Home 
Home Search search Menu menu Not logged in - Login | Register
> Jensen Healey & Jensen GT Tech > Engine & Transmission > 907 2L high compresion pistons whats avaliable

 Moderated by: Greg Fletcher
New Topic Reply Printer Friendly
907 2L high compresion pistons whats avaliable  Rating:  Rating
AuthorPost
 Posted: 08-11-2006 03:09 pm
  PM Quote Reply
1st Post
normv
Member


Joined: 08-07-2006
Location: Sydney, Australia
Posts: 46
Status: 
Offline
I am currently building a Jensen Healey to race in Historic sports car racing in Australia, I looking for pistons in the 10.5-11:1 compression ratio for a 2L 907 , I have not been able to find anyone who lists such a piston, As I am on the other side of the world to most piston manufactures I am a little reluctant to get full custom ones made, however if this last ditch attempt to find some suitable ones fails that is the way I will have to go. I have tried CP and JE with no success so far excluding the full custom option
.

Back To Top PM Quote Reply  

 Posted: 08-11-2006 03:13 pm
  PM Quote Reply
2nd Post
Ron Earp
Member


Joined: 03-12-2005
Location: Cary, North Carolina USA
Posts: 339
Status: 
Offline
You try Delta Motorsports? They've got flat top pistons for some decent compression ratios. Club Store might have those too.

Back To Top PM Quote Reply

 Posted: 08-11-2006 03:54 pm
  PM Quote Reply
3rd Post
Joel
Member
 

Joined: 07-01-2005
Location: San Diego, USA
Posts: 184
Status: 
Offline
Call Jim Bean Engineering.  Even if they don't have them they'll give you good advice.  And it's pretty easy to get pistons thru Ross Racing Pistons.  Check out their website.  I just had some made for a buddies Cobra - and shipped them to Japan. 


Back To Top PM Quote Reply  

 Posted: 08-11-2006 06:31 pm
  PM Quote Reply
4th Post
Greg Fletcher
Administrator


Joined: 03-11-2005
Location: Lake Nacimiento, California USA
Posts: 430
Status: 
Offline
I think you'll need to go the full custom route on those. Lotus pistons from JE and CP (or any manufacturer) need to be made up in quantity and that is not an item that gets requested, so no one wants to stock it. Typically, if an owner wants higher compression, they also want better bottom end torque to go with and they install a stroker crank and the higher compression 2.2 pistons (which have a revised pin height). Good quality pistons are not cheap. Historic class or not, I'd consider the 2.2 mod as well to make the change worth your time and effort.

Back To Top PM Quote Reply

 Posted: 08-11-2006 08:01 pm
  PM Quote Reply
5th Post
Judson Manning
Member


Joined: 03-14-2005
Location: Atlanta, Georgia USA
Posts: 406
Status: 
Offline
Use Delta's off-the-shelf JE Flat-top pistons....As you can see below, the pistons can produce a CR range anywhere from  9.5 to 11.5 to 1.

 

A 0.030" over-bore = 502cc/cylinder

Combustion Chamber volume = 35cc to 40cc (depending on amount of shaving)

Delta's Flat-top 'dish' volume = 8.5cc

Head-gasket (new) volume = 9cc

CR = [502 + (37.5+8.5+9)]/(37.5+8.5+9) = 10:1

use OEM or Aftermarket copper gasket (0.030" thick) => CR = 10.7:1

Deck the head and/or Block an additional 0.020" => CR = 11.5:1

 

Back To Top PM Quote Reply  

 Posted: 08-11-2006 08:06 pm
  PM Quote Reply
6th Post
Jensen Healey
Super Moderator


Joined: 03-11-2005
Location: San Anselmo, California USA
Posts: 983
Status: 
Offline
My 2 Liter flat tops (no dish) from Delta make 155 psi on my compression tester which works out to about 10.5:1. The engine idles great and requires what we call 93 octane here in the states to prevent pinging (pinking).

Have fun,

Kurt

JH 13148

Last edited on 08-11-2006 08:08 pm by Jensen Healey

Back To Top PM Quote Reply

Current time is 02:18 am  
> Jensen Healey & Jensen GT Tech > Engine & Transmission > 907 2L high compresion pistons whats avaliable Top




UltraBB 1.172 Copyright © 2007-2011 Data 1 Systems