22 replies to this topic

[Steve-O 2014]

Can anyone tell what carb this is from this picture? 

 

And I have ringed bits that are not connected / blanked off, why is this? 

 

Thanks

Attached Files

•  carb.png   663.92K   104 downloads
•  carb2.jpg   43.23K   83 downloads

[Dan]

It's an SU HIF44, the ports running right through the manifold are for heating it with coolant which some people choose not to connect. The one on top of the manifold which is crimped over is a vacuum source normally used for a brake servo. The port on the carb body itself is the emissions port for driving a crankcase ventilation system. If these last two aren't being used they absolutely must be sealed, I wouldn't trust that crimping to be air tight and the open port certainly isn't.

Edited by Dan, 06 February 2014 - 01:17 PM.

[phil hill]

Carb is an HIF of some sort, either 38 or 44.

 

The angled connection on the carb is for the crank-case breather.  There should be a hose there from either the pot on the transfer gear housing, the timing chain cover, or both using a Y connector.

 

The thing which looks like it's been folded over and crimped shut is the servo vacuum line.

 

The other two connections are the water heating to the inlet manifold.

 

Phil.

[Steve-O 2014]

Thanks so is the manifold heating needed? 

 

Also does the vacuum for the brakes make a difference? It has been folded over and welded / soldered shut. 

 

 

Could that open crankcase ventilation port give running issues? 

 

Thanks

[cal844]

1)  no, the heated manifold isnt required, 

 

2)  aslong as this is done to a good standard it will be fine

 

3) no it wont as i have driven my 1275 (1993 L registration) with this disconnected and its fine 

[Steve-O 2014]

Thanks, I looked at a pic of a HIF44 and it says the "Vacuum Advance" connects to the Distributor. On my 998 the "Vacuum Advance" is connected to the top of the manifold.

 

Is that ok?? 

 

 

Also, I put my finger over the open breather port (blocking it off) and the revs dropped. is this how it should be? 

Edited by Steve-O 2014, 06 February 2014 - 02:48 PM.

[lrostoke]

I'd cap that open breather off..but you may need adjust the mixture after,

 

So you are running the dizzy with no vac advance,

 

HIF44 is a pretty big carb for a 998, what mods you running

Edited by lrostoke, 06 February 2014 - 02:56 PM.

[Steve-O 2014]

Where on the dizzy does the vac advance attach? Its how the previous owner left the car so I have no idea on whats going where and why or anything about mini engines :) lol.

 

Previous owner said its rebuilt to 1000cc high compression with I think he said larger valves in the head. 

 

 

either way its not running too good unless the choke is pulled out all of the time..... 

 

Not using the mini right now just incase its running lean, dont want it to go pop and dont want to pay for it to be setup / tuned if it is the size of the  carb causing the problem..

Edited by Steve-O 2014, 06 February 2014 - 03:01 PM.

[phil hill]

Manifold heating : a much discussed topic.  Some say yes, some say no.  It's up to you really, with a couple of caveats.  If you use the car year-round you may have carb-icing problems on a cold but moist day without it.  The plumbing can be problematic as the Mini tends to have 1/2 inch hoses where the Metro manifold has 5/8 hoses.  Later Mini's switched to 5/8 hoses so weren't a problem but the heater taps are still generally 1/2 inch.

 

Servo brakes : again there is much discussion.  If you don't have a servo then you won't miss it I guess.  There are more elegant ways of blocking the port off, a cap screw or bolt for example.

 

Vacuum advance : there is usually a small stub for connecting the vacuum advance.  It's possition changed a few times depending on the carb and model, but fundamentally it's the same.  For a road car it's better to have than not, but if the engine is modified the advance curve is unlikely to be optimum for your engine.

 

Edited to add : Picture two shows both possible vac advance ports, one on the carb and one on the manifold piped together with a short length of 2mm black pipe.  The reason there are two places is because the MG metro had a different vac pick-up (and a different distributor advance curve to suit) than the "normal" 1275 Metros, it looks like you have a mix-and-match set of carb and manifold.  

 

Crankcase vent : Well the open port will be pulling unfiltered air into the carb under certain conditions, mainly part throttle, which is where you'll be running most of the time. This also means that there is more air getting into the engine than the fuelling part of the carb is "sensing", which is perhaps why the engine runs better with the choke out.  From both the points of view some kind of cap is recommended, like a suitable plug, bung or bolt fitted into the hole. 

 

I'm going to guess the engine breathers are either open or have the little "breather filters" on them.  It should be possible with minimum fuss to pipe them back to the carb and get rid of the smell of burnt oil and sticky oily mess over the engine bay !!

 

Phil.

Edited by phil hill, 06 February 2014 - 03:15 PM.

[Steve-O 2014]

Thanks for the reply

 

Going by this image here - 

 

 

the carb is a HIF44 

 

(Attached a pic of one fitted and it matches that image)

 

 

 

Attached Files

•  CarbHIF44.jpg   149.27K   13 downloads

[Steve-O 2014]

Heres a pic of the engine, is that small filter to the right the breather? 

Attached Files

•  Engine.jpg   164.47K   105 downloads

[phil hill]

Yes it looks like an HIF44

 

And yes that is the timing chain cover breather.  There may be another on the other side behind the coil on the transfer gear case, but it depends as not all models had them.

 

If you can I would run the vac advance from the nipple on the Carb to the dizzy and cap off the one on the manifold.  

 

Phil.

 

Edited : Because doh I got the vac ports the wrong way around !!

Edited by phil hill, 06 February 2014 - 03:22 PM.

[Steve-O 2014]

I cant see anywhere to connect it to the dizzy? anyone got a picture of where to connect it?

 

Thanks

[Steve-O 2014]

is it supposed to look like this disc with the nipple on? If so this Mini doesnt have one fitted -

 

[phil hill]

That picture is correct, but if the dizzy has been changed for a different type, typically an Aldon recurved one, then it may not have a vacuum unit fitted.  This is the disc bit with the nipple on it for the vac line to attach to.  

 

Any idea of the spec of this engine ??  An HIF44 and a recurved non-vac dizzy is starting to make it sound like quite the build.

 

Phil.