Streetable compression

[dodge freak]

I would run race gas if it was $3 a gallon, its not. Fuel cost too much as it is right now. If gas was still $1 a gallon, my car would have 10,000 miles put on it this last summer and not only 1,500 miles. I be going on so many road trips but when I do the math I see I don't have $200 for fuel when another car would cost me only $50 for gas.

 

[MoparAnglia]

Yes, you are missing something. A few things actually.

1. I'm not recommending "low compression", I'm recommending 9.5 to 9.75 to 1. This cam in a stock CR engine would certainly be a dog and the only reason it runs fairly well is that the OP had his block zero decked.

2. This eddy cam is ground on a 112 LCA which boosts cylinder pressure at low RPM, right where there's a tendency to detonate. This is also why it "appears" that the valve timing is so long.

3. Both Lunati's have more duration, are ground on a tighter lobe center and have a greater rate of lift vs. the eddy cam. Also, don't forget that seat timing is not what you use when calculating dynamic compression ratio.

You are correct in that running a cam of this size in a stock comp engine is a mistake.

2. This eddy cam is ground on a 112 LCA which boosts cylinder pressure at low RPM, right where there's a tendency to detonate. This is also why it "appears" that the valve timing is so long.

The valve timing doesn't appear long. It IS long. The wide LCA will offset that but only so much.

3. Also, don't forget that seat timing is not what you use when calculating dynamic compression ratio.

While some calculators use duration @ .050" plus 15 degrees to give the dynamic compression, there are plenty that DO use seat timing.
I'm not saying that's right but it's a fact.

All this said, I wouldn't retain the RPM cam just to run a higher static comp.

 

[ramcharger]

Just for Ha ha's, I picked up the Purple 288/.508 oval track cam ground for a flat track. THIS cam is not for the street and idled like a lumber jack on crack chopping for his life for his next fix, while having a heart attack. :violent1:

Once in the power band, and there's no mistaking when that happens, the power was "ON!"

LOL! I love this.... Cracks me up and i've been up and down the too big and small cam road not only on V-8's, but bikes that run up to 14K+ rpm. No joke.

 

[ramcharger]

2. This eddy cam is ground on a 112 LCA which boosts cylinder pressure at low RPM, right where there's a tendency to detonate. This is also why it "appears" that the valve timing is so long.

The valve timing doesn't appear long. It IS long. The wide LCA will offset that but only so much.

3. Also, don't forget that seat timing is not what you use when calculating dynamic compression ratio.

While some calculators use duration @ .050" plus 15 degrees to give the dynamic compression, there are plenty that DO use seat timing.
I'm not saying that's right but it's a fact.

All this said, I wouldn't retain the RPM cam just to run a higher static comp.

Once again, it's not about "long timing", but about overlap. In otherwords, it's about how long in degrees that both the intake and exhaust valves are open, not about total duration. 1wild&crazyguy tried to put this forth before, but you would not listen.

KB pistons use .006 figures for dynamic CR ratios and that's a fact.

Anything else?

Please understand that I'm not trying to be rude, but I CANNOT reccomend a 10.5 as a MINIMUM for this cam not knowing this man in person. Can it be done? Yes! With flat tops and Magnum heads with quench set to .040" or less easy or aluminum closed chamber heads. Could it be done with open chamber J heads? Yes it can.... Here at 5280' in Denver. I'm running 10.2 with a Lunati 604053 in a 4WD Ramcharger w/3.55's and 33x12.5's and I'm running a Mallory programmable ignition and distributor with a total of 32 and no vac advance and I'm on a hare's breath of detonation.

This being said, I just may name my next Rottweiler Guiness, because he/she'll be black and tan..... :cheers:


Or maybe...... They'll be named INDEPENDENCE!!!!!! lol!

Just messing with ya!

Edit: Just threw ya a thanks for the band Iron Maiden....which is what I'm listening to right now.

 

[dodge freak]

3.55 gears and 33 inch tires and in a heavy 4WD truck is lugging the heck out of that motor. Same motor in a lightweight A body with 3.91 gears and 27 inch tires would be a world of difference.

