Installing timing belt

[Lucas03es]

So im installing my gates blue timing belt on my freshly rebuilt motor. I dont know if it matters, but it has 1mm oversized valves and bc 280 cams. I did the timing belt according to vfaq, but when I removed the tensioner pin and rotated the motor 6 times over, when I realigned the cam gears, the crank sprocket doesn't line up to the timing mark on the block. Its 1 maybe 2 teeth past the mark. I just dont know if this is supposed to be true TDC? I have the Jay racing tool kit as well. Thanks!

 

[bryanwheat]

Wondering where you're pulling the 'Year and a Half' time ratio? - NOTE : (03-22-2010, 08:45 AM ) Oooh the first post of mine concerning a timing belt job on my 92 Non Turbo Eclipse Base Model, 4G37 - 4G63 Swap that I did in my carport without any prior knowledge to it. I see what you did there. Way to go out of your way.


As for owning a shop where one comes to bring their vehicle, drop off, sign a piece of paper, I head in, snap my gloves, perform a duty, and get paid on a weekly basis by distributing funds on and extracting my General Ledger to perform my book-keeping : No. I do not.

Now by performing work and research on my own vehicle, the vehicles of others who need help in my area, re-performing timing belt jobs out of need or concern that an oil droplet has deteriorated the integrity of the belt (IE being anal), and by that of helping those around me who need the assistance while performing a vital routine in upkeep : Then I guess you could say yes.

That is how I've performed, loosely, "A few dozen. "

Not once has a timing job I've done resulted in failure. So I'd say I'm at least 24-0.



1 : It is 'off' as it's a 'work around' to correct one's mistake in an easy fashion instead of doing it right, which is why this sideways endorsement from others tossed in here and there is starting to irk me.

2 : I made the comment about chicklets based on the fact that they are now overseen by privileged individuals on the board, thus assessing that somehow, someone like me has been approved of three with zero negative counts - which goes to state that the input that I've given in situations like this has obviously not been incorrect. No hint towards "I'm better than anyone else" just moreso - "Stop telling people it's alright to goof your timing and then try to correct it by flipping your CAS 180* out. That's bad information."

I thought we were about doing things right here at Dsmtuners.com - Not screwing up your Mechanical timing and suggesting to not worry about it - "flip your CAS around, It should be alright but we're not sure. "

Again, i am not telling one single person that it is ok to set it like that, stop saying that, get it out of your head. I am only stating the FACT that if you time it the dowels down and the timing marks on the cams lined up along with the crank that the cams WILL be in time. That is a fact, you can't argue with that. I know for a fact that it works like that, it works like that on every 4 cycle engine, the cams spin half as fast as the crank.

 

[Calan]

Again, i am not telling one single person that it is ok to set it like that, stop saying that, get it out of your head.

Everyone realizes that Bryan. Don't worry about it.

You have me thinking about this now; I actually want to try it sometime and see if it would work. The only issue I see with it (based on being pretty tired at the moment) is with the ignition dwell that I mentioned in post #43.

 

[XiKeiyaZI]

Again, i am not telling one single person that it is ok to set it like that, stop saying that, get it out of your head. I am only stating the FACT that if you time it the dowels down and the timing marks on the cams lined up along with the crank that the cams WILL be in time. That is a fact, you can't argue with that. I know for a fact that it works like that, it works like that on every 4 cycle engine, the cams spin half as fast as the crank.

Don't misunderstand - I know what you're saying. 100% understand what you're saying. If the CAMS are 180* and you flip your CAS to match it, then when you bring it back into time, the CAMs and the CAS will be in synch. But it's not right. We do not suggest altering the way that you perform a task that has been taken to heart, proven, and found to have no faults and come up with a work around because you screwed up, period. It will promote people destroying their engines. Something else stupid? Sure. Washers behind your shocks to create a ghetto camber? Alright - Whatever. But this is your Mechanical timing. If you mess up, you do it again. To see this promoted and backed baffles me.

 

[Calan]

To see this promoted and backed baffles me.

