Volvo Community Forum. The Forums of the Volvo Owners Club

Forum Rules Volvo Owners Club About VOC Volvo Gallery Links Volvo History Volvo Press
Go Back   Volvo Owners Club Forum > "Technical Topics" > PV, 120 (Amazon), 1800 General

Notices

PV, 120 (Amazon), 1800 General Forum for the Volvo PV, 120 and 1800 cars

Information
  • VOC Members: There is no login facility using your VOC membership number or the details from page 3 of the club magazine. You need to register in the normal way
  • AOL Customers: Make sure you check the 'Remember me' check box otherwise the AOL system may log you out during the session. This is a known issue with AOL.
  • AOL, Yahoo and Plus.net users. Forum owners such as us are finding that AOL, Yahoo and Plus.net are blocking a lot of email generated from forums. This may mean your registration activation and other emails will not get to you, or they may appear in your spam mailbox

Thread Informations

Dash pot oil

Views : 1392

Replies : 21

Users Viewing This Thread :  

Reply
 
Thread Tools Display Modes
Old Jul 18th, 2018, 15:16   #1
arcturus
arcturus
 
arcturus's Avatar
 

Last Online: Today 09:21
Join Date: Mar 2006
Location: Sagres Portugal
Default Dash pot oil

I know that the book recommends ATF or similar but what effect would it have on performance using a heavier, engine oil for example, or a lighter oil ?
__________________
life's too short to drink bad wine
arcturus is offline   Reply With Quote
Old Jul 18th, 2018, 15:46   #2
Clan
Experienced Member
 
Clan's Avatar
 

Last Online: Today 14:09
Join Date: Jun 2007
Location: L/H side
Default

Quote:
Originally Posted by arcturus View Post
I know that the book recommends ATF or similar but what effect would it have on performance using a heavier, engine oil for example, or a lighter oil ?
a heavier oil would make the piston rise slower restricting power and increasing fuel consumption .
__________________
My comments are only based on my opinions and vast experience .
Clan is offline   Reply With Quote
Old Jul 18th, 2018, 18:08   #3
classicswede
Trader Volvo in my veins
 
classicswede's Avatar
 

Last Online: Yesterday 23:41
Join Date: Dec 2004
Location: Anglesey
Default

Stromberg carbs should use ATF

SU carbs should have SAE20 oil but I find 10w40 works well. Slightly thicker oil will give more enrichment is acceleration, something these engines tend to need.
classicswede is offline   Reply With Quote
The Following User Says Thank You to classicswede For This Useful Post:
Old Jul 18th, 2018, 20:58   #4
arcturus
arcturus
 
arcturus's Avatar
 

Last Online: Today 09:21
Join Date: Mar 2006
Location: Sagres Portugal
Default

Quote:
Originally Posted by classicswede View Post
Stromberg carbs should use ATF

SU carbs should have SAE20 oil but I find 10w40 works well. Slightly thicker oil will give more enrichment is acceleration, something these engines tend to need.
That was my understanding. Thicker oil slows the rise of the piston under heavy acceleration and momentarily causes a richer mixture.
__________________
life's too short to drink bad wine
arcturus is offline   Reply With Quote
Old Jul 18th, 2018, 22:17   #5
CLIVERALLY
Master Member
 
CLIVERALLY's Avatar
 

Last Online: Mar 7th, 2024 18:17
Join Date: May 2010
Location: wetherby
Default

ATF is more stable across a range of temperatures
__________________
Clive


"Lets turn up the juice and see what shakes loose"
CLIVERALLY is offline   Reply With Quote
The Following User Says Thank You to CLIVERALLY For This Useful Post:
Old Jul 19th, 2018, 13:26   #6
amazon69
Premier Member
 

Last Online: Mar 26th, 2024 19:07
Join Date: Jan 2006
Location: Falmouth
Default

ATF is more stable, because it is single weight. Straight SAE20 weight oil is ideal really, in my experience, and as recommended by SU/Burlen: http://sucarb.co.uk/technical-carbur...gs-chamber-oil

I found some single 20w oil for much less however (I think it was for a lawnmower, can't remember).
10w40 etc would change characteristics as the engine warmed up.
__________________
Falmouth, Cornwall.
1970 California white 131.
amazon69 is offline   Reply With Quote
Old Jul 19th, 2018, 13:40   #7
ASt85
Premier Member
 

Last Online: Today 17:41
Join Date: Aug 2010
Location: Walderslade....Kent
Default

