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View Full Version : Cheapest way to retard cam timing?



BlueDragon
09-25-2012, 04:45 PM
I was wondering if anyone else has ever wondered how much one tooth of retardation on the exhaust cam on the timing belt in relation to the other cam and crank would come out to degree wise?
I was thinking about counting the teeth and dividing by 360 would that give you a close estimate? I see people buying adjustable cam gears to mimic the 3rd gen exhaust cam... and I was putting my new water pump and timing pulleys and belt in and kinda had that idea.

I know it sounds super ghetto but I figured it was worth a post.
Plz keep your flames bic sized.

BlueDragon
09-25-2012, 05:05 PM
360 divided by 46 teeth = 7.8 degree per tooth slightly too much IIRC.

BlueDragon
09-25-2012, 05:50 PM
is the degree based on the crank revolutions or the cam revolutions?

alltracman78
09-28-2012, 06:14 PM
They're the same thing, both are 360*.
But you're not degreeing your crank, that's a base that should always stay at TDC when you're adjusting cam timing.

You can get a few degrees from the pins in the camshaft that the cam gear slides onto.
Notice the 3 holes in the gear and 3 holes in the camshaft? That's there for very small timing adjustments. Exactly how much I don't know. Probably less than 6*, but it may be better than nothing.

Just to clarify, if you're actually going to degree your engine, first you set the crank to 0*, which is the #1 cylinder at TDC.
Then your cam timing [degrees] is adjusted off that.

MrWOT
09-28-2012, 08:50 PM
Just get the damn cam gears :p

BlueDragon
09-30-2012, 04:04 AM
I cannot really justify spending anymore on more horsepower at this point I just bought a clutch a timing kit with pump and a steering rack and a ct20b. At this point my goal is just to finish what I started, I can do the cam gears later while the engine is in when I get the money. I was just hoping I could cheat a few hp out of this setup lol I think I might try the mess with it like you said alltracman thanks for the advice, like you said a little is better than nothing probably. I have the 6th gen throttle body on my intake now with the 540s w/dualfeed rail, supra pump, ct20b, MAPECU, fmic, 3inch exhaust. I just know that this setup will gain alot from just a little exhaust cam retard.

Luni
09-30-2012, 06:02 AM
Dude. Honestly. One cam gear is 75 dollars. It's worth it. It's worth it to not have to do the damn timing belt in the car just to change a cam gear later. Good advice here and from life lesson. 75 bucks is small fry compared to the rest of the stuff you bought. Do it right once and not have to worry about it again. I'd seriously think about it if I were you.

alltracman78
10-01-2012, 12:04 AM
A Gen III TB on a Gen II intake mani is a bad idea IMO, unless you've completely ported out the intake mani so there's no disruption of flow.
Same idea goes for the ST205 IC on a gen II 3S.

Anyhoo, I dug around for you. I've only seen the pins in the middle hole. According to the repair manual [it's in the check valve timing section] moving it over 1 spot changes timing ~2*.
Moving it across all 3 [from the 1st to the last] moves it ~ 5*.
So it looks like if you move it over 1 you'll get a lil under 2* of retard.

BlueDragon
10-02-2012, 03:25 AM
yeah i ported it to match, otherwise it would be a pointless upgrade.
Thank you Luni for your advise, I really wish I could afford it but it looks like its going in without it.
So that being the case I will take the much appreciated knowledge from alltracman and retard it as much as I can....
I still didn't get a clear response on my tooth counting and degree calculation, was that right or will it not work the way I am thinking?
Seems you could jump it back 7.8 and then skip the pin over one hole for about a 6* retard total, am I wrong?

alltracman78
10-02-2012, 05:37 PM
It sounds right.
You NEED to make sure your cam is at 0* before you start though. They can be off a couple of degrees from the factory. Fine for normal driving, but if you start adjusting.....

BlueDragon
10-02-2012, 09:29 PM
How would I go about checking that?

BlueDragon
10-04-2012, 11:34 PM
ok... well i guess i am gonna go for it and see what happens.... Could I blow something up if I am off a few degrees? or would it just be down to having to redo the timing? what is the worst case? I know our engines are non interference sooo.....?

alltracman78
10-05-2012, 04:17 PM
To accurately check it you need a degree wheel.

But you're not going to blow anything up, it will just run like poo and you'll have to redo the timing.

BlueDragon
10-06-2012, 03:12 AM
Houston we are go for launch. lol

BlueDragon
11-12-2012, 03:37 AM
i have no way to measure and make sure exactly where it is but im going to have to go ahead and say this worked as planned. I took the car out for a test today and it ran like a champ no issues during driving. It's not wanting to idle but that could be due to one of the many other things I modded... anyone else have idle issue after doing this with an adjustable cam gear?

BlueDragon
11-13-2012, 12:44 AM
nobody out there excited about this mod? or all just wishing you hadn't bought a gear? lol just kiddin

underscore
11-13-2012, 12:56 AM
I've been following this and I'm very tempted to do this when I change my timing belt next winter.

BlueDragon
11-22-2012, 03:18 AM
idle issue solved, just forgot to plug an unused vac port, car purrs like a kitten now.