24 replies to this topic

[28hodge]

Hi, couple small issues that I could do with some advice on.

 

First one is to do with a odd noise, like a rattle/rasping type sound, it only occurs when I come off the throttle whilst in gear, it seems to do it more/louder at lower road speeds, though this may just be because there is less noise so it is more noticeable. If I apply a tiny amount of throttle then it will stop, as if when I put the tiniest amount of load through the drivetrain it stops as if it removes any backlash if that makes any sense. Also if I dip the clutch it will stop. If the car is in neutral or stationery there is no noise. It seems to be coming from the centre of the bulkhead as if its coming from the diff? any ideas what it could be?

 

Next is my awful MPG, I took the mini to work last Friday, about 40mile each way and it seemed ok, it was fast A roads (A6 from Kendal to penrith) so was about 4000rpm most of the way at 60-70. 2 things happened, the temp gauge only got about halfway between cold and normal, but it was running cold as the heater wasn’t very hot, only warm. It also used the best part of a full tank of fuel! For about 90miles I reckon its done about 20mpg, I need to refill the tank to confirm.

 

The car is as follows

 

MG metro 1330

Twin hs4 with AAA needles, fully rebuilt before fitted last month.

ITG filter with MED sub stacks

Mini spares Evo 1 cam

Std head

Unknown LCB exhaust with RC40 box

 

Now on the way home I heard a rattle so pulled over and it had lost a wheel nut, not to worry as I had my socket set with me and had ordered some new nuts and wheel studs anyway as a couple are quite short. Only numb nuts here had forgotten he had taken the socket set out so I had to call a mate to nip out wit an socket and breaker bar. Anyway he followed me home, and said that he thinks most of the fuel I was putting in the engine was coming out again!! He said he could smell fuel all the way home so its running rich, could this also be causing the cool running temp? Additionally I had to move it last night between garages, is been cold up here, around 0degrees, it’ll start up with no choke! However using the lifting pin it’ll react as it should with a slight increase in revs.

 

I have ordered some AAK and AAU needles so will give them a try when they land this week, and will have a look at the thermostat when the gasket that I have ordered turns up also.

 

Any advice

 

 

[Ethel]

You could jack it up so you can turn a wheel back and forth to investigate the amount of free play across the diff. I'd also give the ignition a once over before chasing fuel faults.

[racingbob]

my front wheel turns 35 mm in gear and got new dif pin. my mates all new drive train about 20mm. before my dif pin and pot joints was 50mm

[28hodge]

You could jack it up so you can turn a wheel back and forth to investigate the amount of free play across the diff. I'd also give the ignition a once over before chasing fuel faults.

 sorry should have said ignition is Aldon Yellow advanced to 12deg and running lumenition elec ignition.

 

I'll jack up one side and turn the wheel and see what i get the gearbox is a MED rbg2 3.44 x-pin rod change, i have an invoice for it but have no clue what it actually is and neither do MED when i rung them. I bought the car and didnt build it myself hence why I am a little hazy on some details.

[wile e coyote]

Has this been set up on a rolling road? Assume not.....Does the oil smell of fuel -  IMHO for a road going car twin HS4's look nice but are overkill - if I remember rightly the AAA needle is the one supplied by Minispares as part of the stage 1 kit for a single HS4 carbed car - a pair must be chucking in a huge amounts of fuel, washing the bores and doing generally unhealthy things to your engine... a single HIF44  would suffice...I don't want to appear alarmist but a decent set up, should be first order of business.

 

I'd hazard a guess that your rattle may be linked - possibly the oil being thinned by unburned fuel and for example the rockers being inadequately lubricated as a consequence......

[dyshipfakta]

Agreed. A hs4 and AAU needle thats leaner then aaa supplys plenty of fuel for my 998 stage one.

[28hodge]

I'd like to run a hif44 but the car is a historic rally car to be used in hrcr events, so has to run hs4's, it was also minispares who told me to put the AAA's in and I did query them, the oil I have changed at the same time as the hs4's went on and the oil level has dropped a little (all minis leak right!!)

Set up on a rolling road would be great but there isn't one within an hour of me so can't happen in the immediate future.

Not sure I completely agree with what your saying about the carbs and metering of fuel though, as the cylinder will only see one carb when on the correct stroke same as if it was on a single or a twin set up? It hasn't got access to both carbs and the available fuel/airflow from both. That said the needles are too rich.

For the cost of it I'll change the oil again and give it a good look at and see if it's been thinned, swap the needle to the leanest and start a fresh from there.

Edited, typo, it needs to run hs carbs not specifically hs4's

Edited by 28hodge, 19 March 2018 - 10:20 PM.

[28hodge]

my front wheel turns 35 mm in gear and got new dif pin. my mates all new drive train about 20mm. before my dif pin and pot joints was 50mm

Just checked when got home, 30mm so shoulda fine

[cal844]

Change the oil then change the needles too AAK OR AAU

[Rorf]

You are using a standard head so definitely do not need twin HS4s. Rattle on over run could be the timing chain.

[28hodge]

Ta for the pointers, I was advised to install hs4's over hs2's as they will cope with anything I do to the engine in the future, also asked MED their advice and they suggested twin HS4's along with the ITG filter set up, either way that's whats on it so will have to stay on it for now.

 

I'm not really after maximum power out of it just clean fuelling and drive ability as that's more important for the HRCR events. I'll see how i go once the needles are leaned off.

 

The rattle is an odd one, if it was due to the oil being thinned with petrol then i would assume then it would rattle at idle/revved up when stationary, and dipping the clutch would make no difference, same for the timing chain, that's why I am a bit puzzled by it?

[Rorf]

Rattle could also be coming from the drop gear in the transfer case. Is it linked to engine speed or road speed?

[28hodge]

Hmmm,

 

Just rung minispares again now to see if the gave me different advice and they said the exact same AAA. Also as we are going to Motorpoint in Burnley on friday to get a new car for the GF I gave minisport a ring to see if i could take the mini and get it on the rollers, however they rollers are currently broken so thats not happening.

 

They are the only rollers within an hour of me! 

[28hodge]

Rattle could also be coming from the drop gear in the transfer case. Is it linked to engine speed or road speed?

 

Road speed, and it seems worse/loudest when off the throttle at lower road speeds sort of 30 and down. When I did a search the other week the drop gear was something that came up, i think from reading this wants looking at pretty sharpish as it will soon wear the housing?

[Rorf]

Drop gear would be engine speed related. Diff components would be speed related. Also gearbox could be where the rattle comes from.

 

Looks like strip down time before any major damage happens.