jensenracing77

How do you detect pre-ignition? I know the obvious is to hear it but is it possible to have it and not here is? I thought I read somewhere that it is harder to hear on an aluminum engine, is this true?

I can not here any hint of it on our Jetfire but it is an aluminum engine with 10:1 compression and 6.5 psi of boost. It does inject water to cool the intake air when it is working correct. Yesterday I was doing some testing and put a heavy load on it to get it to boost but I had the water deactivated. I did not go to full boost but likely around 3 psi. I still did not hear any knock. I just want to be sure I am not doing harm to the engine by thinking things are fine because I can't hear a knock.

oldcutlass

Preignition and detonation are 2 different things. Preignition is something that happens prior to the spark plug firing and detonation is after. Inspecting the spark plugs for extremely burned ends or deterioration of the ceramic is a good indication of preignition. I would think you need to keep the rocket fluid injection operating as that is the only way to cool the mixture to prevent it using recommended tuneup settings.

MDchanic

The only way that I know of to reliably sense detonation is with a detonation sensor that is bolted to the head, as they have on newer computer controlled cars.
With all of the other noises inherent in driving (tire noise, wind noise, exhaust noise, mechanical engine noise), it is impossible to reliably hear it.

I know that they do sell sensors and computer units that can be retrofitted, but I believe that they are expensive, and I know nothing about them.

Failing that, set timing to factory spec, use fuel with the required octane rating, be sure water injection is functioning properly, and keep your ears open.

- Eric

marxjunk

use meth injection...snow is the best on the planet..google it..meth adds tons of octane...and theres a diff between real meth and window washer fluid...

you have water injection already..meth is water on steroids..

theres so much going on you really need to research it

theres a lot of myths about turbos...if you keep it out of detonation, they are extremely easy on engines...

its hard to tell if its detonating or not..better to be safe , or that is pro-active instead of reactive...

reading plugs goes a long way...theres tons of info on it too

jensenracing77

Turbo Rocket Fluid and their Boost Juice are 98% the same. Mine is 49.5% meth and 49.5% distilled water and 1% is just a water soluble lubricant for the diaphragms in this 1962 crude system and to cut the corrosivenes of the meth. Theirs is 49% meth and 51% water. They claim theirs has nothing else added but they had to add a dye to make it red. They can get away with no lube because there system has no steal parts to corrode. My original Oldsmobile system has a steal tank that will be gone quickly without the lube. It also has a filter that has a metal casing. When I took my system apart last winter this filter was rusted inside and clogged up. I increased my lube from .5% to 1% and hope that is enough to keep it from happening again. I may increase it to 1.5% on my next batch.

I don't believe this car is detonating but I have no experience with aluminum engines. I read someplace that it is hard to hear an aluminum engine detonating, I just don't know if that is true. I am running a 160 T stat and it stays there most of the time. On a real hot day and in town it will get to 190. I typically don't let it boost much till it is back down to 170 or less just to help. I know that is not cylinder temp but it is still going to be cooler a little.

11971four4two

Hey Eric
Hope you are at least running a high octane number non oxy fuel.
110 leaded racing fuel keeps the ping out and temp down in my olds cars

jensenracing77

93 is the highest I can get at the pump. Can't afford race gas. As long as the water is working properly I should not have a problem. Would be nice if 110 was less money because I could just run that and skip the water.

Railguy

X2
If your octane is to low it will be hard to start and hard to keep running until warm.
Railguy

11971four4two

The water mist should keep the ping detonation at bay with 93 octane.
Race gas is only $ 6.45 110 proof at the pump here
Enjoy the ride

does the car have gauges?? temp / boost etc??

jensenracing77

Starts fine, It is only 10.0-1 till it creates boost.

jensenracing77

Only factory gauge is vacuum/boost but it don't have numbers on it. I added a temp gauge and for a short while I had an accurate vacuum pressure gauge on it to know where my factory gauge was at different PSI.

marxjunk

ive had alum engine buicks my whole life..and the only thing i did was once in awhile pull a plug and use a magnifying glass and make sure there was absolutely no alum specks on the plug...its all i could do...modern alum engines run at about 215deg i think...i think you are over thinking it

you can run 1 full point higher with alum than iron heads...as far as the block who cares..it has liners..so the piston doesnt know its an alum block.

detonation beats the pistons and bearing out of the motor..kills the ring lands..and if you cant hear it..you cant fight it..

my advice...keep it tuned..keep it full of meth and enjoy it...remember the meth adds a lot of octane..and the water with the meth is chemical inter cooling...plus its draw thru..so even the fuel is like a chemical inter cooling agent..if you want i will send a pm with an in depth discussion on a scientific level..article i found on line