Reccomendations for 4AG cam open angle

[Adsport]

Hi, chasing opinions on what angle people have experienced to be best for 264x8.35 (or close) cams in 4AG applications. particular motor in question is supercharged with other breathing modifications. Bilzilla reccomends to set them to full open at 110-110 Webpage .

Thanks

[fixeruperer]

what does the cam manufacturer say ?

[Adsport]

sadly i do not possess the cam spec card.

if anyone DOES have a scan of HKS cam card/ specs for 4AG motors i will have your babies.


related video i found in my travels setting gears on 2JZ

[oldcorollas]

start at 110 and move around on the dyno and see what your particular engine likes best?

[Adsport]

might be the better way to go , ive emailed the guy who will be tuning it to see what he thinks . he has spent many years playing with 4ag and would most likely know a good ballpark to start with. just trying to reduce my dyno time by setting up as much as i can on my own in all honesty because it all costs money !

[30psi 4agte]

In ref to OC post.
This is the ONLY way to do it right. Like OC said every engine is different and will respond different even if it was std.

But seeing as you dont even have a starting point id go with anywhere from 100 - 110..... what does the cam sit at now if you just wack it in with the gears set to 0 ?

IE.... put the cam in and check where it is opening and closing at.

I assume you have adjustable cam gears.

[oldeskewltoy]

alas... I do have a cam spec card for HKS... but only their newer grinds....
(please no babies)




I'm in the cam hunt now.... you may have seen my thread "4AG headwork",

I'm looking for either a 264/268 cam with about 8.35 lift. Ones I've looked into.... Tomei Poncams, Web's 577, HKS, and Toda of course, also I'm looking into a cam being developed at this time by Colt cams in Canada.... They call it a "Tri-flow" cam. One intake lobe has just a hair more(2 or 3 degrees) duration, then the second intake lobe. The thought is to open one valve first add a swirl to the intake charge, and close both in tandam

http://www.coltcams.com/container.html

[Hen]

The following is some possibly relevant info I copied to my computer from the old Toymods forum. I'm afraid I can't remember the original poster so I can't give credit, or vouch for its accuracy.

---------------------------------------------------
I am using the wade 267 cams on a 4agzte sc14 supercharged / Turbo engine. At .050 there is very little overlap.

I set the cams up on my Pc Desktop dyno program with the inlet cam max lift at around 109 deg ATDC and exhaust cam max lift 117 deg ABDC. 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. The above Figures acheived this when i put it on the dyno. I never adjusted the cam timing since setting them up to the above specs as i have been very happy with them. 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 then your engine is flowing the air with less restriction, which could be out the exhaust valve on overlap or the intake 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 adjusting the cams. I have found lobe centre angles from 110 deg to 112deg on the inlet cam is best 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 timing seems to make the most difference when you adjust it on a TURBO engine.

------------------------------------------------------

Please inform me if you know the original poster and I'll edit accordingly.

I'm also interested in the outcome of this thread.

Hen

[Adsport]

In ref to OC post.
This is the ONLY way to do it right. Like OC said every engine is different and will respond different even if it was std.

But seeing as you dont even have a starting point id go with anywhere from 100 - 110..... what does the cam sit at now if you just wack it in with the gears set to 0 ?

IE.... put the cam in and check where it is opening and closing at.

I assume you have adjustable cam gears.

i havent touched the motor yet , i just got my new dial gauge the other day and im hoping to be able to get busy on it during the weekend so im gathering information in preparation.

the engine doesnt run very well at idle (or below 1300rpm for that matter) with them set to 0 i can say that at least , but that may be attributed to several factors. ive put in aftermarket management recently and got it to a very steady idling and revving state and it has a base tune now which enables it to drive. i felt it was very important to get this done first before i go messing with the particulars i am taking care of now so that i had a base to revert to if necessary !

gears are HKS Duralium

alas... I do have a cam spec card for HKS... but only their newer grinds....
(please no babies)



I'm in the cam hunt now.... you may have seen my thread "4AG headwork",

I'm looking for either a 264/268 cam with about 8.35 lift. Ones I've looked into.... Tomei Poncams, Web's 577, HKS, and Toda of course, also I'm looking into a cam being developed at this time by Colt cams in Canada.... They call it a "Tri-flow" cam. One intake lobe has just a hair more(2 or 3 degrees) duration, then the second intake lobe. The thought is to open one valve first add a swirl to the intake charge, and close both in tandam

http://www.coltcams.com/container.html

thank you immensely , its some information at least.

the colt cams seem to be an interesting concept i wonder how they go in the real world.






i will post the eventuating outcome after the dyno session


edit: Hen that actually sounds like the words of Nick Parker the more i read it.

[oldcorollas]

for those that can't read the HKS cam cards

when measuring from opening angle and closing angle at 1mm lift,
lobe centre for intake is 105 ATDC and for exhaust is 110 BTDC... so a 5 deg split with exhaust opening earlier...

