-9 High Compression '63 XKE 3.8 - Jaguar Forums - Jaguar Enthusiasts Forum

Notices
E type ( XK-E ) 1961 - 1975

-9 High Compression '63 XKE 3.8

 
  #1  
Old 08-24-2018, 10:35 PM
GusRiley's Avatar
Junior Member
Thread Starter
Join Date: Aug 2018
Location: West central Illinois
Posts: 8
Thanked 0 Times in 0 Posts
Default -9 High Compression '63 XKE 3.8

I have been led to believe that most 3.8 XKEs were -8 models. -8 referring to an 8 to 1 compression ratio. I also have learned there were -7 models, but none were sent to the US. My '63 XKE Series 1, 3.8 is a -9 (9 to 1 Compression). All the numbers match my chassis. Does anyone have any idea how special this might be if special at all?
 

Last edited by GusRiley; 08-24-2018 at 10:38 PM.
  #2  
Old 08-24-2018, 11:13 PM
Veteran Member
Join Date: Mar 2008
Location: Pacific Northwest USA
Posts: 19,690
Thanked 6,265 Times in 4,691 Posts
Default

First I'll disclose that I'm no authority on E-types, but......

My impression is that 9.0 compression was standard specification with the lower ratios being "at request" or for select markets. I think all USA models got the 9.0 engine until the introduction of the Series II.

Cheers
DD

 
The Following User Says Thank You to Doug For This Useful Post:
GusRiley (09-11-2018)
  #3  
Old 09-10-2018, 02:30 PM
XKEsGoFast's Avatar
Junior Member
Join Date: Sep 2018
Location: El Dorado Hills
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
Thumbs up E Type Compression Ratios

My 1963 E Type coupe has its original 9:1 compression ratio engine as well. I would be interested if anyone knows how many of these were built.
 
  #4  
Old 09-10-2018, 08:17 PM
Member
Join Date: Jul 2017
Location: Michigan
Posts: 58
Thanks: 0
Thanked 16 Times in 14 Posts
Default

99.9% of the series 1 e-types sent to the USA were 9:1 compression ratio. The 8:1 engines were mainly sent to countries with lower grade fuel. Therefore 9:1 CR is not special at all.
 
The Following 2 Users Say Thank You to Bob_S For This Useful Post:
enderle (09-11-2018), GusRiley (09-11-2018)
  #5  
Old 09-12-2018, 04:38 PM
Member
Join Date: Jul 2017
Location: Michigan
Posts: 58
Thanks: 0
Thanked 16 Times in 14 Posts
Default

Actually the only difference between the 9:1 and the 7 or 8:1 compression head is the number stamped into the head, i.e. there the same head RXXXX-7,8 or 9. The compression ratio is mainly controlled by the size of the dome/crown of the pistons. You could have a head that claims to be 9:1 compression ratio but if it was rebuilt with 8:1 compression pistons then the engine is really 8:1. Except when the head is shaves then it would be somewhat higher than 8:1. Some people rebuild their engines with 8:1 CR pistons because of the lower octane that is around today.
 

Last edited by Bob_S; 09-12-2018 at 06:47 PM.
The Following User Says Thank You to Bob_S For This Useful Post:
GusRiley (09-12-2018)
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Big Worm
S-Type / S type R Supercharged V8 ( X200 )
5
11-20-2009 11:12 AM
skanoski
XJ XJ8 / XJR ( X308 )
9
06-22-2008 09:11 AM
chicago bob
XJ XJ8 / XJR ( X308 )
1
04-28-2008 08:22 PM
kilo
XJS ( X27 )
1
02-12-2008 09:55 AM
S-Type / S type R Supercharged V8 ( X200 )
7
02-25-2007 10:38 PM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 

Thread Tools
Search this Thread
Quick Reply: -9 High Compression '63 XKE 3.8


Advertising
Featured Sponsors
Vendor Directory

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: