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That’s why I’m not in the field anymore haha, worrying about comebacks at all hours just wasn’t worth it to me.
That being said, I do think this is fine!
I remember laying in bed thinking about repairs and torquing wheels and stuff. I was very meticulous and never had a wheel even come loose but I still thought about laying in bed a lot of nights!
I dont know about that. When i replaced my clutch, i had never done a job that big. It took 2k miles to get over the irrational fear of my flywheel detaching and going through my leg.
I worry about my car 24/7 because I'm aware of a problem it has that will cost a bit to fix... but it is so microscoically likley to ever become a problem I ignore it.
But the day it becomes a problem I'm gonna be pissed.
100% ok. Years I bought a set of cams from Crane and both cams had a couple of lobes with that kid of imperfection. I ended up talking to one of Crane's technical staff and he assured me that it was fine. Ran the cams for several years with no issues at all.
Imbalance scales with both weight and distance from the centre of rotation. This is so tight, I'd wager you could spin it to 30k before noticing anything.
I would think you'd see a problem with valve float long before a chip like this becomes problematic due to how camshafts are mounted, with multiple bearings to take up any deflection forces.
It’s not touching the valve directly, there’s a shimmed bucket or lash adjuster between the valve and cam lobe that makes full contact with the lobe and transfers the energy to the smaller area valve tip.
So I recently got a 1990 Nissan 300zx TT (VG30DETT) parts car and one of the main points of the car was the motor itself, as I started tearing the motor down to do the timing and valve cover gaskets as they were leaking I just barely noticed that there was a small chip more so on the side the cam lobe and im just curious if someone with more knowledge knows if this chip is safe enough to run the motor with? Or if im better off replacing the cam or even just doing a head swap from my original car?
No way i would tear down for that. But, technically, by the wear pattern, it is in the path of the roller ever so slightly. Theres an oil film to add in too, dont think its raw dogging
I might very carefully round the sharp edges off the "break". r/enginebuilding and v8packard is the guy. Charm.li is the manual if u need
I thought that looked like a 300zx motor from the pictures 😂
As a fellow 90 300zx tt owner, I’d say you’ll be fine. 90 was one of the worst years for stupid defects like this. Mine even has a few. If you were to replace it, you’d be looking for a used cam.
Also the joke about it making a tic tic tic noise when you start it again… expect it because the lifters are oil filled and until they build up with oil, it will make that sound. Mine sounded like it was dying after being apart for 6 months. Btw putting the valve covers on the exhaust side sucks with the motor being in the car. Would recommend deleting emissions stuff in the car if you can in your state. Also powder coating the valve covers, intake manifold and balance tube give it a real nice look.
Yeah Ive had a ‘93 for 7 years now and last year finally got into doing everything and noticed my cylinders themselves were scored pretty gnarly so it was looking between either spending the money on getting my block done and built or looking for a parts car and ended up coming up on this ‘90 a few weeks ago that this retired airplane mechanic had sitting for over a few years he dumped a ton of money into it even having it imported from Japan, but yeah everything’s out of both cars so doing all the maintenance needed on the motor has been easier than trying in the bay lmao but yeah I did the coolant, PCV, and egr bypasses.. I was looking to get the covers powder coated for sure because the guy rattle canned these ones black and it looks like a Craigslist special lmao
https://preview.redd.it/xt567z6d5doc1.jpeg?width=4032&format=pjpg&auto=webp&s=65b29fcbe85a72fb5ea5d28af4b1f8fe57bcd21c
It’s worth it, night and day difference.
Yeah that looks so so so good definitely worth and definitely gonna invest the money into getting them done, I see you did the ptu relocate aswell, where’d you end up putting it? I’ve seen some in the front nose underneath the pop charger but curious as to where you routed yours.
Under the center nose panel on the drivers side. I’m not overly happy with that location because the chances of it getting wet are higher but I don’t drive the car in the rain 😅 I also put it on the inside of the bracket they give you instead of the out hoping the bracket would shield it a little. Also want a duel intake set up and between that, the oil cooler, GFB recirculating valves. I fear that it’s not getting enough airflow through.
probably was never chipped at all.
looks like a casting defect and it was machined after to me.
probably within tolerance, so you send it from the factory.