[Adsport]

inlet set to 105 (needed a 7 degree retard at the cam)

exhaust set to 110 (needed about 0.5 degree retard)

had SO many dramas and spent an appauling amount of time just trying to get the dial gauge to be consistent, this was the most frustrating thing..

ive hurt my eye so thats where im at for the time being.

[DeftAnesthetik]

I'm in the cam hunt now.... you may have seen my thread "4AG headwork",

I'm looking for either a 264/268 cam with about 8.35 lift. Ones I've looked into.... Tomei Poncams, Web's 577, HKS, and Toda of course, also I'm looking into a cam being developed at this time by Colt cams in Canada.... They call it a "Tri-flow" cam. One intake lobe has just a hair more(2 or 3 degrees) duration, then the second intake lobe. The thought is to open one valve first add a swirl to the intake charge, and close both in tandam

http://www.coltcams.com/container.html

well now an idea begins to take shape in my head.... to get this "swirl" effect on any other cam could one get creative with shims? i explain: i know its best to set everything up with the stock clearance specifications, however stock spec is not "it must be this amount of clearance, no more no less" its a range (in 0.006" - 0.010", ex 0.008" - 0.012") so with that in mind and KEEPING WITHIN CLEARANCES could on say set one valve/cylinder at say 0.006" clearance and then the other at the other extreme 0.010" and get somewhat the same effect, i know shims adjust lift NOT duration but the initial lobe contact would still come sooner with the lower clearance thus affecting duration (just a little). would this difference in opening be enough to get the air "swirling" as it were. and if so would it be enough to get decent gains from? biggest cost would be the time it takes to get it done, most of us who would be considering it should be at the stage where we have a bucket of shims hiding somewhere. or am i chasing less than (insert your worthwhile percentage gain here)

ad sport, sorry again, not trying to hijack its early and ive got half a pot of coffee in me.

[oldeskewltoy]

Not a hijack..... a thought.......

When I set up my current engine I was very weird... I made sure ALL the clearences were identical... and all dead center in the middle of the spec............. (this is the engine I have in my car for the past 6 years)

Anyone notice the HKS card???? Did you take a close look at peak power and @ what rpm???

256 = 8k rpm
264 = 8.3k
272 = 8.8k

So.... if "your" engine doesn't go above 8k(stock rev limiter is 7500)......... are you getting more performance from the longer duration cams even though you never get to the peak???

Assume for now that on a stock engine, or one limited to say 8k.... Wouldn't modifing the intake closing event and the lift on a 256 cam be the way to tune it????

Or to put it another way.... if you are not planning on spinning over 8k rpm... is there a benefit to running a cam with duration that is designed to make peak power above that rev limit????

[DeftAnesthetik]

Not a hijack..... a thought.......

When I set up my current engine I was very weird... I made sure ALL the clearences were identical... and all dead center in the middle of the spec............. (this is the engine I have in my car for the past 6 years)

Anyone notice the HKS card???? Did you take a close look at peak power and @ what rpm???

256 = 8k rpm
264 = 8.3k
272 = 8.8k

So.... if "your" engine doesn't go above 8k(stock rev limiter is 7500)......... are you getting more performance from the longer duration cams even though you never get to the peak???

Assume for now that on a stock engine, or one limited to say 8k.... Wouldn't modifing the intake closing event and the lift on a 256 cam be the way to tune it????

Or to put it another way.... if you are not planning on spinning over 8k rpm... is there a benefit to running a cam with duration that is designed to make peak power above that rev limit????

Is it DESIGNED peak limit or the peak for the RECOMMENDED TIMING SPEC ?

Can the cam be dialed differently to achieve lower power goals?

[Adsport]

well now an idea begins to take shape in my head.... to get this "swirl" effect on any other cam could one get creative with shims? i explain: i know its best to set everything up with the stock clearance specifications, however stock spec is not "it must be this amount of clearance, no more no less" its a range (in 0.006" - 0.010", ex 0.008" - 0.012") so with that in mind and KEEPING WITHIN CLEARANCES could on say set one valve/cylinder at say 0.006" clearance and then the other at the other extreme 0.010" and get somewhat the same effect, i know shims adjust lift NOT duration but the initial lobe contact would still come sooner with the lower clearance thus affecting duration (just a little). would this difference in opening be enough to get the air "swirling" as it were. and if so would it be enough to get decent gains from? biggest cost would be the time it takes to get it done, most of us who would be considering it should be at the stage where we have a bucket of shims hiding somewhere. or am i chasing less than (insert your worthwhile percentage gain here)

ad sport, sorry again, not trying to hijack its early and ive got half a pot of coffee in me.

hmm a quite interesting thought, my concern is that the excess valve lash (you really want minimum ideally) could cause the shim to be lifted out of the bucket ?

Is it DESIGNED peak limit or the peak for the RECOMMENDED TIMING SPEC ?

Can the cam be dialed differently to achieve lower power goals?

yeah they sure can, i think the best way as mentioned is to dial them in as the card specifies and then run it up on the dyno and tune them specific to your setup