Notices
944 Turbo and Turbo-S Forum 1982-1991
Sponsored by:
Sponsored by: Clore Automotive

Long block vs short block crankshaft question

Thread Tools
 
Search this Thread
 
Old 04-17-2005, 04:17 PM
  #1  
ehall
Addict
Lifetime Rennlist
Member
Thread Starter
 
ehall's Avatar
 
Join Date: Jun 2003
Location: long gone.....
Posts: 17,413
Likes: 0
Received 1 Like on 1 Post
Default Long block vs short block crankshaft question

Is there any difference in the crankshaft for 3.0 crankshaft? Also, other than"longer or shorter" what's the diff. between long and short blocks, and are their cranks interchangeable? TIA
Old 04-17-2005, 04:38 PM
  #2  
SkippyCrunchySmooth
Advanced
 
SkippyCrunchySmooth's Avatar
 
Join Date: Dec 2002
Location: Boston
Posts: 70
Likes: 0
Received 0 Likes on 0 Posts
Default

The cranks are the same. In my experience, a "short block" is a term used to describe an engine block with crank, con rods, and pistons assembled. A "long block" can mean anything from a short block plus valvetrain to a complete, running engine with ecu and everything. Others may have different experiences.
Old 04-17-2005, 05:56 PM
  #3  
Jakerx
Hitsquad Ninja
Rennlist Member
 
Jakerx's Avatar
 
Join Date: Nov 2003
Location: Texas
Posts: 10,406
Likes: 0
Received 2 Likes on 2 Posts
Default

a difference between a 3.0 crankshaft and what else? the 3.0's are the same from 968's and s2's. but yes they are different than 2.5 cranks.
Old 04-17-2005, 06:47 PM
  #4  
Ski
Addict
Rennlist Member

 
Ski's Avatar
 
Join Date: Nov 2001
Location: Heber Springs, AR
Posts: 7,897
Likes: 0
Received 2 Likes on 2 Posts
Default


short block


long block


almost complete motor.

2.5 crank has a 78.9 stroke, 3.0 crank has 87.8 stroke, the next photo will show WHY you have to use custom rods with 3.0L cranks or you have to cut on the rod bolts, machine girdle, etc if you use stock rods; the clearance.
Old 04-17-2005, 08:23 PM
  #5  
fast951
Addict
Rennlist Member


Rennlist
Site Sponsor

 
fast951's Avatar
 
Join Date: Mar 2002
Location: Atlanta
Posts: 6,885
Likes: 0
Received 37 Likes on 27 Posts
Default

Ski, it looks great!
__________________
John
Email
www.vitesseracing.com
Old 04-17-2005, 08:31 PM
  #6  
KuHL 951
Hey Man
Rennlist Member

 
KuHL 951's Avatar
 
Join Date: Jul 2003
Location: Nor Cal, Seal Rock, OR
Posts: 16,509
Received 177 Likes on 105 Posts
Default

Ski,
Nice shots. I'm curious though, what are the heat discolorations on the crank adjacent to the rod caps? I don't think I've ever seen that before.

Steve
Old 04-17-2005, 10:12 PM
  #7  
Tom M'Guinn

Rennlist Member
 
Tom M'Guinn's Avatar
 
Join Date: Jan 2002
Location: Just CA Now :)
Posts: 12,567
Received 533 Likes on 287 Posts
Default

"2.5 crank has a 78.9 stroke, 3.0 crank has 87.8 stroke..."

The 3.0 liter crank is 88mm, no?
Old 04-17-2005, 10:46 PM
  #8  
Dal Heger
Addict
Rennlist Member

 
Dal Heger's Avatar
 
Join Date: Nov 2001
Location: NW Calgary, Canada
Posts: 1,306
Received 0 Likes on 0 Posts
Default

Originally Posted by KuHL 951
Ski,
Nice shots. I'm curious though, what are the heat discolorations on the crank adjacent to the rod caps? I don't think I've ever seen that before.

Steve

Don't know why you've never seen them before, it's the normal heat treat for all of the cranks in our cars, 3.0l and 2.5l.

Dal.
Old 04-17-2005, 11:38 PM
  #9  
Ski
Addict
Rennlist Member

 
Ski's Avatar
 
Join Date: Nov 2001
Location: Heber Springs, AR
Posts: 7,897
Likes: 0
Received 2 Likes on 2 Posts
Default

Tom, I thought it was 87.8 exactly...I just thought everyone used 88. Thanks John but that's Jims motor. Mine is still in the the trailer. I'll start on it after Hallett.
Old 04-18-2005, 12:33 AM
  #10  
Tom M'Guinn

Rennlist Member
 
Tom M'Guinn's Avatar
 
Join Date: Jan 2002
Location: Just CA Now :)
Posts: 12,567
Received 533 Likes on 287 Posts
Default

The tech spec book says 88. If you run the math, an 88mm stroke with 104 bore comes out to 2990, which is the published displacement. If the crank was only 87.8, the displacement would be only 2983. I've never actually measured one though...
Old 04-18-2005, 12:35 AM
  #11  
fast951
Addict
Rennlist Member


Rennlist
Site Sponsor

 
fast951's Avatar
 
Join Date: Mar 2002
Location: Atlanta
Posts: 6,885
Likes: 0
Received 37 Likes on 27 Posts
Default

3L crank is 88mm just had one measured last week while examining a newly purchased 3L cranK.
Old 04-18-2005, 03:55 AM
  #12  
ehall
Addict
Lifetime Rennlist
Member
Thread Starter
 
ehall's Avatar
 
Join Date: Jun 2003
Location: long gone.....
Posts: 17,413
Likes: 0
Received 1 Like on 1 Post
Default

As ususal Ski, you're the man. i have a lead on a crank, but never really knew the diff. in the two terms...'long block","Short block" In essence "long block" means that the engine has been built up "vertically" from the block, and "short" means that the bottom end is complete. I didn't want to dig up the dumb assed quesion thread that i started, but I'll add this.( Ski the pics really help us atist types.)

p.s. John, if anyone trades in a stage V kit, let me know. or is it stg IV......anyway, the one for a 3.0 8 valve.
Old 04-18-2005, 08:05 AM
  #13  
Ski
Addict
Rennlist Member

 
Ski's Avatar
 
Join Date: Nov 2001
Location: Heber Springs, AR
Posts: 7,897
Likes: 0
Received 2 Likes on 2 Posts
Default

Engine M44/43


M44/44 (Tiptronic)
Number of Cylinders 4
Bore 104 mm
Stroke 87.8 mm

Ok, 88mm, the above is copied from Clarks-Garage...but I know different now.



Quick Reply: Long block vs short block crankshaft question



All times are GMT -3. The time now is 06:20 PM.