View Full Version : Degreeing BC Stage 2 Camshafts with JWT Adjustable Cam Gears
ExtaZ33
06-22-2013, 02:06 PM
I am trying to install these JWT adjustable cam gears to go with the BC stage 2 cams that have been installed for a while now. Is there anyone that can give me a quick answer as to how I should degree the gears specific to these cams to avoid going through the hassling process of finding out the opening and closing positions of the valves? I have a degree wheel and dial indicator, but the wheel doesn't fit with so many accessories in the way and trying to get this wrapped up. Any help is appreciated.
Kingtal0n
06-22-2013, 03:59 PM
adjustable cam gears on an SR20 are the biggest waste of cash I could imagine, and I bet you want a reason. Okay, here is my reason.
#1. The only way to get your money's worth out of adjustable camshaft gears is to actually adjust them. On a Dyno. With a laptop in hand to adjust the timing and air/fuel ratio, pass after pass after pass after pass, to determine the proper, "correct" valve timing.
#2 Lets say you go through that entire process and finally, after 50-80 dyno passes, you have it perfect. yay, you gained 20 horsepower at the expense of 5 ftlbs of torque. not to shabby. Then, you decide to change your intake manifold, or your exhaust manifold, or something. anything. Guess what? You have just un-done ALL of your work.
#3 Even if you combo is finalized, and you never change anything, and you have adjusted your combination perfectly, two more problems persist. problem A is that fact that the camshaft gears could slip and ruin your "perfection". Problem B is the fact you just wasted some percentage of life of your engine, on a dyno doing WOT passes. All engines will go WOT only a limited number of times before they wear out. I Knew a guy who went through ALL of that dyno-time and made his 50 passes on an RB25 Neo engine to get it "perfect". He drove it to the track, and on the FIRST pass, it blew the engine due to oil pump failure.
IF he had made ONE less pass on the dyno, he could have at least gone down the track ONE time before toasting the engine. My opinion? Re-install OEM gears and don't look back.
Lesson learned.
jr_ss
06-22-2013, 04:03 PM
They aren't a complete waste of money when you purchase cams that don't come with the cam dowel on center line...
They also aren't a complete waste of money when you have decked the head and block too much and want to get the cams degreed back to factory specs.
There are other reasons they are used besides trying to get every last horse out of the engine.
Kingtal0n
06-22-2013, 04:08 PM
They aren't a complete waste of money when you purchase cams that don't come with the cam dowel on center line...
They also aren't a complete waste of money when you have decked the head and block too much and want to get the cams degreed back to factory specs.
There are other reasons they are used besides trying to get every last horse out of the engine.
Have you ever done that? I Mean decked a head and block, installed some cams straight up, and then dyno'd the engine. THEN gone back, re-adjusted the gears to match "factory settings" and re-dyno'd the engine?
I have not. But I can tell you this, its not worth 50 horsepower. Probably not worth 40 either. Or 30. Or 20. I mean, how much money you spend vs how much power you supposedly "lose" (we arn't sure how much you lose OR gain so speculation alone is not worth the effort...)
In other words, whos to say factory setting is better than your "screwed up setting"? Since neither of us have actually dyno'd the difference. Factory settings are not automatically "better" as you seem to be suggesting...
It begs the question to the OP: Did you deck the head and block, and if so, do you require for self satisfaction re-configuration of the OEM camshaft settings? also, remember, comp cams always includes a ground in advance. I wonder if BC does the same?
jr_ss
06-22-2013, 04:16 PM
I'm not suggesting factory settings are optimal, but they work and that's the point. Stop reading so far into basic responses.
Kingtal0n
06-22-2013, 04:58 PM
I'm not suggesting factory settings are optimal, but they work and that's the point. Stop reading so far into basic responses.
Okay. So you are sitting on the operating table, and the doctor comes in and asks you, "where does it hurt?" and you say "my head" Do you want him to start drilling on your head or do you want him to read into your basic response to try to find the real source of the pain?
Sorry if it upsets you but it's my job to read into things. everything.
Consider you installed a comp cam on an engine that's been decked. does the ground in advance hurt, or "fix" the difference due to the deck? Or both.
ExtaZ33
06-22-2013, 05:02 PM
adjustable cam gears on an SR20 are the biggest waste of cash I could imagine, and I bet you want a reason. Okay, here is my reason.
#1. The only way to get your money's worth out of adjustable camshaft gears is to actually adjust them. On a Dyno. With a laptop in hand to adjust the timing and air/fuel ratio, pass after pass after pass after pass, to determine the proper, "correct" valve timing.
#2 Lets say you go through that entire process and finally, after 50-80 dyno passes, you have it perfect. yay, you gained 20 horsepower at the expense of 5 ftlbs of torque. not to shabby. Then, you decide to change your intake manifold, or your exhaust manifold, or something. anything. Guess what? You have just un-done ALL of your work.
