Notices
928 Forum 1978-1995
Sponsored by:
Sponsored by: 928 Specialists

I've been bitten by the stroker bug.

Thread Tools
 
Search this Thread
 
Old 07-19-2018 | 11:30 PM
  #46  
GregBBRD's Avatar
GregBBRD
Former Vendor
 
Joined: Feb 2005
Posts: 15,230
Likes: 2,481
From: Anaheim
Default

I'm going to change my entire set of recommendations to others. Actually, I'm never going to recommend anything to anyone, ever again. Please ignore all prior posts about rod offset....hell, forget all my prior posts. Too much brain damage to try and teach people about cylinder offset and how this defines rod offset. Too much brain damage to try and teach anyone anything!

In short, I no longer give a **** what anyone/everyone else does.

"Why did I ever care?", is the question I keep asking myself.

I now think that everyone else should run a Chevy offset connecting rod in a 928 engine.

Makes total sense that a connecting rod designed for a small block Chevy would be dimensionally perfect for a completely different application with a completely different cylinder offset, right?

WTF was I thinking?

Slap 'em in there. That rod doesn't need to be centered on that pin (like every engine engineer makes sure occurs.) Everything will be fine!

There.

I'll never mention or bring it up, again.
The following users liked this post:
bertram928 (12-26-2019)
Old 07-19-2018 | 11:48 PM
  #47  
GregBBRD's Avatar
GregBBRD
Former Vendor
 
Joined: Feb 2005
Posts: 15,230
Likes: 2,481
From: Anaheim
Default

Originally Posted by SwayBar
Greg, how many motors did you build with the Chevy rods?
I recalled and changed the Carrillo "A" beam "Chevy offset" rods in six engines.

Lots of work and lots of $$$$.

If I only knew then what all the armchair engineers on Rennlist know, I wouldn't have wasted my time and $$$$!
The following users liked this post:
bertram928 (12-26-2019)
Old 07-19-2018 | 11:53 PM
  #48  
GregBBRD's Avatar
GregBBRD
Former Vendor
 
Joined: Feb 2005
Posts: 15,230
Likes: 2,481
From: Anaheim
Default

Heh,

I've got 6 sets of barely used (and some new sets) Carrillo "A" beam connecting rods with Chevy offsets sitting on my shelf. Will fit any 2.100" Moldex or Scat crank. 5.850" in length. Made for 968 wrist pins.

This is (according to Rennlist 928 Forum armchair engineers) the perfect set-up for 6.5 liter stroker engines.

Get these super trick parts.....cheap.

$600 a set!

One set per customer.
The following users liked this post:
bertram928 (12-26-2019)
Old 07-20-2018 | 01:26 AM
  #49  
Ladybug83's Avatar
Ladybug83
Burning Brakes
 
Joined: Dec 2013
Posts: 1,120
Likes: 82
From: So-Cal/OC
Default

Originally Posted by danglerb

Is there some mid range stroker combination that doesn't need custom rods and crank (using 968 pistons)?
Not using 968 pistons but, Greg was gracious enough to build for me a "mini-stroker" starting with my damaged M22 engine and using mostly factory parts. I don't have all the stroke #s and specs in front of me, nor would I want to reveal any secrets if there are any, but the jist of it is Steel sleeved, carillo 100mm pistons 5.4L, a factory GTS crank and R1 rods with the rest being original Euro goodies. some machine work of course but no porting or any custom work that I'm aware of.

My goals and budget were different than others perhaps. I needed the cylinder repair work anyways and took the opportunity to open it up a bit while still maintaining factory appearance and improved performance.

I've only been lucky enough to drive it so far 12mi from home to Greg's shop for tuning but boy it felt nice. Greg and Jake probably have more miles behind the wheel and could probably add more to the experience so far. I think I'm going to be really happy with it.

Of course there's lots of potential opportunity still it sounds like with the block, intake, custom parts, exhaust, fueling and electronics, I'm sure a lot of ponies could be gained. But I don't expect it to be the monster motor like Marks, Robs, Vans, Andy's, etc. Somewhat of a mid-range stroker like you suggest.
Old 07-20-2018 | 09:14 AM
  #50  
Kevin in Atlanta's Avatar
Kevin in Atlanta
Thread Starter
Rennlist Member
 
Joined: May 2002
Posts: 8,254
Likes: 864
From: Roswell, GA
Default

^^^ Me, too. Greg and I were discussing using a modified GTS crank, an 86 block, my 968 pistons, my '89 heads and custom Carrillo rods.

I was waiting until he completed the shop move when this 'kit' was offered to me. Sounded too good to be true, and it was.

