilt;
I should pull off the valve covers to try to find casting numbers to see if I've got lt4 heads or intake, as well as stamping on the rockers;
But for the cam I'm lost, is there any way to tell before I pull it out? And even once it's out, will there be a model number on it somewhere?
Thank you!
I'm sorry if any of this sounds ignorant, but I'm trying to learn the right way sooner rather than later:
My question is, how can I find out what's been done? For example, has it been rebuilt, is my intake just painted or is it an lt4 piece, did someone send the heads out to get ported, do I have 1.6rr's, or what kind of cam is in it?
As far as I know, I should try to pull off the oil pan to look for tooling marks to see if it's been rebuilt;
I should pull off the valve covers to try to find casting numbers to see if I've got lt4 heads or intake, as well as stamping on the rockers;
But for the cam I'm lost, is there any way to tell before I pull it out? And even once it's out, will there be a model number on it somewhere?
Thank you!
08-14-2016, 06:17 AM
#2
TECH Enthusiast
You're on the right track with everything you have suggested.
A couple really obvious thing to consider: How clean is the front of that motor? If you have to drag your fingernail over the optispark cap to see that it is in fact yellow then it is safe to say that anything below the heads was never touched. People paint their intakes red all the time. I was one of those idiots years ago and it was instant regret. Whether it is an LT4 or not you can assume that the intake has been removed at least to fix either vacuum/oil leak, noisy lifter, bent pushrod or head gasket let alone mods because I haven't heard of anyone wasting the effort on just painting/swapping the intake. Stock manifolds with the factory rusty bolts is a good sign the heads have not been off since the bolts would show some kind of wear from a wrench being on them. Keep in mind this is the average craigslist LT1 and while it works on the majority, it is not the rule.
A couple really obvious thing to consider: How clean is the front of that motor? If you have to drag your fingernail over the optispark cap to see that it is in fact yellow then it is safe to say that anything below the heads was never touched. People paint their intakes red all the time. I was one of those idiots years ago and it was instant regret. Whether it is an LT4 or not you can assume that the intake has been removed at least to fix either vacuum/oil leak, noisy lifter, bent pushrod or head gasket let alone mods because I haven't heard of anyone wasting the effort on just painting/swapping the intake. Stock manifolds with the factory rusty bolts is a good sign the heads have not been off since the bolts would show some kind of wear from a wrench being on them. Keep in mind this is the average craigslist LT1 and while it works on the majority, it is not the rule.
08-15-2016, 03:51 PM
#6
Make sure you look for a dial drop indicator, dial is how the instrument displays it's info. There are digital and dial drop indicators. There are also dial test indicators which usually have a smaller range of measure.
People will refer to both as dial indicators short hand, happens in my shop alot, but they have different applications. You would rarely use a dial test indicator in an automotive application unless you're doing machine work.
Measuring with the drop indicator will allow you to see how much the valve opens (lift) and how long it stays open (duration) by measuring how many degrees of crank shaft rotation you see with the valve moving. Unless you have a degree wheel though it will be hard to get an accurate number.
Truth is though since you have a hydraulic roller motor, lifter bleed down will keep you from getting accurate numbers and you will have to get pretty close to pulling the cam out to get to a point of accurate measure. You will have to either remove the lifter or use a solid one. At that time you're not far off from just looking at the grind numbers on the front of the cam.
People will refer to both as dial indicators short hand, happens in my shop alot, but they have different applications. You would rarely use a dial test indicator in an automotive application unless you're doing machine work.
Measuring with the drop indicator will allow you to see how much the valve opens (lift) and how long it stays open (duration) by measuring how many degrees of crank shaft rotation you see with the valve moving. Unless you have a degree wheel though it will be hard to get an accurate number.
Truth is though since you have a hydraulic roller motor, lifter bleed down will keep you from getting accurate numbers and you will have to get pretty close to pulling the cam out to get to a point of accurate measure. You will have to either remove the lifter or use a solid one. At that time you're not far off from just looking at the grind numbers on the front of the cam.
Last edited by myltwon; 08-15-2016 at 04:02 PM.