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p76 4.4 knock board.

Posted: Sun Feb 17, 2019 11:03 am
by barana
Mornin Gents,
Looking at a Conversion for a mate, 808 into 4.4. I've located a knock board from a 4.1v8 Cadillac, bore size is 88mm with a stock Leyland v8 bore size is 88.9. This results in a knock frequency of 6.444 hz for the 4.1 and 6.51 for the 4.4 .
For the ones in the know, is this going to be too far apart to be effective?
If yes, is it possible to attach a trimpot to one of the knock board legs for adjustment?
TIA - Barana.

Re: p76 4.4 knock board.

Posted: Sun Feb 17, 2019 11:15 am
by delcowizzid
Should be close enough can you get the matching knock sensor too

Re: p76 4.4 knock board.

Posted: Sun Feb 17, 2019 12:05 pm
by barana
Aye, I can, rockauto.com sells the sensor.

Re: p76 4.4 knock board.

Posted: Sun Feb 17, 2019 1:49 pm
by antus
trim pots are no good because the filter outputs timed pulses to transmit the level of knock to the pcm. resistance wont make any difference to any part of the system other making it not work at all if the signals cant get through.

Re: p76 4.4 knock board.

Posted: Tue Feb 19, 2019 10:55 am
by barana
I was thinking , on the analogue side, but I see the idea just wouldn't work.
The thought was there may be an adjustment pin , like a frequency pin on a 555... But I spouse there wouldn't be on a factory asic.