What the hell Keiya?

He's only said like 3 times that he is not suggesting doing it, and others have said it also. We're simply trying to have an interesting discussion about the IDEA of doing it.

If you can participate in that discussion, fine. Otherwise, just stop posting...please.

 

[XiKeiyaZI]

What the hell Keiya?

He's only said like 3 times that he is not suggesting doing it, and others have said it also. We're trying to simply have an interesting discussion about the IDEA of doing it.

If you can participate in that discussion, fine. Otherwise, just stop posting...please.

And I'm only stating that it's not right to be suggested. The idea of it is faulty - Otherwise it would be documented in repair manuals or suggested on the various resources that this community has used for over 2 decades to do this. There is a reason no one suggests doing it in this fashion - Likely because there's some ill side effect.

As far as I can see, I am participating - By suggesting to not be lazy and do it correct. If you can't appreciate that then hey - Not my problem. But I will not simply sit there and not voice that this is incorrect. We only say " Double, triple, and quadruple check your timing to make sure it's correct " For a reason. That reason is not to follow up and say " And oh - If you messed up, don't do as the Major names in the business have done for 20 years and redo your timing... Just flip your CAS! "

However - I'm done. Finished. If this is what you want people to get an idea of as being 'alright' then so be it. It's your image and title on the line. Not mine.

 

[Calan]

If this is what you want people to get an idea of as being 'alright' then so be it. It's your image and title on the line. Not mine.

Well seeing as how we've all said many times that it's not "alright" and nobody has ever suggested to actually run out and do it, I think we'll be just fine.

 

[turboglenn]

So im installing my gates blue timing belt on my freshly rebuilt motor. I dont know if it matters, but it has 1mm oversized valves and bc 280 cams. I did the timing belt according to vfaq, but when I removed the tensioner pin and rotated the motor 6 times over, when I realigned the cam gears, the crank sprocket doesn't line up to the timing mark on the block. Its 1 maybe 2 teeth past the mark. I just dont know if this is supposed to be true TDC? I have the Jay racing tool kit as well. Thanks!

this is wqhere there's one paragraphin the vfaq that talks about setting the exhaqust camonetooth advanced and then rotating both bock to even them outat a half tooth off eachand the crank will line up, ibattle it every time


here's a quote from vfaq

NOTE: THE EXHAUST CAMSHAFT SPROCKET MAY ROTATE IN THE COUNTERCLOCKWISE DIRECTION. THIS SHOULD BE CONSIDERED WHEN INSTALLING THE TIMING BELT. (What this means is that in some cases, lining up the timing marks on the sprockets won't work - when the tensioner is tightened, it will pull the exhaust sprocket, and the camshaft marks won't line up, while the bottom ones are lined up. If this happens to you, try setting the exhaust sprocket one tooth off in the clockwise direction (mark below the head plane), clamp the belt to the sprockets, then rotate the sprockets a little so the intake mark is slightly above the head plane and the exhaust is slightly below, with the bottom 3 marks lined up. Then the marks should align when you tension the belt - but try with the marks lined up with the head plane first)

 

[XiKeiyaZI]

IF you turn the crank one full rotation than the marks will be lined up with the dowels straight up. There is no 180 out here. The cam's spin 180 degrees for every 360 degrees of the crankshaft. Why remove the belt when it is already in time. You accomplish the exact same thing either way.

That would be solved by turning the cas 180 degrees.

Well seeing as how we've all said many times that it's not "alright" and nobody has ever suggested to actually run out and do it, I think we'll be just fine.

There's not a Clever Emote I can use.

Plus - Unless someone can explain exactly how Piston Stroke is accommodated into the Egg-Shaped lobes of the Cams, the idea simply can't be grasped. At 180* difference, wouldn't the Lobes be set opposite? If I recall, the #1 Piston at TDC calls for the Intake Cam to be on the Exhaust Phase with the Lobe pointed at 3:00. If this is set as you are.. uh... 'Theorizing' then the lobe would be at 7:00ish? Or vice-versa if I can't recall which direct the cam lobe actually points right off the top of my head. The idea is still there.