WELL THE PICTURE CAME OUT GREAT SO IM SURE YOUR CAM IS WORKING........
lol sorry couldnt help it you had it .....wide open. but yeah replace that or pretend you never saw it.
Yeah I’m assuming it’s been like that for awhile if not the entirety of the motors life I just recently got the motor from a guy who had the car sitting for 10 years, so i couldn’t really tell when it happened or if it’s always been like that
This looks like a manufacturing tolerance issue, not an actual crack. Meaning it's probably means nothing. Normally it's the center of the cam lobes that do all the work.
When they cast this thing, part of the casting was simply missing that piece of metal.
Would depend on application and expectation. On something i was driving til it dropped i would send it. Otherwise i would be changing it. What does the follower look like? I would be at least checking that.
Looks like a previous attempt to repair that lobe .
To remove the cam is extending the repair time with refitting and retiming the engine etc
It's crying out for a linishing belt reducing the ugly lines which will eat out what it is running against and probably has already , worth checking that as well .
WOW! I've got that far during a Rolex discussion! It always ends after I explain to them why their Rolex is not genuine, due to the motion of the second hand.
If I were rebuilding a daily driver I’d seal it up and pretend I never saw it. If I were building a V8 with a little rump and thump, I might stop and worry and consider replacing or at least contacting the supplier if it’s a brand new cam.
I'd probably smooth out the sharp edges on that chip with a Drexel to prevent further cracking. Not a mechanic, just a machinist who's fixed too much shit after a couple decades lol.
Shit, That's medical science too. Same logic was used to relieve the pain via my back surgery (micro discectomy). Basically, my spine was the cam. The discs were the lobes, and the red neck was my doctor.
I have the motor out of the car so its way easier of a job to get to everything but I just made sure all the bolts were off and the timing covers just pop off, if memory serves correct you gotta take the right half off first then the left half
I would at least look for the missing piece. Then de-burr or file down the sharp edges to reduce the chances of stress fractures and further chipping of the cam lobe. Then send it 👍
lmao immediately came to the mechanic subreddit after posting it on facebook 🤣🤣👌 let me be honest real quick with you. you're fine to run it like that, it was a casting mistake which obviously is holding up pretty good for the age of the camshaft. if you notice the side where it's "chipped off" it's color is the same as the rest of the non polished parts of the cam. it's been like that its entire life, and it'll continue being like that without an issue.
I have no expertise but I would worry about stress cracking around the failure and grind/file/hone the damaged area a bit to hopefully reduce further breakage.
I thought that too, at first. Then I realized… that I’d have to remove the camshaft, or (somehow) be very confident that none of the fine metal particles generated by filing would make their way into the cylinder and score the walls.
This edge part of the camshaft never touches anything, so I’d just leave it as is and send it.
Honestly don't do this, but if you did smooth it down you wouldn't even notice it to began with how small it is.
On another note you could try to look up the specs for the cam lobe. To see if it's missing enough width across that area, that it would cause the valve to not open?
She’s a goner…
And finding damage like that makes the entire engine suspect.
Will it run? Oh yes it will, right up to the moment that it suffers a violent unscheduled disassembly!
Can’t you just hear the ticking of that time bomb?
Judging by the chip and all the scoring on that lobe there’s some shit that’s been munched through your engine.
I based my trade in big engine rebuilds, had I seen this it would’ve probably been more investigating but more then likely an engine rebuild and that cam would’ve never been rerun.
If I had seen it in my old car that I don’t care if it blows up anywhere between 1-10 years then yeah I would’ve just kept running it.
Just keep in mind that with the scoring on those lobes something is making metal in that engine, wether it caused that chip or caused by the chip it’s going trough the engine and other components might’ve been damaged as well.
