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Exotic "SOUNDING", high revving V8! Read "ENTIRE" thread before posting!!!


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Yea, I cut slightly into the journals on that first slice. On the last one I did I made sure not to.

 

I really wish I had a crank in my hands to work off of. I've been basing my work on pictures and basic part specs on the parts availible. Through the parts catalog on summit I can get:

 

Main Journal Diameter

Rod Journal Diameter

Rod Width

Rod Big and Small end Diameter

Rod Length

 

And I know the bore spacing for the motor, so it becomes a guess work of the thickness of the main journal....

 

It's an educated guess, but still a guess. If I was going to be working on a "final" mockup before having it made I'd make sure to have the block in hand so my specs were perfect.

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  • 2 weeks later...

Yes I could. It's the matter of time to go to the junkyard to spend X amount of hours pulling a crankshaft for an "engineering excersize".

 

Realistically it would have to be on a weekend, and my weekends have been booked SOLID all summer. Maybe when fall rolls around I'll find some time to pick up a used crank.

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Even if I had the dough I'm not sure I'd want to.

 

The beauty of the idea of putting a flat plane crank in a SBC or SBF is that so many of the parts are dirt cheap. Rebuild costs are next to nothing. Sure you'd be spending some extra change on the valve train and piston coatings and such, but not enough to make a real ferrari engine look cheap.

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Even if I had the dough I'm not sure I'd want to.

 

The beauty of the idea of putting a flat plane crank in a SBC or SBF is that so many of the parts are dirt cheap. Rebuild costs are next to nothing. Sure you'd be spending some extra change on the valve train and piston coatings and such, but not enough to make a real ferrari engine look cheap.

 

We share similar sentiments. Yes an actual Ferrari engine would be uber cool, it possesses massive WOW factor, but the cost of the SBC/SBF, and to a greater degree, having had a hand in the transformation of a power plant on this level is a common primal male craving. It’s a guy thing, more of a power trip really. To have control over an inanimate object and harness the laws of physics in such a way to work in harmony, from the efforts of our own creativity, ideas and sweat, not just our bank account alone.

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If you' date=' ([i']the reader[/i]) want to contribute to this thread, do yourself and all of us a HUGE favor. Please go back and actually READ the thread, the ENTIRE thread first! THEN, If you feel your comment or input fits, by all means post, otherwise, please do NOT post in it, until you have actually read the thread!

 

.

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Guest jrsb202001

not to get of the subject but, this goes back to the same thing rotary guys go through. it most certainly can be done, but the one part that is needed costs mad pesos to make. only difference is u guys seem to be getting closer to making it a reality without spending 100k to do it. best of luck this will be viewed as a technical marvel when u guys get it. cad drawings, crank pin calculations, you guys on another level. I just can't get over the fact that it feels eery. almost like that movie with keanu reeves when he stumbles upon hydrogen energy and the government wants to take him out. hope u guys go in witness protection when u get it. ferrari might send a couple of cleaners to stop u from discovering there secret.:icon55:

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Fortunately I don't think there's too many secrets about it. I think in reality it won't be THAT much different than designing a regular crank, which is still a huge undertaking in itself.

 

The thing about dual plane cranks is that they're everywhere and easy to copy and get safely close. Single plane cranks aren't common, especially in the displacement we're talking about potentially seeing, and very uncommon in pushrod engines which have been a hot topic in this thread. So finding a design to copy isn't exactly easy.

 

I'm still wondering if it might make sense to use removable counterweights (as I've seen on a F1 design), as this allows you to remove as much weight as possible from the rod journal area, and also use a heavier material for the counterweight, making it smaller (close to the center, which is GOOD :D )

 

I've also been wanting to find some good documentation on high RPM pushrod builds, as I want to know what they do in the area of the crank. Anyone out there listening??? Anyone find anything???

 

Questions I'd have:

 

1. Did they change the diameter of either journal, if so why?

 

2. What percentage counterweight did they use, and what did they do to make sure it wouldn't create destructive harmonics?

 

3. What RPM do they expect the crank to be able to reach, despite other engine limitations?

 

 

I don't know about you guys, but if I'm going to be going through to work of designing, or even being part of a huge group buy for flat plane cranks, I'm going to want it to be able to live at 15,000, not just a mere 10,000. I'm going to want something that basically removes all RPM limitations due to the crank. Then we could run a valve train, piston, and cam setup as our limiting factor.

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Guest jrsb202001

the shorter the stroke the more durability u get as well. I don't know if u may or may not have considered this:

 

I know I read in a issue of super street a couple of years back they had an engine damper in the form of a "mini shock" to counter the rotational forces of the sr20det's guy's were building to prevent motor mounts and and frames from getting mangled. they would mount the damper in the same place u might mount a strut bar. maybe u could mount one off each bank to sustatain the vibrations at low rpm. this isn't a problem for ferrari cuz they have lightweight internals I know but when u break the "formula" u have to take certain measures to "stabilize" the "potion" (poison IMO cuz if u get this right there will be alot of kills to be made).