Edit : By Default, the Lobes 'point' towards 10:00ish. With cam dowels down, they are at 4:30ish. With the #1 Cylinder at TDC, expecting the cams to be set correct - No, that certainly wouldn't pose a problem. Regardless of flipping the CAS or the cams lining up, the initial Timing of the CAMS at 12:00 and the #1 Piston at TDC is IMPERATIVE as the cam lobes are single action-shaped, thus they have no 180* equal to counter act and compensate VS Piston movement as far as mechanical timing goes.

Theory ended. Have an amazing day.

 

[Bomalleygst]

Well seeing as how we've all said many times that it's not "alright" and nobody has ever suggested to actually run out and do it, I think we'll be just fine.

Haha my thoughts exactly. I dont understand why people are gettin the butts hurt over this. Its the wrong way to do it. I feel like everybody has agreed with that. No more preaching please. I just find this interesting in theory. Keyword "theory". Because i surely will not try it .

 

[Calan]

Unless someone can explain exactly how Piston Stroke is accommodated into the Egg-Shaped lobes of the Cams, the idea simply can't be grasped. At 180* difference, wouldn't the Lobes be set opposite? If I recall, the #1 Piston at TDC calls for the Intake Cam to be on the Exhaust Phase with the Lobe pointed at 3:00. If this is set as you are.. uh... 'Theorizing' then the lobe would be at 7:00ish? Or vice-versa if I can't recall which direct the cam lobe actually points right off the top of my head. The idea is still there.

I'm not following you. Forgetting about the ignition and injectors for a minute (controlled by the CAS), what difference does it make if the dowel pins are pointed down? At a 2:1 crank/cam ratio, the motor is still in time mechanically.

 

[BogusSVO]

Yesterday, I wrote a post for this thread, and my net went out before I hit submit, so I will try to say now what I said then.

This is still a four stroke engine, so the strokes are in a given order.

When setting the timing belt it is based of #1 cylinder being on the compression stroke
Stroke 1 piston is at TDC, Both I&E valves closed,cam dowels at 12 O'clock, cam gear marks at E/3 and I/9

Stroke 2,power stroke, Piston moves to BDC,I&E valves closed, Cam moves 90*,crank moves 180*,Cam gear marks are E/6 and I/12, cam dowels are 3 O'clock

Stroke 3, Exhaust stroke, Piston moves up to TDC, Exhaust valves open, Intake valves closed, Cams move 90*, crank moves 180*, Cam gear marks are E/9 and I/3, cam dowels are 6 O'clock

Stroke 4,Intake stroke, Piston moves down to BDC, Exhaust valves close, Intake valves open, cams move 90* crank moves 180* , cam gear marks are E/12 and I/6, cam dowels are 9 O'clock

Now repeat.. again..again..again..

so it you drop the time belt on with the cam dowels at 6 o'clock and not 12, you set the time by the exhaust stroke on #1 cyl or the compression stroke of #4
At any time a 4 cyl engine has 2 pistons at TDC and 2 at BDC.

Now I understand why the 4g has to be rotated 6 times, compaired to 4, is to get the BS makes to line up.

If the 4g has a BSE, then the cam dowels at 6 can be done.

I think the confusion of the cas flip would be if the head was machined/changed. Not due to just a timing belt replacement.

 

[XiKeiyaZI]

Yesterday, I wrote a post for this thread, and my net went out before I hit submit, so I will try to say now what I said then.

This is still a four stroke engine, so the strokes are in a given order.

