I'm going to order my full Bassani exhaust next week. I really want to fire the truck up and maybe go for a spin around the block with straight headers. Will this damage anything?

Thanks,

Jason
87 XLT 302

 

I have heard that it is possible to suck a valve doing that, but I have seen it done before with no problems.

 

i have also heard the same, it may also cause warped valves because it allows cool air in once its shut down and they cool faster then everything else. i wouldnt at least not for to long

 

I doupt a short trip arond the block wont hurt anything, just dont push it too hard, burnouts ect. I think problems like burning a valve come in if you drive it a long ways and let it get hot.

 

okay...that's enough to scare me into not doing it! I'll crank it up just to hear it...maybe record it so I can load it on the computer and listen to it whenever I want to re-live the moment!

Thanks,

Jason
87 XLT 302

 

It's ok to drive it, but you have to richen the fuel air mixture so you don't burn out an exhaust valve. What people don't understand, is that the exhaust in your pipes is in the form of a sine wave. Depending on where that wave gets disected when exiting the pipe will either give you positive or "negative" pressure. The short exhaust, if cut off at the bottom of the wave could give you "negative" pressure (ie. Vacuum) which will relate back to the valve and if the mixture is not rich enough it will in turn burn the valve. Kind of hard to explain, but I would play it safe and wait for that new exhaust, its been engineered for your truck.

 

I did it...went around the block with the Bassani's on it and no pipes. No further...the guys are right about the scavenging capabilities of these headers and the lack of pipe behind them will let air thats TOO cool up in at the exhaust valves. Moreover the risk is cooling a guide and seizing a valve. Guide-to-valve tolerances are very very tight to begin with. Cooling off a guide too quickly will cause it to contract (shrink) around the valve shaft

 

...are they long tubes? cause i was thinkin about putin my 351w headerson my old 302 and runnin them till i get the 351 build done...so about a month or so..so can cold air still get into them long tubes?

 

Bassani's are shorties that are a direct replacement for the OEM manifolds. What makes them work so well is the fact that they are "equal length". In other words the length of the tubing used from each exhaust port on the cylinder head to the collector flange at the base of the header is the exact same length. This keeps the amount of exhaust gas in the collector the same ALL the time no matter which cylinders are firing. Since no two cylinders on one side of the engine are on the same stroke at the same time the collector NEVER has to handle more than the gas from one cylinder at a time. This makes getting the gasses out and away so there is room for more from the next cylinder very easy and very efficient. Since the cylinders fire sequentially, this actually IMPROVES the movement of the exhaust by lining up the exhuast coming into the collector in a "one behind the other" form from each cylinder. The PUSH from each successive cylinder-full of exhaust helps keep things moving as well. This is also why they will work well even if you don't buy the rest of the Bassani exhaust sytem. Being direct replacement parts they will bolt up to the OEM exhaust without any modifications necessary. The complete Bassani system flows far better than the OEM setup though. (Sounds really frekin' cool too)!

 

still...do u think the 302 in my 88 bronco will handle full length, hooker headers? the collecter is 2 3/4, and im gonna put a reducer to 2 1/2 then put 45" turn downs to keep stuff on under the truck from bein toasted. think that would make enough back pressure. while annoying the sound police fora month or so?

 

I personally have gotten enough "excessive vehicular noise" violations in my life to not want to consider it. However, long tube headers, while they may not be AS susceptable to the conditions mentioned above, most are designed to have SOME sort of extension to the exhaust on them to achieve full effectiveness. There is a LOT to be said for a certian amount of backpressure and well designed headers virtually eliminate it, leaving the job of creating backpressure to the muffler or some other section of the exhaust system. If its only temporary, I doubt you will have too much trouble but you may actually see your fuel mileage worsen until you "finish" the sytem.

 

its gonna have atleas a foot or 2 of pipe per header lol...but yea, i plan on beat this 302 till it dies..then ima drop the 351w in and be nice to it forawhile....after i gett outta boot camp i gotta drive it co california from michigan lol

 

Years ago I had a '69 convertible Mustang that I used as a street racer. My buddies and I weren't the brightest apples on the tree but we knew how to build motors. It was common practice for us to unbolt the exhaust and run straight headers on the weekends while we were playing. We got lots of noise tickets from the men in blue. It was common for a motor to burn valves every couple of months but since we were young dumb gearheads with nothing on our minds except cars and women it didn't bother us a bit to rework a set of heads every few months.

Bottom line... around the block a few times shouldn't hurt anything but don't over do it.

 

my friend has managed to run about 4 feet of pipe on his chev fora bout 4 monthes now..thats what got me thinkin about runnin mine like that

 

It'll be alright we've been running Stockcars for years with open headers. Have never lost a valve or had any ileffect.

Pat