Why different cam gears? - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


General Miata Chat A place to talk about anything Miata

Reply
 
 
 
LinkBack Thread Tools
Old 02-02-2016, 09:54 PM   #1
Elite Member
Thread Starter
iTrader: (10)
 
IcantDo55's Avatar
 
Join Date: Apr 2007
Location: VA Beach
Posts: 1,764
Total Cats: 18
Default Why different cam gears?

This is a 2004 msm. Why are the cam gears different? The one on exhaust side is standard. What's the other one? Is it an msm thing?
Attached Thumbnails
Why different cam gears?-20160202_205205.jpg  
IcantDo55 is offline   Reply With Quote
Old 02-02-2016, 09:56 PM   #2
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,366
Total Cats: 1,327
Default

It has timing "teeth" for the CAS
Savington is offline   Reply With Quote
Old 02-02-2016, 09:57 PM   #3
Elite Member
Thread Starter
iTrader: (10)
 
IcantDo55's Avatar
 
Join Date: Apr 2007
Location: VA Beach
Posts: 1,764
Total Cats: 18
Default

Is it on right? Or does "I" go up?
IcantDo55 is offline   Reply With Quote
Old 02-02-2016, 09:57 PM   #4
Elite Member
Thread Starter
iTrader: (10)
 
IcantDo55's Avatar
 
Join Date: Apr 2007
Location: VA Beach
Posts: 1,764
Total Cats: 18
Default

On does it matter?
IcantDo55 is offline   Reply With Quote
Old 02-02-2016, 10:17 PM   #5
Elite Member
Thread Starter
iTrader: (10)
 
IcantDo55's Avatar
 
Join Date: Apr 2007
Location: VA Beach
Posts: 1,764
Total Cats: 18
Default

Another question.... This msm gear shown here on intake swappable with NA gears?

In other words they are the same.
IcantDo55 is offline   Reply With Quote
Old 02-02-2016, 10:21 PM   #6
mkturbo.com
iTrader: (24)
 
shuiend's Avatar
 
Join Date: May 2006
Location: Charleston SC
Posts: 13,776
Total Cats: 1,106
Default

It looks like it is on right as best as I can tell. No you cannot swap a na intake cam gear onto the msm. The NA cams do not have the marks for the crank sensor. You could swap intake cam gears from a 99/00.
shuiend is offline   Reply With Quote
Old 02-02-2016, 10:23 PM   #7
Elite Member
Thread Starter
iTrader: (10)
 
IcantDo55's Avatar
 
Join Date: Apr 2007
Location: VA Beach
Posts: 1,764
Total Cats: 18
Default

Ok. Got ya.

Feel stupid, done 1000 timing belts and never seen this configuration before. 1st msm tho.
IcantDo55 is offline   Reply With Quote
Old 02-03-2016, 03:10 AM   #8
Elite Member
 
codrus's Avatar
 
Join Date: Mar 2007
Location: Santa Clara, CA
Posts: 3,877
Total Cats: 344
Default

Interesting that the MSM only has CAS nubs on the intake gear, the NB1s have it on both. Unused on the exhaust side, but it's the same part.



I'd guess the Toda NB gear should work. I put one on my car -- saw basically no effect from it on the dyno though.



--Ian
Attached Thumbnails
Why different cam gears?-cam-gear1.jpg   Why different cam gears?-timing-belt-check2.jpg  
codrus is offline   Reply With Quote
Old 02-03-2016, 12:39 PM   #9
Junior Member
 
Join Date: Jul 2013
Location: TX
Posts: 319
Total Cats: -12
Default

Did you actually play with the settings?
ihiryu is offline   Reply With Quote
Old 02-03-2016, 12:46 PM   #10
Junior Member
 
Join Date: Jan 2015
Posts: 272
Total Cats: -22
Default

The MSM intake cam gear is different from the NB1 because the timing is different. It's more than appearance.
Alternative is offline   Reply With Quote
Old 02-03-2016, 12:56 PM   #11
Elite Member
Thread Starter
iTrader: (10)
 
IcantDo55's Avatar
 
Join Date: Apr 2007
Location: VA Beach
Posts: 1,764
Total Cats: 18
Default

Quote:
Originally Posted by Alternative View Post
The MSM intake cam gear is different from the NB1 because the timing is different. It's more than appearance.
Nope, it's the same except the timing nubs. Matched them up last night, identical.
IcantDo55 is offline   Reply With Quote
Old 02-03-2016, 01:14 PM   #12
SADFab Destructive Testing Engineer
iTrader: (5)
 
aidandj's Avatar
 
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 17,997
Total Cats: 1,463
Default