When setting the timing belt it is based of #1 cylinder being on the compression stroke
Stroke 1 piston is at TDC, Both I&E valves closed,cam dowels at 12 O'clock, cam gear marks at E/3 and I/9

Stroke 2,power stroke, Piston moves to BDC,I&E valves closed, Cam moves 90*,crank moves 180*,Cam gear marks are E/6 and I/12, cam dowels are 3 O'clock

Stroke 3, Exhaust stroke, Piston moves up to TDC, Exhaust valves open, Intake valves closed, Cams move 90*, crank moves 180*, Cam gear marks are E/9 and I/3, cam dowels are 6 O'clock

Stroke 4,Intake stroke, Piston moves down to BDC, Exhaust valves close, Intake valves open, cams move 90* crank moves 180* , cam gear marks are E/12 and I/6, cam dowels are 9 O'clock

Now repeat.. again..again..again..

so it you drop the time belt on with the cam dowels at 6 o'clock and not 12, you set the time by the exhaust stroke on #1 cyl or the compression stroke of #4
At any time a 4 cyl engine has 2 pistons at TDC and 2 at BDC.

Now I understand why the 4g has to be rotated 6 times, compaired to 4, is to get the BS makes to line up.

If the 4g has a BSE, then the cam dowels at 6 can be done.

I think the confusion of the cas flip would be if the head was machined/changed. Not due to just a timing belt replacement.

Awesome. I was hoping you'd chime in with a post like this.

So due to the difference in the Cam Lobe position and the movement of the crank and pistons, how can we rightfully say that ignition timing makes up at all for the mechanical timing? Wouldn't that lead us down the same road as a 6 Bolt Swap in a 2G where you have to reverse the firing order which would be more of a process? Each Cam lobe is 90* different along each cam in relation to which cylinder is going to fire, which cylinder is on the compression stroke, and so on.

Aside from it coming out as a convoluted mess of factors of what all would need to be changed now that the cycle of the cams is directly different from a mechanical aspect - How would you properly compensate having Cylinder #3's intake cam lobe at the 11:00 position opposed to the #1 cylinder which is now resting at the 4:30ish position, keeping in mind that at TDC of #1 Cylinder, the Intake Valve Cam Lobe is expected to be resting at the 11:00 position? The Crank knows no different and Cylinder one is still at TDC.

This causes a Mechanical flaw.

 

[BogusSVO]

[/B]

Plus - Unless someone can explain exactly how Piston Stroke is accommodated into the Egg-Shaped lobes of the Cams, the idea simply can't be grasped. At 180* difference, wouldn't the Lobes be set opposite? If I recall, the #1 Piston at TDC calls for the Intake Cam to be on the Exhaust Phase with the Lobe pointed at 3:00. If this is set as you are.. uh... 'Theorizing' then the lobe would be at 7:00ish? Or vice-versa if I can't recall which direct the cam lobe actually points right off the top of my head. The idea is still there.

Edit : By Default, the Lobes 'point' towards 10:00ish. With cam dowels down, they are at 4:30ish. With the #1 Cylinder at TDC, expecting the cams to be set correct - No, that certainly wouldn't pose a problem. Regardless of flipping the CAS or the cams lining up, the initial Timing of the CAMS at 12:00 and the #1 Piston at TDC is IMPERATIVE as the cam lobes are single action-shaped, thus they have no 180* equal to counter act and compensate VS Piston movement as far as mechanical timing goes.

Theory ended. Have an amazing day.

I think I explained the theroy in the first part, of my post, do not get hung up on lobe placement.

The mechanical time is set, in stone or belt if you like with the 2:1 movement between cam and crank.

When the directions of how a timing belt is installed, there has to be a starting point and logic.

 

[Calan]

... how can we rightfully say that ignition timing makes up at all for the mechanical timing?

You can't; they are two totally separate things.

Without a reference to ignition and fuel... the dowels pointed down with the crank at TDC is no different mechanically than the dowels pointed up with the crank at TDC; it's just two different snapshots of the motor's rotation.

...unless I'm just missing something really obvious due to being up for 24 hours.

 

[XiKeiyaZI]

I think I explained the theroy in the first part, of my post, do not get hung up on lobe placement.

The mechanical time is set, in stone or belt if you like with the 2:1 movement between cam and crank.

When the directions of how a timing belt is installed, there has to be a starting point and logic.

