Weird camshaft finding

[Terry Posten]

I just got done doing the waterpump, timing pully job on my cousins car. This was V8eaters old ride.

Everything went as expected until we were getting ready to redo the alt/PS stuff.

I was looking at the cam gears and saw that they were upsidedown. The marked (with white paint) tabs were together but the dowels were pointing down. We did not spin the motor or cams when the belt was off.

It has been like this since before we got it.

I pulled the CAS and sure enough, it was 180 out of phase as well.

There was no way I meesed up the timing job because the white marks would always be together but the dowels were down.

I pulled the VC, took the cams loose, spun them, deflated the lifters, retorqued the cams, retimed everything and she runs good.

It tripled the timing job.

Why did this thing run with the cams and the CAS 180 out?

Was it firing on #4 top-dead-center instead of #1? (waste spark)

what would be the drawbacks of this performance wise?

It ran just fine before we started today, just had a slight bearing noise from the front cover and that is why we did the whole job.

 

[Rausch]

you are a busy guy!

edit: i assume this was with the crank showing 0*? if you rotate it another revolution, would the pins then be facing up,? at which point the white marks would be facing opposite each other instead of together?

 

[belize1334]

THe crank spins twice for every revolution of the cam, so if the cam was out of phse by 180* wrt the block, then it was 360* out of phase wrt the crank, which isn't out of phase at all since Sin[theta]=Sin[theta+360*]. So the cams were fine wrt the crank, it would just be the ecu input which was out of phase. But if the CAS was also 180* out, then you'd never know because the cams and CAS are in phase wrt each other, and that's in phase wrt the crank. All that was happening is that you had switched your combustion and exhaust events within the cycle. It probably would even have run ok if the CAS wasn't rotated 180* since we have wasted spark ignition. The only problem would have been the injector timing, but alot of cars used to use batch fire injectors anyway and all it really does is hurt economy a little since the fuel isn't fired into fast moving air so your atomization is poor.

Long story short, it was put together wrong, but it was wrong in the "right" way, so everything was fine.

 

[Terry Posten]

Yup.

 

[atc250r]

If you switch the intake and exhaust gears then the marks will be 180* out when everything is perfect.

John

 

[Terry Posten]

Yes, I could have but the gears are stamped "E" and "I" and are in the correct spot.

I scratched off the old paint and put new paint on them in the correct side.


I see waht you mean about the fuel "squirt". That can also be kind of dangerous due to having that fuel "sitting" for a full crank rotation.

It is correct now.

 

[loser3000]

Where were the balance shafts aligned to the first time? How are they now? Or did I miss something and it has none anymore?

 

[Terry Posten]

Does not have BSs.

 

[jepherz]

That's funny, I remember when Andy was having problems after putting his motor back together and it was mentioned that his dowel pins were down rather than up.

WTF has that guy been up to anyways? I haven't heard from him in a while!

 

[V8EATER]

I've just been chillin, making babies.

That is so strange that it was all out of whack, Terry. Didn't you guys do 3g lifters after you got it? I know I was having a hell of a time getting it back together before, but I'm suprised I f'ed it up that bad! /ubbthreads/images//graemlins/blush.gif

 

[gtluke]

it was set up right, you were just 360 out on the crank. if you spun the crank around 360 it would all line up correctly.
nothing was wrong, you just didn't have the crank on 0deg on compression stroke.

 

[Terry Posten]

Yeah Andy, It was running good. And yes, I did do 3G lifters and did not even think to look at the cams. I did them just by prying the lifters off while the cams were still in place.

How many babies do you have now?

 

[V8EATER]

One, and one on the way. June due date!

Well, I'm glad you figured out the issue before it became a problem. Everything else been going all right with the car?

 

[Terry Posten]

yep. Congrats.

It now has my old EIII turbo on it now. Runs good. Kvin is SSLLOOOOOWWWLLLLLYYYYY getting parts. I don't know how he can be so patient.