Home  |  Forums  |  914 Info  |  Blogs
 
914World.com - The fastest growing online 914 community!
 
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG. This site is not affiliated with Porsche in any way.
Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners.
 

Welcome Guest ( Log In | Register )

 
Reply to this topicStart new topic
> 1.7 Pistons, 90 mm high compression
Downunderman
post Oct 4 2018, 04:38 PM
Post #1


Senior Member
***

Group: Members
Posts: 852
Joined: 31-May 03
From: Sydney, Australia
Member No.: 766
Region Association: Australia and New Zealand



Who makes forged pistons for a 1.7 with a compression ratio about 10.5:1 or thereabouts? I need to source some for my historic racer engine. TIA. Howie.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
ChrisFoley
post Oct 5 2018, 06:33 AM
Post #2


I am Tangerine Racing
*****

Group: Members
Posts: 7,908
Joined: 29-January 03
From: Bolton, CT
Member No.: 209
Region Association: None



JE or Wiseco
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Downunderman
post Oct 5 2018, 03:37 PM
Post #3


Senior Member
***

Group: Members
Posts: 852
Joined: 31-May 03
From: Sydney, Australia
Member No.: 766
Region Association: Australia and New Zealand



JE have just said they dont have an off the shelf one but will do a custom one. Waiting to hear from Wiseco.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Downunderman
post Oct 5 2018, 05:08 PM
Post #4


Senior Member
***

Group: Members
Posts: 852
Joined: 31-May 03
From: Sydney, Australia
Member No.: 766
Region Association: Australia and New Zealand



What I want is probably what is used in F Production. What do you use Chris?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Driver174
post Oct 12 2018, 02:10 PM
Post #5


Member
**

Group: Members
Posts: 106
Joined: 2-February 17
From: Nevada
Member No.: 20,806
Region Association: None



JE made a custom set for my 914/4 - 2.0. It was an easy process and they pretty much had all of data required. They were simple flat tops and I machined to valve pockets. Fly cutting the head down to 45cc chambers gave me 10.5:1 compression ratio.

JIM


QUOTE(Downunderman @ Oct 5 2018, 04:08 PM) *

What I want is probably what is used in F Production. What do you use Chris?

User is offlineProfile CardPM
Go to the top of the page
+Quote Post
ChrisFoley
post Oct 13 2018, 10:09 AM
Post #6


I am Tangerine Racing
*****

Group: Members
Posts: 7,908
Joined: 29-January 03
From: Bolton, CT
Member No.: 209
Region Association: None



QUOTE(Downunderman @ Oct 5 2018, 07:08 PM) *

What I want is probably what is used in F Production. What do you use Chris?

I've seen popup pistons that someone else used to get high compression without flycutting the heads too deeply, but I think that much shape on the piston crown affects the flame path too much.
Cutting the heads has its drawbacks too. Mostly because one of the exhaust stud bores is very close to a combustion chamber and may break thru when trying to get below 40cc.
My pistons were made to order by sending them a set of dimensions to work with.
Pin height, ring groove widths, piston dia., dome height & dia.
I used a stock high compression 1.7L piston as my model.
I've had 91mm pistons made for 1.7L and 94mm pistons made for 1.8L.
I cut my own eyebrows for the valves after doing a full mockup.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



- Lo-Fi Version Time is now: 20th April 2024 - 12:54 AM