↓ Advertise on Defender2 ↓

Home > V8 > 3.5/3.9
Post Reply  Down to end
Page 1 of 1
Print this entire topic · 
ian series 1



Member Since: 17 Nov 2014
Location: south
Posts: 2205

United Kingdom 2008 Defender 90 Puma 2.4 CSW Bonatti Grey
3.5/3.9

Question...

Has anyone done, or know if you can happily run a 3.9 on carbs (SUs)?

I've been offered a good 3.9 engine with a fried ecu, and injectors,
It's a low mileage engine at 64,000 miles.

I'm wondering if the SUs would cope, or need re jetting?

Cheers 80" 80" 86" 88" 90"

Post #669176 5th Dec 2017 5:47pm
View user's profile Send private message View poster's gallery Reply with quote
Devon-Rover



Member Since: 22 Jan 2015
Location: South Devon
Posts: 422

United Kingdom 2014 Defender 110 Puma 2.2 USW Aintree Green

Hi Half an answer as I have lost / forgotten the info.

Yes you can but it will need different needles and springs and possibly a bit of time with a dyno and wideband exhaust gas analyser to check the mixture and fine tune the needles to get the best mixture.

Post #669212 5th Dec 2017 7:37pm
View user's profile Send private message View poster's gallery Reply with quote
ian series 1



Member Since: 17 Nov 2014
Location: south
Posts: 2205

United Kingdom 2008 Defender 90 Puma 2.4 CSW Bonatti Grey

Thanks for confirming what I had thought Wink

I was thinking maybe a phone call to Burlen?
https://burlen.co.uk/


I'm sure they could shed some light on what would be needed?

Cheers 80" 80" 86" 88" 90"

Post #669213 5th Dec 2017 7:47pm
View user's profile Send private message View poster's gallery Reply with quote
JeremyJ



Member Since: 16 Nov 2011
Location: Aylesbury
Posts: 1370

United Kingdom 1990 Defender 110 V8 Petrol CSW Eastnor Green

Yes, will work. My 2b is running a 4.6 on SU’s

Post #669217 5th Dec 2017 8:08pm
View user's profile Send private message View poster's gallery Reply with quote
ian series 1



Member Since: 17 Nov 2014
Location: south
Posts: 2205

United Kingdom 2008 Defender 90 Puma 2.4 CSW Bonatti Grey

is that on standard carbs Jeremy?

I suppose I ought to just get it, put the carbs on and run it up,
And see how it runs and sounds? 80" 80" 86" 88" 90"

Post #669225 5th Dec 2017 8:34pm
View user's profile Send private message View poster's gallery Reply with quote
JeremyJ



Member Since: 16 Nov 2011
Location: Aylesbury
Posts: 1370

United Kingdom 1990 Defender 110 V8 Petrol CSW Eastnor Green

Yes, but I can’t remember which needles are in them.

What about keeping the efi?

Post #669228 5th Dec 2017 8:44pm
View user's profile Send private message View poster's gallery Reply with quote
ian series 1



Member Since: 17 Nov 2014
Location: south
Posts: 2205

United Kingdom 2008 Defender 90 Puma 2.4 CSW Bonatti Grey

I'm a big fan of the twin SUs, there is just something about them?

Not a fan of Strombergs, had nothing but trouble with them on an old 2 door RR,

the engine I've been offered is being ditched because of ECU malfunction,
I thought it would be a fun project to strip and rebuild it on carbs.

(Not like I've enough to do).... Neutral Laughing

Thumbs Up 80" 80" 86" 88" 90"

Post #669241 5th Dec 2017 9:05pm
View user's profile Send private message View poster's gallery Reply with quote
mikeh501



Member Since: 07 Jan 2013
Location: United Kingdom
Posts: 787

United Kingdom 1994 Defender 90 V8 Petrol SW Alpine White

wont it need a different front end with distributor? and a diff intake manifold etc?

Post #669378 6th Dec 2017 7:58pm
View user's profile Send private message View poster's gallery Reply with quote
ian series 1



Member Since: 17 Nov 2014
Location: south
Posts: 2205

United Kingdom 2008 Defender 90 Puma 2.4 CSW Bonatti Grey

Yes, there is a fair bit to swap over,
But all doable. 80" 80" 86" 88" 90"

Post #669379 6th Dec 2017 8:02pm
View user's profile Send private message View poster's gallery Reply with quote
oneten110



Member Since: 02 Jul 2011
Location: North Yorkshire
Posts: 57

United Kingdom 

Why not just stick with the EFi. Sourcing a replacement ECU shouldn't be a problem and a set of injectors can be repaired in the same way as a set of diesel injectors can.

try having a chat with these people.
http://www.tornadosystems.com

Post #669512 7th Dec 2017 10:38am
View user's profile Send private message View poster's gallery Reply with quote
ian series 1



Member Since: 17 Nov 2014
Location: south
Posts: 2205

United Kingdom 2008 Defender 90 Puma 2.4 CSW Bonatti Grey

I want it to keep it simple, it's for a series 3, 80" 80" 86" 88" 90"

Post #669514 7th Dec 2017 10:51am
View user's profile Send private message View poster's gallery Reply with quote
oneten110



Member Since: 02 Jul 2011
Location: North Yorkshire
Posts: 57

United Kingdom 

Honestly it is probably simpler to set up than carburetters.
I took my 3.5, that I had fitted with a 3.9 EFI system, to Tornado and they set it up in about an hour, managing to double the power output at the same time

Post #669517 7th Dec 2017 11:12am
View user's profile Send private message View poster's gallery Reply with quote
ian series 1



Member Since: 17 Nov 2014
Location: south
Posts: 2205

United Kingdom 2008 Defender 90 Puma 2.4 CSW Bonatti Grey

I did think about going EFI when I started the project,
But as I said, i much prefer them on carbs.

I don't think anything can beat it when they are set up properly Wink 80" 80" 86" 88" 90"

Post #669520 7th Dec 2017 11:28am
View user's profile Send private message View poster's gallery Reply with quote
muddypaws



Member Since: 22 Jan 2013
Location: Leicestershire
Posts: 43

England 2009 Defender 90 Puma 2.4 SVX Station Wagon Santorini Black

This is your man for advice on SU's

http://www.johnealesroverv8.co.uk/ Richard

Defender 90 SVX
Discovery D4
Mini Cooper S

Post #669895 9th Dec 2017 6:14pm
View user's profile Send private message View poster's gallery Post Reply
Post Reply  Back to top
Page 1 of 1
All times are GMT

Jump to  
Previous Topic | Next Topic >
Posting Rules
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum



Site Copyright © 2006-2017 Futuranet Ltd & Martin Lewis