MG6 engine (non turbo) in 1.8 Freelander - inlet & exhaust manifold issues

Hi Guys,

Some of you may have read my other posts about me having mated an MG6 cylinder block to an FL1 cylinder head, I’ve solved the cooling system issues but now I’ve noticed something else. This is a non turbo project as well.

When I took the inlet manifold off, I could have sworn that the outer 2 ports look brand new as in unused. Only the 2 middle ports look like fuel has entered them. I also notice that the exhaust manifold isn’t really getting hot like it should be, I can actually touch it, this is when I’ve let the car idle for about 20 mins. It’s hot but not hot like you can’t touch it, mines hot but you can touch it.

I’m using the original FL1 fuel pump, do I need to upgrade something? Sth doesn’t sound right.

Have you done a compression test ?

Could be inlet valve not closing allowing combustion gases back into inlet manifold, hence the discolouration.

Thanks Lynall I haven’t done a compression test as it runs nice and smooth when I start it up. I’ll look in to it.

I'd be doing a compression test. You'll be looking at a pressure of about 175 PSI, with about 15 PSI spread over the 4 cylinders.
Was the block definitely a non turbo block? A turbo block will have a lower compression ratio, so will run with less power than a higher compression unit.
Are you sure it's running on all 4 cylinders, as the exhaust runners from each cylinder should be way too hot to touch, 250°C or so at idle, and 600°C plus when under load.

Nodge68 said:

I'd be doing a compression test. You'll be looking at a pressure of about 175 PSI, with about 15 PSI spread over the 4 cylinders.
Was the block definitely a non turbo block? A turbo block will have a lower compression ratio, so will run with less power than a higher compression unit.
Are you sure it's running on all 4 cylinders, as the exhaust runners from each cylinder should be way too hot to touch, 250°C or so at idle, and 600°C plus when under load.

Click to expand...

Hi Nodge,

It’s definitely a Turbo engine block which I mated to the FL1 cylinder head with non Turbo set up. I’ll have to get a compression tester. If the car idles normally, I wonder why. The other thing that didn’t exist before is that I’m using the large MG6 coolant reservoir, I have installed it in the spare area opposite the camshafts, I’ll try find some photos. Ive also introduced an engine oil cooler (coolant based) which is from the MgTF, it’s bolted to the back of the block, the same bracket fits as on the MGTF. I have a Tpiece on the bypass coolant hose with a 16mm hose snaking it’s way to feed the oil cooler. As for coolant leaving the cooler, I drilled an extra hole on the coolant metal pipe and a single 16mm hose simply goes from the oil cooler to the metal pipe. So the coolant network is a lot bigger than the original Freelander one. Takes about 7L of coolant as opposed to the 5L for the original Freelander coolant network.
Could it be over cooling? I have monitored the coolant temperature last weekend as I bled all the air out, it idled nicely on the spot and in 25 minutes the temperature eventually showed 105 and the cooling fans came on slow speed resulting in the temperature dropping rapidly to the low 90s and the fans turn off.

Here are some photos of the metal coolant pipe I’ve customised with a 2nd hole and coolant port professionally welded in, to accept coolant from the nearby engine oil cooler. There’s a few photos there of the engine oil cooler also.

These photos show where I fitted the MG6 coolant reservoir.

If you are using a turbo block, then the compression will be lower than a normal k series, so it'll limit power output.

The K series was over cooled in standard form, so the cooling system doesn't need anything extra in the cooling department.

So just an update, it turns out all 4 exhaust manifolds are getting hot, previously when I thought they were cool to the touch was after I shut the car off, and I also note that they were wet from me having washed the coolant amongst the engine bay after having bled it.

But I let the car idle a few days ago and grabbed a laser type temperature thermometer, and the 2 middle pipes of the exhaust manifold are the hottest, about 150 degrees C, the two outer ones were 120 degrees C.

So it’s all good.