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Last edited by jabbatron on Wed Aug 26, 2015 10:42 am, edited 1 time in total.
Re: Cyl's 1 & 2 always knock first
Would be interesting if you had EGT's on each cylinder. Could give an indication if it was lean on those cylinders that nock first.
I would add fuel to the cylinders that are knocking and see if it helps. Adding fuel isn't going to hurt it as long as its not way to much added.
A mates big power SR20 with as aftermarket inlet manifold needed a fair bit more fuel on one of the cylinders due to the manifold. Manifold was fine around 20psi, but weird things happen when running 40+psi. We had it flow tested and the manifold ported and a plate welded in it to help with turbulence. It helped.
I would add fuel to the cylinders that are knocking and see if it helps. Adding fuel isn't going to hurt it as long as its not way to much added.
A mates big power SR20 with as aftermarket inlet manifold needed a fair bit more fuel on one of the cylinders due to the manifold. Manifold was fine around 20psi, but weird things happen when running 40+psi. We had it flow tested and the manifold ported and a plate welded in it to help with turbulence. It helped.
CB70 12V 3cyl 993cc Daihatsu | MS2X Sequential Fuel and Spark | Flex Fuel Launch Control | Raspberry Pi Dash
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Last edited by jabbatron on Wed Aug 26, 2015 10:42 am, edited 1 time in total.
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Matt Cramer
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Re: Cyl's 1 & 2 always knock first
Cylinders can have different levels of knock sensitivity due to unequal fueling, unequal cooling, or other factors. What sort of engine is this?
Matt Cramer -1966 Dodge Dart slant six running on MS3X
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old guy
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Re: Cyl's 1 & 2 always knock first
Do some research on reading spark plugs. It will tell you a lot. This was how it was done before widebands,egt's and all the other high tech stuff we now have.
Even with all the hi tech stuff, we would still look at the plugs when doing dyno runs just to verify our data.
I also found that what looks good on the dyno is sometimes different than actually running the engine under real world conditions.
It only took about 40 years to master this stuff.
Even with all the hi tech stuff, we would still look at the plugs when doing dyno runs just to verify our data.
I also found that what looks good on the dyno is sometimes different than actually running the engine under real world conditions.
It only took about 40 years to master this stuff.
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turbo conversion
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Re: Cyl's 1 & 2 always knock first
What condition are your injectors in?
I have seen this issue happen with unbalanced (dirty) injectors.
David
I have seen this issue happen with unbalanced (dirty) injectors.
David
1976 Datsun 280Z L28ET Garrett GT35R T3-T04E stage3 50 trim 63 A/R housing custom grind cam 2000-6000 rpm 440cc injectors intercooled 18 lbs. boost
3" exhaust turbo back LC-1 o2 sensor Hallman manual boost controller EDIS 6 ignition batch fire 60mm throttle body 5 spd T5 borg warner 3.54 lsd
3" exhaust turbo back LC-1 o2 sensor Hallman manual boost controller EDIS 6 ignition batch fire 60mm throttle body 5 spd T5 borg warner 3.54 lsd
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Last edited by jabbatron on Wed Aug 26, 2015 10:42 am, edited 1 time in total.
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Last edited by jabbatron on Wed Aug 26, 2015 10:43 am, edited 1 time in total.
Re: Cyl's 1 & 2 always knock first
also mark the balancer each 90 degrees and check the timing for each cylinder