stock cam gear adjust-ability
- Thread starter SeeUSmile
- Start date
I've really meant to mean "you meant Yamaha right?" 
I'm not sorry, that's not my bad.
BTW, Please check Toyota M Lasre Alpha-X project:
Finally, from the 5M repair manual:
Conclusion, that's +/-3° adjustement overlapping camshaft and camgear holes.
That's documented:
- Toyota has thought about VVTi and ASICs back in 80's.
- Toyota has intention of adjustability of fixed cam timing, each pair of holes give +/-3°, some 5M (on Cressida) have 5 holes, other 5M/6M and 7M Supra have 3.
- Honda drew up those plans and it works quite well also!
Edit: for some reasons, I haven't read Bmettie post. He is right! I like his avatar (see above) haha.
I'm not sorry, that's not my bad.BTW, Please check Toyota M Lasre Alpha-X project:
Finally, from the 5M repair manual:
Conclusion, that's +/-3° adjustement overlapping camshaft and camgear holes.
That's documented:
- Toyota has thought about VVTi and ASICs back in 80's.
- Toyota has intention of adjustability of fixed cam timing, each pair of holes give +/-3°, some 5M (on Cressida) have 5 holes, other 5M/6M and 7M Supra have 3.
- Honda drew up those plans and it works quite well also!
Edit: for some reasons, I haven't read Bmettie post. He is right! I like his avatar (see above) haha.
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Rollus;2057075 said:I've really meant to mean "you meant Yamaha right?"
BTW, Please check Toyota M Lasre Alpha-X project:
View attachment 76896View attachment 76897
Finally, from the 5M repair manual:
View attachment 76898
Conclusion, that's +/-3° adjustement overlapping camshaft and camgear holes.
That's documented:
- Toyota has thought about VVTi and ASICs back in 80's.
- Toyota has intention of adjustability of fixed cam timing, each pair of holes give +/-3°, some 5M (on Cressida) have 5 holes, other 5M/6M and 7M Supra have 3.
- Honda drew up those plans and it works quite well also!
Edit: for some reasons, I haven't read Bmettie post. He is right! I like his avatar (see above) haha.
My mate showed me a pic of that project didn't know if that went ahead or not?? Ahhh Cheers for the find rollus!
Bmettie;2057037 said:
Ehh how did I miss this.... makes a whole lot sense now, this whole time I thought it moving the top centre of the pin towards the whole of the camshafts which looked way too much to adjust. I'll to be careful not to drop the pin in the timing case. Dropped a bolt in there once and couldn't get an impact gun to fit between crank bolt and a/c cooler but got very lucky with a magnet before it was it was lost to oblivion.
Cheers!
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FredMk3;2057058 said:
Not an issue. Honda developed adjustability, and did a damn good job with it.
I have to disagree in the case of the 7M.
Looking at the attached pic, the holes in the cam appear to match the 74° angular separation of the cam gears.
By my workings, if the cam dowel holes are any closer than 25° apart, they would in fact not be separate holes!
Looking at the attached pic, the holes in the cam appear to match the 74° angular separation of the cam gears.
By my workings, if the cam dowel holes are any closer than 25° apart, they would in fact not be separate holes!
This is a 7MGE/7MGTE. And to stop the confusion, the repair manual from Helm was corrected. Just not with head torque.
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=EM&P=29
You want to make it run not as well, go ahead.
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=EM&P=29
You want to make it run not as well, go ahead.
Nick M;2057324 said:
Yes, the TSRM is right:
"Check that the the straight pin hole position is in the same position it was at disassembly, insert the straight pin."
So, position matters, else this HINT wouldn't be there.
71° appart as Pi said is enough for 3° cam adjustment, that's 6° crank adjustment, that allows to advance or retard a little intake or exhaust:
Advance intake and exhaust => more low-RPM power, less high-RPM power
Retard intake and exhaust => more high-RPM power, less low-RPM power
Less overlap => lower EGTs, faster turbo spool, less fuel
More overlap => higher EGTs, slower turbo spool, more fuel
All it does is moving the powerband, and possibly turbo efficiency. 3° is very little when most adjustable cam gears go +/- 12°
I will measure my stock cam when at home.
Alright, so got a degree wheel printed and got the cam profile of the GE cams integrated with the degree wheel.
I don't have a magnetic dial indicator yet and challenges I've come across is there isn't much room to be able to mount the dial indicator pin on the bucket shim to measure lift, as the cam card doesn't state if this is measured at a specified lift or when the valve is cracking open. Tried to see if I was able to figure out how much degrees it actually adjust through LSA which is at 111° but figured it was hard to do without a dial indicator.
Also went to confirm offset pins Bmettie mentioned.
Also need to get around tools to find true TDC as there's a bit of play on the crank pulley after finding out the woodruff key was worn. But still not a bad idea to degree the cams to see if it's within the specifications.
I don't have a magnetic dial indicator yet and challenges I've come across is there isn't much room to be able to mount the dial indicator pin on the bucket shim to measure lift, as the cam card doesn't state if this is measured at a specified lift or when the valve is cracking open. Tried to see if I was able to figure out how much degrees it actually adjust through LSA which is at 111° but figured it was hard to do without a dial indicator.
Also went to confirm offset pins Bmettie mentioned.
Also need to get around tools to find true TDC as there's a bit of play on the crank pulley after finding out the woodruff key was worn. But still not a bad idea to degree the cams to see if it's within the specifications.
