Question – Timing Belt Camshaft Sprocket.

[boydg1]

Question – Timing Belt Camshaft Sprocket.

…. This may be an irrelevant question. Why are there TWO timing marks on the Timing Belt Camshaft Sprocket when we only use ONE in the manual to set the timing belt on my Festy? Am I missing something here and maybe you have wondered the same thing?
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[link5186]

I use both marks. There's an alignment notch on the valve cover "v" AND one on the head "<". Look close they're both visible in your pic. One notch for each mark on the pulley.

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[frogman]

^ Right you are Sir.

[hodginsa]

So you can time it without the valve cover.

[georgeb]

^^^Best answer

[boydg1]

.... You Sir get an A+ for that answer. But if you look at the manual you will see that the horzintal MARK (Line) does NOT line up correctly and if you go by that, it appears you will miss the mark by 1 or 2 timing belt teeth. (Haynes Repair Manual page 2A-7). I have always preferred to mark the camshaft sprocket myself that way I know for sure how it relates to the crankshaft. So, now the saga goes on. :p
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So you can time it without the valve cover.

[Movin]

I use the movement of the valves to identify the position. The desired power profile of the engine and the cam if other than stock will determine exactly how the cam is timed.
The marks will likely be lined up..fairly close.

Advancing a cam will give more power at lower RPM's, less top end. Retarding give the opposite affect. Cams can be ground for all kinds of applications that will determine how
you use this timing knowledge to your benefit. We do not have much available
for cam grinds other than stock..

DOHC gets a lot more fun especially if separate advance-retard controls are used.

For this application I would be looking at the valve opening and closing happening
on number 4 cylinder. I would mark the spot where the exhaust is about .002"
farther open than the intake. This would give a stock B3 5sp the best mid to top
power with any cams available. Given all stock components for timing sprockets
I would then choose the best cog to reflect this desire.
Adjustable gears would obviously give perfect timing.
An auto tranny I would do all I could to improve low to mid power.
You all with all that you do..you can pick your own spot. Low to mid
power would have the intake of number 4 a few thousands farther
open than the exhaust and would actually help smooth a bumpy cam.

The point, I do not use timing marks, I use the cams profile.

The argument.. heads are reman, surfaces are not stock, dimensions
are changed, festy block, aspire head, Mazda whatever,
The timing marks will get you in the ball park, but if you are truly
building an engine you need to degree the actual opening, closing
of the valves and dial the cam in that way. Marks mean nothing except
that you are close and close may not be what we desire.