Changed my XFI reference angle, now have spark knock

[CS99]

I have a weber 109 stroker with TA balancer. I had to move the refence angle from 10 to 12 to get the timing to match the xfi. how much does changing the angle by 2 affect the timing?

 

[norbs]

2 degrees =2 degrees

 

[CS99]

2 degrees =2 degrees

Thank you

 

[norbs]

But if you have the reference angle right your timing will be correct now, so it was out 2 degrees before.

 

[kidglok]

I'm not doubting webers ability to set the balancer correctly, but this is something that should be verified as well.

 

[CS99]

I'm not doubting webers ability to set the balancer correctly, but this is something that should be verified as well.

I'm just guessing they did it correct. The balancer is keyed, so I don't see how it could be off. Unless the timing mark on the balancer is scribed in the wrong location. It is a TA balancer.

 

[bison]

The question I'd ask is is they verified tdc and is the mark on the timing tab corresponding to the verified zero. IMO it's the tuners responsibility to verify the timing is correct relative to what's installed just like you did. The assembler needs to check tdc relativity. If the crank/hub isn't keyed correctly then the timing could still be off unless the true tdc was verified.

 

[CS99]

The question I'd ask is is they verified tdc and is the mark on the timing tab corresponding to the verified zero. IMO it's the tuners responsibility to verify the timing is correct relative to what's installed just like you did. The assembler needs to check tdc relativity. If the crank/hub isn't keyed correctly then the timing could still be off unless the true tdc was verified.

Ok, when I bring piston 1 to tdc, should the pointer be on zero?

 

[bison]

Ok, when I bring piston 1 to tdc, should the pointer be on zero?

You need a piston stop with a degree wheel to find tdc. The piston dwells at tdc for a few degrees. With the piston stop you can go forward and backward and half way in between the unswept area on the wheel is true tdc. Then you can check to see if zero is actually zero on the tab. If it's off you can take note of the amount or alter your timing tab so it displays zero at true tdc

 

[HighPSI]

I couldn't agree more with Bison. The crank referance angle is not the engine builders responsibilty. It is the tuners. To add what he said about verifying the timing mark. I would recommend loosening the rockers on that cylinder before you put the piston stop in.

 

[CS99]

You need a piston stop with a degree wheel to find tdc. The piston dwells at tdc for a few degrees. With the piston stop you can go forward and backward and half way in between the unswept area on the wheel is true tdc. Then you can check to see if zero is actually zero on the tab. If it's off you can take note of the amount or alter your timing tab so it displays zero at true tdc

Thanks. Will do this ASAP

 

[CS99]

I couldn't agree more with Bison. The crank referance angle is not the engine builders responsibilty. It is the tuners. To add what he said about verifying the timing mark. I would recommend loosening the rockers on that cylinder before you put the piston stop in.

thanks Cal