Balancer ATI question

ExorsistzL1 · 08-18-2020, 08:33 PM

I had a whipple heads and cam build with an ATI balancer on my new zl1 at the time i broke in the motor 650miles and did the build . When i got the car back after about 45miles 48hrs i noticed a knocking sound from engine area i freaked out thinking motor was gone .after further investigation we find the keyway was warped and mushroomed hypothesis is the balancer was not installed correctly causing it to wobble and damaged the keyway. I was pissed and wanted the car back to stock . Fast farward 2yrs and now im heads cam 2650 .my question is adding the balancer to prevent vibration necessary? Can i do with stock lower ?All my friends have had success with lower and it was a nightmare for me.

ExorsistzL1 · 08-19-2020, 04:11 PM

Please help

Markoz28 · 08-19-2020, 04:20 PM

Your previous bad experience could have been a fluke or the fault of the installer. I believe the a better balancer is needed as its not that you are spinning the crank faster but more so quicker. Its still revving to 7k RPM with no problem with either balancer but once you punch it itll get to 7k faster with all the power you have added. That power and torque can really make things move around more.

I think it was just a bad install and if you could swing another ATI, then you should add it. Just my opinion really.

ExorsistzL1 · 08-19-2020, 05:06 PM

Thank you so much ill go for it !

ExorsistzL1 · 08-19-2020, 07:52 PM

Can i just put the balancer without changing the lower pulley ?

ExorsistzL1 · 08-19-2020, 08:02 PM

If not what combination would you recommend? Boost required 14 to 16lbs . The 2650 came with 90mm but i put an 85mm now before the cam boost was around 18psi too high butwith the cam 32% lobe i assume 16? But adding a lower ring to pair with the balancer may increase the boost again . Im on 93 no meth so im trying to be conservative with boost

laynlo15 · 08-20-2020, 06:47 AM

With a stock lower and 85 mm pulley you should be about 11-12 lbs with the 2650, 80 on stock lower is about 14-15, 75 mm is 16-17 with stock lower. Your pushing the limits with 93 above 14 psi. You need to be able to log your current tune. If you increase the lower pulley on the 85 you might be 17 to 18 lbs. You need to make sure your injector pulse width is in the limits and your not running out of fuel on the low side. I don't know what other fueling mods you have but safety is critical with these motors. I've been thru a couple myself and as you know its expensive to replace a short block. Feel free to PM about the 2650.

08-18-2020, 08:33 PM	#1
ExorsistzL1 Drives: 2018 zl1 10 speed Join Date: Oct 2018 Location: Georgia Posts: 86	Balancer ATI question I had a whipple heads and cam build with an ATI balancer on my new zl1 at the time i broke in the motor 650miles and did the build . When i got the car back after about 45miles 48hrs i noticed a knocking sound from engine area i freaked out thinking motor was gone .after further investigation we find the keyway was warped and mushroomed hypothesis is the balancer was not installed correctly causing it to wobble and damaged the keyway. I was pissed and wanted the car back to stock . Fast farward 2yrs and now im heads cam 2650 .my question is adding the balancer to prevent vibration necessary? Can i do with stock lower ?All my friends have had success with lower and it was a nightmare for me.

08-19-2020, 04:11 PM	#2
ExorsistzL1 Drives: 2018 zl1 10 speed Join Date: Oct 2018 Location: Georgia Posts: 86	Please help

08-19-2020, 04:20 PM	#3
Markoz28 Drives: 18 ZL1 nightfall grey A10 Join Date: Apr 2018 Location: RGV Texas Posts: 1,527	Your previous bad experience could have been a fluke or the fault of the installer. I believe the a better balancer is needed as its not that you are spinning the crank faster but more so quicker. Its still revving to 7k RPM with no problem with either balancer but once you punch it itll get to 7k faster with all the power you have added. That power and torque can really make things move around more. I think it was just a bad install and if you could swing another ATI, then you should add it. Just my opinion really.

08-19-2020, 05:06 PM	#4
ExorsistzL1 Drives: 2018 zl1 10 speed Join Date: Oct 2018 Location: Georgia Posts: 86	Thank you so much ill go for it !

08-19-2020, 07:52 PM	#5
ExorsistzL1 Drives: 2018 zl1 10 speed Join Date: Oct 2018 Location: Georgia Posts: 86	Can i just put the balancer without changing the lower pulley ?

08-19-2020, 08:02 PM	#6
ExorsistzL1 Drives: 2018 zl1 10 speed Join Date: Oct 2018 Location: Georgia Posts: 86	If not what combination would you recommend? Boost required 14 to 16lbs . The 2650 came with 90mm but i put an 85mm now before the cam boost was around 18psi too high butwith the cam 32% lobe i assume 16? But adding a lower ring to pair with the balancer may increase the boost again . Im on 93 no meth so im trying to be conservative with boost

08-20-2020, 06:47 AM	#7
laynlo15 Drives: 2022 Lt1 A10 Join Date: Nov 2015 Location: clark, mo Posts: 8,882	With a stock lower and 85 mm pulley you should be about 11-12 lbs with the 2650, 80 on stock lower is about 14-15, 75 mm is 16-17 with stock lower. Your pushing the limits with 93 above 14 psi. You need to be able to log your current tune. If you increase the lower pulley on the 85 you might be 17 to 18 lbs. You need to make sure your injector pulse width is in the limits and your not running out of fuel on the low side. I don't know what other fueling mods you have but safety is critical with these motors. I've been thru a couple myself and as you know its expensive to replace a short block. Feel free to PM about the 2650.

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