Flat Plane Cranks

Shooting the bull on historic motor racing and motorsport history.
SPman
Semi-Pro Racer
Posts: 232
Joined: Mon Jan 28, 2013 3:00 am
Location: Toodyay Western Australia

Flat Plane Cranks

Post by SPman »

This issue has been bugging me for years.

Did one of the guys racing Mustangs back in '66-67, re engine his car with a flat plane crank motor? I can't recall the exact meeting, but one of the Mustangs - white with stripes, I'm sure , had an engine that sounded decidedly different - more like a straight eight (think Bugatti-ish). It wasn't Fahey - could have been Coppins. The announcer said he was running a flat plane crank in his engine!
At the time, I thought "Oh yeah, that's interesting", but thought little more about it. When Yamaha put a flat plane crank in the R1, it re-awakened the niggle.

Anyone?
GD66
Semi-Pro Racer
Posts: 792
Joined: Thu May 26, 2011 8:11 am

Re: Flat Plane Cranks

Post by GD66 »

I'm sure Coppins was running an engine with a flat-plane crank at the Easter '68 Bay Park meeting where the lightweight Aussie minis guested. Sounded fabulous, and the howl exited through a big collector exhausting just in front of the left rear wheel. Also had Gurney Weslake heads fitted for that meeting as I hotfooted it to the pits to get a look under the bonnet at what the hell was making that wicked tone. Lucky me, I was flag marshalling for that meeting at the entry to the right hander, so also had full benefit of the cars (and bikes) on full song half way down the back straight. Later I recognised that the sound of the GT40 was the same, confirming my suspicions... :cool:
User avatar
Steve Holmes
World Champion
Posts: 12255
Joined: Thu Apr 07, 2011 6:25 am

Re: Flat Plane Cranks

Post by Steve Holmes »

Yes I'm sure GT40s had these cranks. They make a completely different sound once the revs come up. I thought they sounded almost like a big 4 cylinder.
Lurker
Weekend Warrior
Posts: 36
Joined: Wed Jan 11, 2012 10:55 pm

Re: Flat Plane Cranks

Post by Lurker »

I could be wrong but my understanding was that distinctive sound from GT40s was due to the cross over (nest of snakes) exhaust system. This was probably what the Mustang had. I think the first experience with flat plane cranks in NZ in a V8 (apart from the Cosworth DFV) was with the Repco Holden F5000 engines. However I am willing to be proven otherwise.
car mad
Weekend Warrior
Posts: 27
Joined: Wed Nov 02, 2011 7:56 am
Location: Invercargill

Re: Flat Plane Cranks

Post by car mad »

wheres Jac Mac when ya need him he,s bound to know
grelley
Weekend Warrior
Posts: 37
Joined: Sun Jun 12, 2011 3:52 am

Re: Flat Plane Cranks

Post by grelley »

The exhaust on the GT40s had the two centre cylinder exhaust pipes of one bank coupled to the the two outer cylinder exhaust pipes of the other bank just behind the engine in order to give better scavenging. This is probably what made them sound different. With a flat plane crank you could run a seperate exhaust system down each side of the engine. With a flat plane crank you virtually have two inlne four cylinder engines side by side.
User avatar
Chris Read
Journeyman Racer
Posts: 103
Joined: Wed Feb 29, 2012 8:59 pm
Location: Arrowtown, Central Otaaaaaaago

Re: Flat Plane Cranks

Post by Chris Read »

SPman wrote:This issue has been bugging me for years.

Did one of the guys racing Mustangs back in '66-67, re engine his car with a flat plane crank motor? I can't recall the exact meeting, but one of the Mustangs - white with stripes, I'm sure , had an engine that sounded decidedly different - more like a straight eight (think Bugatti-ish). It wasn't Fahey - could have been Coppins. The announcer said he was running a flat plane crank in his engine!
At the time, I thought "Oh yeah, that's interesting", but thought little more about it. When Yamaha put a flat plane crank in the R1, it re-awakened the niggle.

Anyone?

I remember a F5000 at Wigram over 30 yrs ago that had a flat plane crank...I was a different sound and it was new to me so I asked and was told why. For 10 points who was it? (Hint an Aussie). Chris Read, Arrowtown.
Carlo
Semi-Pro Racer
Posts: 371
Joined: Thu Jun 02, 2011 7:42 pm

Re: Flat Plane Cranks

Post by Carlo »

Chris Read wrote:I remember a F5000 at Wigram over 30 yrs ago that had a flat plane crank...I was a different sound and it was new to me so I asked and was told why. For 10 points who was it? (Hint an Aussie). Chris Read, Arrowtown.


John McCormack Elfin MR6
Lurker
Weekend Warrior
Posts: 36
Joined: Wed Jan 11, 2012 10:55 pm

Re: Flat Plane Cranks

Post by Lurker »

I think he had one in his Charger also
Habu
Semi-Pro Racer
Posts: 150
Joined: Tue Mar 13, 2012 8:18 pm

Re: Flat Plane Cranks

Post by Habu »

Anyone remember the little Nissan Sunny's that Terry Gladstone used to race in Sport Sedan series? Powered by Rover V8's - pretty sure they had flat plane cranks in them.
shellsport
Weekend Warrior
Posts: 47
Joined: Sat Sep 03, 2011 5:26 am

Re: Flat Plane Cranks

Post by shellsport »

That sounds feasible as a flat crank Olds was an option .
bigbanger
Journeyman Racer
Posts: 89
Joined: Tue Jul 26, 2011 7:39 am

Re: Flat Plane Cranks

Post by bigbanger »

Trevor Crowe had a flat plane crank in at least one of his many Olds V8 engines that he used his Starlet V8s.
bigbanger
Journeyman Racer
Posts: 89
Joined: Tue Jul 26, 2011 7:39 am

Re: Flat Plane Cranks

Post by bigbanger »

Carlo wrote:John McCormack Elfin MR6


Was that the Repco Holden or Repco Leyland V8? Both engines could be had in flat plane crank versions.
Habu
Semi-Pro Racer
Posts: 150
Joined: Tue Mar 13, 2012 8:18 pm

Re: Flat Plane Cranks

Post by Habu »

"Was that the Repco Holden or Repco Leyland V8? Both engines could be had in flat plane crank versions."

Wasnt the Leyland engine in the McLaren F5000 car that he built?
Dale Harvey
Semi-Pro Racer
Posts: 163
Joined: Sat Aug 27, 2011 5:55 am
Location: Marks Point. NSW. Australia

Re: Flat Plane Cranks

Post by Dale Harvey »

The MR6 was built for the Leyland engine. Later it was installed in a McLaren M23 (ex F1).
Dale.
928
Semi-Pro Racer
Posts: 393
Joined: Sun Nov 11, 2012 9:32 pm

Re: Flat Plane Cranks

Post by 928 »

friend of mine bought the red dawson mustang around 1970 I think. That had a true 180 degree header system fitted which was a PIA to remove, but it did sound nice. from memery the SBF would rip the centre mains out if run with a flat plane crank as did the rover V8s
Post Reply