advice on cam timing?!

jakes_hachiroku
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advice on cam timing?!

Postby jakes_hachiroku » Fri Dec 08, 2017 6:13 am

so this is just a quick one hopefully :lol: i have a smallport 4age with 272 cams on intake and exhaust and its my drift car (ae86). i DO have some adjustable cam gears on but i haven't had the courage or knowledge to really play with them yet! so any advice on what cam timing (ball park) would be more beneficial for drift. would i retard it slightly, advance it. just intake or both intake and exhaust? leave it alone!? haha any thoughts guys?

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totta crolla
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Re: advice on cam timing?!

Postby totta crolla » Fri Dec 08, 2017 9:22 am

Ideally you would know how far you can adjust before the valves hit the pistons so with that in mind...
Generally, once armed with the knowledge as above the cam timing would be adjusted whilst the engine is on a dyno.
What would I do ?
Advance the inlet first (cam timing wheel held still, turn the centre bolt clockwise) by a few degrees, maybe 2 small segments (always turn the engine over by hand after any adjustment) and go for a drive, once you are happy with the inlet try retarding the exhaust (turn centre bolt anti-clockwise) remember that each time you adjust the exhaust cam the ignition timing will change too. Whilst any combination is possible I have found advancing the inlet and retarding the exhaust gives the best results. Have fun !

jakes_hachiroku
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Re: advice on cam timing?!

Postby jakes_hachiroku » Fri Dec 08, 2017 10:54 am

totta crolla wrote:Ideally you would know how far you can adjust before the valves hit the pistons so with that in mind...
Generally, once armed with the knowledge as above the cam timing would be adjusted whilst the engine is on a dyno.
What would I do ?
Advance the inlet first (cam timing wheel held still, turn the centre bolt clockwise) by a few degrees, maybe 2 small segments (always turn the engine over by hand after any adjustment) and go for a drive, once you are happy with the inlet try retarding the exhaust (turn centre bolt anti-clockwise) remember that each time you adjust the exhaust cam the ignition timing will change too. Whilst any combination is possible I have found advancing the inlet and retarding the exhaust gives the best results. Have fun !


hey thanks man that sounds reasonably simple! I will give it a go!

mr2mk1hero
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Re: advice on cam timing?!

Postby mr2mk1hero » Mon Dec 11, 2017 5:57 am

Here you have the basics on cam timing. Demonstrated on a 4age engine using t3 adjustable cam gears. Demonstrated by me :)

https://youtu.be/Yv4Ao7WMmS8
Check out my YouTube channel: https://www.youtube.com/channel/UCwosUn ... xtqkNJ3Fbg
Check out my blog: http://www.driving4answers.com/
Heaps of 4A-GE and MR2 mk1 aw11 content on both.

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oldeskewltoy
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Location: Portland, Oregon

Re: advice on cam timing?!

Postby oldeskewltoy » Thu Dec 14, 2017 1:34 pm

Do you have the camshaft timing card?

Which(whose) 272 cams do you have?


To properly set them you need a few tools....


a piston stop

Image



and a timing wheel w/pointer - I had made my own piston stop... but found the manufactured one (above) easier to use.

Image


You use the above tools to "find" true TDC.




Once you know where TDC is, then you can begin to set cam timing
OST Cyl head porting, - viewtopic.php?f=22&t=300

Building a great engine takes knowing the end... before you begin :ugeek:

Enjoy Life... its the only one you get!

ga_goosh
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Location: Texas

Re: advice on cam timing?!

Postby ga_goosh » Wed Dec 20, 2017 12:36 pm

look up jafromobile on youtube. he builds 4g63 motors but it is all the same concepts. here is the video. the whole series is pretty good.

https://www.youtube.com/watch?v=wbWWCKPuZG4
https://www.youtube.com/watch?v=4s2X3VUwADA&t=1s
I <3 my AE86

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