Jump to content
Sign in to follow this  
Weasel73240Z

Fork oil in SU dashpots?

Recommended Posts

As I continue to learn the many joys of tuning and balancing SU's, I got the thinking about my dashpot oil. I have always used straight 20W motorcycle fork oil. It seems way too difficult to lift the dashpots (enough force that my wife couldn't lift them) when the engine is cold. My most recent tuning/tweaking attempts have me running very strong right through the powerband, up to about 5,500 rpm, but I have the slightest bit of hesitation when I back off the gas (for cornering, etc.), then get back on it.

Could this relate to the viscosity of my dashpot oil? I have read recently about some people using a combination of 20W or 30W oil cut down 50% with light oil. Constantly tweaking is fun, but I am so close, I'm wondering if I should try a different oil mix before I try anything else. I plan to get the car on a dyno soon, and I'd like to make sure I am using the best possible dashpot oil viscosity for the cold MA climate before I do.

Thoughts?

Share this post


Link to post
Share on other sites

Paul, I've been using out of the same can of ATF for about 23 years now. So long, in fact, the can I'm drawing from is made out of cardboard. Remember those?

Share this post


Link to post
Share on other sites

Bruce,

Is there any problem using SU Zennith Damper oil?

Mike

That's what I used when I had my Roadster. Used to buy it at a British auto parts shop in Ontario, Ca. that's now closed. The best oil is what works best in your car, in your area. Some people like 3-in-1, or ATF, or proper SU oil but the thing is these are mostly 20W or 30W. Use lighter weight to get the damper to rise faster, and vice versa. Edited by sblake01

Share this post


Link to post
Share on other sites
Bruce,

Is there any problem using SU Zennith Damper oil?

Mike

The only reason I'd counsel against the Zenith oil is that it's British and by definition will end up leaking on the ground.

Oh, look out, run, Here comes Arn carrying his "my british car didn't leak" banner!! nyuck nyuck

If you've ever owned British, you probably know what this is about. If you've never owned British, count your blessings and move on folks. Nothing to see here.....

Share this post


Link to post
Share on other sites

I use 3-in-1 multipurpose oil you can find it at the local hardware store (I got mine at lowes) and comes in a handy little bottle with a tip for squirting it in there.

Share this post


Link to post
Share on other sites

Thanks everyone for the ideas. I am going to try a few different things, starting with ATF (thanks Bruce) and see what I feel. Ive always thought the fork oil just seemed too thick. Doing my internally regulated 60 amp alternator upgrade this weekend, I plan to get to the carbs too. Just to be clear, the Z Therapy carbs are great, and the car has run really excellent since I fine tuned them.

I just cant resist constantly playing with fuel, timing.....really everything, in my quest for more power! Thats the fun, right? :laugh:

Share this post


Link to post
Share on other sites

The only reason I'd counsel against the Zenith oil is that it's British and by definition will end up leaking on the ground.

That's FunnyROFL

Dean

Share this post


Link to post
Share on other sites

I have though about using fork oil but hav enot tried it. There are multi viscosity fork oils available. Perhaps it will help even the cold to hot changes.

I tried the SAE 20 3-in1 oil. It works ok. It seems to get consumed faster that engine oil.

I ended up using 10W-30 or 10W-40 engine oil. It works as good as the others and I always have some since that is what I use in the engine.

Share this post


Link to post
Share on other sites
Oh, look out, run, Here comes Arn carrying his "my british car didn't leak" banner!! nyuck nyuck
As the good sergeant used to say, "I hear NUTTING..."

Share this post


Link to post
Share on other sites

I tried 3in1 oil , 10w 30, ATF and 20w and the only issue I've had is the well runs dry quickly and so I have to keep adding with the eyedroper. I have taken these round

domed carbs apart several times and they still slurp the oil down. Does timing cause

something like that?

Share this post


Link to post
Share on other sites

I removed all the oil from mine and kept a light spray, silicone or the like, on them. It resulted in a quick response. JLP

Share this post


Link to post
Share on other sites

If you are filling to the threads then yes the excess oil will be sucked right in and burned.

With the aircleaner off reach in the mouth of the carb with a finger and lift the piston. Look down inside that little moving tube and you may see a line scribed around the inside of the tube, that the fill line. If there is no line, fill to within a half inch or so of the top of the tube or fill the whole tube and the puck on the rod will push the excess oil out when you install it.

Just keep in mind it is the little tube that needs to get checked not the cavity you see that has the treads in it. After that I check mine about once every lunar eclipse. Unless one is OCD, every couple of months should be fine.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.