AC 428 owners experience?

[Roy Gardiner]

I'd be interested in knowing users experience - good and bad - arming myself with that knowledge prior to, maybe, buying one.
   
   I love distinctive, classic cars.  I love 'no depreciation', too [].
   
   The coupe, rather than the convertible, would probably be my choice, with auto rather than manual box (laziness; dodgy knees).
   
   Any help appreciated.

[david langford]

Dear Roy
           The only problem I've had with mine is trying to keep the engine temp down.It chucks out loads of heat so,if you get a coupe,
    make sure the electric windows work or carry your dinner with you and have it cooked when you get home.
                            Dave

[Emmanueld]

Hi Roy,
   
   I own a convertible and I have the same problem with heat, I am in the process to insulate the whole car inside and underneath, we will see what happens afterward. Also the car is being converted to a manual box. Heat should be reduced as well! Also watch out for rust! These cars were coach built and not well rust proofed. The sills and the floors are particularly prone to rust. They are easy to repair but it will take a lot of labor to replace all the tubing and sheet metal that has gone bad. I suspect that one of the reason why the car is so undervalued is that most of them are quite rusted and that people have not been willing to spend the money to repair them properly!
   
   Engine is straight forward big block Ford! Cheap and easy! Aluminum heads are the way to go with modern fuel. You can run your engine with 10.1 compression and it will never overheat. An oil cooler might be a worthwhile addition as well. There are other mods if you are interested, all the Shelby guys have done the modifications over here.
   
   The other weakness of the car is the suspension, it is set too low and it touches the ground every time you get in a driveway or a garage. The problem is that the rear upper control arms are not adjustable, so they should be replaced by Cobra 427 control arms. Shocks are too soft, spring rate is too low. My original springs were rated at 325 Lbs all around vs 400Lbs Front and 600Lbs Rear on a 427 Cobra, Meanwhile the car weight 1,000Lbs more. A nice set of Konis' will change that! With stiffer springs and shocks the car drives a lot better and still has a good ride! I might install a front sway bar as well. The Frua was never fully developped and can be improved easily. It is a true exotic and with a bit of twicking, it will leave in the dust just about any 60's or 70's Ferrari or Lamborghini.
   
   Emmanuel

[Emmanueld]

By the way, a friend of mine has a really nice AC Frua Coupe, California car since new, the car looks like it came out of the factory when put on the lift. He has the same problem, heat, heat and touching the ground. He will do the same modifications as I did soon.
   Emmanuel

[AC Ace Bristol]

Hi
   
   All 428 Fruas have heat dissapation problem/s,  there is insufficient air comming into the engine bay,  most that enters becomes stagnet over the top of the engine.
   
   Best solution to get rid of build up of under bonnet heat is to have two rows of 15 or 16 louvres cut into the bonnet,  major problem solved !!
   
   Try this little test........ Run the car hard on the road or track & monitor temperature ( Do not exceed 120 degrees).
   
   Let the Beast cool down, Have a coffee, Now do the same run again just as hard with the bonnet securely held open by about 25 / 35 mm....... you should find that the temperature is substantially lower.... problem solved.
   
   Either run with the hood partially open or cut the louvres in the bonnet and enjoy driving hard and fast with-out constantly looking at the bloody temp gauge.
   
   This test was carried out by a few ACOC members at Nurburgring or Spa many years ago, a article actually appeared in a very old back issue of ACtion. When I get some spare time I will try to find the Article and get it published on the forum, ( I think the article was in back issue during the period..... late 70s or early 1980s.
   
   Please try the test and come back with your results, you should be pleased, U then  O Me a bottle of Malt.!!   Go and Seriously Enjoy the Frua as it was intended but never experienced.
   
   Keith

[Emmanueld]

Keith, Thanks I will try this and get back to you! I will not mess up the original hood which is still gorgeous! what I will do if this works is have an new aluminum hood made up with louvers to correct the problem! I had to pull the motor out last year for mechanical reasons and we insulated the firewall with aircraft insulation, did not make much difference. I think the floors behind the front fender panel would benefit from insulation as well. I will try that as well and report! Here in LA the car is almost impossible to drive in the summer, even with the top down!
   
   Emmanuel

[AC Ace Bristol]

Emmanueld
   
   Have made time and found the article, reference a solutionto curing overheating problem on  AC 428s Cobras even Cobra Daytonas'.
   