I always used 3-in-1 oil as dashpot oil for a pair of SUs fitted on a 60s 997S engined mini - it was quoted as an SAE20 oil.
__________________
The saddest moment is when the one who gave you the best memories....becomes a MEMORY

V70 SE 2004 2.3L T5 Geartronic, C70 2005 2.0T Automatic, Sold 2.4l 20 Valve Automatic Torslander Sold 854 GLT 20v Auto
ASt85 is online now   Reply With Quote
Old Jul 19th, 2018, 20:05   #8
CLIVERALLY
Master Member
 
CLIVERALLY's Avatar
 

Last Online: Mar 7th, 2024 18:17
Join Date: May 2010
Location: wetherby
Default

I will stick to ATF used in my cars including rally stuff and in my commercial repair business for 40 + years..but basically its personal choice.not wishing to get into a pi##ing competition. No offence to anyone as if you ask 100 people they will all give well intentioned advice
__________________
Clive


"Lets turn up the juice and see what shakes loose"

Last edited by CLIVERALLY; Jul 19th, 2018 at 20:10.
CLIVERALLY is offline   Reply With Quote
The Following User Says Thank You to CLIVERALLY For This Useful Post:
Old Jul 19th, 2018, 20:24   #9
ASt85
Premier Member
 

Last Online: Today 17:41
Join Date: Aug 2010
Location: Walderslade....Kent
Default

Quote:
Originally Posted by CLIVERALLY View Post
I will stick to ATF used in my cars including rally stuff and in my commercial repair business for 40 + years..but basically its personal choice.not wishing to get into a pi##ing competition. No offence to anyone as if you ask 100 people they will all give well intentioned advice
Experience always counts in these matters - as far as I'm concerned it always comes down to personal experience/expertise and what you know works for you and the machine in front of you at the time and how you want it to perform.

The biggest mistake I ever made was changing the SU needles for richer needles and using a lower 10SAE oil giving a faster drop/drop on pair - trying to balance them was a nightmare so eventually they replaced them with a pair of Webers on a smoothed & re-profiled inlet manifold, but that was a wholly different balancing act!
__________________
The saddest moment is when the one who gave you the best memories....becomes a MEMORY

V70 SE 2004 2.3L T5 Geartronic, C70 2005 2.0T Automatic, Sold 2.4l 20 Valve Automatic Torslander Sold 854 GLT 20v Auto
ASt85 is online now   Reply With Quote
Old Jul 19th, 2018, 21:26   #10
Ron Kwas
Premier Member
 
Ron Kwas's Avatar
 

Last Online: Today 16:40
Join Date: Jul 2007
Location: Connecticut, USA
Default

AS;

Don't take this wrong, but where do I start...based on what did you change Metering Needles and Damper oil viscosity?...if for any reason less than full range dynamometer motor tests, where engine response and exhaust gases are checked under all load (steady-state and transient) conditions, I expect that explains half of the tuning problems...

From: https://www.sw-em.com/su_carbs.htm
"...this is exactly why wrong Metering Needles get into carbs: ...he says: "...you can kinda look at the chart....I think I'm going to go to an XXX needle". What kind of a system for picking a needle is that? None! Metering Needles for a particular configuration of engine (mostly influenced by camshaft, manifolding - intake and exhaust flow) were arrived at after countless hours on a manufacturer's motor test stand (dynamometer), running at various RPMs, loads, throttle settings, and with exhaust gas analyzers... very few casual mechanics or even shops are equipped enough (mentally or hardware) to get this any better than the factory!...but they think they are!...so they'll try...and that's why incorrect needles are found in carbs! Do not change Metering Needles unless you can put motor/vehicle on a dynamometer to scientifically check the results...like so! (see Reference: B18 on dynamometer) ...and if you feel the need to change the mixture slightly (for instance seasonably), adjust the Mixture Adjustment Nut only...no more!"

...and Damper Oil should be 20 weight (and because that is what ATF is, and because it has a wide operating Temp range, and is available inexpensively in quarts, it is a popular alternative)...and BTW... Dashpot Drop is not dampened...only Rise!


I doesn't surprise me that you gave up in the end and went to Webers...I wonder how that went...

Cheers
Ron Kwas is offline   Reply With Quote
The Following User Says Thank You to Ron Kwas For This Useful Post:
Reply


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

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 17:43.


Powered by vBulletin
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.