Home  |  Forums  |  914 Info  |  Blogs
 
914World.com - The fastest growing online 914 community!
 
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG. This site is not affiliated with Porsche in any way.
Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners.
 

Welcome Guest ( Log In | Register )

6 Pages V  1 2 3 > »   
Reply to this topicStart new topic
> Anyone tried an aircooled Flat 8, With two fours?
r_towle
post Jan 28 2005, 12:49 PM
Post #1


Custom Member
***************

Group: Members
Posts: 24,658
Joined: 9-January 03
From: Taxachusetts
Member No.: 124
Region Association: North East States



Has anyone tried to build a flat 8 with two type 4 motors?

Theoretical questions.
Assumptions
2 motors each producing 100 HP and 100 Lb/ft of Torque

The motors are end to end, front to rear.
The cranks are fastened together either bolted or welded.

1) Would you get 200hp and 200 lb/ft or torque? or is there some multiplier...seems like you would produce more torque..

2) could it be done with a single ignition system available for sale off the shelf.

3) could you do it without two distributors? crank fired ignition system..I am thinking that there could be a wheel placed in between the motors to give you something to time from.

4) I am assuming either a nice FI system, or four carbs.

Has anyone done this?
I would like to see some articles or web pages if this has been done in the aircooled world...

Thanx in advance
Rich
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Mueller
post Jan 28 2005, 01:03 PM
Post #2


914 Freak!
***************

Group: Members
Posts: 17,150
Joined: 4-January 03
From: Antioch, CA
Member No.: 87
Region Association: None



yep, a few have been done........I know I've posted pictures as a well as a few others....

for a 914 application, the motor wouldn't fit unless you moved the assembly back a few inches...even without the cooling fan, I don't think it would fit in the stock location

for the cost/time/ it would take to make one, there are a dozen better engine choices unless one just wants to do it for the novelty of doing it....

since it's already been done a few times, there is no novelty in it....nothing ground breaking....kinda boring (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
sanman
post Jan 28 2005, 01:05 PM
Post #3


Leaving California
**

Group: Members
Posts: 341
Joined: 17-June 04
From: Houston, TX
Member No.: 2,219
Region Association: None



I thought of it but I think it would be


too long to fit in a 914 and
you would loose 1 fan for cooling

now on the other hand If some one made a 6 case that took t4 or t1 P/C,rods, and heads it may work
but that just my thoughts

forget it! you would need a 6 crank, and cam
Just get a chevy v8 or a porsche 6 and be done (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
r_towle
post Jan 28 2005, 01:05 PM
Post #4


Custom Member
***************

Group: Members
Posts: 24,658
Joined: 9-January 03
From: Taxachusetts
Member No.: 124
Region Association: North East States



i was hoping you would answer...you always think outside the box...

So what about the torque numbers...is it simply double???

It just seems that is would be multiplied somehow..
and where would i find some pics....
Rich
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
andys
post Jan 28 2005, 01:08 PM
Post #5


Advanced Member
****

Group: Members
Posts: 2,165
Joined: 21-May 03
From: Valencia, CA
Member No.: 721
Region Association: None



It's been done both ways. I saw a pic years ago of a specially cast block for 8 cylinders. Also, the Fittipaldi brothers raced a Bug in Brazil where they coupled two motors together similar to what you describe, in a mid-engined configuration. They were apparently very successful with this car. Interesting way that they ducted air to cool the motors: they slanted the windshield back into the driver compatment. Air was ducted over the driver, then down to the two motors.

Andy
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
r_towle
post Jan 28 2005, 01:14 PM
Post #6


Custom Member
***************

Group: Members
Posts: 24,658
Joined: 9-January 03
From: Taxachusetts
Member No.: 124
Region Association: North East States



honestly cooling seems like a simple part of it ...
A custom horizontal system would work.

What are the numbers...in theory???

Rich
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
eeyore
post Jan 28 2005, 01:22 PM
Post #7


Senior Member
***

Group: Members
Posts: 889
Joined: 8-January 04
From: meridian, id
Member No.: 1,533
Region Association: None



Double displacement does not usually equal double torque or horsepower. Not sure why.

