Landracing Forum
Tech Information => Technical Discussion => Topic started by: woz on March 01, 2015, 05:17:45 PM
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All things being equal with weight and packaging not a big consideration, what are the thoughts regarding optimum engine type (V8, V6 or inline) for say a "D" or "E" engine?
Is it all about potential rpm, firing pulses, etc...?
Obviously V8's are used much more but just curious as to the benefits/drawbacks of a larger 6 or smaller 8.
Thanks
Woz
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Destroked NASCAR would be my choice. Pick a brand and make some calls 2 year old tech from them is considered obsolete and available. I've heard Toyota is the toughest to get. Good Luck.
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I would shoot for something with a short stroke, double overhead cams, four valves per cylinder and all the cylinders you can get :-o
YMMV :cheers: :cheers:
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I would go with what sets records.
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I would go with what sets records.
x 2.
DO NOT reinvent the wheel . . . . .
Make an intelligent choice based on affordable parts availability, for not only the displacement limit of the class, but also for the target horsepower required.
The target bhp required to be competitive, (in bhp/cubic inch or bhp/litre), will help you decide whether older 2V Nascar tech will be adequate. If not, you will need to upgrade to more expensive 4V DOHC technology.
:cheers:
Fordboy
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Also:
Pick something at the displacement limit for the class, or that can be enlarged to the displacement limit.
It's not smart to give away displacement, you just handicap yourself.
:cheers:
Fordboy
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I would shoot for something with a short stroke, double overhead cams, four valves per cylinder and all the cylinders you can get :-o
YMMV :cheers: :cheers:
:cheers: :cheers:
Moving air into the motor and then adding the fuel is what makes HP and most of those items you list sure contribute to the amount of air you are going to potentially have available. NASCAR engines make HP but don't forget they are stuck with that design and have refined them but tell them they could design any engine they wanted and I'm sure we would see something different in those cars,
Sumner
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For 250-305" engines its tough to beat Small block Chevy at least in hp/$
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I would go with what sets records.
x2
I'm an admitted simpleton... pushrod engines instead of OHC, boost instead of 13:1+ CR,
but many people have had success with the aforementioned engine types. Destroking an
already small stroke SB2 (2.85" stroke for 305ci, 2.43" stroke for 260ci) seems like it would
only find effect over 7,000 rpm, whereas starting with an already "small" 250ci Chevy I-6 or
231ci Ford V-6 (E) , 294ci LS or 302ci Ford (D) and getting your desired CI through a good
bore/stroke combo is the way I'd go. Of course, the ubiquitous destroked 4-bolt SBC seems
to be a crowd favorite, and for good reasons.
Thinking outside of the box is cool, but I don't have the money or engine building experience
to turn those ideas into a fast machine. A 4" bore & 3.6" stroke @ 9:1 CR + boost is my MO.
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I would go with what sets records.
i've been told i can't go wrong with whatever M Lefevers recommends :cheers:
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Is this naturally aspirated or blown? Fuel choice? These make a big difference.
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Keep in mind that complexity adds costs, the formula is usually something like this:
Greater complexity = cost ^ x, where the x value is usually 2 or 3.
Resulting in cost squared or CUBED . . . . .
Consult with Dr. LeFevers for the best cost/bhp.
JMO
:cheers:
Fordboy
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The only caveat I can think of - use internal combustion, thrust will not set records at Speed Week.
DW
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Last years Engine Masters Challenge first 2 were 4 valve Ford mod motors. This year they weren't allowed. This engine has aftermarket support, could be stroked or destroked for either class. They're bulky, though.
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Destroked NASCAR would be my choice. Pick a brand and make some calls 2 year old tech from them is considered obsolete and available. I've heard Toyota is the toughest to get. Good Luck.
In doing this, you obviously need a new crank but then do you need new rods or pistons or both?
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Destroked NASCAR would be my choice. Pick a brand and make some calls 2 year old tech from them is considered obsolete and available. I've heard Toyota is the toughest to get. Good Luck.
In doing this, you obviously need a new crank but then do you need new rods or pistons or both?
Destroking requires new crank and new rods minimum. (Or at least "different" as they do not need to be "new")
The next question is: What else needs to be "optimized" for the new, smaller engine?
:cheers:
Fordboy
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i've been told i can't go wrong with whatever M Lefevers recommends :cheers:
Ive heard that too, or what John Beck recommends. Both really good choices
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i've been told i can't go wrong with whatever M Lefevers recommends :cheers:
Mike will not steer you wrong. You could go a long way to find someone as good.
:cheers:
Fordboy
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The traditional V-8 path is well worn by generations of folks with lots of money and talent. It is hard for anyone to make a big performance increase there. The weak spot with them in NA form is breathing. Bikes are pretty much dominated by four valve engines with downdraft intake ports, updraft exhaust ports, efi, and the ability to rev well over 10,000 rpm. My bet would go to looking for an engine with good architecture that has these attributes. The way to success is to recognize and capitalize on things the other guys/gals have not figured out, yet. That is my advice, although I am a bike racer and have no idea what this engine would be.
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"tell them they could design any engine they wanted and I'm sure we would see something different"
X2!