Cam Degreeing (4AGE)

[GeeEss]

Hi there,

I recently bought a Cam-Degree-ing kit and it seems to suggest that I need to zero the "lash"; i.e. reduce shim clearance to zero. I also Googled this and other people also say this needs to be done.

Can anyone confirm this as it's an unexpected expense / hassle to have to go out & buy a set of shims just to do this. . .

[oldcorollas]

there needs to be some clearance, and how much clearance depends on the particular engine

from here http://forums.toymods.org.au/index.p...rt=0#msg_81228
Inlet .006" - .010"
Exhaust .008" - .012"
( COLD )

what is in your cam degreeing "kit"?
what links say to reduce it to zero?
are you trying to destroy your cams?

[TERRA Operative]

Yeah, 0.35mm for exhaust, 0.25mm for intake.

I made a degree wheel that you can print out that suits the 4AGE a while back.

Here it is:
http://bayfiles.com/file/ip6t/GB6tTd...egreeWheel.pdf

[allencr]

...seems to suggest...zero... ...people also say this needs to be done.

I doubt that it says & reads like you & people think it says.
You could zero it as they say for checking the opening/closing checking [email protected]/1.0mm/whatever, OR, simply subtract the lash/gap from the checking height.
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Also, if you wanna, you don't need a different shim just something, metal paper plastic alum. foil whatever, to put under the shim.

[GeeEss]

1. Kit is a "Trick Flow" Cam Degreeing kit comprising;

• 2 x low tension checking springs (don't see need for these in my application)
• 1 x wire pointer
• 1 x TDS stop (head on engine type)
• 1 x 11" degree wheel
• 3 x adapter bushings
• 1 x flat washer
• 1 x magnetic base
• 1 x dial indicator

2. Part 6 of Link: http://www.motoiq.com/magazine_artic...gree-cams.aspx

3. Er, No. . . . that's why I'm here asking questions before laying a spanner on the car

[GeeEss]

OK so basically; unless clearances are out of spec I won't need to buy shims?

[TERRA Operative]

They are talking about a different system, 4AGE engines don't have rocker arms, so the lash adjustment is not applicable. Just make sure your clearances are within spec and measure straight from the top of the bucket/shim.

[allencr]

OK so basically; unless clearances are out of spec I won't need to buy shims?

I can see the future.
It's going nowhere.

[jondee86]

I recently bought a Cam-Degree-ing kit and it seems to suggest that I need to zero the "lash"; i.e. reduce shim clearance to zero. I also Googled this and other people also say this needs to be done.

As far as I can figure, the only benefit of "zeroing" the lash is that your measured values for lift and duration will indicate the actual values ground into the cam. Easy enough to do on an engine with screw-type lash adjusters, but a pain in the a$$ with shim adjustment. If you are only interested in finding where the cam centrelines are, then zeroing is totally unnecessary.

Cheers... jondee86

[GeeEss]

Very clever . . . Save the droll remarks for your drinking buddies - this Forum doesn't need them.

I think I can tell the diff. between an OH Rocker & OHC reference. If you read the article you can see that if you're not familiar with the procedure - it could be construed that you have to zero the lash [U]whatever the cam arrangement.

Jesus, do you need to score points that badly?

[oldcorollas]

ahh, i thought you were talking about dialing the cam in, to the engine..

they are talking about checking centreline of cams to check they are in spec, while cam is still installed (as others have said)

In order to degree cams, you'll need to verify that the centerline of both the intake and the exhaust (intake only if SOHC) are where the cam manufacturer says they should be. Locate the intake lobe you'll be measuring and close its valve lash completely

check your bucket^cam clearance, and if ok, leave along and don't need to buy shims.
then you can find centreline of cam by checking various heights on both sides of the lobe (assuming it is symmetrical), ie 1mm, 2mm lifts.


no need to worry abotu the cam itself, cos the first xxdeg of ramp is not that important anyway (ie, the cam ramp until the clearance height)

[metcap]

I'm thinking if you dun zero the lash when degreeing a set of cam how do you determine if the cam spec are as per the cam card or factory figures in the first place even before finding the centerline and overlap figures.