In WWII, Pratt & Whitney took 2 14 cylinder radials and joined them onto a single case, resulting in a 28 cylinder that made 50% more HP. In the '90s Honda simply upped the size of a 600cc four to 900cc and got 20% more power (50% more displacement). Granted, the stock T4 is restricted, so using a RAT 2270 as a basis, maybe 250 HP would come from a T4x2. Just guessing.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
nebreitling
post Jan 28 2005, 01:36 PM
Post #8


Member Emeritus
****

Group: Members
Posts: 3,314
Joined: 26-March 03
From: San Francisco
Member No.: 478



i would think that you could never get double the power. maybe 150%, 175% if lucky.

entropy's a bitch.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Jake Raby
post Jan 28 2005, 01:59 PM
Post #9


Engine Surgeon
*****

Group: Members
Posts: 9,398
Joined: 31-August 03
From: Lost
Member No.: 1,095
Region Association: South East States



Already have a print in with moldex on the crank.
Already dissected 4 engine cases to find the best mating points.... Just need time
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
machina
post Jan 28 2005, 02:19 PM
Post #10


Advanced Member
****

Group: Benefactors
Posts: 2,030
Joined: 21-June 03
From: Miami Beach, FL
Member No.: 848



asked the same question a while back....

here's what I got.


Attached image(s)
Attached Image
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
eeyore
post Jan 28 2005, 02:23 PM
Post #11


Senior Member
***

Group: Members
Posts: 889
Joined: 8-January 04
From: meridian, id
Member No.: 1,533
Region Association: None



Hans Dahlbeck? Isn't he the brain donor in 'Young Frankenstein'? Seems fitting.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
machina
post Jan 28 2005, 02:54 PM
Post #12


Advanced Member
****

Group: Benefactors
Posts: 2,030
Joined: 21-June 03
From: Miami Beach, FL
Member No.: 848



QUOTE (Cloudbuster @ Jan 28 2005, 03:23 PM)
Hans Dahlbeck? Isn't he the brain donor in 'Young Frankenstein'? Seems fitting.

No, I think you mean Mr. Abby Normal (IMG:http://www.914world.com/bbs2/html/emoticons/wacko.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
BigD9146gt
post Jan 28 2005, 03:33 PM
Post #13


OCD member
**

Group: Members
Posts: 376
Joined: 24-January 05
From: Sydney, Australia
Member No.: 3,502
Region Association: Australia and New Zealand



You'd be better off starting with two early 2.0 911 engines. By cutting the center two cylinders out of one case and placing them in the center of the other case, you add two cyclinders to an already superior design. Having small cylinders to begine with (width wise) helps keep the lenth of the motor down too. Then a Scat crank and some custom cams, you have the better overhead cam design, better cooling, and better head flow. Plus with the early cases, they're all aluminum like the 914 case, making welding them together easier... and stronger.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Jake Raby
post Jan 28 2005, 03:47 PM
Post #14


Engine Surgeon
*****

Group: Members
Posts: 9,398
Joined: 31-August 03
From: Lost
Member No.: 1,095
Region Association: South East States



Nah.... Can't make a statement with a 911 engine!

Plus, they cost too damn much to play with at this level..

I'm using 964 heads though..

Engine will go in a mid engine 1961 VW Single cab truck, under the bed.....
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
r_towle
post Jan 28 2005, 05:15 PM
Post #15


Custom Member
***************

Group: Members
Posts: 24,658
Joined: 9-January 03
From: Taxachusetts
Member No.: 124
Region Association: North East States



QUOTE (Jake Raby @ Jan 28 2005, 01:47 PM)
Nah.... Can't make a statement with a 911 engine!

Plus, they cost too damn much to play with at this level..

I'm using 964 heads though..

Engine will go in a mid engine 1961 VW Single cab truck, under the bed.....

I had a funny feeling you would be looking at this at some point in your life...

I may try to get this done, just to see if it can be done smoothly, easily, and if it has benefit.

I am thinking why not use the heavy strong crank and push rods, lighter cylinders and pistons, and turbocharge the whole thing....
It would be a cool way to use parts that may be inferior for a hopped up T4 motor, but rugged enough for a T8 motor.

