4AGZE camshaft experimentation

[nick.parker]

Hi,
Just thought I'd share some info.... since I was asking ages ago and no-one could comment on mixing cams on the 4AGZE. My SC14 4AGZE AW11 has been running a pair of Wade 267 camshafts for 6 months now, and while the car really takes off above 4Krpm, the low end is lacking compared to stock cams. Not ideal for an SC!!! With the stock crank pulley I was pulling very close to 1 bar on the boost gauge. Now, I have been playing with a simulation program which showed that low end torque could be improved a fair bit by putting my a smaller inlet cam in with the Wade 267 exhaust. So this is what I did on Saturday - I used my old bigport 240deg inlet cam. Luckily inlet clearance were all just in spec (expect one was 11thou (10 is max)) Next over 3 or 4 drives I remmapped Volumetric Efficientcy, which was MASSIVELY improved everywhere, especially low RPM, and had to back my timing off 6 degrees at full boost to stop detonation.

The SOTP dyno results ::
-----------------
My idle vacuum is higher (more vac), the torque at vacuum and 0psi boost is twice as good. I can now get up my driveway without my SC engaging due to low vacuum (70kPa asolute) My boost gauge now only shows 0.75 bar boost, peak 0.8bar.(datalogged)
So where did my boost go? The cars torque has remarkably improved (guestimate 5-10%) all over the rev range, more at low revs. From 6K its probably the same as with the two Wade cams. How about that! 20kPa of boost gone! I can only figure I must have made the engine a lot happier breathing wise.

So maybe the overlap with the two cams was causing blow back into the inlet and exacerbated by the restrictive (still stock :-) ) exhaust? Or maybe they were just setup incorrectly...but I've had help setting them up and tried so many different timing configurations with my adjustable cam wheels. So, now I thinking if I put a big pulley back on and get back up to 1.2 bar again its gonna get exciting!

Regards, Nick.

[myne]

How much for the other wade cam?
Ah... crap... no dizzy gear on it, or is there?

Got dyno pics?

I'd say you might be right on the overlap - you were probably getting a fair bit of blow-through. Fresh mixture exiting the exhaust. Was it noticably rich on acceleration?
You might benefit from re-fitting the wade cams and retarding the inlet 5 or so degrees to reduce overlap and increase the advantage of pressure after BDC. The stock cam might do the same.

I dont suppose you know for sure how to tell what degrees the stock cams are? I picked up a bluetop, and I'm assuming from the 28mm base circle and 35.56mm overall height that they're 240* 7.56mm cams. Is there a part number though?

Bah! I realised what SOTP means

[nick.parker]

Hi,
No dyno yet. I did dyno it a month ago with both wade cams and it was a bit sad (for 1 bar) with 150rwhp at 6900, even though torque was o.k. Since then I have leaned fuel out from 10:1 to about 12:1 (dyno operators AFR meter was bad) which got some more power, and now with the cams, its got to have gone up to 160+ rwhp... I wish I had done a dyno at 18psi (with my big pulley now RIP) and stock cams for comparison too, the torque was huge, but the car ran out of puff by 5700ish rpm.

Unfortunately the other Wade cam has no dizzy gear, but on the bright side they are only $440inc GST per set of two = bloody cheap compared to say modyour car where one 4AGZE cam can be $650..

1. Buy some $50 digital verniers
2. Measure cam base circle on a lobe and zero calipers at this measurement
3. Rotate cam 90 degrees, read caliper LCD, number = lift.

If it is 7.5X mm, you cams are 240degrees.
=QED (quite easily done )

Cheers, Nick.

[myne]

Bummer, coz the 4ag cams are interchangable if they have the dizzy gear. Meaning you can fit the exhaust cam to the inlet if you so desired.

That's exactly how I measured the cams

440$? that's bloody cheap! Wonder if they'd let you order 2x ex cams.

I notice you say 267*, they only list 268, a point I'd normally ignore, but they're counting duration from .05" and "Race only, full mods 4500 - 8000" grind #827
Are these the ones you have?
Or do you have smaller cams, counting total duration?

[nick.parker]

No way , mine are not that extreme, the 267s (grind 872A) are 220 degrees at/above 50 thou of lift. I guess the hassle of machining the dizzy drive might as well be avoided if possible to sav-a-da-money.
Cheers, Nick.

