Cam timing

MightyBoy tech questions and answers.
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Brayden
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Here's the scenario:

I pulled down the front of my engine to replace a bung crank seal, and also replace the timing belt to avoid any slippage related to the oil leak. In the process of trying to remove the cam sprocket to get at the rear timing cover, I "may" have accidentally spun the cam through 180 degrees, something I didn't even think about until I'd put the motor back together.

Now I'm 99% sure that the sproket is in the right position, (arrow was pointing down) but I need some advice.

When turning the crank to TDC for the first cylinder, none of the valves are moving, (compression/combustion stroke) however the exhaust valve on #2, and the intake on #3 are both opening. Does this sound right?

It makes sense to me, but just thought I'd double check.
F8B EFI turbo - Three pots and a snail.
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evilgidget
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Bung seal in your new motor? :evil:

:alco: Hmm, after a little inspiration, i believe you should be...


...um...

...looks ok from here.
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fritz
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Now its a whil since I did mine, but I can vaguely remember that there was a marking on the cam pulley & the crank one (I only noticed this after I did it), but I think they are supposed to line up or something???
:?
Surely if they do, then it cant be 180° out?
Can anyone verify this?
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Brayden
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The marks did line up, but that could mean that in an effort to straighten the sprocket (if indeed it was out by 180) I could have turned it an additional 180 and it is 360 out - I really should have paid more attention at the time.

As for the bung seal, well thats just a $2 part that ended up costing $50. I could only imagine the repair bill if the timing belt had've slipped though. Prevention is better than cure as they say.
I suspected that the seal was leaking when I first installed the motor last year, and Mick at Suziworld told me that if that was the problem I should get it fixed and bill him for it. But owing to the fact the sump was loose I put the oil leak down to that. However after pulling off the timing cover when the engine was out and discovering oil on the timing belt I decided to replace the seal while the motor was on the bench.

At any rate, once I get it all back in on the weekend its back to trying to set up the weber properly. I've been messing around with the emulsification tubes and air jets to try and stop it from flooding the engine. I pulled the plugs out and after only 2000k they were black and gummed up from the fuel wash that was lifting oil from the rings. Bring on the turbo is all I can say. :twisted:
F8B EFI turbo - Three pots and a snail.
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fritz
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Just thinking out load here. - by no means am I qualified to officially comment here.
Two turns of the cam equals 1 turn of the crank.
Now assuming there is some alignment between the markings on the cam & crank - if the cam was 180° out then the crank would actually point away from the cam & not to it? If it is 360° out it is actually perfect?

Just throwing it out there?
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Brayden
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It's actually the other way around - two turns of the crank equals one rotation of the cam.

Given that the crank must complete two rotations for a full combustion cycle then having the cam out by 360 would mean that it was half a cycle out.
F8B EFI turbo - Three pots and a snail.
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Colin
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Location: South Coast (NSW)

if you didnt remove the distributor line up the cam on No1 it can point up or down pending on what timing gears you have on it (found this out on mine) then put it back together if you get stuck call me
MORE BEER! :beer:
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Brayden
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Yeah see I had the dizzy off at that time too. :roll:
So I can't rely on that to tell me where abouts the cam was/should be.

Anyway, I just checked the workshop manual, and everything appears to be in order - guess I'll soon know when I try to crank it over!
F8B EFI turbo - Three pots and a snail.
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eDave
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*hides*
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Colin
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set it up on No1 and check you have tappet clearence on No1 inlet and exhaust
MORE BEER! :beer:
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Brayden
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#1 is at TDC and both valves are closed - exhaust on #2 and intake on #3 are both opening at that point.

Apart from that I have discovered that the screws on the rocker shafts are all loose - I think it might be wise to swap them for hex nuts and loctite them in.
F8B EFI turbo - Three pots and a snail.
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Colin
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there tapered dont forget
MORE BEER! :beer:
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fritz
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dodgy... :lol:
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evilgidget
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If the cam is 360 degrees out, the motor will run normally, assuming that the distributor is lined up correctly when you refit it.

Just out of curiousity, do the f8b carb's jets fit into the weber? Can't believe it's giving you so much grief - was set up great for the old f5 i had (maybe there was more to my old motor than i knew about? :crazy: )
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Josh
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evilgidget wrote:(maybe there was more to my old motor than i knew about? :crazy: )
I suspect that may be the case... :lol:
[url=http://www.tamon.org/?page=owners&id=10][img]http://www.tamon.org/forum/images/ute_specs.gif[/img][/url]
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