home register FAQ memberlist calendar

Go Back   Turbobricks Forums > Mechanical > performance & modifications

Reply
 
Thread Tools Display Modes
Old 10-28-2021, 01:32 PM   #1
dannyman742
Board Member
 
Join Date: Jun 2021
Question Is a 2.5l stroker crank worth it?

Im building a 93 240 drift car and im going to do rods and pistons. I thought about swapping the crank while in in there for 86mm and 2.5l of displacement. How much difference does this 0.2l make throughout the powerband? And is it worth it?

Specs:
Ported 531 head
93 squirter block
Yoshi rods pistons
Holset he341 30 psi
Enem k15 turbo cam
E85
Haltech 1000
Kl racing turbo manifold and cast intake manny
Do88 intercooler with 2.5 inch piping
dannyman742 is offline   Reply With Quote
Old 10-28-2021, 02:14 PM   #2
poulrais
Board Member
 
poulrais's Avatar
 
Join Date: Sep 2006
Location: Quebec, CAN
Default

Quote:
Originally Posted by dannyman742 View Post
Im building a 93 240 drift car and im going to do rods and pistons. I thought about swapping the crank while in in there for 86mm and 2.5l of displacement. How much difference does this 0.2l make throughout the powerband? And is it worth it?

Specs:
Ported 531 head
93 squirter block
Yoshi rods pistons
Holset he341 30 psi
Enem k15 turbo cam
E85
Haltech 1000
Kl racing turbo manifold and cast intake manny
Do88 intercooler with 2.5 inch piping
It's also a forged steel crank btw...
__________________


1990, Volvo 740 16v +T
1991, Volvo 745T 16V - crushed
build thread: http://forums.turbobricks.com/showthread.php?t=249553
poulrais is offline   Reply With Quote
Old 10-28-2021, 02:18 PM   #3
culberro
Ronald Culberbone III
 
culberro's Avatar
 
Join Date: Feb 2010
Location: Redmond, OR
Default

Quote:
Originally Posted by poulrais View Post
It's also a forged steel crank btw...
Cast redblock cranks aren't exactly known for failing....
__________________
Cult Person. Pissing in your Kool-Aid.

Quote:
Originally Posted by Toyotahead View Post
That's why you give blowies with a mouth full of Listerine, sanitizes the sausage and leaves everyone with a fresh clean wintergreen taste or scent!
Quote:
Originally Posted by megulon-7 View Post
Sigh…. It leads to the hard stuff. Hot sauce or I can’t get off now.
culberro is offline   Reply With Quote
Old 10-28-2021, 02:19 PM   #4
Stiggy Pop
Board Member
 
Stiggy Pop's Avatar
 
Join Date: Feb 2011
Location: Granville, MA
Default

I'm not sure anyone has any real data to answer the question but my thoughts on this:

I bought a complete boat engine for $100 and the 2.5l crank is sitting in my shed. If I ever have to build another engine/replace my current forged rods & pistons I'll certainly take advantage of it and build a stroker. I'm not sure I would spend ~$500 to buy a crank from someone else, though.

side note: I have 158mm rods in my 2.3l with Wiseco pistons and the lighter pistons make a difference in how quick the car revs over the regular 156.
__________________
'79 242
943 pickup
Stiggy Pop is offline   Reply With Quote
Old 10-28-2021, 02:23 PM   #5
JohnMc
PV Abuser
 
JohnMc's Avatar
 
Join Date: May 2004
Location: St. Louis
Default

I'd comment, but really, have no experience with a stroker motor.

I do have a B20 in my old car with another .2(ish)L of displacement added to it, but that was with bore, not stroke, and AFAIK a stroke change will make more of a difference than a bore change. The .2L of added bore displacement didn't really add much in the way of peak HP, but did add torque, especially down low. And I think it has continued to benefit the HP as I've added other mods which raised the torque range.

But that's normally aspirated, and I think the effects of .2L on a boosted motor would still exist, they'd just be relatively less important than all of the other aspects - efficiency of the turbo, how much boost, intercooler, intake manifold, etc.

In other words, yes, it would make a difference, but so would turning the boost up another psi.
__________________
'63 PV Rat Rod
'93 245 16VT Classic #1141
JohnMc is offline   Reply With Quote
Old 10-28-2021, 02:29 PM   #6
Harlard
Hurlurd?Harland?Bueller?
 
