Waynebaby Posted July 13, 2017 Report Share Posted July 13, 2017 Hi Folks, I wonder if any GT6 owners who have a mill-board radiator cowl would mind taking a look at the attached photo and letting me know if their cowl looks like mine? I fitted it about 2 years ago using the Canleys drawings as a guide. Ever since fitment the leading edge of the cowl has got progressively lower and more concave to the point where I'm now starting to think that it may well be obscuring the radiator rather than directing cool air into it. I can imagine that when the car gets moving the air coming in through the gap between the bonnet and the bumper probably hits the top of the cowl and flattens it in front of the radiator. The car is running slightly hotter than usual and I'm trying to eliminate easy-to-fix causes first. What do people think? Is the cowl meant to do this and am I worrying for no reason? Do the aftermarket aluminium cowls have this issue? (I'm guessing not) Thanks Wayne Link to comment Share on other sites More sharing options...
dougbgt6 Posted July 13, 2017 Report Share Posted July 13, 2017 I have an original cowl and it's exactly like this! Don't know what yours is made of but the original is not far off cardboard and with age. droops. The club shop sell aluminium ones I'm tempted, but first I'm going to try a wood or metal strap on the underside, out of sight, to pull it back to shape. Link to comment Share on other sites More sharing options...
AidanT Posted July 13, 2017 Report Share Posted July 13, 2017 I have the Aluminium replacement and yes it does not droop! The idea is to force more air through the radiator fins rather than escape around it and it does make a difference. The material looks similar to the replacement glove boxes i have which started to curl up. I think you could use the same solution I used, which was to cut out some this ply wood and epoxy glue it to the card to stiffen it up. I would be concerned that your droop is stopping the airflow through the radiator rather than helping maybe? Or just replace it with an Ali one! Aidan Link to comment Share on other sites More sharing options...
dougbgt6 Posted July 13, 2017 Report Share Posted July 13, 2017 I would hesitate to use plywood as it to can easily sag. I'm going to try a fairly heavy piece of wood , all that will be visible will be the bolt heads on either side of the cowl. The only problem with the ally one is that it doesn't have the holes for the carb air box inlet pipes, they would have to be cut in. Link to comment Share on other sites More sharing options...
Waynebaby Posted July 13, 2017 Author Report Share Posted July 13, 2017 Thanks everyone, Looks as if I'm going to have to do something for my droop then (oo-er missus!) I'll probably go down the aluminium route since the whole thing seems too flimsy to do the job it was intended to do and I'm concerned that if I start modifying it with any heavier material then it might just finish it off completely. I got it from a good supplier but it was a toss-up whether the cowl or the packaging it came in was made of the stronger material. Wayne Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 13, 2017 Report Share Posted July 13, 2017 i can only add if you have droop problems youre on the wrong forum again . the guy who invented Millboard should be sent on a long trip to timbuktu theres a joke around Pete Link to comment Share on other sites More sharing options...
Colin Lindsay Posted July 13, 2017 Report Share Posted July 13, 2017 You can make a good reinforcement by rivetting a thin strip of metal along the underside of the top edge to retain the shape - the long strip you get for radio supports with the elongated bolt holes is perfect for this. Link to comment Share on other sites More sharing options...
dougbgt6 Posted July 13, 2017 Report Share Posted July 13, 2017 I just said much the same as that. Nobody listens. Link to comment Share on other sites More sharing options...
Adrian Posted July 13, 2017 Report Share Posted July 13, 2017 I've got a picture of the club museum car, whilst a lot straighter it is showing a slight droop. I think we can all agree a droop is part of the ageing process! Link to comment Share on other sites More sharing options...
Waynebaby Posted July 19, 2017 Author Report Share Posted July 19, 2017 Just to finish off this thread I've attached a picture of the aluminium radiator cowl (ordered from and dispatched promptly by the club shop) now fitted on the car. It definitely looks a lot better but it remains to be seen if it'll help cool the engine better than the old droopy item. Wayne Link to comment Share on other sites More sharing options...
euan douglas Posted July 19, 2017 Report Share Posted July 19, 2017 I don't have any overheating problems on my GT6, but have sometimes wondered if an aluminium cowl would keep it cooler, so I'll be interested to hear your experiences. By the way, how is the cowl attached to the radiator as I can see no obvious places to attach one on mine? I like the intake hose attachments, how did you do that? Euan Link to comment Share on other sites More sharing options...
dougbgt6 Posted July 19, 2017 Report Share Posted July 19, 2017 Wayne, I'm all excited, did it come with the air intake holes or did you cut them? Link to comment Share on other sites More sharing options...
Waynebaby Posted July 19, 2017 Author Report Share Posted July 19, 2017 Euan and Doug, The cowl fits with three bolts on either side. The bottom two go through the holes in the bottom radiator mount that the engine bay valance fastens to and the top bolt attaches the cowl to the hole at the top/front of the engine bay valance. I've attached a photo which might help. I had to cut holes with a 2" hole cutter and used two 1.25" hose-tail adaptors from the local fish-pond shop to attached the hoses (cost about £10). I've also attached a couple of photos to help show what I've done. Wayne 1 Link to comment Share on other sites More sharing options...
