Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Air Intake improvements

Interesting report Paul. Would love to see photo's of your Roadster air inlet installation. Maybe compare it with this ARV6 setup.

My Rover V8 car gets very warm under the bonnet. I have done a couple of checks and the incoming air temp is > 20 degC higher than ambient. Based on the assumption of 1% more bhp per 7deg difference in theory I should get 2-3% more bhp. I may look to getting cool air in and see if I can feel a difference. The ultimate test would be a rolling road though. I wonder how the Gems system would react to the cooler air. That is the crux. The MAF is just after the filter box and no easy moving of it without fairly major surgery.
I am not chasing more bhp/torque but cooler air is beckoning.

Do you remember the thread when Lockheed Martin in the USA reported about the investigations in the wind tunnel? At that time, someone (an employee?) had his Rover Plus 8 tested there. The result was very interesting. The engineers' recommendation was to install a base plate in the front. In this way the air can flow through the radiator. This base plate should cover the area from the radiator to the engine.

Since I have an aluminum radiator in my 4/4, two things have changed. And I think it has something to do with the fact that this new radiator is wider and deeper.

The first thing I noticed was that now even more cold fresh air is being sucked up directly behind the radiator. That's good and really noticable during acceleration because my airbox is right behind the radiator...with the intake hole facing down.

The second thing I notice with my 4/4 is negative, but it's also an effect of the larger radiator: There's even less air flowing through the radiator, because the larger amount of fresh air coming from directly behind the radiator in form of an upstream from below will reduce the flow of air through the radiator even more. One air flow blocks the other.

So I notice quite clearly that the engine becomes much warmer at higher speeds, so from 140 km/h, than with the smaller original plastic radiator in the past. If it used to be 90 degrees, it's now 105 degrees.

This is a dilemma, and I want to experiment with a base plate in spring, to block the upstream so that more air flows through the radiator.

At the same time I want to make an opening with a pipe in this new base plate so that the airbox gets cold air, but the radiator continues to have air flowing through it.

In this way, the overall temperature in the engine compartment would have to drop, even in Plus 8.

I fitted neoprene side panels inside my cowl to stop air passing either side of the radiator. That's a simple mod using polyethylene (high density) neoprene.

The front of the Trad is messy, and fitting an under-tray between the cross-head and engine was an early mod. All that takes is a piece of sheet aluminium (cut to shape). You don't need to drill the chassis because it can be fixed securely with overlapping penny washers.

When I ran my Roadster with a front spoiler, the ducted air was directed onto the bottom radiator tank, and the under-tray kept it in the engine bay until it could spill out around the exhausts.

At that time I didn't have the confidence to make a curved front valance. Once I could I removed the spoiler, but there's no obvious difference in cooling.

Cain has been experimenting with a super undertray around his engine, and talking to him it seems he's found a big difference.

So anything you can do to tidy up the messy airflow has a good chance of reducing temperature, and might even reduce drag!

Heinz, quick but maybe stupid question.
When you changed the radiator did you change anything else?
Thermostat maybe?
Hope my question doesn't seem insulting.

HI Richard.
I would post you some photos if I could work out how to compress to the required size on my windows 7 lap top.

IvorMog, your Q is in no way insulting. All good:)
The thermostat remained and it works. It is just the new effect when I drive faster than lets say 130 km/h. There is a significant hotter engine temprature than with the original smaller radiator. Normally you will expect a better coolant capacitiy with the bigger surface of the new aluminium one. And this works as expected e.g. when being in a stop and go situation.

I have the same problem but it's always been there, fitted an aluminium rad, still the same, fitted an aluminium block plate from the base of the intake behind the grill shaped down to the bottom of the rad to prevent spillage, not sure about the result of this because I did it recently after the cold weather started but it looks like it'll be the same so it's interesting to read about the air pressure build up in the engine bay, hadn't thought of that with all those louvres facing aft. I'll wait till warm weather and bear that in mind.

Take a look here: https://www.tm-img.com/page/ifu
Join TM-IMG (if you don't have an alternative photo hosting site available) and post links to your photos stored there

I ran a full valance (not just flap) and flat floor under the engine on my 4/4 racer. It makes a lot of positive difference in terms of managing airflow correctly.