unintentionally retarded cam timing: how bad is it?

[anubis]

PLEASE HELP!

ok, here's my latest and greatest problem...

i started my car last night and put it into gear. i started moving and the car just stalled. i turned off my stereo and tried to restart it. the starter was just spinning. we tried push starting it a few times but it wouldn't start. long story short: my intake cam has been retarded 10+ degrees! my adjustable cam gear slipped! :thumbdown

so my question is: how bad is this going to be? i'm scared to death that i may have bent my valves. i just did a head rebuild this past fall and i only have 5 days before i have to go back to college. also, should i just put my cam gear back to normal and start it up?

PLEASE HELP! any advice or input will be appreciated. i've searched this site for an hour and can't find what i'm looking for.

 

[DSM90AWD]

Go ahead and reset the Cam Sprocket and do a cold compression test.
If you hear metal on metal, stop as you'll know somethings wrong (i.e. bent valve or 16).

If compression reads normal, then go a head and fire it up.

All the horror stories I've heard about adj cam gears is reason enought to stay away from them

 

[91orangeGST]

I would just try fireing it up once you adjust the cam back to normal. When I first got into dsm's I set my timing to a 92-94 setting instead of a 90-91. needless to say it was off by about 100 degrees or more and it didnt bend anything. So i think you should be in good shape!

 

[anubis]

thanks for the input.

all the input i've recieved (from here, satan, friends) seems to say the same thing. i suppose i can't really be sure without doing a comperssion test or doing a tear down. i'm going to start praying that i didn't totally screw up my head. i'll try the compression test in a little while.

after reading the second reply, i'm curious as to how much the cams can be advanced/retarded without smashing the valves. i've hear that 1 or 2 teeth off on the cam can ruin valves, and then 91orangegst tells me he was off 100 degrees without damage. that doesn't seem to make any sense.

i'll update as the situation develops.

thanks again. any more input would be appreciated.

 

[anubis]

it seems the deeper i go, the more trouble we find. me and my buddy just pulled my valve cover (it's tough to pull off when it's 20 degrees outside) and discovered something interesting: all of my intake rollers were sitting in the head, not on the valves. so with that considered, the odds that i bent all of my intake valves is probably growing, right? i don't know what i'm going to do! i have a couple options: i can use my buddies head (he's in the middle of a full rebuild on his 4G63T), i could go get one from a scrap yard, or i can have mine rebuilt. any advice? i don't have a lot of time or money right now and i don't want to have to park my car until summer, but if i have to i can.

i'm also curious about something: can i hold the manufacturer of my adjustable cam gears responsible for the damages? i know that the gears were installed perfectly and ever since they've been installed, i haven't had a chance to drive the car very hard. any advice here would also be appreciated.

 

[StreetSleeper34]

it seems the deeper i go, the more trouble we find. me and my buddy just pulled my valve cover (it's tough to pull off when it's 20 degrees outside) and discovered something interesting: all of my intake rollers were sitting in the head, not on the valves. so with that considered, the odds that i bent all of my intake valves is probably growing, right? i don't know what i'm going to do! i have a couple options: i can use my buddies head (he's in the middle of a full rebuild on his 4G63T), i could go get one from a scrap yard, or i can have mine rebuilt. any advice? i don't have a lot of time or money right now and i don't want to have to park my car until summer, but if i have to i can.

i'm also curious about something: can i hold the manufacturer of my adjustable cam gears responsible for the damages? i know that the gears were installed perfectly and ever since they've been installed, i haven't had a chance to drive the car very hard. any advice here would also be appreciated.

More than likely you smacked the valves of the intake cam. Either get a new head or plan on buying new valves, guides, and possibly pistons if they are badly scuffed into the chamber walls. Pray the valves didn't bend back into the block, where you either need to shave the deck or get a new head. So basically, to make your life easier, just plan on buying a new head and hope that the pistons are fine. Either way, it is going to be a job for ya. :thumbdown

 

[anubis]

well, the head's coming off right now. we had to take a break so our feet could warm up. it's darn cold here in michigan! i definately have bent intake valves. i was wondering about the pistons being messed up. i really hope they're fine. i'll know soon enough. i'm thinking that i'm going to return the stock cam gears. maybe when i do some more modifications and thinking about racing, i'll put the adjustables back on, but i'm not leaving them on during the off season. i'll update after we're too cold to work again. thanks for the help. i'd still like some info on whether the manufacturer of those adjustables can be held responsible. maybe i'll ask my lawyer.