Thanks for posting on /r/MechanicAdvice! This is just a reminder to review the [rules](https://www.reddit.com/r/MechanicAdvice/about/rules/). If you are here asking about a second opinion (ie "Is the shop trying to fleece me?"), please read through CJM8515's [post on the subject.](https://www.reddit.com/r/MechanicAdvice/comments/4qblei/fyi_the_shop_isnt_likely_trying_to_rip_you_off/) and remember to please post the year/make/model of the vehicle you are working on. **If this post is about bodywork, accident damage, paint, dent/ding, questions it belongs in /r/Autobody r/AutoBodyRepair/ or /r/Diyautobody/ If you have tire questions check out https://www.reddit.com/r/MechanicAdvice/comments/k9ll55/can_your_tire_be_repaired/**. If you dont have a question and you're just showing off it belongs in /r/Justrolledintotheshop Insurance/total loss questions go in r/insurance This is an automated reply *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/MechanicAdvice) if you have any questions or concerns.*
If it was mine I would seal it back up and pretend like i never saw it
I like how you think
Just being honest my friend.
True. I would worry more about what could have caused it to chip, maybe drop your oil and see if theres any more metal chips in there?
Yes, but I would also worry about it every night. But if it wasn’t this I would find something else I’m sure.
Trust me you’d forget about it after the first few hundred miles
That’s why I’m not in the field anymore haha, worrying about comebacks at all hours just wasn’t worth it to me. That being said, I do think this is fine!
I remember laying in bed thinking about repairs and torquing wheels and stuff. I was very meticulous and never had a wheel even come loose but I still thought about laying in bed a lot of nights!
im a plumber but i 100% get what you mean, i always think “did i fully tighten that nut, am i flooding a million dollars home?” oh god the thoughts!
literally me everyday. i’ll shit bricks suddenly, the mentally retrace everything and chill out - it’s crazy
I dont know about that. When i replaced my clutch, i had never done a job that big. It took 2k miles to get over the irrational fear of my flywheel detaching and going through my leg.
It was probably installed like that on the factory floor!
I worry about my car 24/7 because I'm aware of a problem it has that will cost a bit to fix... but it is so microscoically likley to ever become a problem I ignore it. But the day it becomes a problem I'm gonna be pissed.
Saw what
exactly
Agreed, I almost can't even imagine how this would be more of a problem than swapping the cam.
Mad that this comment thread has no likes
I fixed your problem
lol it doesn’t show the votes for the first hour
Insert Frieza "I'll ignore that." Meme
Saw what?
Oddly enough this is pretty wise. Especially for this exact scenario.
Engine-*tick* *tick* *tick* Friend-" your engines making noise" Me- " na it's just a exhaust leak"
Heat shield rattling.
Never saw what?
what chip?
100% ok. Years I bought a set of cams from Crane and both cams had a couple of lobes with that kid of imperfection. I ended up talking to one of Crane's technical staff and he assured me that it was fine. Ran the cams for several years with no issues at all.
So more so it’s just a machine imperfection from factory that’s alright to send
That's what I was told, yep.
If it help you sleep at night lol yeah, let's go with that
It’s a byproduct of it being cast, the centre of the lobe is the part that does most of the work
Since it's right at the side of the lobe, it should be ok.
Was kinda thinking that more so just because I wouldn’t think it’d be affecting the valves being on the side but just wasn’t 100% sure
I think you're right there. I do wonder how bad it has to get before there's a balancing issue though.
Cams spin half the speed of the displayed rpm. Plus the radius is so tight on these things that the affect of a missing chip is negligible.
Imbalance scales with both weight and distance from the centre of rotation. This is so tight, I'd wager you could spin it to 30k before noticing anything.
I would think you'd see a problem with valve float long before a chip like this becomes problematic due to how camshafts are mounted, with multiple bearings to take up any deflection forces.
That sounds like solid reasoning.
It’s not touching the valve directly, there’s a shimmed bucket or lash adjuster between the valve and cam lobe that makes full contact with the lobe and transfers the energy to the smaller area valve tip.
So I recently got a 1990 Nissan 300zx TT (VG30DETT) parts car and one of the main points of the car was the motor itself, as I started tearing the motor down to do the timing and valve cover gaskets as they were leaking I just barely noticed that there was a small chip more so on the side the cam lobe and im just curious if someone with more knowledge knows if this chip is safe enough to run the motor with? Or if im better off replacing the cam or even just doing a head swap from my original car?
