Identify My carbs, i think HS6 SUs not Hitachi. Good, Bad, Indifferent?
Posted 29 December 2014 - 04:10 PM
Interestingly, I run (I think, should check again one day) BAX needles converted to suit "fixed" needle carbs on my overbored L18 (so around 1.9litre). But it is quite modified and I don't care for fuel consumption or low speed running (because race car). These were chosen by a very good dyno guy with lots of MGB / SU carb experience, after I rebuilt them initially with BAZ needles from a recommendation by another guru with SU's on Datsuns.
Posted 29 December 2014 - 04:14 PM
Posted 29 December 2014 - 09:00 PM
Posted 30 December 2014 - 06:09 AM
New needles are 14 each.
Posted 30 December 2014 - 03:18 PM
Posted 30 December 2014 - 04:44 PM
Looks like I have a pair of "SR stamped needles" in my glove box. I think they came with the car many years ago. They seem to be unused and a quick Google search it looks like they might be the profile for a Jaguar XK140. Which is a 3.4 ltr motor. Probably would run too rich I'd assume.
They most likely would , but why not give them a try ?
It doesn't take long to fit them and costs you nothing.
Posted 30 December 2014 - 06:36 PM
SU Carburettor High-Performance Manual (SpeedPro Series) by Des Hammill
I was wondering if it was of any use? I have the ZTherapy DVD at home in Sydney but am currently in Melbourne and don't have access to it.
Posted 30 December 2014 - 07:11 PM
Posted 30 December 2014 - 10:00 PM
Posted 16 January 2015 - 12:36 PM
Does this needle swapping work for the Hitachi SU's also? I need to find out what needles are in mine, but I suspect my L28 is running out of fuel higher up in the rev range due to the L24 size needles in it and hence feeling flat.
anyupdate on which needles to put in 240 hitachi carbs when theyre on an L28?
Just pulled mine out but needles have no id on them.
Posted 16 January 2015 - 01:32 PM
SU needles will however fit in there.
Posted 16 January 2015 - 01:56 PM
If not, which are??
Posted 16 January 2015 - 02:54 PM
For Datsun Hitachi carburettors, you need fixed needles, these have two letters on them, such as SM, SH etc.
For SU carburettors, you have two types of needles, swing and fixed. The swing needles use a small spring to apply pressure to one side of the jet, this was done for emissions and low throttle response.
All Hitachi carburettors, standard on datsun, have a fixed needle, so it fits in direct to the based of the piston.
From what i have researched and found, L28 running Hitachi, try SM or SH needles.
Use this tool to play around with
Posted 16 January 2015 - 03:55 PM
Posted 30 January 2015 - 06:57 PM
Posted 06 June 2015 - 02:08 PM
I was just comparing your needle tests (SM, BAX, BCH) to the needles currently in my l26 - HS6's with BBK needles.
Im not totally sure what to make of the comparison, considering the differences in engines, however,
Mine start leaning out at about station 7, which is probably having a negative impact at higher revs.
I just replaced my sparks, which to my inexperienced eyes looks to be either quite normal or maybe a bit of high speed glazing (according to that picture scale in the haynes manual and posted on this site in colour).
This is the part that confuses me somewhat, as the car is running quite rich (smell and sound), yet seems to drop power at high accel, but the plugs dont appear to be burning overly hot (NGK BP6ES).
Who else has some SU HS6 Carbs on a stock l26, and what needles are you running?
I also cleaned my carbs up somewhat a few days ago, turns out my rear dashpot cover is a "front" cover (turned 90 degrees to make screw holes line up) - doesnt seem to be an issue as it doesnt really do much, unless it affects suction. biggest issue I found is that my springs are different lengths, which is the reason my rear piston falls back more slowly (carby cleaner has fixed this somewhat though, it was sticking a bit).
Posted 22 June 2015 - 09:15 PM
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