16 replies to this topic

[liirge]

Dear all, 

 

Can anyone provide me with information on modding the HIF 44 damper to the fast drop type. I know I've seen information on it before I'm just not sure where. 

 

 

Regards

A

[Blatherskite]

Search "hif44 damper" in the technical forum. You'll find items like http://www.theminifo...4/?fromsearch=1 and more.

[liirge]

Search "hif44 damper" in the technical forum. You'll find items like http://www.theminifo...4/?fromsearch=1 and more.

That's not actually what I inquired about at all, but thank you for trying. 

I remember seeing somewhere that you could modify the damper of the slow fall to act like a fast fall damper. I was hoping that someone remembers this like I do, and can either detail what is done, or the relevant material online. 

[carbon]

AC Dodd is the best person to answer this one.

 

To make the SU damper offer less resistance when dropping the height of the floating brass cylinder at the end of the damper needs to be reduced (from memory by about 1mm).

[ACDodd]

No, do not shorten the sleeve. Reduce the diameter of the top hat rim.

 

AC

[carbon]

I stand corrected, go with AC Dodds recommendation!

[whistler]

No, do not shorten the sleeve. Reduce the diameter of the top hat rim.

 

AC

By how much should you reduce the diameter of the top hat rim please?

[racingbob]

what difference is there in the fast drop

and why do you need it done

[whistler]

what difference is there in the fast drop

and why do you need it done

Whilst I am fully capable of stripping and rebuilding an SU I am an amateur when it comes to the complexities of the accurate workings of it. I have a HIF44 with a LZX1511 damper fitted. This, apparently, is the wrong damper for this carb; it should be LZX2085. After reading various forums I have come to the conclusion that the LZX2085 lifts and falls quicker than the LZX1511 due to the smaller diameter of the top of the plunger assembly. I have a problem with hesitancy when touching the throttle which could be because the piston is not lifting quick enough to allow an increase in fuel through  the jet assembly. A reduction in the diameter of the plunger 'top hat' makes sense to me and rather than pay £12 or more for a new LZX2085 I can reduce the diameter myself so I was merely asking by how much should I reduce the diameter. Hope that makes sense.

I am using 3 in 1 oil in the dashpot.

[racingbob]

I use 3.1 and got the 2085 seems ok

 

wasn't as good till I put the 2085 on

[whistler]

I use 3.1 and got the 2085 seems ok

 

wasn't as good till I put the 2085 on

I'm just trying to do the same by modding the 1511 and saving £12! Lol

[ACDodd]

Reduce the top hat rim to 7mm diameter.

 

AC

[blacktulip]

Is this an actual benefit or is this a tuning aid?

[ACDodd]

It simply removes flat spots between gear changes.

Ac

Edited by ACDodd, 18 May 2015 - 05:22 PM.

[whistler]

Reduce the top hat rim to 7mm diameter.

 

AC

Thanks, that's the info I needed.