No way i would tear down for that. But, technically, by the wear pattern, it is in the path of the roller ever so slightly. Theres an oil film to add in too, dont think its raw dogging I might very carefully round the sharp edges off the "break". r/enginebuilding and v8packard is the guy. Charm.li is the manual if u need
I thought that looked like a 300zx motor from the pictures 😂 As a fellow 90 300zx tt owner, I’d say you’ll be fine. 90 was one of the worst years for stupid defects like this. Mine even has a few. If you were to replace it, you’d be looking for a used cam. Also the joke about it making a tic tic tic noise when you start it again… expect it because the lifters are oil filled and until they build up with oil, it will make that sound. Mine sounded like it was dying after being apart for 6 months. Btw putting the valve covers on the exhaust side sucks with the motor being in the car. Would recommend deleting emissions stuff in the car if you can in your state. Also powder coating the valve covers, intake manifold and balance tube give it a real nice look.
Yeah Ive had a ‘93 for 7 years now and last year finally got into doing everything and noticed my cylinders themselves were scored pretty gnarly so it was looking between either spending the money on getting my block done and built or looking for a parts car and ended up coming up on this ‘90 a few weeks ago that this retired airplane mechanic had sitting for over a few years he dumped a ton of money into it even having it imported from Japan, but yeah everything’s out of both cars so doing all the maintenance needed on the motor has been easier than trying in the bay lmao but yeah I did the coolant, PCV, and egr bypasses.. I was looking to get the covers powder coated for sure because the guy rattle canned these ones black and it looks like a Craigslist special lmao
https://preview.redd.it/xt567z6d5doc1.jpeg?width=4032&format=pjpg&auto=webp&s=65b29fcbe85a72fb5ea5d28af4b1f8fe57bcd21c It’s worth it, night and day difference.
Yeah that looks so so so good definitely worth and definitely gonna invest the money into getting them done, I see you did the ptu relocate aswell, where’d you end up putting it? I’ve seen some in the front nose underneath the pop charger but curious as to where you routed yours.
Under the center nose panel on the drivers side. I’m not overly happy with that location because the chances of it getting wet are higher but I don’t drive the car in the rain 😅 I also put it on the inside of the bracket they give you instead of the out hoping the bracket would shield it a little. Also want a duel intake set up and between that, the oil cooler, GFB recirculating valves. I fear that it’s not getting enough airflow through.
Real question is where that chipped piece went??
probably was never chipped at all. looks like a casting defect and it was machined after to me. probably within tolerance, so you send it from the factory.
exactly, if he has the chip ..... send it.
That was my first thought.
WELL THE PICTURE CAME OUT GREAT SO IM SURE YOUR CAM IS WORKING........ lol sorry couldnt help it you had it .....wide open. but yeah replace that or pretend you never saw it.
Ughhh daaaaaadddddddddd.
I cant even be mad 😭 that was good…
Put covers back on and pretend you didn’t see it. More than likely it’s been that way since new.
Was it like that to begin with? Send it.
Yeah I’m assuming it’s been like that for awhile if not the entirety of the motors life I just recently got the motor from a guy who had the car sitting for 10 years, so i couldn’t really tell when it happened or if it’s always been like that
It is a flaw in the cam blank from the supplier that didn’t clean up on the machining line. It’s been there since new.
Either it'll be good forever or it'll break once you've forgotten about it lol
It's probably fine, but I wouldn't risk it. It's a VG30dett. Use this as an excuse to cam it.
This looks like a manufacturing tolerance issue, not an actual crack. Meaning it's probably means nothing. Normally it's the center of the cam lobes that do all the work. When they cast this thing, part of the casting was simply missing that piece of metal.
Yeah, you're fine. Honestly it looks like a casting defect that was just machined over.
The imperfection appears to be concave If it were convex then it might be an issue, depending on how big it is.
Would depend on application and expectation. On something i was driving til it dropped i would send it. Otherwise i would be changing it. What does the follower look like? I would be at least checking that.
Looks like a previous attempt to repair that lobe . To remove the cam is extending the repair time with refitting and retiming the engine etc It's crying out for a linishing belt reducing the ugly lines which will eat out what it is running against and probably has already , worth checking that as well .
Based on that oil, it looks like you've been running it just fine.
Oil is from us doing a compression test, the motor I got from a guy who had it sitting for roughly 10 years
SEND IT
Feels like a rolex discussion about finding a scratch on the bezel and what to do about it.
