Flat-plane vs. Cross-plane crank
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Joined: Jan 2002
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From: Valley of the Sun
Car: 82 Z28
Engine: Al LT1 headed LG4 305
Transmission: TH350
Axle/Gears: 3.73 posi with spacer
Its totally not worth it. You have to get a custom crank and cam. BS if you ask me. Spend the money on heads, you will be way ahead!
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Joined: Jan 2002
Posts: 3,852
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From: Valley of the Sun
Car: 82 Z28
Engine: Al LT1 headed LG4 305
Transmission: TH350
Axle/Gears: 3.73 posi with spacer
You'd think they would be cheaper than the twist formed forged cranks. After all its the same crank with less work done to it (no twist).
If your gonna build a flat-plane motor, why not do it right. Get yourself a aftermarket block and build a 454 SBC. Now that would be a bad *** motor.
If your gonna build a flat-plane motor, why not do it right. Get yourself a aftermarket block and build a 454 SBC. Now that would be a bad *** motor.
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Joined: Aug 2001
Posts: 5,388
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From: Caldwell,ID
Car: 2005 BMW 545i
Engine: 4.4L N62B44
Transmission: 6spd auto
Axle/Gears: Rotating
Originally posted by Rembrandt
F1 cars are V10s, it wouldn't work for a V10. Just multiples of four. for an even fire V10 you would want 720(=2 rotations for 4-stroke)/10(=number cylinders) = 72 degree bank angle and rod journal displacement angles.
F1 cars are V10s, it wouldn't work for a V10. Just multiples of four. for an even fire V10 you would want 720(=2 rotations for 4-stroke)/10(=number cylinders) = 72 degree bank angle and rod journal displacement angles.
that doesn't make sense to me
under that math a v6 would have a 120* bank angle but I thought they where either a 60* or 90* v6
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From: Caldwell,ID
Car: 2005 BMW 545i
Engine: 4.4L N62B44
Transmission: 6spd auto
Axle/Gears: Rotating
Originally posted by Rembrandt
I'm not sure what the optimal firing order would be, whether you want the next piston firing to be as far away as possible for balancing purposes or some compromise where the cylinders scavenge and breathe most efficiently.
actually you could just swap plug wires to the appropriate bank and piston, because the 90 degree interval is still the same, just in a different place; the computer and distributor don't care. if you had TBI or bank-to-bank batch fire, it wouldn't matter much. sequential EFI would be different, so you would have to swap the injectors' wires' around with respect to the spark plug swaps.
I'm not sure what the optimal firing order would be, whether you want the next piston firing to be as far away as possible for balancing purposes or some compromise where the cylinders scavenge and breathe most efficiently.
actually you could just swap plug wires to the appropriate bank and piston, because the 90 degree interval is still the same, just in a different place; the computer and distributor don't care. if you had TBI or bank-to-bank batch fire, it wouldn't matter much. sequential EFI would be different, so you would have to swap the injectors' wires' around with respect to the spark plug swaps.
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Joined: Aug 2001
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From: Caldwell,ID
Car: 2005 BMW 545i
Engine: 4.4L N62B44
Transmission: 6spd auto
Axle/Gears: Rotating
Originally posted by Rembrandt
false. flat plane crank V8 still fires ONE cylinder every 90 degrees of crank rotation.
if it fired two it would shake itself to dust. that means it would be firing 2 cylinders, on the same bank, simultaneously if it worked like you said.
false. flat plane crank V8 still fires ONE cylinder every 90 degrees of crank rotation.
if it fired two it would shake itself to dust. that means it would be firing 2 cylinders, on the same bank, simultaneously if it worked like you said.
or would that be a normal 8 cylinder crank?
almost wonder what it would be like if 1 and 2 fired at the same time
then 5 and 6
then 7 and 8
then 3 and 4
and just to let you know my numbering order sinceI don't recall offhand the GM cylinder number ordering scheme.
1 2
3 4
5 6
7 8
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Joined: Aug 2001
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From: Caldwell,ID
Car: 2005 BMW 545i
Engine: 4.4L N62B44
Transmission: 6spd auto
Axle/Gears: Rotating
Originally posted by Rage13
if i can find all the info i need, i'm building one. 350 block with 4 dual barrel webber carbs. thats my dream right now :hail:
i e-mailed Carobu about any info they could give me about the engine, hope to hear back soon with good news.
Ferrari's firing order is like looking for the fountain of youth, searching for over 3 hours and no luck yet, but still looking
if i can find all the info i need, i'm building one. 350 block with 4 dual barrel webber carbs. thats my dream right now :hail:
i e-mailed Carobu about any info they could give me about the engine, hope to hear back soon with good news.
