Toyspeed.org.nz Message Board

by **TRD_ZERO** » Mon Jun 29, 2009 5:24 pm

This might be a stupid question but id just have a questions about setting my timing. When i took the engine apart i marked the cam gears to the cam belt and the crank gear to the cam belt there too.
Now when i put it all back together i marked the new cam belt in the same spots and lined the cam gears and crank gear up to the correct markings on the belt. I made sure the gears and crank were in approximatly the same spots as when i took it off but are in exactly the same points on the cam belt as before i took it apart.

Can timing be done like this as i figured it is exactly the same as before i took it all apart.

I hope this all makes sense

by **Adamal** » Mon Jun 29, 2009 5:37 pm

The sheild behind the cam gears has a marking on it that should be lined up with a marking thats on the cam gears (You may have noticed the indented dots on them).
This is the position they should be in when piston #1 is at TDC. Theres also a marking on the crank pulley for finding TDC. When all of those line up, thats when you put the cambelt out.

by **YeMs** » Mon Jun 29, 2009 6:14 pm

yeh what he said, but i do it the way you have done it when i do cambelts.

i line up TDC with the timing marks just so its basically right. then i mark the belt and pulleys when i pull the belt off. swap the marks over to the new belt, this also gives me the oportunity to check the teeth shape/design and count are the same. then fit the new belt according to the marks. its much easier, and some belts/vehicles use it, IE gates belts on ej20 and 1kz motors etc.

i always double check the timing marks line up after i have tensioned the belt and done 2 engine rotations.

by **TRD_ZERO** » Mon Jun 29, 2009 6:32 pm

Nice info guys thanks but my engine is back in the car and feel it is going to be a hasstle setting it all up again. Is it fine the way i have done it can i leave it like that?

by **rollaholic** » Mon Jun 29, 2009 6:44 pm

its not hard to check the timing against the timing marks with the engine in the car

by **bluemaumau** » Mon Jun 29, 2009 6:57 pm

blacktops are interference engines too arnt they, meaning if youve got it wrong, your in trouble.

why didnt you just put all three pulleys at there markers? then youd have been sweet

by **Crampy** » Mon Jun 29, 2009 6:59 pm

Are they interference? I thought all 4AGES were non-interference motors.

by **bluemaumau** » Mon Jun 29, 2009 7:00 pm

Crampy wrote:Are they interference? I thought all 4AGES were non-interference motors.

yea im not sure, for some reason i thought blacktops are the only ones, dont quote me on it tho

by **Crampy** » Mon Jun 29, 2009 7:02 pm

I thought the pistons had valve cutouts, which made them non-interference.

by **RomanV** » Mon Jun 29, 2009 7:09 pm

Pistons can have valve cut outs and still be interference, it lets them have more duration/lift with the cutouts.

by **TRD_ZERO** » Mon Jun 29, 2009 7:21 pm

bluemaumau wrote:blacktops are interference engines too arnt they, meaning if youve got it wrong, your in trouble.

why didnt you just put all three pulleys at there markers? then youd have been sweet

Cause i thought that the way i had done it would have been sufficient.

red car · by pc » Mon Jun 29, 2009 7:28 pm

I would never rely on marking the belt... it's not the way it's ment to be done, besides why assume it is correct when you pull it apart.

Use the timing marks on the cam wheels & crank pulley and it wont fail.

by **jondee86** » Mon Jun 29, 2009 8:20 pm

TRD_ZERO wrote:Can timing be done like this as i figured it is exactly the same as before i took it all apart.

No, not a foolproof method. The crank does two turns to one on the cams.
So the crank marks can still line up even tho the crank is 360 degrees
away from where it should be. You have to reference TDC on number
one to make sure you have the timing right according to the dots.

Cheers... jondee86

by **rx7guy** » Mon Jun 29, 2009 8:32 pm

How can anything be 360 degrees from where it is supposed to be... It doesn't really matter if the bottom end has turned round once.

It should be ok. If it can be turned over you might as well start it up and see if it runs ok. But if you have any doubts check the timing marks.

by **fivebob** » Mon Jun 29, 2009 8:36 pm

jondee86 wrote:even tho the crank is 360 degrees away from where it should be.

Might I suggest that you try marking a crankshaft and rotate it 360° to see where it ends up in relation to it's original position :roll:

by **CAMB01** » Mon Jun 29, 2009 8:49 pm

All 4ages are non interference including 20 valves.

by **Crampy** » Mon Jun 29, 2009 10:53 pm

CAMB01 wrote:All 4ages are non interference including 20 valves.

Thought so.

by **Crucible** » Mon Jun 29, 2009 11:16 pm

...so what if a DOHC engine breaks the cam belt for example, so you cant take note of pulley position, and say the cam gears have two seperate marks on each cam pulley, where or how would you time it?

you can use this same method if youve lost the marks also, its pretty obvious when you think about it lol....

by **TRD_ZERO** » Mon Jun 29, 2009 11:29 pm

CAMB01 wrote:All 4ages are non interference including 20 valves.

I dont know about that one.

Anyway i had a play with it and lined the cam gears up to the marks on the rocker cover and when lined up i checked the crank pulley and saw a little v cut sitting between 5 and 0 but the 10 has been highlighted with what looks like twink. So is the v supposed to line up with the 10? Saves me taking the crank pulley off and looking at the crank gear.

by **CAMB01** » Mon Jun 29, 2009 11:36 pm

Should line up the crank with the 0 first, then check to see where the cams are.

Believe me if they are factory and havnt been dicked around with (i.e. shaving the head etc) they wont bend valves at all.

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