HarleyTechTalk

Dyno & Tuning Zone => AFR & Tuning Zone => Topic started by: Slider1950 on July 15, 2020, 11:33:44 PM

Title: Herko Blocks
Post by: Slider1950 on July 15, 2020, 11:33:44 PM
Is it common for a Dyno tuner to use Herko Blocks or a equivalent and then installing wide band O2 sensors as opposed to using exhaust sniffers installed in the mufflers when doing a Dyno tune?
Title: Re: Herko Blocks
Post by: aharp on July 16, 2020, 02:53:55 PM
I very much prefer to use the blocks and not the sniffer method.
Title: Re: Herko Blocks
Post by: Slider1950 on July 16, 2020, 08:21:49 PM
Do you ever have any issues with the blocks sealing and leaking after you remove the O2 sensors once you are finished Dyno tuning?
Title: Re: Herko Blocks
Post by: remington007 on July 17, 2020, 06:55:53 AM
If the inserts are properly installed they don't leak.
Title: Re: Herko Blocks
Post by: aharp on July 18, 2020, 12:59:58 PM
Quote from: Slider1950 on July 16, 2020, 08:21:49 PM
Do you ever have any issues with the blocks sealing and leaking after you remove the O2 sensors once you are finished Dyno tuning?
As stated the inserts have to be in there squarely and properly. Sometimes with the install tool that can be a PITA. The correct size hole helps for sure to stop the insert from moving around when tightening the tool to expand the insert.
Title: Re: Herko Blocks
Post by: Finn on July 31, 2020, 06:42:07 AM
If I may continue this topic:

When using Herko blocks and wideband O2 sensors are you supposed to have vacuum in the hoses when dynoing/tuning?

(https://i.imgur.com/na17ywI.jpg)
Title: Re: Herko Blocks
Post by: remington007 on July 31, 2020, 06:47:32 AM
Hoses on mine are about 5 feet long no vacuum needed. I tried it both ways. 
Title: Re: Herko Blocks
Post by: Buglet on July 31, 2020, 07:50:32 AM
  Any time it on the dyno  with the Blocks I always use the vacuum, it's there it's not going to hurt any thing. Plus depending on the build it helps on the low rpm and idle.
Title: Re: Herko Blocks
Post by: rigidthumper on August 01, 2020, 04:56:57 AM
I believe the Dynojet units work better at idle/low RPM when the sensor is placed in the airstream, and exhaust allowed to flow across the tips. Place the sensor in the other hole, and attach a vacuum line, via an adapter, in the hole where your sensor is now.
Title: Re: Herko Blocks
Post by: JMHD on August 01, 2020, 06:32:05 AM
Quote from: rigidthumper on August 01, 2020, 04:56:57 AM
I believe the Dynojet units work better at idle/low RPM when the sensor is placed in the airstream, and exhaust allowed to flow across the tips. Place the sensor in the other hole, and attach a vacuum line, via an adapter, in the hole where your sensor is now.
That was just a picture from google, but I have experienced what you say about the idle. I will will definitely test the way you suggest.  :up: :up: I will try and post some results when I get a chance to test.