[GeeEss]

Actually OC. . .I AM trying to Degree the Cams to the Engine. I wasn't even factoring in determining the symmetry of the Lobe - I thought (hoped) I didn't need to get involved with that aspect.

Recapping; I'm running ST Quads, , Jasma / FGK headers and 264 Tomei PonCams on a Bigport. The heads been shaved so CR is up from 9.4:1 to about 10.5:1, which apparently is still too low to make them work effectively. Ignition is via COPs+4AGZE CAS. Injectors are Denso 250cc Pink. ECU is an Adaptronic e420d. I'm only getting 78kW ATW so have just learnt how to spend $X,000+ bringing a Bigport's power upto about the level of a small-port with much less tractability.

My biggest bugbear isn't the lower than hoped for power; it IS the tractability referred to above. The car revs like a goddam pig and runs too rich. I reckon the Cam timing is suspect. It was set by a local Mechanic I took the car to (as he was a supposed Multi-Carb/TB specialist) prior to Dyno-ing.

When I queried this (the engines coarse running & possible cam timing issue) with the Adaptronic Dealer I took the car too (and spent $1000+ with) his response was that he didn't get involved with the cam timing (i.e. he just assumes the cam timing is correct?) but agreed the car was very rough / buzzy. He advised that if I wanted to Degree the Cams he would need to re-dyno it and I would be looking at another 8+ hours = $1500.

Brilliant: Fair enough re. $2200 to get the Head+Block+ITB's overhauled and $2K for the Harness and ECU; I can cop that - but another $2500 for Dyno tuning - WTF?

Feel free to hit me with another sanguine comment. . . . but I thought as a supposed solution-provider a good Dyno guy would have recognised something as fundamental as bad cam timing and would have / should have suggested I needed the Cam's degreed in the first place; especially when the Engine has been modified so much from stock (and he's been advised of the Mods).

I would gladly have paid the (extra) money to have it Degreed+Dyno'd 1st time round - but not now, hence my purchasing the Degree-ing kit. I know I won't achieve as good a tune as Dyno-ing but I figure I might as well learn how to Degree the Cams & test the results via a series of road runs.

[trdee]

who's doing the tuning? it isnt a mob up on the central coast by any chance???

[GeeEss]

No; they're not up the Central Coast; they're in NW* Sydney. I could go the Name & Shame route a la AE86 DC but it was my choice to take the car to them (what are they going to do; refuse the business?) so I don't feel like grinding the axe anymore.

Regarding my choice of Mechanic? I had a pretty heavily modified 4AGE and they had no track record in that area. I should have done more research (i.e. more than accepting the recommendation of the local Ultratune guy) and taken it to a proper Motorsport workshop with A-grade 4AGE credentials. Unfortunately I didn't (and still don't) know anyone fitting that description in the Sydney Metro area. Only Co. that comes to mind is Yager Performance - who aren't exactly just up the road. . . .

Regarding the Adaptronic tuner? Was recommended by others after two Adaptronic tuners in my local area (Sutherland Shire) couldn't even be bothered returning my calls. Go figure. . .

At any rate I will try & get the best out of the present set-up and then decide if I want to keep it or not. I'm a bit over it now and have other fish to fry. . .

Looking back on all this; my thoughts are that if you want to keep things feasible $-wise and just have a bit of fun on the Track. . . Get a 20V 1/2 cut from an Importer w/ std loom/ECU. If/when the Engine blows - go get another one. If you want more grunt, stick to proven aftermarket bolt-on bits. You will have a proven solution "out of the box" where the R&D has already been done by top-end Engineers with mega $$$ behind them.

*Revised - Previously stated as Sth Sydney which is location of Mechanic.