That poor little engine, LOL

 

[MoparAnglia]

Once again, it's not about "long timing", but about overlap. In otherwords, it's about how long in degrees that both the intake and exhaust valves are open, not about total duration. 1wild&crazyguy tried to put this forth before, but you would not listen.

KB pistons use .006 figures for dynamic CR ratios and that's a fact.

Anything else?

Please understand that I'm not trying to be rude, but I CANNOT reccomend a 10.5 as a MINIMUM for this cam not knowing this man in person. Can it be done? Yes! With flat tops and Magnum heads with quench set to .040" or less easy or aluminum closed chamber heads. Could it be done with open chamber J heads? Yes it can.... Here at 5280' in Denver. I'm running 10.2 with a Lunati 604053 in a 4WD Ramcharger w/3.55's and 33x12.5's and I'm running a Mallory programmable ignition and distributor with a total of 32 and no vac advance and I'm on a hare's breath of detonation.

This being said, I just may name my next Rottweiler Guiness, because he/she'll be black and tan..... :cheers:


Or maybe...... They'll be named INDEPENDENCE!!!!!! lol!

Just messing with ya!

Edit: Just threw ya a thanks for the band Iron Maiden....which is what I'm listening to right now.

I listened. Hell, I already knew - that's why I didn't take issue with what 1wildandcrazyguy said.

I was just quoting what you wrote - 'it makes it appear like long timing' - I'm well aware that its a very gentle opening ramp....

.006 is advertised duration anyway, or as close to seat timing as most disclose. Including Edelbrock.
The KB Silvolite calculator uses closing point @ .050" +15.

Oh, and Guinness is Irish...

Kudos on listening to Maiden though. Hope it was some early stuff.

 

[Dustin The PcP]

Ok, so whole new ball game now. I am going to be buying the RHS heads, which flow amazingly well and have closed chambers from everything I have read.

 

[Cudafever]

Ok, so whole new ball game now. I am going to be buying the RHS heads, which flow amazingly well and have closed chambers from everything I have read.

Closed chamber iron, GRATE!

You need to rethink you "dome" piston

Flat top "0" decked is my recamendation.

 

[Mad Dart]

Water injection doesn't boost octane. It puts the fire out to stop detonation. It actually reduces power. It sucks.

What? The water or meth atomizes before it reaches the cylinder "steam" which cools the intake charge and reduces cylinder temps. This process allows you to run more compression and more timing before detonation, which will increase the output of the engine "more power" on cheaper fuel. So the 14:1 engine on VP 110 can more than likely run pump premium with water or meth injection/water mix and leave the timing as is with the same results as the more expensive fuel...... You would recoup the cost of the injection system very quickly and be able to actually drive the car more for a heck of alot less $.

I am going to build a High Compression 14:1 motor some day and prove it First Hand. For now we will see how it works on the TT engine at 15PSI.

 

[RustyRatRod]

What? The water or meth atomizes before it reaches the cylinder "steam" which cools the intake charge and reduces cylinder temps. This process allows you to run more compression and more timing before detonation, which will increase the output of the engine "more power" on cheaper fuel. So the 14:1 engine on VP 110 can more than likely run pump premium with water or meth injection/water mix and leave the timing as is with the same results as the more expensive fuel...... You would recoup the cost of the injection system very quickly and be able to actually drive the car more for a heck of alot less $.

I am going to build a High Compression 14:1 motor some day and prove it First Hand. For now we will see how it works on the TT engine at 15PSI.

I get it.......I do. We were runnin water injection on 12.5 and higher motors in 1980-1983. You're spot on with everything you say. It cools not only the intake charge, but the combustion as well. Best thing to do is run race fuel.....but sometimes it's cost prohibitive....so water injection. I think in your app though, you'll see more to it for sure. One things for sure.....whatever you do is gonna be badass.

 

[RustyRatRod]

Closed chamber iron, GRATE!

You need to rethink you "dome" piston

Flat top "0" decked is my recamendation.

If his domed piston creates a good quench area, he'll be better off with the closed chamber. A good quench engine can see 11:1 or greater on pump gas.