The MSM and NB1 heads are the same.
aidandj is offline   Reply With Quote
Old 02-03-2016, 01:15 PM   #13
SADFab Destructive Testing Engineer
iTrader: (5)
 
aidandj's Avatar
 
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 17,997
Total Cats: 1,463
Default

Quote:
Originally Posted by ihiryu View Post
Did you actually play with the settings?
No, I'm sure he just stuck it on and then spent money on the dyno and didn't dial it in at all.
aidandj is offline   Reply With Quote
Old 02-03-2016, 01:26 PM   #14
Elite Member
 
Join Date: Jul 2005
Location: Anacortes, WA
Posts: 2,476
Total Cats: 114
Default

The one on the left is NB1 the one on the right is NA. NB1 put the cam sensor on the front of the head and used nubs on the cam gear for it to sense. NA cam gears are a bit lighter but if you are using the sensor on the front of the cam cover you need a gear with the tabs on it. NB2 put the sensor in the top of the cam cover and reads nubs on the intake cam but still uses an NB1 cam gear on the exhaust side.
bbundy is offline   Reply With Quote
Old 02-03-2016, 01:40 PM   #15
Elite Member
 
codrus's Avatar
 
Join Date: Mar 2007
Location: Santa Clara, CA
Posts: 3,877
Total Cats: 344
Default

I ran the cam gear through its range on the dyno (-10, -5, 0, +5, +10), one way it lost spool but had no measurable high-end gains, the other way did basically nothing, so I set it back to zero and it's remained there.

Looking at the MSM photo more closely, it does appear that the nubs are in slightly different positions than on the NB1 gear. NB1 has the single nub and double nub 180 degrees opposite each other, while on the MSM looks like one of them is offset slightly. I wonder if the factory ECU cares? I'm pretty sure the megasquirt isn't going to, the non-VVT code is just looking for cam sensor pulses to occur between crank sensor pulses, and if the cam is off by 10 or 20 degrees it doesn't care.

--Ian
codrus is offline   Reply With Quote
Old 02-03-2016, 05:38 PM   #16
Junior Member
 
Join Date: Jul 2013
Location: TX
Posts: 319
Total Cats: -12
Default

Quote:
Originally Posted by codrus View Post
I ran the cam gear through its range on the dyno (-10, -5, 0, +5, +10), one way it lost spool but had no measurable high-end gains, the other way did basically nothing, so I set it back to zero and it's remained there.

--Ian
Hmm, I wonder if it's because it's just the intake cam? I have heard a few folks (on non BP platforms) have retarded cam timing in the lower RPM's to increase spool. I have also heard advancing both intake and exhaust causes a shift of the power to the higher RPM's. I've mainly heard this on VVT-style engine

Again it's all hearsay. You are actually the first I've heard that has adjustable cam gears on a BP engine.
ihiryu is offline   Reply With Quote
Old 02-03-2016, 10:59 PM   #17
Elite Member
 
codrus's Avatar
 
Join Date: Mar 2007
Location: Santa Clara, CA
Posts: 3,877
Total Cats: 344
Default

Quote:
Originally Posted by ihiryu View Post
Hmm, I wonder if it's because it's just the intake cam? I have heard a few folks (on non BP platforms) have retarded cam timing in the lower RPM's to increase spool. I have also heard advancing both intake and exhaust causes a shift of the power to the higher RPM's. I've mainly heard this on VVT-style engine

Again it's all hearsay. You are actually the first I've heard that has adjustable cam gears on a BP engine.
According to Jeremy @ FM, the exhaust cam does almost nothing, which is why I only bought one. The intake cam is supposed to trade off between low end spool and high end power, but all it seemed to do on mine was hurt spool without adding any power.

Next time I have it apart I may revert the cam gear back to stock and sell the Toda, dunno.

--Ian
codrus is offline   Reply With Quote
Old 02-03-2016, 11:00 PM   #18
SADFab Destructive Testing Engineer
iTrader: (5)
 
aidandj's Avatar
 
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 17,997
Total Cats: 1,463
Default

Get a VVT head and have best of both worlds
aidandj is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
MSM Going V8 for sale thread Preluding Miata parts for sale/trade 23 03-10-2016 03:02 PM
MSM swap onto 1.8 FastLane17 DIY Turbo Discussion 8 02-14-2016 03:32 PM
Turbo kit off 2004 MSM fourwhls Miata parts for sale/trade 13 02-14-2016 03:18 PM
MSM 6-speed - $850 Savington Miata parts for sale/trade 6 01-05-2016 10:39 AM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 04:07 AM.