TeamSwift

Home of the Suzuki mini-compacts ! Your Home for all things Suzuki Swift, Geo Metro, Holden Barina, Chevy Sprint, Pontiac Firefly, and Suzuki Cultus. TeamSwift is a technical performance oriented community!
It is currently Thu Sep 21, 2017 11:52 pm

Underbody braces, turbos and more!

All times are UTC - 5 hours




Post new topic Reply to topic  [ 57 posts ]  Go to page Previous  1, 2, 3
Author Message
 Post subject:
PostPosted: Sun Jun 18, 2006 5:22 am 
Offline
User avatar

Joined: Sat Jun 03, 2006 11:54 pm
Posts: 673
Location: Illinois
:? I stumbled on to this while looking at turbododge.com.
http://metricmechanic.com/pg27.htm
http://metricmechanic.com/pg28.htm
It's kind of like singh's grooves, but on the intake valve. On page 28, it's hard to see, but look closely at the pic's of their combustion chambers. It's like they put radial steps around the intake valve on the chamber floor as well as on the valve to better mix the air & fuel. I don't know, I just thought I'd share my find....


Top
 Profile  
 
 Post subject:
PostPosted: Mon Jun 26, 2006 7:53 am 
Offline
User avatar

Joined: Sun Aug 28, 2005 6:24 pm
Posts: 61
Location: Deer Lodge, Montana
Here's an update on my grooved 3 cylinder Metro;

http://jeremiahsviolins.com/grooves.htm

I modified the grooves. This car is seriously quick for being a N/A 3 cylinder setup for fuel economy, now.

Jeremiah

_________________
55 MPG daily driver


Top
 Profile  
 
 Post subject:
PostPosted: Wed Jun 28, 2006 9:23 pm 
Offline

Joined: Sat Oct 11, 2003 7:44 am
Posts: 451
Location: near Burbank, Calif
Congratulations on the nice looking combustion chamber modifications.

Just one question (for now).
Its my understanding the igition advance in any piston ic engine is essentially the time it takes for the flame front to travel across the combustion chamber completely by the time the piston reaches tdc.

If the Singh grooves reduces that time due to better flame propagation would not it be best to reduce the ignition advance so that complete burn does NOT occur BEFORE tdc?
Besides increased efficiency you might eliminate the pinging on lower octane fuel?

Just wondered if you have tried the above and what results you might have encountered from delaying ignition advance.

Keep up the good work.
Pres


Top
 Profile  
 
 Post subject:
PostPosted: Thu Jun 29, 2006 8:48 am 
Offline
User avatar

Joined: Sun Aug 28, 2005 6:24 pm
Posts: 61
Location: Deer Lodge, Montana
Yes, I've experimented a little with ignition timing. Too much advance and the pinging gets too bad; too little advance and the torque drops off... I may experiment a bit more to find the best power level.

Jeremiah

_________________
55 MPG daily driver


Top
 Profile  
 
 Post subject:
PostPosted: Tue Aug 15, 2006 11:07 am 
Offline

Joined: Fri Jun 03, 2005 4:36 pm
Posts: 493
Location: Roscommon, MI
Sorry for digging (I've been busy for the past couple months), I just wanted to thank you jsenner for posting the results. It sounds like the grooves really do help indeed!

With regards to pinging, although I know this is a completely different car and engine and setup (turbo), I've noticed with my Eclipse that I can lean the car out while leaving timing stock and detonation will not increase. I've actually leaned the car out too much for the octane of the fuel, and while power dropped, there was zero knock and timing didn't get pulled at all.

Which just further leads me to believe that improper timing is the major cause of detonation, and that tuning should be accomplished by first getting the AFR where you want it, and adjusting the timing accordingly. Both AFR and timing will affect the "timing" of the flame front, but richening the car up to run X amount of timing is like doing things ass-backwards. Timing is simply a necessary evil due to the inefficiencies of the engine.

By the way, that tuning strategy has worked GREAT with my Eclipse; just this last Friday I ran a new personal best of 11.91 @ 115. :D


Top
 Profile  
 
PostPosted: Thu Sep 14, 2006 10:06 am 
Offline

Joined: Fri Mar 03, 2006 11:37 pm
Posts: 4
Location: Minneapolis Minnesota
You might recall some post I made earlier about this car http://cleverlever99.blogspot.com/ (note links)

I helped some guys straighten out the motor cycle carbs they put on a 3 cylinder metro they had put in a lawn tractor that they take to Threshing shows. Was pretty impressed with the engine.

I may make a serious effort to put a variable event valve mechanism on a 3 cylinder.

I already have a 3 cylinder Corvair that I poured a small fortune into in the early 1980's.

What I need is a SOHC engine with the valves all parallel or very close to parallel. My goal is to make a variable valve event mechanism that is much cheaper than the VTEC system.

The real goal is to demonstrate that there is no practical advantage to having more than 2 valves per cylinder in an engine with variable size valve events. Upper RPM isn't a problem because my mechanism is semi desmodromic.

Could you guys help me out with some detail schematics or photos of the 3 cylinder head. I would also like to know a little detail about the differences of the engine in the high MPG version.

Are any of you near Minneapolis Minnesota?

Thanks for considering my request for information

Cob


Top
 Profile  
 
 Post subject:
PostPosted: Thu Sep 14, 2006 3:08 pm 
Offline
abby normal
User avatar

Joined: Mon Mar 13, 2006 10:59 pm
Posts: 1835
Location: NorCal, USA
If you want a 3 cylinder head, post your request in the items wanted section, a scrap head should help your project. :)

http://www.teamswift.net/viewforum.php?f=35

Also, this is an interesting statement:

cleverlever wrote:
The real goal is to demonstrate that there is no practical advantage to having more than 2 valves per cylinder in an engine with variable size valve events. Upper RPM isn't a problem because my mechanism is semi desmodromic.


Please keep the rest of us updated on your project. :)


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 57 posts ]  Go to page Previous  1, 2, 3

All times are UTC - 5 hours


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group