[nick.parker]

Has anyone else got any notes/results from playing with camshafts they want to share? Has anyone else noticed (well with SC anyway) manifold pressure decreaseas a result of a shorter duration inlet camshaft?
Cheers, Nick

[myne]

Manifold pressure decreases at idle on ALL engines with lower duration cams.
That's just how airflow characteristics change over the rev range.
Big cams = flow reversion at lower revs.

IF you made some 180* cams, and fit them, You'll probably be able to get the engine to idle nicely at 400rpm. It just wont rev much past 3k.

[oldcorollas]

did you see Robs 4AGZE pages (tig.com.au site)? i am not sure if they are still there in their glory but you could use a way back machine to see them www.archive.org

[nick.parker]

Hi,

Myne : To be more precise thats definitely true for the same cam timing (lobe centres).
Yes Old Corollas, I have seen Robs stuff, looks like the 272s totally stuff the GZE, so I guess it makes sense that my 267s didn't give me my ideal end result.
A place in Canada (TEDs components) said I should try their 10.6mm lift 262's that apparentlyy work good on the GZE OMG thats a lot of lift...would need to spend a lot of $ on the head to do that!

Cheers, Nick

[takai]

10.6mm of lift is HUGE for a 4A head, but there isnt so much which you would have to do. From memory the HKS valve springs are specified to max 11.5mm lift, so they would be the go (over 9.8mm max stock). You would certainly be in flicking shims territory though, but the easy solution for that is the 1SZ conversion (see my thread in FAQ).

It would definately be an interference engine by then though, and so timing would have to be spot on.

[myne]

Any reason not to fit bigger valves?
IIRC Billzilla thinks 7mgte valves will fit, but will need 2mm thicker shims.

[Ben Wilson]

The TED cams apparently work with standard shims, but need TRD valve springs. They also need some relieving of the head for the lobes to turn...

I really want some of them....

[takai]

Hm, i would be wary about using 10.6mm cams with standard shims, but who knows. With my 9.6mm lift cams i have about 1.5mm clearance. All depends on where the 10.6mm lift is.

[Joshstix]

10.6mm is big lift for such a small lifter. Especially when the top of it is smaller due to the shim.

[Cameron_Datto]

Iam using the wade 267 cams on a 4agzte .. sc14 supercharged / Turbo engine ,, at .050 there is very little overlap with these cams .. and was told they are the largest you can run with a std 4age N/a ECU ..So i thought they would be good for a forced induction engine ,,
I set the cams up on my Pc Dest top dyno program .. with the inlet cam at around 109 deg ATDC max lift and exhaust cam 117 deg ABDC max lift ,, So the exhaust Cam is Advanced alot compared to a N/a engine but reduces you overlap at TDC .. My aim was to set the cams up to give a widest TORQUE BAND [not max HP] in the mid to high RPM band to 7000rpm .. And the above Figures acheived this when i put it on the dyno .. I never adjusted the cams timming since setting them up to the above specs , as i have been very happy with them set up this way .. max hp is at 6800rpm and hp dosent drop off much till 7500rpm ..Torque band is wide and flat ,, I agree that the inlet cam could be a bit smaller when your using the Cam program to set up the cams ,, But with the turbo as well i have way to much torque in the low rpm so i have no reason to change them ,, .. Just remember Flow makes it GO ! and Boost pressure is the Restriction of the Flow .. if you have less boost pressure with the same pulley ratio on the super charger .. your engine is flowing the air with less restriction ,,which could be out the exhaust valve on overlap .. or the inlet take side is more efficient giving more hp at lower boost ,,

I have set up a few other turbo cam engines and as a general rule I like working in Lobe centre angles when adjust the cams ,i have found lobe centre angles from 110 deg to 112deg on the inlet Cam ,, while the exhaust is good around 114 deg to 116 deg ... the milder the Cams the closer to 110deg lobe centres it would be going on both cams ,, from seat of the pants feel ,, the Exhaust Cam seems to make the most difference when you adjust the timming on a TURBO engine .. .. ANY way hope it makes sense ,, if any one has a other ideas on Cam set up iam always happy to listen as there is alot of time in playing with set up ..


Cheers Cameron
oh add some postive feed back to my reputation ..Please