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Pete. (l33t FS)
Pete. (l33t FS) MegaDork
10/8/23 3:37 p.m.

VWAG made a lot of V10s.  It is essentially two 07K five cylinders the way the 3.6 is two 1.8 16Vs.  Found in some S6s, S8s, R8s, and Lambos.  (It annoys Lambo people when you fix their engines with Jetta parts)

 

Downside, they may be tricky engine management wise, and they may not have an easy transmission solution.  And all power upgrades involve turbocharging.

Audi fives made up to 170-190hp naturally aspirated, that is a lot more power than many V8s wink

mr2peak
mr2peak Dork
10/9/23 8:38 a.m.

lol a 170-190hp V8 isn't worth it's scrap weight as a swap. Malaise era killed a lot of things.

The VW Group V10 sounds very complicated. Dual ECUs in a master/slave configuration, etc. The S85 is well documented as a RWD swap, solutions exist for many of the problems presented. Both are right on 530lbs, about the same weight as a 2j with the turbos. Unfortunately, I know that's enough weight to ruin the feel of the car, lots of 2j swaps don't last in FDs for that reason. I can't imagine a V12 being lighter or easier hahahaha


Well, I guess my thoughts are confirmed. Unless I can get an LT6, or figure out a cheaper F136 solution, the flat plane crank V8s are simply out of reach.

APEowner
APEowner UltraDork
10/9/23 10:06 a.m.

I think Scat still makes a flat plane crank for the old school small block Chevy. 

codrus (Forum Supporter)
codrus (Forum Supporter) PowerDork
10/9/23 10:09 a.m.
Pete. (l33t FS) said:

And all power upgrades involve turbocharging.

And with turbocharging, 4 digit power numbers are apparently not too hard to attain. 

 

mr2peak
mr2peak Dork
10/9/23 10:24 a.m.

But listen to this.. Cosworth DFV, flat plane crank V8 goodness.

https://www.youtube.com/watch?v=Jzbn3yrkLnk

Not goodness. Greatness.

iansane
iansane Dork
10/9/23 11:25 a.m.
codrus (Forum Supporter) said:
Pete. (l33t FS) said:

And all power upgrades involve turbocharging.

And with turbocharging, 4 digit power numbers are apparently not too hard to attain. 

 

From what I understand unless you convert to port injection or go with a 10k ecu, you're not turbo'ing easily.

codrus (Forum Supporter)
codrus (Forum Supporter) PowerDork
10/9/23 12:41 p.m.
iansane said:
codrus (Forum Supporter) said:
Pete. (l33t FS) said:

And all power upgrades involve turbocharging.

And with turbocharging, 4 digit power numbers are apparently not too hard to attain. 

 

From what I understand unless you convert to port injection or go with a 10k ecu, you're not turbo'ing easily.

Yeah, it's not cheap.  I know of a V10 R8 making 1200+ at the wheels with aftermarket turbos (friend of a friend), but there are many, many cubic dollars in that car.

 

mr2peak
mr2peak Dork
10/9/23 1:17 p.m.

I'm trying to avoid extra power adders. It's not a crazy goal, an LS with a cam would do it. But I wanna do it in style. I do wish the S85 was lighter. It's definitely cheaper than the F136 route 

paddygarcia
paddygarcia HalfDork
10/9/23 1:41 p.m.
VolvoHeretic said:

Build your own boxer flat 8 or better yet flat 12 out of two vertically stacked Subarus connected together with chain drives. smiley

Why stop at a flat-8 when you could have a flat-16?

British Racing Motors (BRM) H16 | Autos y motocicletas, Motores, Coches y  motocicletas

But we're getting far afield. Best I can tell, just like Porsche, BRM couldn't get them to run well with a flat-plane crank either.

Yorkshire Ferret: The BRM H16 engine – part 4: The quest for reliability  and conclusions

codrus (Forum Supporter)
codrus (Forum Supporter) PowerDork
10/9/23 2:08 p.m.
mr2peak said:

I'm trying to avoid extra power adders. It's not a crazy goal, an LS with a cam would do it. But I wanna do it in style. I do wish the S85 was lighter. It's definitely cheaper than the F136 route 

How about an S65?

 

Appleseed
Appleseed MegaDork
10/9/23 3:00 p.m.
mr2peak said:

I'm trying to avoid extra power adders. It's not a crazy goal, an LS with a cam would do it. But I wanna do it in style. I do wish the S85 was lighter. It's definitely cheaper than the F136 route 

I still maintain that an LS with 180 deg. headers is the answer. They sound exotic. If you never pop the hood, they'll be guessing for years.

mr2peak
mr2peak Dork
10/10/23 4:34 a.m.

An LS with 180 headers just tricks other people. I'd be sitting there knowing it's an LS. It is the most accessible way to get the sound. Maybe I should just buy a Tesla and play V8 noises through the speakers? haha

S65, would love a P65. A few people have tried to make P65 clones, but I'm not sure anyone has been successful. I think you'd exceed Ferrari engine cost building one. For the cost of an S65 I could build a monster 3UZ and those are a whole lot more plentiful.