Harlard's Avatar
 
Join Date: May 2007
Location: PDX
Default

Expect a specific output increase commesurate with the change in displacement. I'm swapping in a 2.5L block into my car, which would correspond in a ~20 lbs-ft bump in the 2000-3500 range where my current engine makes very little torque. You can expect a minimal improvement in spool time out of that turbo also.

If you are already forking over money for rods and pistons, figure out whether the incremental cost increase is worth the nominal performance improvement and go from there.
__________________


Herr Harlard am Erstens

1979 242 DL

Quote:
Originally Posted by t8fanning View Post
My knob has a big chunk of steel on it
Harlard is offline   Reply With Quote
Old 10-28-2021, 02:30 PM   #7
Stiggy Pop
Board Member
 
Stiggy Pop's Avatar
 
Join Date: Feb 2011
Location: Granville, MA
Default

Quote:
Originally Posted by Harlard View Post
2000-3500 range where my current engine makes very little torque.
16v problems
Stiggy Pop is offline   Reply With Quote
Old 10-28-2021, 02:37 PM   #8
Harlard
Hurlurd?Harland?Bueller?
 
Harlard's Avatar
 
Join Date: May 2007
Location: PDX
Default

Quote:
Originally Posted by Stiggy Pop View Post
16v problems
Show me them 8000 RPM pulls from your tractormotor
Harlard is offline   Reply With Quote
Old 10-28-2021, 02:44 PM   #9
Stiggy Pop
Board Member
 
Stiggy Pop's Avatar
 
Join Date: Feb 2011
Location: Granville, MA
Default

Quote:
Originally Posted by Harlard View Post
Show me them 8000 RPM pulls from your tractormotor
Stiggy Pop is offline   Reply With Quote
Old 10-28-2021, 02:53 PM   #10
dannyman742
Board Member
 
Join Date: Jun 2021
Default

Quote:
Originally Posted by Harlard View Post
Show me them 8000 RPM pulls from your tractormotor
But tractor motors are cooler beacause theyre like... from a tractor or something
dannyman742 is offline   Reply With Quote
Old 10-28-2021, 03:23 PM   #11
linuxman51
BRANDSCHUTZVORSCHRIFTEN!
 
linuxman51's Avatar
 
Join Date: Dec 2002
Location: mont, AL
Default

Quote:
Originally Posted by Harlard View Post
Show me them 8000 RPM pulls from your tractormotor
speaking of, where are your 8000 rpm pulls?

I've had both cranks up to 8000+ rpms

__________________
"They bum rushed them in their own crib, they drank all their beer, they partied with their ladies and they left with the trophy"

Now with in-house Dyno tuning!

Megasquirt Tuning!
linuxman51 is offline   Reply With Quote
Old 10-28-2021, 03:35 PM   #12
mikep
The MP
 
mikep's Avatar
 
Join Date: May 2003
Location: 38° 27' N 75° 29' W
Default

*ABIGGERHAMMER has entered the chat
__________________
Quote:
Originally Posted by Forg View Post
It was a Datsun, it was more likely rust in something ...
Quote:
Originally Posted by propav8r View Post
Ain't my couch.
F*ck that couch.
mikep is offline   Reply With Quote
Old 10-28-2021, 03:39 PM   #13
dannyman742
Board Member
 
Join Date: Jun 2021
Default

Quote:
Originally Posted by linuxman51 View Post
speaking of, where are your 8000 rpm pulls?

I've had both cranks up to 8000+ rpms

Is that 8v or 16v power?
dannyman742 is offline   Reply With Quote
Old 10-28-2021, 03:44 PM   #14
culberro
Ronald Culberbone III
 
culberro's Avatar
 
Join Date: Feb 2010
Location: Redmond, OR
Default

Quote:
Originally Posted by Harlard View Post
Show me them 8000 RPM pulls from your tractormotor
The rally car with its stock b230 bottom end went to around 8k+ for an extended period of time on many occasions.
culberro is offline   Reply With Quote
Old 10-28-2021, 03:47 PM   #15
culberro
Ronald Culberbone III
 
culberro's Avatar
 
Join Date: Feb 2010
Location: Redmond, OR
Default

~8% power increase from displacement alone + ~4% torque and power increase from longer stroke.
culberro is offline   Reply With Quote
Old 10-28-2021, 03:51 PM   #16
2manyturbos
Moderator
 