Rich
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Mueller
post Jan 28 2005, 05:29 PM
Post #16


914 Freak!
***************

Group: Members
Posts: 17,150
Joined: 4-January 03
From: Antioch, CA
Member No.: 87
Region Association: None



QUOTE
I may try to get this done, just to see if it can be done smoothly, easily, and if it has benefit.


if it was even one of those choices above, you'd see more than a few running around (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

it'll have all of the same problems or issues a /4 has, the only benifit is if you are trying to reach a certain hp level...if stock /4 has 100 and you want 175, then the /8 should be able to give you 175 horsepower easier than the /4

I'm betting that hp per liter would be the same and if anything, the /8 would be under more stress if you try to push it too hard.....
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
jwalters
post Jan 28 2005, 06:06 PM
Post #17


Sooo Close.......
***

Group: Members
Posts: 1,677
Joined: 14-May 04
From: Huntsville, AL
Member No.: 2,068
Region Association: Europe



(IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif) An aviation supplier / builder / design company called "Able Experimental" has done this with full success--albeit a T1 engine---Developed over 210 HP and almost 280 ftlb of TQ---key was 90.5mm P/C and a 80mm stroke---it was made for experimental aircraft--the same company makes the altimizer carburetor--this is an injected carburetor which automatically compensates the mixture for changes in air density--very popular carb in aviation.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Jake Raby
post Jan 28 2005, 06:10 PM
Post #18


Engine Surgeon
*****

Group: Members
Posts: 9,398
Joined: 31-August 03
From: Lost
Member No.: 1,095
Region Association: South East States



It won't cost a whole lot for me to do it, other than the crank and heads... The rest of it I have gobs of....


Its all in time and putting the imagination to work..

Its no fun if you don't push the envelope.... I'm sure I'd learn something beneficial to my other normal engines from doing it!
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Mueller
post Jan 28 2005, 06:13 PM
Post #19


914 Freak!
***************

Group: Members
Posts: 17,150
Joined: 4-January 03
From: Antioch, CA
Member No.: 87
Region Association: None



QUOTE (jwalters @ Jan 28 2005, 05:06 PM)
(IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif) An aviation supplier / builder / design company called "Able Experimental" has done this with full success--albeit a T1 engine---Developed over 210 HP and almost 280 ftlb of TQ---key was 90.5mm P/C and a 80mm stroke---it was made for experimental aircraft--the same company makes the altimizer carburetor--this is an injected carburetor which automatically compensates the mixture for changes in air density--very popular carb in aviation.

considering thier 100 hp /4 motors cost $6000, I'd hate to see the price of that /8 motor (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

they do have some cool stuff...
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
jwalters
post Jan 28 2005, 06:28 PM
Post #20


Sooo Close.......
***

Group: Members
Posts: 1,677
Joined: 14-May 04
From: Huntsville, AL
Member No.: 2,068
Region Association: Europe



(IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif) Yea they do---imagine there is allot of machining and welding up a crank and cam and MAGNESIUM case ( Can you say,,sparkler??) Those engines require even more prep than or = to Mr. Raby does to his to make them a viable high power aero engine If the balances of the entire assembly are off more than .10 inches per second the crank will grenade itself--even at the max rpm of 3600 these engines are rated for--and bye bye propellor--the cranks are rough prepped by CB's--they actually forge a crank just for this purpose---kool stuff indeed

Don't know ifn I would ever get into something like that, manufacturing wise--the liability factor is an ass pucker!!!

But it would be kool to see Jake the man do it---400+HP anybody???

I myself have a really doable engine make-up I am dreaming of---it uses the stock bottom end--but the cyl and up is off the shelf from a manufacturer that has been in business since 1908--

Not going to reveal it yet,,need to get measurements and geometric values looked at--plus I don't want to get sand bagged just yet! (IMG:http://www.914world.com/bbs2/html/emoticons/laugh.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/hide.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post

6 Pages V  1 2 3 > » 
Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



- Lo-Fi Version Time is now: 25th December 2024 - 07:34 AM