Home 
Home Search search Menu menu Not logged in - Login | Register
> Jensen Healey & Jensen GT Tech > Engine & Transmission > Dellorto/Weber upgrade is a carburetorism

 Moderated by: Greg Fletcher
New Topic Reply Printer Friendly
Dellorto/Weber upgrade is a carburetorism  Rating:  Rating
AuthorPost
 Posted: 06-02-2006 03:44 am
  PM Quote Reply
1st Post
OverdriveGear
Member


Joined: 06-01-2005
Location: Gainesville, Georgia USA
Posts: 17
Status: 
Offline
Here is an interesting website about customizing an ECU for any car (and obviously this post is in respect to JH).  http://www.megasquirt.info/  This company offers you boards and processors to basicly make electronic fuel injection (among other things) from the ground up.  It's really quite ingenious.  I go to the Georgia Institute of Technology (Ramblin Wreck type) and the SAE racing club uses this system on their BMW 325e race car and it is absolutely amazing.  Take a look at this site and see what you all think.  The weber/dellorto manifold is designed to accept port fuel injectors.  Once you had the board, processor, and software to tune it; all you need from there is the easy stuff:  the mechanical.  This would be a throttle body w/ MAP sensor, fuel injectors, rail, and camshaft position sensor.
I suppose the most difficult parts of the system would be to fashion an airbox and figure out a way to put on a honda/mitsubishi/toyota cam position sensor.
If you aren't afraid of some computer science (code written in C) and mechanical engineering, this would be really nice.  It sure beats the hell out of ANY carburetors and throttle body injection (which isnt a whole lot better).

Back To Top PM Quote Reply  

 Posted: 06-02-2006 07:26 am
  PM Quote Reply
2nd Post
Jensen Healey
Super Moderator


Joined: 03-11-2005
Location: San Anselmo, California USA
Posts: 976
Status: 
Offline
Let's not start insulting carburetors. Some of us here like old cars and the parts that came with them. When you finish your project you can compare your dyno plots to Yellow Dog's and do some bench racing. http://jhppg.com/gallery/album62

I have seen the Megasquirt website. Pretty cool stuff. You'll have a great time building the system. Certainly modern technology "beats the hell" out of 30 year old carburetors and a Honda Civic went 195 mph at Bonneville but I wouldn't trade my Jensen or the Dellortos.

I think Jensini dyno'd at 240 hp with port on port injection and Elgin cams.

We're all having fun!

Back To Top PM Quote Reply

 Posted: 06-02-2006 05:04 pm
  PM Quote Reply
3rd Post
Greg Fletcher
Administrator


Joined: 03-11-2005
Location: Lake Nacimiento, California USA
Posts: 421
Status: 
Offline
What, computer boards on our beloved Jensens? Heresy I say! I actually prefer to tinker with my mechanical JH to get away from all the computer crap and endless problems I have to deal with all week long. That's no therapy, leave the Frankenstein stuff for the Hondas- there are endless candidates other than a JH available for that.

Back To Top PM Quote Reply  

 Posted: 06-02-2006 06:02 pm
  PM Quote Reply
4th Post
Jensen Healey
Super Moderator


Joined: 03-11-2005
Location: San Anselmo, California USA
Posts: 976
Status: 
Offline
That's my take on it but to each his own. As long as your having fun it's the right thing to do. Perhaps some others on the board with the electronics bug would like to continue this thread.

I just want a supercharger. He He

Kurt

(What ever happened to the JH Camper Abortion?)