 

[anubis]

god did not answer my prayers... maybe he has bigger and better things in mind for my dsm.

the head came off a lot easier than last time, maybe it's from all the experience. anyways, my intake valves were indeed bent - all 8 of them. the pistons appear to have suffered a little damage as well. there was a lot of carbon buildup (from what i don't know. was i running too rich or too lean?) and there were small gouges(sp) from the valves. the cylinder walls appear to be fine though, so that's good. thursday we're going to pull a piston and take it in to the guy at the machine shop to see what he thinks.

we're going to take the day off tomorrow so i can spend some time with my fiance before she sets fire to my precious laser. besides, i've got some thinking to do. i don't know where i want to go from here. it all depends on my future financial status. i've got school books to buy, school bills to pay, insurance, and let's not forget that 3/4 karat rock my fiance is sporting. so if my financial outlook is good, i might bore or stroke the block, gett bigger better valves and springs, and maybe have the head ported. i don't know, we'll see. i've always wanted a non-turbo that could keep up with the turbos. if the finances don't look so good, i'll just keep the dsm around for parts because no one will want to buy it. i don't know...

lastly, my balance shaft belt was destroyed. i don't know what the heck happened there. we pulled the lower timing belt cover and pieces of the belt just fell to the floor. i don't know how or why or what that means, so any input about that would be appreciated.

 

[StreetSleeper34]

lastly, my balance shaft belt was destroyed. i don't know what the heck happened there. we pulled the lower timing belt cover and pieces of the belt just fell to the floor. i don't know how or why or what that means, so any input about that would be appreciated.

If this is the case, then it may not be the cam gears that caused this problem to begin with. From what I have understand, it takes around 14 degrees before the valves and pistons get close to each other. Which means that the 10 degrees retarded that it slipped to, really should not have caused this problem. However, your situation sounds very similar to mine where the balance shaft belt broke, got wrapped up into the timing belt causing the crank to skip a couple teeth and SMACK! Thus any DSM that has some moderate mods done to it should remove the balance shafts...the belt can't take the abuse. So literally in my case a $5 belt cost me a lot more in the end. And if this is what actually happened, there is no case to be had with sueing anyone. :thumbdown

Sorry for the bad news.

 

[anubis]

my car's first rebuild! yeah! (slight sarcasm). i have mixed feelings about doing this rebuild, but regardless, i'm doing it anyway. my guy at the machine shop showed me that my head was pretty messed up. so instead of having all that work done to my old head (valve job, new valves, new guides, remilled, etc.) i'm just going to save myself some money and buy a "new" head. we've pulled the block to have it cleaned, painted, and to isntall a balance shaft eliminator kit. i was considering getting some new rods and pistons, but we'll see about that depending on the finances. i'll continue to update until the car gets back together and on the road again. if anyone has any suggestions or tips for making the rebuild easier or picking up some extra horsepower, please share.

 

[anubis]

so i was thinking about stroking my motor while it was out. i've decided to just do a hybrid motor. stage I p&p 4g63 DOHC head, meet the 2.4L g4cs short block. i may need to have the block bored due to a scratch in the #1 cylinder, so i might end up having a 2.5L naturally aspirated beast. i've still got some supporting mods to gather (safc, pocketlogger, fuel system upgrades) so i can tune that bad boy. i'd like to think that i'll be pushing 200hp when i'm finished with this build. we'll see...

 

[StreetSleeper34]

so i was thinking about stroking my motor while it was out. i've decided to just do a hybrid motor. stage I p&p 4g63 DOHC head, meet the 2.4L g4cs short block. i may need to have the block bored due to a scratch in the #1 cylinder, so i might end up having a 2.5L naturally aspirated beast. i've still got some supporting mods to gather (safc, pocketlogger, fuel system upgrades) so i can tune that bad boy. i'd like to think that i'll be pushing 200hp when i'm finished with this build. we'll see...

Get larger cams if you want to optimize your gains. Also think about getting either a GM MAF or convert it over to a 2g set-up. This will give you more airflow as well.

 

[anubis]

i've got a set of turbo cams that i was running before the breakdown. if i ever come across some better ones for a good price i'll pick them up and throw them in there. as far as a different maf setup... i've looked into it. i don't think that i can do anything other than hack the maf i have. there are extra wires on the turbo mafs (both 1g and 2g) that the non-turbos don't have. i don't know of anyone who has done a n/t to turbo maf swap. i'll look into it this summer when i have more time. besides, my maf will flow just fine for this setup. i'm not going to be running 400hp with this car so my maf will suffice. thanks though.