Yeah the cowl hood sounds good, Im not sure if i want a tonou cover. I think i'd rather just remove the rear tailgate. Im trying to add as little weight as possible. thanks rich!

 

Well, now that I have at least 4 people who disagree with my interpretation of Boyle's law, it would seem obvious that I am missing something. So let me begin by stipulating that I am wrong. Ok?

Now, will someone please solve the following:

On an 8:1 engine, assuming 75% volumetric efficiency, If the intake temperature drops 20 degrees, what is the change in temperature at the top of the compression stroke?

A brief explanation of what I have done wrong to Mr. Boyle's theory would really be appreciated!

 

kerno, I think your focused on combustion temps and therefor stress on the short block as a result of inlet charge density. And I think your assuming this is the cause of recently posted blown engines.

Problem is.. that is not as big a factor as is poor gas & too much timing. The spike in pressure exerted on the piston face from detonation is exponentually higher the greater the detonation. So much more that your *valid points* really are insignificant IMO.

I guess the real problem is that way too many guys have thier tune too close to the edge. *FOR THE FUEL* & ambient temps they are running in.

Time after time I don't see people questioning the fuel. They assume that it is always a constant. I know for a fact how the business world works... And I also know for a fact that gas from the same supplier will vary in it's octane rating.

If guys are gonna go WOT daily? Thier tune ought to accomidate thier needs to be able to run fuel that is'nt always up to par.

This may shock some of you... in one particular industry that I was in, we had our motors tuned/protected for 82 octane fuel. Know why? Bcause once the product leaves the factory we cannot control the fuel that the costumer will have in thier tank. And guess what we found when we did a cross sectional study our our products in the field?

Rich

 

RUSLOW, are you going to chime back in with some info? im curious.

 

Rich; you got any pictures of how it looks? I have been wondering about that same thing myself.

 

wydopnthrtl:

Thanks for your response. I'm looking for answers and am perfectly happy to admit that I'm wrong. I agree that the pressure spikes that occur during detonation are far beyond what the pistons and rods would ever see under normal combustion, no matter how we port the Eaton or what pulley we put on. I'd like to get into the theory that increased compression temperatures might play into it, but I don't think I'll go there. I, like everyone else here, really enjoys what happens when we climb into boost. But, as I'm sure several members of this forum will agree, there's not much joy when you can see the crank from the side of the block.. As such, we might have a common goal and that might be to extract as much fun as possible without catastrophic failure. Like everyone else, I'm both willing to share what I know (or in this case, what thought I knew) while looking for answers. So I offer my thanks to you accordingly.

It certainly makes me feel better that at least one person is willing to come forward and help. But for others, the real question remains: What's to be gained by telling someone they are wrong without telling them what's right?

 

Casey02L, check out the pic of my truck at the gas station (on my web page)

Rich

 

in my house... we call them democrats.

Rich

 

i thought a cowl induction hood inducted air, because at the center of the hood is a high pressure area?

wouldn't that draw more air into the engine bay? i know it would bring in cooer fresh air, but i want to vent out hot air and drag-causing pressure under the hood.

 

NOt yet ,Will post pics of my new mod when it is completed.sTan

 

It is a high pressure area. But the "high pressure" is relative to the surrounding area. It's still low when compared to the underhood pressure. Just think about the air flow through the engine room and it'll make sense.

Raising the rear of the hood has got to be one of the oldest speed secrets in auto racing history.

One thing I did'nt know til recently though.. slightly rasiing the front of the hood near the air filter is also a little way to help keep engine room temps and pressure in check.

Rich