BC 280 cam degreing

[dnhieu]

to my understanding these cams needed to be degreed. what do you have your 280's degreed to? i just ordered a set of fidanza cam gears and am very curious on what to set them to.

thanks in advance
David

[daren_p]

If your looking for max power, that can vary from setup to setup & the only real way to extract max power would be to dial them in on the dyno. Now if you don't want to spend all the extra, extracting every single last hp out of the cams, you still want to degree the cams & set them up to the spec card they came with. This way they will be running in the position they were designed too & will be the way most will want to run them.

[90laserRSfwd]

A lot of parts of a motor are cast, which makes it impossible for someone to say, for example, degree the intake cam to 0 and the exhaust cam to -3. There are to many variables to pick a number and be correct. Every motor is different. Sorry man, it's the truth...

[dnhieu]

so no one has an idea on what to set them to? i just might call brian crower to see what he recomends. im trying to get the to the dyno in the next few months and bought cam gears so they could be dialed in for every hp. at the same time tho i would like to get them close before i bring the car their for very minimal adjustments to be made.

[1992awdlaser]

Brian Crower just says to drop them in and that no degreeing is required.

[The_EE]

The most common setup for cam gears is -3* Exhaust and +1 Intake, so I have been able to find.

Here is some good info for you.

This article assumes that you have a clear understanding of what cam gears are and that you have at least one of them installed. Keep in mind that your modifications (turbo, fuel setup, etc.) might yield different results for your application. Use the explanation below to experiment with your cam gear settings but we HIGHLY advise not exceeding 5 degrees in either direction, advance or retard. As with all of our tech tips and how tos, You should have a certified mechanic working on your car, or if you wish to do yourself, Pro Street Industries is not responsible for the modifications you perform on your own vehicle.

On the 4g63 DOHC engine you can dial-in intake and exhaust timing independently of each other to regulate overlap. As you'll start to see as you make changes, combined with the use of a chassis dyno (highly recommended) you can fine-tune your cam's entire operation by advancing or retarding its action, squeezing as much horsepower and torque from your state-of-tune as possible.

It's important to note that adjustable cam gears have no direct effect on the duration and lift of the valves, that's the job of the camshaft lobes (profile) as dictated by the cam manufacturer.

*TIP - Always make sure your cam gears are tightened correctly to combat cam gear slippage. Slippage refers to the bolts that hold your cam gear to the settings you desire loosening up and allowing the cam timing to advance or retard fully often with catastrophic results. DO NOT LET THIS HAPPEN TO YOU. And not to state the obvious, but... make sure your car is in tip-top working order before you adjust your cam gears.

Generally, advancing a cam gear opens a valve sooner, and closes it sooner... retarding the cam gear, opens the valve later, and closes it later... since all you've done is "move" the fixed event.

Advancing Intake and Exhaust : This will provide the car with more bottom end power, and will decrease top end. Advancing both cam gears will move overlap earlier but will not increase it.

Retarding Intake and Exhaust : This will increase the cars top end, but will decrease low end. Retarding both cam gears will move the overlap later and but will not change the amount of overlap.

Advance Exhaust Only : This will help the cars top end, and it reduces overlap.

Retard Exhaust only : This will help the cars mid range power, very useful for cars with big turbos / big cams. By increasing overlap, It decreases lag significantly. Doing this will bring the boost on all at once. Very common DSM modification.

Advance Intake only : This will increase overlap and helps the cars bottom end and mid range power. This mod will bring the turbo on all at once, although isnt a very common mod for DSMS.

[TurboAnything]

BC cams are off timing that is what he is talking about. You need a dial indicator and your cam card. You also need a degreeing wheel installed on the crank. Then you rotate to TDC and check the valve lift when you get to .050 lift you look at the degree wheel on the crank and you should be at the degree the cam card says on it if not then you move the cam till it matches up. I would go into more detail but you need some special tools to do this.

[dnhieu]

Originally Posted by The_EE

The most common setup for cam gears is -3* Exhaust and +1 Intake, so I have been able to find.

Here is some good info for you.

This article assumes that you have a clear understanding of what cam gears are and that you have at least one of them installed. Keep in mind that your modifications (turbo, fuel setup, etc.) might yield different results for your application. Use the explanation below to experiment with your cam gear settings but we HIGHLY advise not exceeding 5 degrees in either direction, advance or retard. As with all of our tech tips and how tos, You should have a certified mechanic working on your car, or if you wish to do yourself, Pro Street Industries is not responsible for the modifications you perform on your own vehicle.

On the 4g63 DOHC engine you can dial-in intake and exhaust timing independently of each other to regulate overlap. As you'll start to see as you make changes, combined with the use of a chassis dyno (highly recommended) you can fine-tune your cam's entire operation by advancing or retarding its action, squeezing as much horsepower and torque from your state-of-tune as possible.

It's important to note that adjustable cam gears have no direct effect on the duration and lift of the valves, that's the job of the camshaft lobes (profile) as dictated by the cam manufacturer.