   Pages 9 , 10 & 11 in ACtion Vol 8 No6  ( October 1984 ) written by Wolfgang Rudolf.  I will attempt to get it reproduced on the Form.
   
   Most Sports / Exotic cars with plenty of grunt have either or / And,  not only adaquate cold air intake but also have features eg Louvres or shaped body panels to allow hot air to be drawn out and away from the heat source.
   
   Unfortuneatly ACs restricted the frontage of the car, put inadaquate side vents which incidentaly they then obstructed with other items, The heat builds up and has no where to go.
   
   Fitting bigger rad would help a little, extra electric fans can move the air, but does not extract and take the stale stagnent air away from under the hood ( BonnetExtract from ACtion feature.
   
   Test drives on the Nurburgring Grand Prix Circuit with an air scoop and opened bonnet (Hood) showed no overheating tendencieseven under extreme driving conditions.  With the bonnet (hood) closed overheating showed itself within a few minutes, which clearly showed that air inlet and outlet are entirely disproportionate.
   
   Carrol Shelby, Bob Bondurant etc all experienced similar / same problems with the Daytona Cobra/s.You MUST get rid of the engine heat with a  continuos adaquate flow of cold air, 20% to30% of engine heat is taken away by coolant (water), 30% or more needs to be removed by air flow around the engine.
   
   Some of the Cobras and Aces racing in the UK, especially endurance 1 -1/2 hours or more run with the rear edge of the bonnet locked open by using extended securing pins.( 1" t0 !.5") Doesnt look too pretty but does the job, however two rows of 15 louvres looks purposfull, looks cool and allows the engine to run cooler, the occupants can enjoy the drive and arrive at there destination reasonably dry and comfortable.
   
   Check out 1960s.... Aston Martins, Jensons, Iso Grifo, Bizzarrini, Ferrari 250s etc etc,  all have adaquate heat extraction built into the contours of the body, these features are expected and serve a purpose, pity AC didnt spend a little more time in the wind tunnel or design stage  to overcome this persistant problem. Carry out the test and you will enjoy the 428 like never B4.
   Enjoy ! !
   
   Keith
   
   Keith

[Emmanueld]

Thanks Keith,
   
   About building louvers on each side inside the fender wells? and channeling the heat to the side vents? This should be relatively easy to do! Maybe using small fans, I used to have a Ferrari Mondial T, This is the way the heat was extracted from the oil cooler on the side! Although louvers in the hood sound like a better idea! The Aston V8 also has a bigger opening in the back of the hood, would that help?
   
   Emmanuel

[AC Ace Bristol]

Emmanueld
   
   The Louvres,  2 rows of 15 are cut in the hood / bonnet, to let the hot air escape from above the engine The  hot stagnet still air needs to be released, The colder air travelling up and over the bonnet will help draw the hot air out and away.
   
   Extra extraction in the inner wing area or from under the car can only help.
   
   Air scoops on the hood / bonnet on the Ace or Cobra do very little if anything regards heat extraction . It does however help force colder air into Carburration which for normally aspirated engines is a positive step in the right direction. The two rows of louvres in the rear of the AC Aceca bonnet release hot air, Why the Ace never wore these we shall never know. But they would certainly help dissipate  the unwanted hot air which is trapped towards the rear of the engine and bulkhead area, hence Ace Bristols run hotter on cylinders number 5 and 6.
   
   Any form of ductwork from the engine bay to lead hot air into a colder stream of passing air is going to in turn help draw more air into the engine bay which will absorb excess heat away from the engine thus reducing your problem of overheating. ( If stuck in heavy traffic putting the heater on full takes heat away from the engine because you are in effect employing a second radiator, however it puts the hot air into the passenger area.
   
   Conclusion:-
   
   You must increase air flow into engine bay and release it away even quicker, In theory easy  However in practice bloody impossible with the basic design of the 428. Try the open bonnet trick to prove the theory, then  be brave and get the body shop to create the 30 louvres.. ..
   
   Keith
   
   Keith
   
   Keith

[Emmanueld]

Would you have a photo of the AC Aceca bonnet by any chance?
   