Join Date: Mar 2003
Location: Monroe, OR USA
Default

Quote:
Originally Posted by culberro View Post
~8% power increase from displacement alone + ~4% torque and power increase from longer stroke.
With a small engine, those are huge numbers. Well worth the cost difference if you are budgeting for an engine build.
2manyturbos is offline   Reply With Quote
Old 10-28-2021, 04:40 PM   #17
linuxman51
BRANDSCHUTZVORSCHRIFTEN!
 
linuxman51's Avatar
 
Join Date: Dec 2002
Location: mont, AL
Default

Quote:
Originally Posted by dannyman742 View Post
Is that 8v or 16v power?
16v. stock crank and pistons.
linuxman51 is offline   Reply With Quote
Old 10-28-2021, 05:01 PM   #18
Harlard
Hurlurd?Harland?Bueller?
 
Harlard's Avatar
 
Join Date: May 2007
Location: PDX
Default

Quote:
Originally Posted by linuxman51 View Post
speaking of, where are your 8000 rpm pulls?

I've had both cranks up to 8000+ rpms

Closest log I have is when it threw the power steering belt at 7750

Last edited by Harlard; 10-28-2021 at 06:01 PM..
Harlard is offline   Reply With Quote
Old 10-28-2021, 06:01 PM   #19
Harlard
Hurlurd?Harland?Bueller?
 
Harlard's Avatar
 
Join Date: May 2007
Location: PDX
Default

As is customary, I fail to deliver:

Harlard is offline   Reply With Quote
Old 10-28-2021, 06:12 PM   #20
linuxman51
BRANDSCHUTZVORSCHRIFTEN!
 
linuxman51's Avatar
 
Join Date: Dec 2002
Location: mont, AL
Default

typical.
linuxman51 is offline   Reply With Quote
Old 10-28-2021, 07:08 PM   #21
culberro
Ronald Culberbone III
 
culberro's Avatar
 
Join Date: Feb 2010
Location: Redmond, OR
Default

The scene:
Harlard gets ready to make pull to 8500 and data log it, just to make Kenny proud.

I patiently await the text about something breaking.
culberro is offline   Reply With Quote
Old 10-28-2021, 07:10 PM   #22
Harlard
Hurlurd?Harland?Bueller?
 
Harlard's Avatar
 
Join Date: May 2007
Location: PDX
Default

Quote:
Originally Posted by culberro View Post
The scene:
Harlard gets ready to make pull to 8500 and data log it, just to make Kenny proud.

I patiently await the text about something breaking.
Joke's on Bobbert: Pig has failed to move under its own power since 8/1/2021
Harlard is offline   Reply With Quote
Old 10-28-2021, 08:22 PM   #23
linuxman51
BRANDSCHUTZVORSCHRIFTEN!
 
linuxman51's Avatar
 
Join Date: Dec 2002
Location: mont, AL
Default

Quote:
Originally Posted by culberro View Post
The scene:
Harlard gets ready to make pull to 8500 and data log it, just to make Kenny proud.

I patiently await the text about something breaking.
hahaha
linuxman51 is offline   Reply With Quote
Old 10-28-2021, 08:58 PM   #24
apachechef
Burnt Sierra Madre
 
Join Date: Jan 2009
Location: An obscure body in the SK system
Default

Quote:
Originally Posted by linuxman51 View Post
speaking of, where are your 8000 rpm pulls?

I've had both cranks up to 8000+ rpms

how is this graph curving under itself like a breaking wave?
brown line?
__________________
Quote:
Originally Posted by lummert View Post
Dammit, Lummert.
Quote:
Originally Posted by Jesse8931 View Post
Well keep us updated on how your dumbass plan goes.
apachechef is online now   Reply With Quote
Old 10-28-2021, 09:02 PM   #25
redblockpowered
cone dodging dilettante
 
redblockpowered's Avatar
 
Join Date: May 2015
Location: In bed, probably
Default

what happens to power and RPM when you lift?
__________________
1993 944 B230FT/M90 thread here: http://forums.turbobricks.com/showthread.php?t=345277
2x 1991 245 B230F/M47 (LeMons car, street car)
I sell chips for LH 2.4!
redblockpowered is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -4. The time now is 02:03 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2022, vBulletin Solutions Inc.