The Lotus Cars Community banner

21 - 38 of 38 Posts

·
Dreaded Prior Owner
Joined
·
687 Posts
I'd like to see a sealed, low rpm version of Suzuki's mechanisim for belt driven cam motors. Nut'in fancy, but would give you a different timing at high rpm w/o electronics or hydraulics.

 

Attachments

·
Dreaded Prior Owner
Joined
·
687 Posts
Suzuki is driving a chain at 13,000 rpm or so in an oil bath, for us one would have to make a belt pulley as a enclosed can with a seal at the rear that held these parts, likely with larger weights/lighter springs to work at our much lower rpms.
 

Attachments

·
Integrator
Joined
·
2,764 Posts
Discussion Starter #25
Suzuki is driving a chain at 13,000 rpm or so in an oil bath, for us one would have to make a belt pulley as a enclosed can with a seal at the rear that held these parts, likely with larger weights/lighter springs to work at our much lower rpms.
Do you have a PN or model number of the bike?
 

·
Dreaded Prior Owner
Joined
·
687 Posts
The feature was introduced on the 2017 Suzuki GSX-R1000, a top of range sportbike. Porabably be implemented to other displacements/models as they go through product cycles
 

·
Integrator
Joined
·
2,764 Posts
Discussion Starter #33 (Edited)
I'm curious why, when you were in there anyhow, you stuck with a black belt instead of the blue?
I have used the PO's old belt for swapping pulleys and repetitive "dry fitting". After finding the sweet spot, I changed to blue belt. I tried to avoid inflicting a damage to the new belt.
 

Attachments

·
Integrator
Joined
·
2,764 Posts
Discussion Starter #34 (Edited)
"Slight" dot misalignment on the cam pulleys translates to 2x crank discrepancy.

If you're off by 1 tooth = huge consequences to the engine!

1 tooth on cam pulley = 9degrees of cam rotation = 18 degrees of crankshaft rotation.
1/2 T = 4.5 deg @ cam = 9 deg @ crank
1/4 T = 2.25 [email protected] = 4.5 deg @crank
 

Attachments

·
Registered
Joined
·
232 Posts
Forgive my stupidity but doesn't that imply the pully has only 20 teeth? (18 degrees x 20 = 360 degrees). It seems like there are way more than 20 teeth on all the pullies.

Edit: On reflection I guess this would make sense if the crank pully has roughly 80 teeth and the cam pullies 40 teeth. Is that about right?
 

·
Integrator
Joined
·
2,764 Posts
Discussion Starter #36
Esprit 4cyl 910 engine cam pulleys have 40 teeth, 9 degree pitch.
9 deg on the cam corresponds to 18 deg of the crankshaft rotation.

1 T cam pulley = 9degrees of cam rotation = 18 degrees of crankshaft rotation.
1/2 T = 4.5 deg @ cam = 9 deg @ crank
1/4 T = 2.25 [email protected] = 4.5 deg @crank
__________________
 

·
Integrator
Joined
·
2,764 Posts
Discussion Starter #37 (Edited)
Suzuki is driving a chain at 13,000 rpm or so in an oil bath, for us one would have to make a belt pulley as a enclosed can with a seal at the rear that held these parts, likely with larger weights/lighter springs to work at our much lower rpms.
Perhaps this type of sealed sprocket could be adapted? There are several of them on eBay, but I never had Volvo or Toyota, so I leave the practical assessment to others.

2001 VOLVO S40 VARIABLE TIMING SPROCKET CRANKSHAFT TIMING ADJUSTER GEAR W/ SOLENOID - this sprocket has 42 teeth (Esprit has 40), so the new sprocket needs to be made.


Last picture shows Toyota GT
 

Attachments

·
Dreaded Prior Owner
Joined
·
687 Posts
And you would need to extensively modify the cam carrier to allow a separate oil feed through the cam to the pulley via the solenoid. Also would need to check oil pressure needed to operate the VVT pulley, the 910 often runs pretty low oil pressure.
 
21 - 38 of 38 Posts
Top