   Emmanuel

[AC Ace Bristol]

Emmanuel
   
   Please confirm your email address  and I will send you some pictures, In the meantime I will speak to Andy Shepherd and a couple of other Frua 428 owners, e.g.  Adrian Dawn (CF73) & Tony Valenti (CF69) to see what mods they have carried out to reduce the heat problem, I will also try to find out a contact for Wolfgang Rudolf, (CFX27)  He is a club member or was in Feb 2004. I can confirm his possible address in Mannheim Germany, assuming he hasn't moved in the past three years,  Might be worth you make contact with ACOC membership sec.  Tony Morepeth.
   
   Keith

[Emmanueld]

quote:Originally posted by AC Ace Bristol
   

   Emmanueld
   
   Have made time and found the article, reference a solutionto curing overheating problem on  AC 428s Cobras even Cobra Daytonas'.
   
   Pages 9 , 10 & 11 in ACtion Vol 8 No6  ( October 1984 ) written by Wolfgang Rudolf.  I will attempt to get it reproduced on the Form.
   
   Most Sports / Exotic cars with plenty of grunt have either or / And,  not only adaquate cold air intake but also have features eg Louvres or shaped body panels to allow hot air to be drawn out and away from the heat source.
   
   Unfortuneatly ACs restricted the frontage of the car, put inadaquate side vents which incidentaly they then obstructed with other items, The heat builds up and has no where to go.
   
   Fitting bigger rad would help a little, extra electric fans can move the air, but does not extract and take the stale stagnent air away from under the hood ( BonnetExtract from ACtion feature.
   
   Test drives on the Nurburgring Grand Prix Circuit with an air scoop and opened bonnet (Hood) showed no overheating tendencieseven under extreme driving conditions.  With the bonnet (hood) closed overheating showed itself within a few minutes, which clearly showed that air inlet and outlet are entirely disproportionate.
   
   Carrol Shelby, Bob Bondurant etc all experienced similar / same problems with the Daytona Cobra/s.You MUST get rid of the engine heat with a  continuos adaquate flow of cold air, 20% to30% of engine heat is taken away by coolant (water), 30% or more needs to be removed by air flow around the engine.
   
   Some of the Cobras and Aces racing in the UK, especially endurance 1 -1/2 hours or more run with the rear edge of the bonnet locked open by using extended securing pins.( 1" t0 !.5") Doesnt look too pretty but does the job, however two rows of 15 louvres looks purposfull, looks cool and allows the engine to run cooler, the occupants can enjoy the drive and arrive at there destination reasonably dry and comfortable.
   
   Check out 1960s.... Aston Martins, Jensons, Iso Grifo, Bizzarrini, Ferrari 250s etc etc,  all have adaquate heat extraction built into the contours of the body, these features are expected and serve a purpose, pity AC didnt spend a little more time in the wind tunnel or design stage  to overcome this persistant problem. Carry out the test and you will enjoy the 428 like never B4.
   Enjoy ! !
   
   Keith
   
   Keith
   

   
   I after thinking and re-thinking, I have come to the conclusion that louvres are not the way to go, the design is more 50's. I am going to set up openings on each side of the hood like the Ferrari Daytona. This should match the style of the car. By the way, now I know why my friend's Frua runs such high oil temp. We will install an oil cooler as well! Thanks for the tip.  []
   
   Emmanuel

[Mark-Anthony]

Just a thought but . . .
   
   I used to have a Maserati Ghibli (1968) and Ghia solved the excess under bonnet heating problem by adding large side vents behind the front wheel arch - thereby leaving the contour lines of the most beautiful fast-back ever built undamaged.
   
   You might want to put side vents into the 428 to improve air flow and it might be easier than putting louvres into the bonnet.
   
   
   Roy, did you find a car?  The only one I've seen is in Hurst Park Classic Cars - a beauty - but be sure that you're seated when they quote you the price!
   
   M-A

[Mark IV]

Fruas already have the same side vents as a MK III Cobra.
   Rick

[Emmanueld]

I used to have a Ghibli as well, it got hot inside, not as much as the 428 but no need for a heater!. I also had a Ferrari Daytona, no problem. I think I am going to build 2 openings on each sides of the hood ala Daytona. I found a spot which should work! They will face rearward, I hope they will be large enough! I am also adding an engine oil cooler instead of the trans oil cooler! Emmanuel