Scat cranks might work, but there are posts suggesting the steel is mild when compared to the Moldex cranks, the Oliver rods may or may not be the proper offset, the Mahle pistons are not suitable for my application and the headers in the package would need to be reworked. Basically, nothing in the package is right for me.
Old 07-21-2018 | 02:27 AM
  #51  
andy-gts's Avatar
andy-gts
Drifting
 
Joined: Aug 2006
Posts: 2,232
Likes: 12
From: lawrence,kansas
Default

I would hold off for a short while.......I hear Louis Ott will soon be ready to make someone very happy......shhhhhh.....
Old 07-21-2018 | 05:58 PM
  #52  
ptuomov's Avatar
ptuomov
Nordschleife Master
 
Joined: Jan 2009
Posts: 5,610
Likes: 82
From: MA
Default

Originally Posted by Kevin in Atlanta
Scat cranks might work, but there are posts suggesting the steel is mild when compared to the Moldex cranks.
Crankshafts can be hardened by case hardening or induction hardening. Induction hardening is generally considered a better technique than case hardening. Induction hardening hardens only the journals. Thus areas like counterweights may often be softer in a better induction hardened crankshaft than in an inferior case hardened crankshaft. Emphasis on "may" as the opposite may also be true. Depends on things like used material.

In terms of materials and manufacturing techniques, the 928 S4 crankshaft is a very, very high quality piece, by the way.

https://www.highpowermedia.com/blog/...method-is-best

Last edited by ptuomov; 07-21-2018 at 07:17 PM.
Old 12-05-2018 | 12:41 PM
  #53  
Kevin in Atlanta's Avatar
Kevin in Atlanta
Thread Starter
Rennlist Member
 
Joined: May 2002
Posts: 8,254
Likes: 864
From: Roswell, GA
Default

Picked up the beginnings of my modest stroker this morning @ 5:30AM off I95 near Savannah, GA courtesy of Stan Shaw on his way to Orlando.


S3 block bored to 104mm and matched to the accompanying pistons

B1 cams from webcam

8 matched pistons

968 pistons with HBC coated skirts.

Piston rings
Old 12-05-2018 | 04:44 PM
  #54  
Kevin in Atlanta's Avatar
Kevin in Atlanta
Thread Starter
Rennlist Member
 
Joined: May 2002
Posts: 8,254
Likes: 864
From: Roswell, GA
Default

Here's the cam details:

WebCam details

Piston details
Old 12-05-2018 | 08:59 PM
  #55  
Kevin in Atlanta's Avatar
Kevin in Atlanta
Thread Starter
Rennlist Member
 
Joined: May 2002
Posts: 8,254
Likes: 864
From: Roswell, GA
Default Piston rod length

How does one determine the correct length of a piston rod?

I have a GTS crankshaft in the works, pistons, a bored block, etc.

Never had to ask that question before - any help appreciated.

Kevin

Old 12-06-2018 | 01:06 AM
  #56  
Mark Anderson's Avatar
Mark Anderson
The Parts Whisperer
Rennlist
Site Sponsor

 
Joined: Nov 2002
Posts: 7,086
Likes: 394
From: Anaheim Ca
Default

Originally Posted by Kevin in Atlanta
How does one determine the correct length of a piston rod?

I have a GTS crankshaft in the works, pistons, a bored block, etc.

Never had to ask that question before - any help appreciated.

Kevin
when I designed my first stroker I took the specs from the 968 piston and compared them to the 928. I think the wrist pin location difference was 8mm so I asked Moldex to build me a crank with 16mm more stroke which allowed me to use stock length rods
Old 12-06-2018 | 05:37 AM
  #57  
Strosek Ultra's Avatar
Strosek Ultra
Rennlist Member
 
Joined: Feb 2011
Posts: 2,248
Likes: 502
From: Mostly in my workshop located in Sweden.
Default

Originally Posted by Kevin in Atlanta
Here's the cam details:

WebCam details

Piston details

WEB 279/264 vs. stock 928S4 camshafts.
Åke
Old 12-06-2018 | 07:01 PM
  #58  
SwayBar's Avatar
SwayBar
Rennlist Member
 
Joined: Feb 2006
Posts: 3,618
Likes: 372
From: Chicago Bears
Default

Nice pieces, and thanks for the detailed cam specs!
Old 12-06-2018 | 10:38 PM
  #59  
Kevin in Atlanta's Avatar
Kevin in Atlanta
Thread Starter
Rennlist Member
 
Joined: May 2002
Posts: 8,254
Likes: 864
From: Roswell, GA
Default

Originally Posted by Mark Anderson

when I designed my first stroker I took the specs from the 968 piston and compared them to the 928. I think the wrist pin location difference was 8mm so I asked Moldex to build me a crank with 16mm more stroke which allowed me to use stock length rods
Thanks, that helps a lot.
Old 12-07-2018 | 06:24 PM
  #60  
andy-gts's Avatar
andy-gts
Drifting
 
Joined: Aug 2006
Posts: 2,232
Likes: 12
From: lawrence,kansas
Default

So Kevin, I take it you did not jump at Louie's awesome 928 with monster horse power.....did you test drive or go up and look at it...??


Quick Reply: I've been bitten by the stroker bug.



All times are GMT -3. The time now is 10:56 AM.