Ferrari's firing order is like looking for the fountain of youth, searching for over 3 hours and no luck yet, but still looking
at least as far as I know webber didn't make a 4bbl though they made a lot of 2bbl and 1bbl carbs
though again I might be mistaken
btw the firing order on one of their v-12s is
1-7-5-11-3-9-6-12-2-8-4-10
for the v8 I found
360 firing order is 1-8-3-6-4-5-2-7
and the cylinders are aranged in this order
/\ front
5 1
6 2
7 3
8 4
don't know how accurate it is but it is what I found at least
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From: Caldwell,ID
Car: 2005 BMW 545i
Engine: 4.4L N62B44
Transmission: 6spd auto
Axle/Gears: Rotating
Originally posted by Rage13
yes LS engines use a crank triger instead of a distributor, but it shouldn't be a problem. the engine is going to fire every 90° weather its got a flat or cross plane crank so i'm just going to have to rewire the coil packs to fire on the right cylinder, as well as the fuel injectors.
the ferrari engines are setup like 2 inline 4s facing the opposite direction
(4) (1)
(3) (2)
(2) (3)
(1) (4)
and fire the same as an I4
also found out that they have 1 distributor for each bank and each distributor has 2 breaker points, 1 for advanced ignition and the other for retarded ignition. the points are controlled by a microswitch on the throttle.
not sure if its something that could be used on one of our cars, but i found it pretty interesting
yes LS engines use a crank triger instead of a distributor, but it shouldn't be a problem. the engine is going to fire every 90° weather its got a flat or cross plane crank so i'm just going to have to rewire the coil packs to fire on the right cylinder, as well as the fuel injectors.
the ferrari engines are setup like 2 inline 4s facing the opposite direction
(4) (1)
(3) (2)
(2) (3)
(1) (4)
and fire the same as an I4
also found out that they have 1 distributor for each bank and each distributor has 2 breaker points, 1 for advanced ignition and the other for retarded ignition. the points are controlled by a microswitch on the throttle.
not sure if its something that could be used on one of our cars, but i found it pretty interesting
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Joined: Aug 2001
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From: Caldwell,ID
Car: 2005 BMW 545i
Engine: 4.4L N62B44
Transmission: 6spd auto
Axle/Gears: Rotating
Originally posted by AJ_92RS
What I don't get is where the real advantage is? To be different?
The HP/TQ numbers of that engine from Ferraris Online isn't very different than achieving the same with a cross plane crank like every other SBC uses.
Yea, it can go to 9,500 RPM, notice the HP falls off after ~7,200 RPM, so why rev it that high? It isn't like the cross plane can't rev that high.
Obviously they have their uses, but why use a flat plane crank if you don't need to?
What I don't get is where the real advantage is? To be different?
The HP/TQ numbers of that engine from Ferraris Online isn't very different than achieving the same with a cross plane crank like every other SBC uses.
Yea, it can go to 9,500 RPM, notice the HP falls off after ~7,200 RPM, so why rev it that high? It isn't like the cross plane can't rev that high.
Obviously they have their uses, but why use a flat plane crank if you don't need to?
those BSFC are really low with the a/f ratios they seem to be using
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Joined: Aug 2001
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From: Caldwell,ID
Car: 2005 BMW 545i
Engine: 4.4L N62B44
Transmission: 6spd auto
Axle/Gears: Rotating
Originally posted by ME Leigh
You'd think they would be cheaper than the twist formed forged cranks. After all its the same crank with less work done to it (no twist).
If your gonna build a flat-plane motor, why not do it right. Get yourself a aftermarket block and build a 454 SBC. Now that would be a bad *** motor.
You'd think they would be cheaper than the twist formed forged cranks. After all its the same crank with less work done to it (no twist).
If your gonna build a flat-plane motor, why not do it right. Get yourself a aftermarket block and build a 454 SBC. Now that would be a bad *** motor.
go a turbo 572... now that would be a bad *** motor
Thread Starter
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Joined: Apr 2002
Posts: 901
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From: Pembroke Pines, FL
Car: 89 Firebird
Engine: 305
Transmission: T5
Re: Back from the dead...
Originally posted by FerrMaro
I know this is reaaaaally old, but this is really interesting and I'd love the option of getting a flat plane crank for my sbc. Has anyone done any more research on this? Rage13? You still around?
™
I know this is reaaaaally old, but this is really interesting and I'd love the option of getting a flat plane crank for my sbc. Has anyone done any more research on this? Rage13? You still around?
™ What I was really going for when looking into this was to have something different and the sound a flat crank makes. The crank Rembrandt posted near the top is from Crower, so they can definitely make you one if wanted. But I've decided for a daily driver car I'm going to stick with GMs engineering on the short block and put the money into making power insted of just making something different. To still get the sound I want I'm looking into 180 degree headers.
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Car: 91 Red Sled
Axle/Gears: 10bolt Richmond 3.73 Torsen
Originally posted by ME Leigh
DAMN RX
Ok an LS7 with a flat crank. That would be freakin nuts.
DAMN RX
Ok an LS7 with a flat crank. That would be freakin nuts.
.Cubes don't MAKE horsepower, air flow makes horsepower and a motor that revs to 10000rpm+ displacing 300cubes can (and would) make for an awesome sound and give the engine the ability to use a dual resonance intake to get that extra hp where it needs it. I'm telling you guys to get the whole displacement OUT or your heads. Displacement does nothing for power, it just moves the powerband around on the RPM axis... airflow = horsepower. More air and fuel burned = more horsepower so just give it the air you want for the horsepower THEN pick the displacement, THEN pick the intake/cam. That's how it should be done and that's how it's been done in racing for decades.
Let's recap; displacement doesn't make power, air flow does
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Originally posted by FerrMaro
For a cam to run with the FP crank??
Crank cost must be stupid high.
For a cam to run with the FP crank??
Crank cost must be stupid high. I think I heard Lunati and Crane were a little more reasonable but its still going to be expensive. Puts a little salt in the idea wound.
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