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Guest jrsb202001

also what did lotus do that allowed them to have such a large stroke on the esprit v8?

 

here's the stats if it helps

 

Configuration: Aluminum-alloy twin-turbocharged V8, 90 degree cylinder bank angle, single-plane crankshaft.

 

Capacity: 3506 cc

 

Power: 350 HP @ 6500 rpm

 

Torque: 295 lb ft @ 4250 rpm

 

Bore: 83 mm

 

Stroke: 81mm

 

Head Chamber Aluminum alloy, four-valve pent-roof combustion

 

Turbochargers: Two Garrett T25 water-cooled, oil lubricated.

 

Valvegear: Dual overhead camshafts with one toothed belt per bank, hydraulic tappets.

 

Inlet valves: 33.5 mm

 

Exhaust valves: 30.0 mm

 

Block: LM25TF aluminum alloy with cast iron "wet" lines, spheroidal graphite cast iron cross-bolted main bearing caps.

 

Fueling: One primary injector per cylinder, one secondary injector per bank.

 

Ignition: Four double-ended coils triggered from crankshaft sensor.

 

Ancillaries: Water pump, alternator, power steering pump, air conditioning compressor.

 

Weight: 485 lb with ancillaries.

 

also the aurora v8 in indy has a 108* crank and that's based off of the production motor (of course it has different materials), and that is based off of the north star v8. just food for thought.

 

I'm pretty sure if it can be done with the vh there will be millions of people wanting a single plane crank to put in the motor. and just think u'd be rich for creating the most unbelievable motor since the rotary cuz I don't see nissan or chevy making production motors with single planes.

 

BUT THAT WOULD BE INSANE IN A 350/370Z!!!!!!!

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Gollum if you want to know what the real deal is with high RPM domestic cranks, just buy one.

 

http://cgi.ebay.com/ebaymotors/NASCAR-BRYANT-BILLET-RACING-CRANK-SBF-3-255-STROKE_W0QQcmdZViewItemQQcategoryZ107063QQihZ023QQitemZ360087116540QQrdZ1QQsspagenameZWDVW

 

You won't find a much better example of a big displacement, high horsepower V8 that can last at 9000+ RPM.

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Guest jrsb202001

it's not about just a big displacement, high reving v8

 

it's about taking the advantages of a flat plane v8 and harnessing them in the 240 or some light-weight car. the ferrari sound is a must. at the same time I wondering....... how is it possible to shorten the stroke of a motor? not that many people sell destroker kits for motors to have the torque taken away.

and one more question are there certain pistons and rods that interchange with the vh45/41's? and if u shorten stroke and decrease bore is it possible somebody will lighten the crank at reasonable cost????

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it's not about just a big displacement, high reving v8

 

Yeah Gollum was just asking about high RPM pushrod motors, and cup cars are probably one of the best examples of that technology. The motors are relatively cheap and simple, they spin high, and they hold together. All this despite the fact that they have relatively long strokes and heavy rotating assemblies, dual plane cranks, and make a lot of power.

 

Add a flat plane crank and drop it in a 240 and you might have one of the baddest rides on this forum. After looking over one of the newer R07 motors in detail I would really like a chance to fiddle around with one. I'm also getting closer to my "dream job" so maybe building a 180 degree crank for an SBC isn't terribly far away.

 

I did recently notice that John Kasse may be turning out some nice canted valve SBF heads with some very impressive flow numbers. If he did then I wouldn't mind seeing a flat plane crank in a 302 with those on top....

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I just wanted to jump in here...since my search seemed to overlap what was going on in this thread...

 

1st...I will need to contact some folks @ Eagle and se what they say regarding availablility of the flat plane crank...I seem to recall that they offered a twisted forging a while back ...and as previously mentioned...it shouldn't be too hard to get a crank "pre-twist" and go to town...

 

2nd...and this is something I just cam up with...

...why not use some 4340 plate that is thick enuff to cover the dimensions of the main journals...??? All you would have to do at that point is EDM the profile of the crank and have the machine shop treat it like a "very" rough casting...and then dill the holes for the lube circuit...

 

you could just weld (build-up) any cheeks that were necessary for the slingers and shoulders..and then weld on or machine for attachment any counterweights...

 

and I don't know if it's been mentioned already...but you can get nearly the same sound with a "correctly" designed x-pipe from about 3500+ rpm on a standard "Windsor" firing order Ford small block.

 

My 408 does...and so does my 347. It has to be a true X and the union needs to be a football-shaped opening. My 408 sounded mean as $hit when it hit 4 grand and revved to 7,000 with that x-pipe...but it was still a potatoe-potatoe-potatoe car down low...

 

Now off to try my luck at a flat crank...will post back if I have any luck...

 

-David

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