#3 Even if you combo is finalized, and you never change anything, and you have adjusted your combination perfectly, two more problems persist. problem A is that fact that the camshaft gears could slip and ruin your "perfection". Problem B is the fact you just wasted some percentage of life of your engine, on a dyno doing WOT passes. All engines will go WOT only a limited number of times before they wear out. I Knew a guy who went through ALL of that dyno-time and made his 50 passes on an RB25 Neo engine to get it "perfect". He drove it to the track, and on the FIRST pass, it blew the engine due to oil pump failure.
IF he had made ONE less pass on the dyno, he could have at least gone down the track ONE time before toasting the engine. My opinion? Re-install OEM gears and don't look back.
Lesson learned.
You really do not even have the most basic understanding of how timing works. At all. I realize that this was posted looking for opinions and help, but it was a pretty specific question. I will not need hundreds of dyno pulls to get my cams tuned to open and close the valves at the correct times.
The goal of this is to get my KA (not SR) back to the point where I can fine tune the timing with the distributor. At this point, the distributor can not adjust for the degree of timing that the aftermarket camshaft has created.
I will be measuring my cam degrees individually with the degree wheel and dial indicator. I just figured someone here may have used this combination before and have a quick answer. Not that I would expect so much from this forum.
ExtaZ33
06-22-2013, 05:03 PM
I'm not suggesting factory settings are optimal, but they work and that's the point. Stop reading so far into basic responses.
:bigok: :bigok:
jr_ss
06-22-2013, 05:05 PM
Like I said...
ExtaZ33
06-22-2013, 05:11 PM
It begs the question to the OP: Did you deck the head and block, and if so, do you require for self satisfaction re-configuration of the OEM camshaft settings? also, remember, comp cams always includes a ground in advance. I wonder if BC does the same?
Nothing has been decked. The Crower cams have been put back into factory settings and the distributor will not compensate for it.
Really I was looking for a quick answer but I will do it the hard way.
Unfortunately the degree wheel does not fit with the timing chain covers installed so I will have to source a bolt to offset it enough to use and not be blocked by the water pump and lower timing chain cover.
ExtaZ33
06-22-2013, 05:12 PM
Like I said...
:coold::coold::coold:
Kingtal0n
06-22-2013, 05:35 PM
I degree'd my first engine with a degree wheel when I was 16 years old
http://i23.photobucket.com/albums/b378/draglarry/th_JordansVideo_zps56433fef.jpg (http://i23.photobucket.com/albums/b378/draglarry/JordansVideo_zps56433fef.mp4)
Dont listen to me.
jr_ss
06-22-2013, 05:45 PM
Then how are you failing to understand what he is trying to do? It's simple really...
Kingtal0n
06-22-2013, 05:47 PM
Then how are you failing to understand what he is trying to do? It's simple really...
then where is your helpful response? If it is simple, as you suggest, then you should be able to help. But instead of helping, you only... talk.
I understand what he is doing. he is removing an OEM component and installing an unnecessary aftermarket one for no good reason. I see it all the time.
I gave him the best advice anyone could- remove his useless aftermarket component and re-install the OEM part.
ExtaZ33
06-22-2013, 05:58 PM
then where is your helpful response? If it is simple, as you suggest, then you should be able to help. But instead of helping, you only... talk.
I understand what he is doing. he is removing an OEM component and installing an unnecessary aftermarket one for no good reason. I see it all the time.
I gave him the best advice anyone could- remove his useless aftermarket component and re-install the OEM part.
It is not for "no good reason" you hard headed tool. There is only one way to correct the timing to compensate for the difference in the aftermarket cam. The OEM part is currently installed and the timing is wrong. It has been verified with a timing light.
Just stay subscribed and try to learn a thing or two.
ExtaZ33
06-22-2013, 06:53 PM
Then how are you failing to understand what he is trying to do? It's simple really...
:l101: :l101:
jr_ss
06-22-2013, 07:10 PM
then where is your helpful response? If it is simple, as you suggest, then you should be able to help. But instead of helping, you only... talk.
I understand what he is doing. he is removing an OEM component and installing an unnecessary aftermarket one for no good reason. I see it all the time.
I gave him the best advice anyone could- remove his useless aftermarket component and re-install the OEM part.
I have no personal experience degreeing cams to offer help. I know what he wants to do, as I had it done on my motor set. My point was, there is more than one reason for cam gears, but obviously you're not getting that.
What don't you understand about wanting to put a cam that is a few degree's out on centerline from the factory, to centerline? He's attempting to correct something that's wrong from the start.
codyace
06-25-2013, 10:05 PM
I know what you are asking in regard to a good 'general' rule of thumb that people use, but in the same regard I'd be apprehensive to assume that everyone's cams are out of CL the same, and that their setups are equal.
You can find smaller degree wheels, or you find a way to space the wheel outward with the correct length center bolt (which may be a little on the pricey side).
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