HS8 vs HD8 on my P6

AndyD

New Member
Hi, I am newly joined to this forum, as I am working on the restoration of a late 1967 TC2000 that was exported new to Malaysia, and registered in Jan 1968. Among a number of challenges (!) I have been slightly confused with the carbs I have. My 1966 (official) workshop manual states twin HD8 are the type used on the TC, with an HS8 on the SC, but I clearly have HS8s fitted. I have recently learned that a changeover from HD8s to HS8s did occur on the TC in 1967, however these all seem to be fitted with plastic floats, whereas my HS8s have brass floats! (no hole in the middle, domed on the top & just floating free, float chamber top has 3 screws). Was this an early type of HS8 as someone said to me? Trouble is, one float is split and probably beyond repair (except by an expert - not me). So I plan to get a set of plastic floats from SU Carbs (HS Stay up float kit), hoping they will fit, as I cannot find a replacement brass float anywhere. Anyone know where one might be obtained before I try to fit the plastic type (may be a hinge problem....). Or would the HD8 brass type with the hole in the middle actually work here?Picture attached I hope...
thanks for any comments
Andy
 

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Sorry, yes, my error, I meant HS6 on the SC, but this was only to allow me to identify the type of carb on my TC - not sure difference between HS6 and HS8 (presume throat size?), main concern is finding early type (?) HS8 brass floats....
The SU Carb kit for plastic floats fits HS6 AND HS8.....so float chamber is the same at least!
 
Misread you question ref brass floats but the AUD330F on the tag will give you the specification. Contact Burlen & ask them The Worlds Sole Manufacturer of Genuine SU Parts - SU Carburetters
I have just spoken to them and AUD 330F is recognised as the front HS8 carb for P6 2000TC.
Interestingly the original float appears to be unique to Rover and they don't have any . Was advised that WZX1300 nylon & WZX1304 Stay Up ,are suitable
 
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Hi, Yes, the number denotes throat size and equates to the number of eighths of an inch over 1", so '6' is 1 ¾" and '8' is 2". Brass or plastic float may better be decided by what fuel is available locally to you. Modern ethanol bio fuels can attack Brass and the solder so plastic floats may be a better option along with Viton tipped float valves.

Colin
 
Unless you get a Goss jet, all the needles & seats will be Viton these days. As mentioned, the brass floats are correct for the Rover HS8, though you can fit a plastic float float bowl cover and convert I'm told. Later cars went to HS6 carbs (actually the 2" carbs are way to big for the engine size) which have plastic floats as I recall.

One other point on the HS8s, they have a unique sized jet assembly so you have to be careful when buying rebuild kits.

Yours
Vern
 
Thanks very much to all comments, much appreciated. Agreed, brass floats (with centre hole) are correct for HD8 type, but seemingly not for the HS6/8, always seemed to have conical (so plastic?) type - but were the very early ones - like mine perhaps - fitted briefly with this brass float (no hole)? I just need one replacement (brass) float, but this type seems to be unique to my car! All similar (brass) floats have the hole in centre, for HD8 type, possibly could use one but I don't want to buy then find it doesn't work properly... Never seen another like mine, either for sale or even in a diagram - looked at a lot - - always the plastic hinged ('stay up') type, or at least conical shape (even if originals were made of brass). The fuel available to me is what is in the pump! Assume the worst for attacking the solder.....I use Shell usually.....So probably I will get the stay up plastic HS8 replacement float (have to get 2) from SU. Only concern is whether the hinge will be too wide for my float cover hinge ears - may need to 'modify' the hinge to fit it.
Thanks again
Andy
 
Your brass float is not unusual but has been overtaken by plastic and that's what suppliers stock rather then two variations. If you look at the workshop manual I think you can see your carb Operation N-3-A and B . TC models with Emission Control, with a brass float.
 
Unless you get a Goss jet, all the needles & seats will be Viton these days. As mentioned, the brass floats are correct for the Rover HS8, though you can fit a plastic float float bowl cover and convert I'm told. Later cars went to HS6 carbs (actually the 2" carbs are way to big for the engine size) which have plastic floats as I recall.

One other point on the HS8s, they have a unique sized jet assembly so you have to be careful when buying rebuild kits.

Yours
Vern
Vern, HS6’s were never fitted to TCs. HIF6s were fitted to 2200TCs though.
 
Thanks again, roverp480 - I have to say, my brass float type (looks similar to the centre hole type, except it has no centre hole) IS apparently unusual. Was it indeed briefly unique to Rover? I am pursuing a forensic sort of search on this float type I have, as I need to replace one anyway, and it seems to be a mystery - so please bear with me.....
What I did find was in SU's online technical section on the HS carb, see snip attached. SU's description is - to me - slightly ambiguous as it refers to
a) 3 screws to fix float cover - like mine - (so obviously no HD8 type float chamber central pin or cover cap nut, or indeed float with hole)
b) a float stated to be with no central hole, -like mine - which is in line with a) - this by the way is the ONLY reference I have ever found to a float with NO central hole. SU does not state if brass or not, but was there ever a non-brass free floating float, and no central hole?
- but then
c) a FORKED float lever, which suggests a central pin in float chamber! (see in the pic my float lever is NOT forked, as no central pin)

d) Also, in my works manual (N3 Operations) it refers to a NYLON float (equiv stay up type I think) in the HS6 carb for the SC2000, so no mention then of any brass float for the HS type carb, even in Aug 1967. So confusing to say the least.
Note the HD8 carb described in the manual for the TC2000 does show a brass float, but with a central hole....

I don't think there is much more to discover on this - so I intend to purchase 2 x SUCarb Stay Up plastic float for HS6/8, and hope I can fit (or modify) the hinge to my chamber cover. What could possibly go wrong......
 

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Just now found this image online, not much text with it (US site I think), at least it shows my type of float and the plastic replacement!brass vs plastic.jpg
 
Andy
I think the reference to the "forked" float lever is a bit of 'Cut& Paste' when the instructions were generated for the HS carb, harking back to the earlier type with central stud fixing. . I worked at Longbridge in the early 60's when SU was owned by BMC . My early dealings with SU indicted that they were quite happy to accommodate all sorts specific manufacturers requirements and it looks to me that this was one of them for Rover. I personally had a completely one off ,none standard double ended fuel pump made for my Land Rover. I trust the 'stay up' float one does the trick. Looking at the pictures, I think you will need to take out the pivot pin , remove your lever and the Stay up float will fit in its place using the original pin, as it has its own built in lever.
PS The float kit with new needle valve looks good value for money.
 
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Hi, thanks, I tend to agree with you, slightly lost in 'translation' - manuals are not always 100% correct, and I am nitpicking the wording - wonder why Rover might have wanted this brass float, as the nylon one was available for the HS6 at the time.....same carb essentially.
The only concern I have is that the lever will be slightly too wide to fit to the cover in place of mine - other pics I have see suggest a wider lever hinge point - but hopefully SU have that covered; if not it is only thin metal!
Thanks for your help - just now ordered 2 kits.
Andy
 
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