Stock, I'm guessing the ones that lost 7&8 didn't have the cooling mod done at the back of the block. The coolant that gets there doesn't have anywhere to go in a hurry, heat builds, pop!

At factory boost, I'm sure you'll be safe -longer- than if you upped the boost, I couldn't give you an accurate amount of time though, anywhere from 30 seconds extra, to two minutes extra at WOT. In the end though, it's only a matter of time if you drive spirited before you lose 7&8 without the cooling system change.

This is just what I've read, though... I trust it, it makes sense, and it's things I'm keeping in mind for when I get my 4v block... before I drop it in, I'm going to be sure the cooling system I drop in with it is MUCH more than the engine needs.

 

Is this a similar situation on a Mustang GT as well. I just goes to show you that there's more involved than just upping boost (half -*** modding will eventually catch up with you).
I really like the Cobra's very much. I'm looking into a daily driver which I will purchase after the first of the year. Although a Terminator is out of my price range I have seen a nice 98Cobra with 57K miles for $11K

 

It's not such a problem on the 2v (or even the Mach 1's and earlier Cobras... reason? No boost from the factory!)

I still don't go WOT with my stang for more than 15-20 seconds at a time, ESPECIALLY when spraying nitrous... Yeah the nitrous cools the incoming air, but you end up with a more powerful combustion, which means more heat. It's a personal choice, saves me from going too fast, AND who knows, maybe it'll save a couple of my cylinders later in my motor's life Not that it's going to be in my stang forever... FastLane034 here on the forums wants it for his 06 v6

I can't speak for the casting of the 03/04 cobra motors... I know it's an iron block (previous Cobra motors were aluminum, transmits more heat, so they have a more robust cooling system than the GT's), but I'm not sure if it is the same casting used for the aluminum blocks, with iron poured in instead. If it's just a GT block cast to fit 4v heads (cam timing equipment), then the GT's will have the same problem when boosted... We don't see many GT's above 450 RWHP though... people around here seem to just get a blower and stop there with plans on rebuilding the motor forged.

I'd say that's good on the Cobra, too, but I'm not entirely sure on the price, it's definitely good on the miles, and there's nothing outstandingly bad with the 98 Cobras... I may go test-drive one soon, it's red and I'll probably give the Pontiac Grand Prix (grand am? They're close enough ) GTP they have sitting there a test run... they're boosted, after all.

 

I read today that the new Grand Prix will have an LSx based motor, okay, I only seen the front cover, but it will be RWD and make 370'ish hp. Grand Prix FTW!

I'm glad I just stick to my all motor car with a big shot of gas.....keeps all the little things from getting in the way.

 

I haven't heard of any cooling problems with the #7 & 8 cylinders on an 03 Cobra running STOCK boost, and the editors at MM&FF have confirmed this. The heat generated by the stock "Heaton" is usually only a problem with cars running additional boost (or, in other words, about 80% of the Cobras out there...)...

There is a cooling mod to help cooling on the #7 & 8 cylinders, or if you've got the cash you can pop for some of the revised Ford heads. They fix the cooling problem with #7 & 8 but they cost around $1400 apiece, or so I've read...[&:]

I plan on going to a new heat exchanger with a larger reservoir to deal with any potential problems before I start flogging my baby on the strip...

 

+1 - that's what im doing with mine.. no strip action and no running WOT for long periods of time (excess of 10-15 seconds) until I get it into the doctor to cool off

 

lol. What year is your Cobra? I rarely see 03/04's and they seem to hold their value extremely well!!!

 

your QUARTER MILE would be less than 15-sec..........go for it

Edit: no n2o. "all motor" runs

 

his profile suggests he's another 2003 guy.. Now just for some pictures..

 

Ha Ha ......Good job catching that one. I think were referring to burying the speedo and holding it for a period of time.............But really, who will consistantly be driving at speeds over 155mph (unless your driving in the boonies)