I was wondering why you chose to do a 2.7 L instead of the 2.85. The cranks cost the same dont they? Just a curiosity
I have had minimal problems with the Felpro gasket, but i can shed a small amount of light on the compressed thickness. I measured one after removing it. It measured .055". I figure that means (by guessing) it is somewhere between .045" and .055" compressed height. You seem to be good with numbers too. Could you possibly tell me how much i lowered the combustion chamber cc's by taking .150" off the head? And maybe the potential static compression ratio. (i could do it with water and measuring tools but i never have)Could a high compression 2.7 be run without the water injection?
The answer is yes; all this depends on where the intake valve closing event occurs and what you consider “high compression”
The later the intake valve closes in the compression stroke, the shorter the effective stroke length becomes. Of course not much compression occurs when the valves are still open.
So this is dynamic compression were talking about here. There are more than a few factors that affect dynamic compression, such as; air intake air temp, spark lead, valve overlap and so on.
So this begs the obvious question; what provides the best balance between power/ efficiency and detonation. If you have done any reading these days, you have probably noticed that cars are getting more and more powerful and a lot of that is due to the fact that engine designers have started to hone in on better ways to combat detonation.
Variable cam timing is a good way to delay the intake valve closing events on an engine and it seems to be the popular choice for a lot of car makers these days. I have been experimenting with a system for this for the past 2 years and there are a few possibilities for building a more universal system for older cars, but I think what is holding the aftermarket back, is most likely their refusal to pay the patent licensing fees.
Using smaller combustion chambers, minimizing deck clearances and crevice volumes are effective ways to improve detonation resistance as well. You can do this by milling the head and using a copper or cometic head gasket. I have never came across anyone on any 2.3 forum, who didn’t think the Felpro 1035 was the best gasket in the entire world for the 2.3 engine, but when I ask them what the compressed thickness is on that gasket, they can never tell me, nor can they tell me why it might be important! The copper and cometic gaskets are as thin as .027” but if you do not ask for the thinner gaskets, you won’t get them.
Weather you are going with an N/A or turbo motor, the piston choice you make will be important. CP pistons seem to be in tune with what is needed for a high performance 2.3 engine and when you look at how close the top ring is to the piston top, you can tell that someone was thinking here.
Spark advance is going to matter here as well. 34-36 total advance is what you want to shoot for on a single plug motor and about 22 on a dual plug, if both plugs fire at the same time. Having a decent spark delivery system and a way to control it is key here as well.
:shitbrickOHC230; said:Water injection is required for this application, since I am running 35 degrees of timing and 12.6:1, with an LSA which would not normally be used in this way, so I am struggling against some high dynamic pressures in the engine.
Well I'm going to have to make some calls and see what I can find about this, because there is no way in hell I'm going to tear down the mess that is the terminator accessory drive any more than i have to, let alone do it with the engine in the car to adjust cam timing. I might even end up running a more middle of the road 111/116.I am going to bounce your cam question off Elgin cams to see what he comes up with. I had a short discussion with some of my colleagues the other day about this and the consensus by 2/3 is that the 109/118 could work, but that isn’t the only factor at work here and empirical data is the only solution we could all agree upon. Test/tune, test/tune………