Author Topic: Herko Blocks  (Read 549 times)

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Offline Slider1950

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Herko Blocks
« 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?

Offline aharp

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Re: Herko Blocks
« Reply #1 on: July 16, 2020, 02:53:55 PM »
I very much prefer to use the blocks and not the sniffer method.
Speed costs money. How fast do you want to spend?

Offline Slider1950

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Re: Herko Blocks
« Reply #2 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?

Offline remington007

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Re: Herko Blocks
« Reply #3 on: July 17, 2020, 06:55:53 AM »
If the inserts are properly installed they don't leak.

Offline aharp

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Re: Herko Blocks
« Reply #4 on: July 18, 2020, 12:59:58 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.
Speed costs money. How fast do you want to spend?

Online Finn

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Re: Herko Blocks
« Reply #5 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?

1997 FXSTSB, 2016 FLSTC

Offline remington007

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Re: Herko Blocks
« Reply #6 on: July 31, 2020, 06:47:32 AM »
Hoses on mine are about 5 feet long no vacuum needed. I tried it both ways. 

Offline Buglet

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Re: Herko Blocks
« Reply #7 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.

Offline rigidthumper

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Re: Herko Blocks
« Reply #8 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.
Ignorance is bliss, and accuracy expensive. How much of either can you afford?

Offline JMHD

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Re: Herko Blocks
« Reply #9 on: August 01, 2020, 06:32:05 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.