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 Fri Oct 20, 2017 6:29 pm

Underbody braces, turbos and more!

All times are UTC - 5 hours




Post new topic Reply to topic  [ 6 posts ] 
Author Message
PostPosted: Sun Sep 02, 2007 9:34 pm 
Offline
User avatar

Joined: Sun May 14, 2006 8:46 pm
Posts: 947
Location: Cambridge, OH
To start off with I'll tell you what I already have.

3Tech cam 226/395
Head planed .020 and ported
Weber 32/36 carb
3Tech under drive pulley

Should i go with flat-top or dish-top pistons? Also, would 75mm pistons be too much? This will be a street driven engine, so I want to keep it on pump gas.

Thanks in advance.

_________________
1988 Chevrolet Sprint (Forsa clone) 3Tech cam and underdrive pulley, MSD 8mm wireset, shaved head, Weber 32/36 carb, Honda short shifter, KYB Gr2 suspension, Summit tach and gauges, Pilot steering wheel, NEW! Summit Multi-spark CDI
Project Page
1993 Geo Metro Only mods so far are a Honda short shifter, Glowshift tach and a 3a Racing ricer muffler (freebie)
Image Image


Top
 Profile  
 
 Post subject:
PostPosted: Thu Sep 06, 2007 7:28 pm 
Offline
User avatar

Joined: Sun May 14, 2006 8:46 pm
Posts: 947
Location: Cambridge, OH
Any info will help...........

_________________
1988 Chevrolet Sprint (Forsa clone) 3Tech cam and underdrive pulley, MSD 8mm wireset, shaved head, Weber 32/36 carb, Honda short shifter, KYB Gr2 suspension, Summit tach and gauges, Pilot steering wheel, NEW! Summit Multi-spark CDI
Project Page
1993 Geo Metro Only mods so far are a Honda short shifter, Glowshift tach and a 3a Racing ricer muffler (freebie)
Image Image


Top
 Profile  
 
 Post subject:
PostPosted: Thu Sep 06, 2007 10:09 pm 
Offline
User avatar

Joined: Mon Jun 18, 2007 1:35 pm
Posts: 2433
Location: Regina, SK
Dish top will lower the compression ratio of the engine. But should result in a more efficient engine due to the cupping effect of the piston against the flame front of the expanding and now burning gas.

Basically, take a look at what the pistons do to a stock engine for compression. See what your mods do for compression.

eg. stock pistons(S): 9.5:1, dished pistons(D): 8.5:1, mods to head(M): 10.5:1

S - D = Difference + M = (new compression ratio)

You still end up with a 9.5:1 compression ratio. You take the difference from the dished piston and the stock piston and take it away from the head mods to get your new compression ratio.

Simple math is always best. So your high end for pump premium is about 11:1.


Top
 Profile  
 
 Post subject:
PostPosted: Thu Sep 06, 2007 11:30 pm 
Offline
User avatar

Joined: Sun May 14, 2006 8:46 pm
Posts: 947
Location: Cambridge, OH
So from this info, I tend to lean towards dish-top. I think I can dig up some reasonably priced 75mm dish-tops.

_________________
1988 Chevrolet Sprint (Forsa clone) 3Tech cam and underdrive pulley, MSD 8mm wireset, shaved head, Weber 32/36 carb, Honda short shifter, KYB Gr2 suspension, Summit tach and gauges, Pilot steering wheel, NEW! Summit Multi-spark CDI
Project Page
1993 Geo Metro Only mods so far are a Honda short shifter, Glowshift tach and a 3a Racing ricer muffler (freebie)
Image Image


Top
 Profile  
 
 Post subject:
PostPosted: Thu Sep 06, 2007 11:34 pm 
Offline
Moderator
Moderator
User avatar

Joined: Sun Feb 23, 2003 4:16 am
Posts: 8033
Location: Ontario, Canada
You should already have flat top pistons, and that is what I would stick with.
In a Mk1, .020" not alot of material to remove from the head, and if you are looking for performance, you could easily take .040", or more, up to about .100", if I recall.
GT pistons, and rods would be a nice addition, and valve clearance should not be a problem.

_________________
Contact 3tech: g10pro@rocketmail.com


Top
 Profile  
 
 Post subject:
PostPosted: Fri Sep 07, 2007 9:46 am 
Offline
User avatar

Joined: Sun May 14, 2006 8:46 pm
Posts: 947
Location: Cambridge, OH
If i can get some reasonably priced rods, I would like to use those. I found a set of decent priced 75mm flat-top pistons that i think I'll use.

_________________
1988 Chevrolet Sprint (Forsa clone) 3Tech cam and underdrive pulley, MSD 8mm wireset, shaved head, Weber 32/36 carb, Honda short shifter, KYB Gr2 suspension, Summit tach and gauges, Pilot steering wheel, NEW! Summit Multi-spark CDI
Project Page
1993 Geo Metro Only mods so far are a Honda short shifter, Glowshift tach and a 3a Racing ricer muffler (freebie)
Image Image


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 6 posts ] 

All times are UTC - 5 hours


Who is online

Users browsing this forum: Yahoo [Bot] 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