XJ XJ6 / XJR6 ( X300 ) 1995-1997

lumps: V8 in x300

Thread Tools
 
Search this Thread
 
  #1  
Old 07-22-2024, 05:28 AM
davoid's Avatar
Member
Thread Starter
Join Date: May 2014
Location: Lancaster
Posts: 53
Received 12 Likes on 10 Posts
Default lumps: V8 in x300

Hello
I'm planning on doing a conversion and wonder if anyone else has done one because it'd be nice to have some validation and I'm sure I'll need advice at some point.
I used to have something like this:
And it was a beast of a thing. Looked great too. Now I want another, but with a bit more power and torque (~420hp/470lbft),and the 4 speed auto (maybe until I save up for a manual), and all the other good things the x300 xjr has.
Anyone done one?
 

Last edited by davoid; 07-22-2024 at 07:40 AM.
  #2  
Old 07-22-2024, 07:08 AM
Doug's Avatar
Veteran Member
Join Date: Mar 2008
Location: Pacific Northwest USA
Posts: 24,927
Received 10,988 Likes on 7,215 Posts
Default

Not aware of any X300/V8 swaps but some X308s have been converted to LS power. Not exactly the same starting point, but close. It should be doable.

Maybe there's some info here?

Jaguar Specialties

Cheers
DD
 
  #3  
Old 07-22-2024, 01:59 PM
davoid's Avatar
Member
Thread Starter
Join Date: May 2014
Location: Lancaster
Posts: 53
Received 12 Likes on 10 Posts
Default

Thanks.

Sadly that guy doesn't do xj40 stuff any more. I could really use the tach converter, which converts from 3-pulse signal. And engine mounts. Advantage of x300 is that apparently a lot of the electronics can be easily retained. Also has GM 4L80 transmission and a LSD, which x308s didn't have.

dave
 
  #4  
Old 07-23-2024, 01:11 AM
countyjag's Avatar
Veteran Member
Join Date: Oct 2014
Location: Scotland
Posts: 1,083
Received 526 Likes on 375 Posts
Default

The V8 conversion would be easier and better with the corresponding 5 speed gearbox and wiring loom. You will need the V8 ECU anyway, and it will be looking for the corresponding 5 speed box.
 
  #5  
Old 07-23-2024, 07:57 AM
davoid's Avatar
Member
Thread Starter
Join Date: May 2014
Location: Lancaster
Posts: 53
Received 12 Likes on 10 Posts
Default

I'm using a carburettor small block, so no engine ECU. It's a 383 gen1 SBC. Also I can firm up the shifts in the GM transmission using a shift kit, but the merc box isn't so amenable. Apparently the electronics pretty much have to be replaced in the x308s, even with a LS motor. Not a simple job. And then there's the differential ...

If money were no object then maybe I'd go for the x308 (
), but money is an object, and part of the challenge is to get a good, quick car on a budget. One that can chirp the tyres going 1st -2nd.
 

Last edited by davoid; 07-23-2024 at 08:01 AM.
  #6  
Old 07-23-2024, 08:05 AM
Spud Maat's Avatar
Veteran Member
Join Date: Oct 2021
Location: Sydney
Posts: 1,116
Received 447 Likes on 289 Posts
Default

here you can not put a carbie engine into a car that came with fuel injection.
it is considered non compliant due to emissions and blah blah blah.
 
  #7  
Old 07-23-2024, 09:34 AM
davoid's Avatar
Member
Thread Starter
Join Date: May 2014
Location: Lancaster
Posts: 53
Received 12 Likes on 10 Posts
Default

TBH I'm not 100% sure it can be done here, but if not I can retrofit an injection system.
 
  #8  
Old 07-23-2024, 09:45 AM
davoid's Avatar
Member
Thread Starter
Join Date: May 2014
Location: Lancaster
Posts: 53
Received 12 Likes on 10 Posts
Default

original plan was straight lpg but it's expensive here, and disappearing. Maybe that'd be cheaper than an EFI system
 
  #9  
Old 07-24-2024, 02:46 AM
Spud Maat's Avatar
Veteran Member
Join Date: Oct 2021
Location: Sydney
Posts: 1,116
Received 447 Likes on 289 Posts
Default

direct vapour injection LPG does give the ability for some pretty good power. and it used to be a real cheap alternative.
here all taxis used to be LPG but since we stopped making local cars that has stopped and so LPG is seeming to become more expensive and will probs become less available.

i would have love to LPG convert back in the day. but would not consider it now.
 
  #10  
Old 07-24-2024, 03:39 AM
davoid's Avatar
Member
Thread Starter
Join Date: May 2014
Location: Lancaster
Posts: 53
Received 12 Likes on 10 Posts
Default

I had a 5.0 VL Berlina on dual fuel. That was good.
 
  #11  
Old 07-24-2024, 11:01 PM
Addicted2boost's Avatar
Veteran Member
Join Date: Mar 2015
Posts: 2,782
Received 1,138 Likes on 869 Posts
Default

I think it would be more fun to pull the charger off and run a turbo. I know it would be a lot of fab work but, having a front mount intercooler would be really cool. You already know that drivetrain can handle (maybe MLS head gasket needed first, if it’s available?) some more power. Too bad all the 5 spd manual transmission components are astronomical, at least here in the US if you can find any.
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Bespokeaddict
XJ XJ6 / XJR6 ( X300 )
0
04-11-2017 05:19 AM
x300
XJ XJ6 / XJR6 ( X300 )
12
11-26-2015 08:10 AM
Geofflvmyjag
XJ XJ8 / XJR ( X308 )
8
11-27-2014 04:42 AM
Geofflvmyjag
XJ XJ6 / XJR6 ( X300 )
5
10-23-2014 12:55 PM
pSyCoSiS
XJ XJ8 / XJR ( X308 )
15
07-15-2012 08:04 AM

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


Quick Reply: lumps: V8 in x300



All times are GMT -5. The time now is 02:26 AM.