*TIP - Always make sure your cam gears are tightened correctly to combat cam gear slippage. Slippage refers to the bolts that hold your cam gear to the settings you desire loosening up and allowing the cam timing to advance or retard fully often with catastrophic results. DO NOT LET THIS HAPPEN TO YOU. And not to state the obvious, but... make sure your car is in tip-top working order before you adjust your cam gears.

Generally, advancing a cam gear opens a valve sooner, and closes it sooner... retarding the cam gear, opens the valve later, and closes it later... since all you've done is "move" the fixed event.

Advancing Intake and Exhaust : This will provide the car with more bottom end power, and will decrease top end. Advancing both cam gears will move overlap earlier but will not increase it.

Retarding Intake and Exhaust : This will increase the cars top end, but will decrease low end. Retarding both cam gears will move the overlap later and but will not change the amount of overlap.

Advance Exhaust Only : This will help the cars top end, and it reduces overlap.

Retard Exhaust only : This will help the cars mid range power, very useful for cars with big turbos / big cams. By increasing overlap, It decreases lag significantly. Doing this will bring the boost on all at once. Very common DSM modification.

Advance Intake only : This will increase overlap and helps the cars bottom end and mid range power. This mod will bring the turbo on all at once, although isnt a very common mod for DSMS.

thank you very much for this information. after reading the thread it definetly does make sence to set the exhaust to -3 and intake to +1. i have read this some where else on these boards but couldnt find it...

[Black_Bullet]

Let me know how your results are because in the future I plan to purchase some cam gears for my bc272s to dial in a little bit of extra power... Ive heard some ppl didnt notice much gains even after correctly dialing it in on a dyno, and ive heard others say their cars revved up much faster once it caught the powerband...

[turboglenn]

I'm not sure how effective this is on DSM's but most of our porsche clun cars don't go to the dyno very often, they just make sure it's running safely to complete the long heats involved in road racing and go race.

But anyway, what we do on the club cars is play with the cams to get maximum compression. Are teh crower cams regrinds? If they are that will make to where each one is slightly different , plus figuring in the modification differences of eah persons engine and then you will realize that you can't just take so and so's cam angles and set your like theirs and expect the same gain because you could still be off a degree or so in either direction compared to that persons cams alone.

But anyway, dial intake for compression, then do exhaust, then use the article above to get gains in what ever area you are looking for the most improvement..i.e. top end, bottom end, spool up etc..

One thing i have heard is that you can't take and say retard teh exhaust AND advance the intake to try and gain spool and bottom end fromboth cams... I guess because of the amount of overlap or whatever (i'm not very smart about the true technical aspect of camshafts :P ) Some one correct me if i've been told wrong as i've never tried doing that.

[1gDSM4g63]

Originally Posted by 1992awdlaser

Brian Crower just says to drop them in and that no degreeing is required.

For some reason other cams are drop-ins and don't need degreeing but it has been a common fact that the BC 272s and 280s need to be degree to set the timing. If I remember correctly, out of the 10 cams that AMS tested on a dyno for comparisons the only cams that needed degreeing was the BC Stage 2 and 3.

[dnhieu]

well you can make good power without degreeing the cams. i have a buddy north of Atlanta that made 420 on a break your heart dyno on race gas with no degreeing the the 280's. i will be pushing my car a lot harder then he did on the dyno to see what she can or cant do. our setups are kinda alike minus a intake manifold that he has and i don't. im going to be trying those setting for the time being and see if i can feel anything as far as my butt is concerned. am i am not expecting to make outrageous power with the same settings but would like to see a little improvement over where im currently at...

[1gDSM4g63]

Without degree the BC 280s hardly measures up to the HKS 272s or any of the other 10 cams that AMS tested.

[dnhieu]

and that would definetly be the reason for this thread

[Black_Bullet]

Is there a link for these tests?
Id like to see how the bc272s did.

[FlatBlackTerror]

Originally Posted by 1gDSM4g63

Without degree the BC 280s hardly measures up to the HKS 272s or any of the other 10 cams that AMS tested.

Last i checked they didn't test the brian crower cams. They tested the crower stages 3s but im pretty sure they are different from the bc280s

[1gDSM4g63]

Originally Posted by Black_Bullet

Is there a link for these tests?
Id like to see how the bc272s did.

Originally Posted by FlatBlackTerror

Last i checked they didn't test the brian crower cams. They tested the crower stages 3s but im pretty sure they are different from the bc280s

Ams Evo Cam Test - evolutionm.net dyno test comparison on an Evo.

[FlatBlackTerror]

Originally Posted by 1gDSM4g63

Ams Evo Cam Test - evolutionm.net dyno test comparison on an Evo.

well an evo is going to respond differently than our motors, and the cams are different as well. similar yes but thats like saying the bc280 cams for the supra made less power than the hks so that must be the case with the bc280s for our cars.

[TurboAnything]

I would be wiling to bet money that the BC280s for the dsm and evo are the same grind. And remember the Evo motor is still a 4G63 and behaves the same way. I always had my suspicions that BCs were not up to par. Plus the fact that they need degreeing is a joke. AMS"Rough idle, sounds mean but power was off. Cams needed to be degreed, were off by 3-5 degrees per cam."