I suppose what I'm not understanding is that the proper way to do this is to have the Cam Dowels at 12:00 - Lobe at 11:30 - #1 piston at TDC on Compression Stroke.

With the Cam flipped, the factor that changes is the cam lobe is now suited incorrect for the piston. The Rotating assembly of the block is going the stay the same. The Cams are not going to match that - In my mind. The Angle of the Valves, the rotation and position of the cam lobes and all that VS where the pistons are just doesn't match. And it surely doesn't seem to be something you can just.. compensate by spinning your CAS 180*.

Maybe I just don't understand the entire function of the rotating assembly VS the Valve Timing enough - Maybe I'm just stuck in my way of doing it by the book. Either way, there are far too many questions that could be asked that I just don't have the time to ask and properly word while here at work for me to feel comfortable even agreeing to start an engine setup like this.

 

[Calan]

With the Cam flipped...

The cam doesn't flip; it rotates.

Without a reference to ignition and fuel... the dowels pointed down with the crank at TDC is no different mechanically than the dowels pointed up with the crank at TDC; it's just two different snapshots of the motor's rotation.

 

[BogusSVO]

Awesome. I was hoping you'd chime in with a post like this.

So due to the difference in the Cam Lobe position and the movement of the crank and pistons, how can we rightfully say that ignition timing makes up at all for the mechanical timing? Wouldn't that lead us down the same road as a 6 Bolt Swap in a 2G where you have to reverse the firing order which would be more of a process? Each Cam lobe is 90* different along each cam in relation to which cylinder is going to fire, which cylinder is on the compression stroke, and so on.

Aside from it coming out as a convoluted mess of factors of what all would need to be changed now that the cycle of the cams is directly different from a mechanical aspect - How would you properly compensate having Cylinder #3's intake cam lobe at the 11:00 position opposed to the #1 cylinder which is now resting at the 4:30ish position, keeping in mind that at TDC of #1 Cylinder, the Intake Valve Cam Lobe is expected to be resting at the 11:00 position? The Crank knows no different and Cylinder one is still at TDC.

This causes a Mechanical flaw.

well when #1 is at TDC, #3 will be at BDC, #1&#4 are paired as #2&#3 are paired.

so when #1 is at piston TDC and cam dowels 6 o'clock, that is its exhaust event
that would make #4 on compression stroke

leaving #2 and #3 on a power stroke and intake stroke.

Lobe placement will not change from its index to the cam dowel.

 

[XiKeiyaZI]

The cam doesn't flip; it rotates.

Holy sh- It all makes sense now!

well when #1 is at TDC, #3 will be at BDC, #1 are paired as #2 are paired.

so when #1 is at piston TDC and cam dowels 6 o'clock, that is its exhaust event
that would make #4 on compression stroke

leaving #2 and #3 on a power stroke and intake stroke.

Lobe placement will not change from its index to the cam dowel.

I'm pickin' up what you're puttin' down now.

So, changing your ignition timing to make up for this..... resolves your issue entirely?

Now we dive into what needs to be changed as far as Fuel/Spark goes, correct?

 

[Calan]

Holy sh- It all makes sense now!

Took long enough.



****

Valve overlap could play a role in this if the cams aren't straight up, which may be what Keiya was trying to describe.

 

[BogusSVO]

Holy sh- It all makes sense now!





I'm pickin' up what you're puttin' down now.

So, changing your ignition timing to make up for this..... resolves your issue entirely?

Now we dive into what needs to be changed as far as Fuel/Spark goes, correct?

No, ingition timing is an event not a stroke, that is set to fire X* BTDC

This is a 4 stroke engine with 5 events

strokes
1) Compression
2)Power
3)exhaust
4) intake

Events
1) Compression
2) Ingintion
3) power
4)Exhaust
5)intake

all is based of crank rotation of 360*
when the crank turns 360*
The cams turn 180*

so when the crank turns 720* the cams have gone 360*

 

[XiKeiyaZI]

I see, I see.

Well, if the residential lord of the Engine speaks it - I'll believe it.