3.9 serpentine swap
Moderator: phpBB2 - Administrators
3.9 serpentine swap
Hi , I have got a 3.9 serpentine type engine (with dizzy and intermediate cover) but want to swap the belt and pulleys for the older type SD1 V belt and pulleys ( space is an issue ) I believe that the serp type water pump runs in the opposite direction , is there a way around this problem? many thanks David.
Re: 3.9 serpentine swap
As long as you get all of the ancillaries, pulleys, etc. etc, then the water pump will be turned in the correct direction.
I think your crankshaft maybe too long and need a spacer too.
Chris.
I think your crankshaft maybe too long and need a spacer too.
Chris.
--
Series IIA 4.6 V8
R/R P38 4.6 V8
R/R L405 4.4 SDV8
Series IIA 4.6 V8
R/R P38 4.6 V8
R/R L405 4.4 SDV8
Re: 3.9 serpentine swap
Are you planning to keep the intermediate cover and serpentive water pump ? I think that you can run the pump in opposite direction since the vanes are in certain angle to the rotation. It will physically run backwards but not pump that effective. Maybe someone has tried this, though ?
Re: 3.9 serpentine swap
Thanks for the replies , yes I am keeping the intermediate cover with the distributor drive, I just wanted to get rid of the serpentine belts and pulleys and use the SD1 set up , but the water pump will run the wrong way , thanks David.
Re: 3.9 serpentine swap
The 'serp-belt' and 'V-belt' front covers use different water pumps - these pumps are centrifugal pumps and need to turn the correct way (as designed) to operate efficiently.
serp vs V-belt pump by Tom Cranmer, on Flickr
I would not just bolt the V-belt pulley onto the pump for the serp-belt
the most compact front cover is the later GEMS/Thor if you don't need a dizzy.
Dax Rush 4.6 supercharged V8 MSII
-
- Helpful or Confused
- Posts: 115
- Joined: Mon Dec 31, 2018 2:29 am
- Location: Thornbury New Zealand
Re: 3.9 serpentine swap
I remember reading somewhere a peep had overheating issues on a serp motor. The guy had done mods as you want to and indeed got the whole thing running .....completely overlooking that the water pump was now running backwards .....so , no , you cant run the pump backwards
I wish I was young again , Id be heaps smarter than the first time
- Ian Anderson
- Forum Contributor
- Posts: 2396
- Joined: Sun Nov 19, 2006 9:46 pm
- Location: Edinburgh
Re: 3.9 serpentine swap
Owner of an "On the Road" GT40 Replica by DAX powered by 3.9Hotwre Efi, worked over by DJ Motors. EFi Working but still does some kangaroo at low revs (Damn the speed limits) In to paint shop 18/03/08.
-
- Helpful or Confused
- Posts: 115
- Joined: Mon Dec 31, 2018 2:29 am
- Location: Thornbury New Zealand
Re: 3.9 serpentine swap
Or even an electric motor driving existing pumpIan Anderson wrote: ↑Mon Nov 02, 2020 9:17 pmElectric water pump?
http://www.super7thheaven.co.uk/rover-v ... ater-pump/
Ian
I wish I was young again , Id be heaps smarter than the first time
Re: 3.9 serpentine swap
I have seen somewhere an electric set up made by morroso, will have a look at one of these , David