Gully Posted July 19, 2017 Report Share Posted July 19, 2017 I fitted an aluminium radiator cowl a couple of years ago and did notice an immediate improvement in cooling efficiency over having no cowl at all - no more higer temperatures on the motorway than A / B roads was the most noticeable difference. I cut two holes in mine for the air box feeds - no such elegant connectors though: I held mine in place with zip ties! Mine also came with 3 fixing holes, but as I don't run the valences the top holes had nothing to connect to and the cowl was a bit loose. I made up some brackets from lengths of aluminium angle and fitted them to the back of the two lower bolts on the back side of the radiator bracket to the cowl and attached the top holes to those, resulting in a solid fixing. Gully Link to comment Share on other sites More sharing options...
John Bonnett Posted July 20, 2017 Report Share Posted July 20, 2017 Euan and Doug, The cowl fits with three bolts on either side. The bottom two go through the holes in the bottom radiator mount that the engine bay valance fastens to and the top bolt attaches the cowl to the hole at the top/front of the engine bay valance. I've attached a photo which might help. I had to cut holes with a 2" hole cutter and used two 1.25" hose-tail adaptors from the local fish-pond shop to attached the hoses (cost about £10). I've also attached a couple of photos to help show what I've done. Wayne Nice job Wayne. 1 Link to comment Share on other sites More sharing options...
dougbgt6 Posted July 20, 2017 Report Share Posted July 20, 2017 Yes, looks good Wayne, are you tempted by the ally side plates? A couple of the guys at East Berks have them and the do look good especially with the vents in them. My cardboard ones have been undone just a few times but the fixing holes are starting to suffer. Do I detect your number plate is over your grill?!! Link to comment Share on other sites More sharing options...
Waynebaby Posted July 20, 2017 Author Report Share Posted July 20, 2017 Doug, I keep looking at the ally side plates and must confess that after seeing the quality of the radiator cowl I'm tempted (although the cardboard originals are still in a pretty good shape so I should probably spend my money on something more urgently needed for the car - like an O/D and gearbox re-furb!) The number plate is indeed hanging off the bottom of the front bumper which is where it was when I bought the car. I know I should move it to improve air-flow to the radiator but don't know the best place to move it to. I've seen some plates hung off the bottom of the front spoiler but I worry about ground clearance. Where is your plate attached? Wayne Link to comment Share on other sites More sharing options...
euan douglas Posted July 20, 2017 Report Share Posted July 20, 2017 Wayne Thanks for the photos etc - gives me something to think about and I'm following the thread with interest. Euan Link to comment Share on other sites More sharing options...
dougbgt6 Posted July 20, 2017 Report Share Posted July 20, 2017 My plate was also under the bumper, but I straightened out the brackets and got it down a further 2 or 3 inches. I intend to put it on the front valence. Other GT6s in East Berks have it mounted here. Lowest point on the car is the exhaust towards the back, lower than a valence mounted plate. I think the problem would be nose on to a high curb. Link to comment Share on other sites More sharing options...
Gully Posted July 20, 2017 Report Share Posted July 20, 2017 Doug, The number plate is indeed hanging off the bottom of the front bumper which is where it was when I bought the car. I know I should move it to improve air-flow to the radiator but don't know the best place to move it to. I've seen some plates hung off the bottom of the front spoiler but I worry about ground clearance. Where is your plate attached? Wayne My number plate was also hung from the bumper - moving it downwards made a real difference to cooling. I've attached a photo which indicates its position. I used four L shaped furniture corner brackets in pairs to form extended U shapes with the inside verticals going through the grille above the valance and returned behind the chassis rail where there are some useful unused holes. The front verticals hold a horizontal bar to which the plate is attached. Took me about an hour to do using bits I had in the shed! Gully 1 Link to comment Share on other sites More sharing options...
dougbgt6 Posted July 20, 2017 Report Share Posted July 20, 2017 Clever! Link to comment Share on other sites More sharing options...
Waynebaby Posted July 25, 2017 Author Report Share Posted July 25, 2017 Hi All, Here are my unscientific observations on the effects of the changes I've made to the cooling air supply on my GT6 Mk3: Although it looks a lot better, the aluminium radiator cowl is no more effective at cooling the radiator than the droopy old mill-board, however running with no cowl did make the engine run noticeably hotter. The biggest improvement came when I took on board Doug's suggestion and copied Gully's method of attaching the number-plate lower down in front of the chin-spoiler (i.e. not hanging off the bottom of the bumper directly in front of the radiator grill) Moving the number-plate here has dropped the motorway temperature by a full interval on the standard temperature gauge so it now runs smack in the middle of the range. Result! Thanks guys. Wayne 1 Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 25, 2017 Report Share Posted July 25, 2017 and make a sponge doughnut to seal the bonnet grill to the heater intake so no stray engine side air goes down the heater intake you cant rely on the baulkhead seal get some cheap foam from places like dunelm etc thick enough to fill the gap under the bonnet heater intake grill, and seal the tunnel and missing grommets . Link to comment Share on other sites More sharing options...
dougbgt6 Posted July 25, 2017 Report Share Posted July 25, 2017 Particularly important on a GT6, it has the standard Spitfire baulkhead seal which doesn't seal to my power bulge. I've modified mine with draught excluder, it works, but looks a bit of a bodge. A sponge donut looks like the way to go. New three piece suite in a couple of weeks, so the old one looks like a donor. Link to comment Share on other sites More sharing options...
Pete Lewis Posted July 25, 2017 Report Share Posted July 25, 2017 you will be making whoopee cushions next !!!! Link to comment Share on other sites More sharing options...
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