Back To Top PM Quote Reply

 Posted: 06-02-2006 06:53 pm
  PM Quote Reply
5th Post
Jim Sohl
Member
 

Joined: 03-26-2005
Location: Chandler, Arizona USA
Posts: 39
Status: 
Offline
Without endorsing either camp, I view 'dell's and all other carbureted engines as a chemically powered, very high gain, analogue amplifier.  A very tiny torque at the throttle shaft becomes a very large torque at the rotating, crankshaft.  As with any hi-gain amplifier, a very small non-linearity when 'processing' the input signal can give rise to a much larger, unwanted result.  'Same for noise.  Given that what 'dell's and most other carburetors do, try to control thousands of psi above a piston using a tiny vacuum signal, it is to be expected that the interactions between the various 'circuits' within the carburetor will at times be counter-intuitive.  In reality, what is happening is that the effect of an alteration to one circuit might be quite small or of a stand-alone nature, while an alteration to another circuit might be quite large or highly interactive with other circuits.  Which is which?  Obviously, if I knew, I would write about it.  It is just interesting to consider that tiny changes in any of the several vacuum circuits can lead to steep, exciting response curves, or, popping, coughing, and you know the rest.  It seems then natural that the passing of air through internally curved tubes creates 'signals.' Have fun, just my one cent's worth.
Jim


Back To Top PM Quote Reply  

 Posted: 06-04-2006 06:12 pm
  PM Quote Reply
6th Post
OverdriveGear
Member


Joined: 06-01-2005
Location: Gainesville, Georgia USA
Posts: 17
Status: 
Offline
Make no mistake about it, performance carburetors get the job done sure enough.  That's quite apparent in Yellow Dog's numbers.
I'm looking at this from an efficiency point of view.  If you can deliver similar power, lower emissions and lower consumption why not do it?
I understand the argument that Greg puts on the table and I can assure you, nobody likes to deal with malfunctioning electronics.  But then again, carburetors have the same type of issues:  Stuck floats, clogged jets, rebuilds, etc.  Over a century-old technology!  The system is way to dependent on the environment and karma in my opinion.
It's just a matter of what you like to tinker with, just as Greg put it.
I'm obsessed with efficency, new designs, and technology; I guess this is a good thing for ya'll in light of the fact that I will be designing your new cars in a couple years.  I will go the electronic route.
Happy tinkering!

Back To Top PM Quote Reply

 Posted: 06-04-2006 07:01 pm
  PM Quote Reply
7th Post
upstate mike
Member
 

Joined: 09-27-2005
Location: New York USA
Posts: 12
Status: 
Offline
Hi, if your seriously looking at fi check out http://www.twminduction.com/Home/Home-FR.html

I've been looking at this for awhile and figure it to cost about the same as 45 mm dellortos. I've been working more and more with fi and I've come to like it .

                                                        Mike K

Back To Top PM Quote Reply  

 Posted: 06-05-2006 07:04 pm
  PM Quote Reply
8th Post
pc
Member
 

Joined: 03-16-2005
Location:  
Posts: 58
Status: 
Offline
Keep us informed as you go!  Sounds like fun.
 
I can never get the thought of doing an EFI out of my head, no matter how hard I try.  So far I’ve managed to keep it on the way back burner but it could rear its ugly head at any moment.
 
I originally looked at stuff like TWM’s throttle bodies but seeing the factory Esprit EFI manifold was an epiphany.  I’m sure you can find them used for a whole lot less than new throttle bodies, they have nice long individual runs for better low/mid torque, they already have port injector bosses built in so there’s no messing with modifying a carb manifold and they have a single throttle body inlet – no synchronizing (you can do this with Del or Strom manifolds too if you build an inlet plenum).
 
Next question; is the electrical system up to running a high pressure fuel pump plus injectors plus everything else at idle with the lights on?  If not, there’s another project.  And while we’re at it might as well throw in a multidimensional mapped crank triggered ignition and…..
 
 
PC.

Back To Top PM Quote Reply

 Posted: 06-07-2006 11:29 pm
  PM Quote Reply
9th Post
edward_davis
Member


Joined: 07-06-2005
Location: Eugene, Oregon USA
Posts: 162
Status: 
Offline
I for one would like to hear about an EFI conversion for the JH.  I love carburetors, but as time passes there are more tools for fixing EFI than for carbs.  Not sure if I would ever change my JH to EFI, but if I ever do a project with some vintage Detroit steel, I would probably go the EFI route.  Then again, there's something elegant about a four-barrel carb....

Definitely interested to see how it goes, though.

Back To Top PM Quote Reply  

Current time is 05:04 pm  
> Jensen Healey & Jensen GT Tech > Engine & Transmission > Dellorto/Weber upgrade is a carburetorism Top




UltraBB 1.172 Copyright © 2007-2011 Data 1 Systems