So. Back to LT6 or F136 as actual options.

The more I learn about the Voodoo, the more I think it's a bad idea. Even Ford stepped back on that one.

Laserface
Laserface New Reader
10/10/23 5:31 a.m.

What makes the 3UZ an option? I fail to see how it is any more special than an LS. Its still crossplane, and seems to be outclassed by the LS in every category.

 

Per the thread title, "Accessible Flat Plane Crank V8s", seems the S65 fits. As you pointed out, they're not cheap, but they're plentiful used and can be had as crate motors.

 

Personally, I'd rather dump the money in keeping it rotary. It doesn't get much more special than that.

mr2peak
mr2peak Dork
10/10/23 6:12 a.m.

3UZ is just as much a flat plane crank as an S65 is. But it is true, I would just be trying to re-create what the S65 already is with a UZ build.

The rotary is very special. There are very few things that could offset removing it. That's why we are talking about the most special and race-bred versions of V8s

Laserface
Laserface New Reader
10/10/23 6:41 a.m.

I misunderstood and thought the S65 was flat plane. I see now its not, but the P65 derivative is.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
10/10/23 7:43 a.m.
mr2peak said:

3UZ is just as much a flat plane crank as an S65 is. But it is true, I would just be trying to re-create what the S65 already is with a UZ build.

The rotary is very special. There are very few things that could offset removing it. That's why we are talking about the most special and race-bred versions of V8s

It does not really matter IMO, I have not driven a piston engine that had the same feel as a rotary.  They don't accelerate, they just have all this rotating mass and internal friction that they overcome with sheer power and the driving feel is just numb.

 

I like to point out that my entire rotating assembly - eccentric shaft, rotors, counterweights, flywheel, and clutch - weighs less than most V8 crankshafts.

Put large independent throttles on one with aggressive porting and you can blip the throttle to redline with just a tap of the pedal.

wvumtnbkr
wvumtnbkr PowerDork
10/10/23 8:16 a.m.

20b?

matthewmcl
matthewmcl Dork
10/10/23 8:32 a.m.

So how close can an LS be? A V8 done in twin VW 4 cyl form has been mentioned, and a 4.8 LS is already a shorter stroke than the VW. The vibration problem goes down as piston weight goes down and rod ratio goes up, yes? If 2.4 is pushing the limits on a 4 with no balance shafts, can you get there throwing money at pistons to get them lighter weight? How much weight can be saved out if a stock 4.8 piston, percentage wise? If crank and cam are not enough to make it work, can crank,  cam, and pistons be enough?

mr2peak
mr2peak Dork
10/10/23 8:57 a.m.

And we come full circle.

If 20b prices stay the same, sure, it's less of a leap. There aren't many 20bs sitting around anymore, it's a larger project than most people realize, and it's 1/3rd more of everything else.

I'd be after 4 rotor n/a power. Out of the 3 different 4 rotor cars I've seen in person this year, only one of them was running right. There aren't many people who can get them going and keep them going. This would exceed anything you can reasonably call a budget.

I'm sure we will see many more billet plates being used for 2 rotor builds.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
10/10/23 1:09 p.m.

In reply to mr2peak :

A lot of tuners only care about WOT and maybe idle, drivability is not given much concern.  It's also the most time consuming part of a tune by far.

Keith Tanner
Keith Tanner MegaDork
10/10/23 1:18 p.m.
mr2peak said:

But listen to this.. Cosworth DFV, flat plane crank V8 goodness.

https://www.youtube.com/watch?v=Jzbn3yrkLnk

Not goodness. Greatness.

Note that when JWR tried to make the DFV work in an endurance car, they found the vibrations caused all sorts of failures after a few hours. They managed to win Le Mans with one that had 2000 rpm cut off the redline.

NOHOME
NOHOME MegaDork
10/10/23 1:40 p.m.

Remind me why we like flat plane crank V8 engines? 

Keith Tanner
Keith Tanner MegaDork
10/10/23 1:43 p.m.

In reply to NOHOME :

Because they sound like two four cylinder cars racing each other so it's like the Fast and Furious :)

Streetwiseguy
Streetwiseguy MegaDork
10/10/23 1:45 p.m.

Two things:  

It's nice that some people have even worse ideas than I do.

Since Frenchy isn't here, why not install an 800 horse stock Jag v12?

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
10/10/23 6:37 p.m.
NOHOME said:

Remind me why we like flat plane crank V8 engines? 

Not sure?  

I mean, there is the sound, but you only really get the proper Sound with an engine in the 3 liter range like the DFVs and the Ferrari "Dino" V8s.  That said, there is something special about having an engine that does not sound like the neighborhood recycling enthusiast's Silverado.

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