Cam Tech

[HotSEXJ]

Is it possible to rotate one of my stock cams with respect to the crank and actually increase performance?

[Aidan]

Im gonna say no.

[MBood82]

I believe they make adjustable cam pulleys for that express reason, it allows you to tune it for optimum timing.

I could be wrong on the purpose of them but I know they do make em and that was how I understood it to work.

[Aidan]

oh yea, i suppose you can adjust the timing of a cam a little bit to optimize that cam, but its not like getting a real new cam or anything. i dont really know, im just throwing out my own ideas.

[HotSEXJ]

I changed my timing belt and may have gotten one or both of the cams one tooth or so off with respect to the crank.

Engine is 'growlier' and has noticeably more low end torque, but has begun pinging at high RPMs (i think)

theories, now that you know what is actually happening?

[MBood82]

if it's off a tooth one way or another it means the valves are opening and closing earlier or later... it would make sense for it to have exactly the symptoms you are describing. it gits and ****s earlier on but it falls on it's face later. or it has nothing down low but might run a little better on the top end. is it a dual overhead cam setup or a single?

[HotSEXJ]

single cam for each bank I'm assuming. It's the 3VZE Toyota engine, designed a hundred years ago (it's the 3.0L V6 they put in every V6 Toyota truck between 1988 and 1994)

http://photos-595.ak.facebook.com/ip002/v49/181/51/6201882/n6201882_31839595_2503.jpg

So the real question is; will this tear my engine apart? i.e. knock -> rod bearings etc

[MBood82]

it might fry a piston or two, so yeah, you should probably get it timed right.

the other thing is, is it an interference engine? your pistons might kiss your valves if it is... which would be bad.

[HotSEXJ]

it might fry a piston or two, so yeah, you should probably get it timed right.

the other thing is, is it an interference engine? your pistons might kiss your valves if it is... which would be bad.


S H I T !

I hated tearing this thing apart, and I really hate to do it twice.

But as my role model Hank Hill says: "That's what being a man is all about: doing things you don't want to do."

:lol:

I reckon I will do it though, since I've lost one engine to a bad rod bearing and lost a whole Jeep to "user error" :lol:

It is a non-interference motor, so no worries there

[MBood82]

you can get on a toyota site and they might know more about your specific engine. in general, knock related to that would be some form of spark knock, predetonation, etc.. generally not good stuff.

[HotSEXJ]

It was honestly more of a pinging than a knocking...hard to explain it to someonen without takin em for a ride, ya know :lol:

[MBood82]

sounds like detonation.. i think i know what you mean.

and yeah... i'd time it right if you think you have it off a tooth.

[HotSEXJ]

I feel like it has to be just one of the cams that is off because of the method I used to reinstall the timing belt

I turned one cam gear out of whack and then put the belt on and then turned the cam gear back to "correct" to make sure ALL the slack in the belt between the two cam gears was gone.

I'd hate to do this 9.5 hour job again when the car is running, and with more bawls than usual :lol:

[phillyzj]

If you put the cams in 180 degrees out of where they should be you'll have exhaust coming out of your intake :D

ask me how i know? I did it to my old motorcycle, haha. I tried to mark them when i took them out, got it wrong, 180 degrees wrong to be exact. Was kind of confused when it didn't start and the exhaust as sucking air and the carbs were blowing air.....

Didn't hurt anything and after several more hours of work i had it running like new...

[HotSEXJ]

I think I just have one cam with the mark at 12 o clock like it ought to be and one cam with the mark at 12:05 :lol: you know, one tooth off.

pics might help illustrate this...
http://photos-595.ak.facebook.com/ip002/v49/181/51/6201882/n6201882_31839595_2503.jpg
I feel like the cam on the left side of your screen is at 12:00 and the cam on the right side of your scxreen is at 12:05, just one tooth off