Another first for me , anyone tried it ?
Seller is a good guy - have had a few dealings over the years.
Paul (Saltwick) recommends such a panel as well as louvering inner wheeler arches / engine bay walls or removing the triangle panels. Somewhere on here there is a good picture of one fitted - if memory serves may have been referred to as a belly pan.
My car will be going in for a few touch ups (scrapes / scratches) in the winter so I might have the bodywork chaps fabricate something from sheet aluminium for our car; I will create a card template first, and might well have a go myself first. What’s the worst that can happen…
I did essentially the same thing with my 3.8S many years ago. Sits on the ledge of the subframe and held on by wing nuts at the front for easy removal for servicing. Do not have the technical equipment to measure if this is effective or not but was told it helps reduce under bonnet air pressures and thus aids flow through the radiator.
I tried one of these after opening up triangles didn’t seem to make any difference. Neither did this kind of a setup.
So I tried to inverse, which is a ramp to scoop air UP towards the engine. You’d be amazed at the difference, the temp actually drops the faster you go and after a long highway run the temp stays steady, or raises maybe a degree or two, at stop.
The only downside is I’ve started to notice at speed hitting dips the lip of the scoop scraped the road
Would it be possible to post a pic?
Interesting point. I get the argument that a blanking plate prevents back pressure reducing the flow through the radiator. The sump has fins presumably so that air flow will help cool the oil. Maybe your scoop directs more air on to the sump? which leads me to think maybe do both - blanking plate to help air flow through radiator and then a scoop to direct air onto the sump?
Am not an engineer, so I could be completely wrong, about my experience is that this approach functionally made a difference. The “ramp” pushes air basically directly onto the crank pulley, so most likely the air flows around either side of the block / sump and then down the trans tunnel and out the back. I have noticed that my trans tunnel gets hot at speed (I have a T5 which should not get hot) so perhaps this is an indication that it’s pushing the heat out of the engine bay and I’m feeling it in the tunnel instead. I would also assume that air coming in through the radiator is then also drawn through the engine bay and out the back. So I hope at least it has a positive affect on that too.
As you imply it’s quite difficult to work out what is going on. I am an engineer, but electronics so I am as in the dark as everyone else. It could well be that your scoop creates an air flow which helps draw air from the back of the radiator and the fact that your transmission tunnel is getting warm is strong evidence that you are moving hot air from somewhere in the engine compartment. Given how ineffectual the heater on a Mk2 is even in the relatively mild winters that we get in England that is another benefit of what you have done. These cars were certainly not optimally designed for air flow as standard! My view is that what you have done is clearly having some beneficial effect and so if it ain’t broke…
As a related aside…If the instrument voltage stabilizer fails, the temperature gage will read higher as engine RPM (read generator/dynamo speed) increases. I discovered this fault when my Morgan +4 began reading warmer than normal when being driven at speed. The gage read cooler when the vehicle was at a stop. After going through all of the usual suspects…Thermostat, cooling system flush, etc…I could not resolve the issue. I then began to focus on the temperature sender and gage itself and that’s when I discovered that the 10v stabilizer had failed and was allowing the voltage to increase/decrease at the gage in conjunction with the generator/regulator output. In the end, the cooling system was operating properly.
This may be more folklore than science but I recall in the early days of this List - of a discussion of the belly pan being installed to avoid airflow hitting the front axle sub frame and the airflow forcing its way up into the engine compartment thereby creating back pressure behind the radiator.
MK2 Cincinnati OH