Detonation
#1
Adolf Hitler Verfechter
Thread Starter
Join Date: Sep 2002
Location: Northern South Africa
Posts: 969
Likes: 0
Received 0 Likes
on
0 Posts
Detonation
Hi.
Well,this might seem like a simple question:
What does detonation/pinging/knock sound like?
I have heard the sound on a boinger before,but never on a Rotary.
Thanks
Well,this might seem like a simple question:
What does detonation/pinging/knock sound like?
I have heard the sound on a boinger before,but never on a Rotary.
Thanks
#4
Adolf Hitler Verfechter
Thread Starter
Join Date: Sep 2002
Location: Northern South Africa
Posts: 969
Likes: 0
Received 0 Likes
on
0 Posts
Hahaha!
I`am running a NA.I think the timing is too advanced,but i dont know what to listen for.
(I live in neighbourhood where i cant rev it past 4000 to set total timing.It way too loud)
I`am running a NA.I think the timing is too advanced,but i dont know what to listen for.
(I live in neighbourhood where i cant rev it past 4000 to set total timing.It way too loud)
Trending Topics
#9
Adolf Hitler Verfechter
Thread Starter
Join Date: Sep 2002
Location: Northern South Africa
Posts: 969
Likes: 0
Received 0 Likes
on
0 Posts
No-no-no-no!
What i meant was:Now i know,when to retard the timing!If/when i hear the mentioned sound,i will retard the timing.So that i dont get detonation.
:-)
What i meant was:Now i know,when to retard the timing!If/when i hear the mentioned sound,i will retard the timing.So that i dont get detonation.
:-)
#10
Senior Member
Join Date: Nov 2002
Location: Chix Beach, Va.
Posts: 330
Likes: 0
Received 0 Likes
on
0 Posts
I woud say its kind of a weird sound. The first time I heard it I thought the exaust shield was loose, Its a Klinging sound. I dont think itll blow your engine real quick but its not a good thing
#16
Rotary Freak
Join Date: Sep 2002
Location: SF BayArea
Posts: 2,815
Likes: 0
Received 0 Likes
on
0 Posts
In the old days, HotRod tuners would advance the timing on a boinger until it rapped too much even for them, then back it off a tad. The common belief then was that resulted in the best timing, which was not supported by dyno tests.
B
B
#18
Absolute Power is Awesome
This is long winded, but I like to write.
Popular opinion is that detonation is damaging to the engine. To some degree, this isn't true.
Combustion doesn't happen all at once, There's a combustion flame front that moves through the combustion chamber. Before the front is the air/fuel mixture, behind it is combusted products.
As the flame front moves through the chamber, the pressure in the chamber increases. This pressure can increase to the point that the air/fuel mixture will ignite somewhere away from the combustion event.
At this point, there are two combustion events going on with flame fronts moving toward each other (and away from each other). When the two fronts meet, there's a bang. This is the most common cause for pinging. This is typically non-destructive.
I say typically because there can be times, especially in a turbocharged car, that the pressure can grow fast enough with two or more combustion fronts that it can cause damage to the engine. In general though, most engines aren't as sensitive to the faster pressure build-up.
Popular opinion is that detonation is damaging to the engine. To some degree, this isn't true.
Combustion doesn't happen all at once, There's a combustion flame front that moves through the combustion chamber. Before the front is the air/fuel mixture, behind it is combusted products.
As the flame front moves through the chamber, the pressure in the chamber increases. This pressure can increase to the point that the air/fuel mixture will ignite somewhere away from the combustion event.
At this point, there are two combustion events going on with flame fronts moving toward each other (and away from each other). When the two fronts meet, there's a bang. This is the most common cause for pinging. This is typically non-destructive.
I say typically because there can be times, especially in a turbocharged car, that the pressure can grow fast enough with two or more combustion fronts that it can cause damage to the engine. In general though, most engines aren't as sensitive to the faster pressure build-up.
#19
Adolf Hitler Verfechter
Thread Starter
Join Date: Sep 2002
Location: Northern South Africa
Posts: 969
Likes: 0
Received 0 Likes
on
0 Posts
Some good answers!
Well,just for reference :My 12A is BP,(as per my sig)so i`am currently working off the dizzy advance chart,seeing that it doesnt idle below 1500 at all.
I retarded it alott last night.Right down to 0 BTDC(so its right on TDC)Went for a test drive.It was revving very slow.So today,i`ll advance it more,trying 20 BTDC total advance.
The difficult part:I have 70`s Rotorhousings,and `82 Rotors,so the timing cant really be set to a spec.Why? ?Because the plugs sit at a different location than in the 80`s rotor housing.
Karis
Ps: Sorry about the long post
Well,just for reference :My 12A is BP,(as per my sig)so i`am currently working off the dizzy advance chart,seeing that it doesnt idle below 1500 at all.
I retarded it alott last night.Right down to 0 BTDC(so its right on TDC)Went for a test drive.It was revving very slow.So today,i`ll advance it more,trying 20 BTDC total advance.
The difficult part:I have 70`s Rotorhousings,and `82 Rotors,so the timing cant really be set to a spec.Why? ?Because the plugs sit at a different location than in the 80`s rotor housing.
Karis
Ps: Sorry about the long post
Thread
Thread Starter
Forum
Replies
Last Post
msilvia
3rd Generation Specific (1993-2002)
15
09-11-15 12:13 PM
A-Spec
General Rotary Tech Support
9
03-15-02 03:52 AM