Such thing as "detonation" on a diesel

G

getblown5.9

Ceritified Kleenex Dealer
Joined
Aug 3, 2006
Messages
7,259
I dunno what you would call detonation on a compression ignition motor, but is it possible to have this condition if the fuel is injected too early and cause problems as the piston is still coming up with the igntion wanting to push back down?

I know boosted gas motors have that problem where its too much pressure with the fuel and air and it ignites before the spark usually ending in catastrophic engine failure if not corrected.

i'm trying to understand the process a little better, so go ahead and school me.
 
It's there...just the engine is built to handle more of it;)

Timing rattle is "kind of" detonation...that's why the 12v guys have to watch how much meth they run in water with higher timing.

At least that's my understanding...I'm sure someone will tell me I'm wrong!
Chris
 
yes, you can have a condition where you have too early of an injection event, and your explosion wave makes a lovely ping/rattle sound as it smacks the piston on its way up...

now, in a situation with static timing (12v) sometimes you have to put up with some more rattle down low so that it'll run right up top!

as piston speed increases (RPM) injection timing needs to be increased so that the force of the explosion is correctly timed to push the piston down

timing is hard on head gaskets and is harder on engine internals, but our engines are way overdesigned, so really the head gasket issue is the only real concern for most people. But that's easily overcome with o-rings, head studs, etc.
 
Running methanol on these static timing 12v's with the timing set high will have bad detonation.
 
What would be considered high timing? I have been playing around with the timing on mine and was wondering where the danger zone is. I know about the injectors spraying out of the bowl but what other risks are there? Water with no meth.
 
with your combo, I wouldn't worry about it... turning 4500-5000rpm, you'll benefit from timing in the mid/high 20's and beyond
 
I don't think black bumper will have the air to make much power over 4200 or so.
 
zstroken said:
I don't think black bumper will have the air to make much power over 4200 or so.
Click to expand...

THe H2 is designed for up to that 4000 range but I'm hoping for a little more mid track when the load is light and I can try and get some more momentum going. Other than the cam I should have the ingredients for some decent air.
 
It will rev to whatever your pump will go to on the line, but you will make a lot of heat at the 4200 rpm. I know a guy with a SPS66 that was trying to run 4200 rpm down the track and burnt his engine up at least once. The 16SS will help a little. When I ran the 66 series chargers seemed like 3800-3900 was really the max point the truck wanted to run under load.
 
Yeah If you look at alot of different dyno graphs, most are no making any power that high up.
 
I have switched turbos this year running a s475 with a 1.1 I agree the PS with the 66 and the 16ss was awfull hot above 3800 and dropped off on power very quickly at the 4000 mark. I was able to get some what of a test hook in last week but the track was horrible and I was about 500 pounds short on the front so I got to bouncing bad and had to let out. The turbo spooled good and even relit after I let out and got back into it. Just couldn't keep the bounce out and didn't want to break anything for a test and tune considering the 2 trucks ahead of me dropped a drive shaft and a transfer case out put.
 
I was reading your signature and it said prostreet 66 16. I see you have changed it.
 
All I remember is running a bunch of timming and a huge shot of propane when I thought It was the thing to run ...

The next thing I know is hearing something like ball bearings rattling against the windshield then a badly leaking head gasket when I was running down the local drag strip !!!

Ouch !!!!! that propane kit was sold very quickly !!!
 
You must log in or register to reply here.
Top