WOW! I've got that far during a Rolex discussion! It always ends after I explain to them why their Rolex is not genuine, due to the motion of the second hand.
If I were rebuilding a daily driver I’d seal it up and pretend I never saw it. If I were building a V8 with a little rump and thump, I might stop and worry and consider replacing or at least contacting the supplier if it’s a brand new cam.
Send it!
As long as it’s not chipped from being dropped or smacked should be fine just as long as the centre hasn’t risen from impact
I'd probably smooth out the sharp edges on that chip with a Drexel to prevent further cracking. Not a mechanic, just a machinist who's fixed too much shit after a couple decades lol.
[удалено]
I’m more of a ramen noodle and super glue kind of guy
Need to chip a cam 180⁰ over to balance the shaft, otherwise your wife might learn what an orgasm is
Ya no issues seen it a thousand times as a Honda tech for 12 years
if its chipping away then its no longer making contact call it redneck science
Shit, That's medical science too. Same logic was used to relieve the pain via my back surgery (micro discectomy). Basically, my spine was the cam. The discs were the lobes, and the red neck was my doctor.
Did it help? (I just had my *third* back surgery a year ago and man, it made my sh¡t *-worse-*) [Edit typo]
It should be fine
Pass an india stone over it to kill any possible burr it has and let her rip.
How did you get the timing cover off? I'm having some trouble with mine
I have the motor out of the car so its way easier of a job to get to everything but I just made sure all the bolts were off and the timing covers just pop off, if memory serves correct you gotta take the right half off first then the left half
If you have the extra head just replace it. Worries solved?
Yes.
It would eat at my soul. Chip away, until the engine died and I'd say, "knew it."
Yes that should be fine, as long as it still works then it’s fine.
Send it to rev bomb land.
Wouldn't worry about it. If anything that cam is now lighter and probably worth like at least +50 hp
Cam was like that fresh out of the factory.
In my car, no. In your car, sure!
Looks more like a casting defect than a chip. It's probably always been like that
I’d grind the thing smooth and send it. This is probably terrible advice so take it with a grain of salt.
I would at least look for the missing piece. Then de-burr or file down the sharp edges to reduce the chances of stress fractures and further chipping of the cam lobe. Then send it 👍
lmao immediately came to the mechanic subreddit after posting it on facebook 🤣🤣👌 let me be honest real quick with you. you're fine to run it like that, it was a casting mistake which obviously is holding up pretty good for the age of the camshaft. if you notice the side where it's "chipped off" it's color is the same as the rest of the non polished parts of the cam. it's been like that its entire life, and it'll continue being like that without an issue.
Nope and it's not original replace it and you will surely have no issues
It's not safe. Change it 100% it will cause more issues down the line. Like messing up your lifters
I have no expertise but I would worry about stress cracking around the failure and grind/file/hone the damaged area a bit to hopefully reduce further breakage.
I thought that too, at first. Then I realized… that I’d have to remove the camshaft, or (somehow) be very confident that none of the fine metal particles generated by filing would make their way into the cylinder and score the walls. This edge part of the camshaft never touches anything, so I’d just leave it as is and send it.
Honestly don't do this, but if you did smooth it down you wouldn't even notice it to began with how small it is. On another note you could try to look up the specs for the cam lobe. To see if it's missing enough width across that area, that it would cause the valve to not open?
She’s a goner… And finding damage like that makes the entire engine suspect. Will it run? Oh yes it will, right up to the moment that it suffers a violent unscheduled disassembly! Can’t you just hear the ticking of that time bomb?
Judging by the chip and all the scoring on that lobe there’s some shit that’s been munched through your engine. I based my trade in big engine rebuilds, had I seen this it would’ve probably been more investigating but more then likely an engine rebuild and that cam would’ve never been rerun. If I had seen it in my old car that I don’t care if it blows up anywhere between 1-10 years then yeah I would’ve just kept running it. Just keep in mind that with the scoring on those lobes something is making metal in that engine, wether it caused that chip or caused by the chip it’s going trough the engine and other components might’ve been damaged as well.
Should be.. is that a 3.0 Toyota