motor suggestions

[Mschaffer92]

Is there anything that I can do to my 97 sierra with vortec to make it a little faster until I have to do my motor rebuild? I have a k&n filter with aftermarket exhaust from cat back. Because my motor knocks on warm up. it has 167000 miles on it. I wanted to get headers but not exactly sure if I am supposed to get long tube or short tube so I dont have to mess with my exhaust all that much. Also what do you guys think about throttle body spacers. Pros vs. cons. Oh you guys know the hose that goes from the top of the motor to the air filter box, would it help if I replaced that with a straight tube with other the groves in it? Because I read somewhere that i should keep my air filter box so I dont suck in warm air from the motor.

 

[SAATR]

When you say that your motor knocks when warm, do you mean a ticking sound or an actual knock, like somebody tapping on the engine with a hammer? In any case, I would fix that before worrying about anything else. That one could be serious, ya know?

 

[Mschaffer92]

From what i was told is it piston slap, that all the vortecs get that after a while. But I kind of wanted to rebuild my motor but it doesnt seem to be a good idea for some reason from what people told me. wheater or not if Im supposed to put a different one in, or just rebuild mine with a cam and exhaust, because i was told the spider injection is a tricky thing and if i did too many upgrades, it will cost a lot more in repairs later on.

 

[am92]

How long does it knock for? if its just a few seconds its ok, but if its more than a minute or so I'd start looking into a rebuild or replacement

 

[Mschaffer92]

It knocks when its cold, and it i drive it right away it is still there for a little bit then it goes away. But I noticed that the bottom half of the motor is wet with oil. The last time I had an oil change done by my friend he said it looks like that front seal is leaking. But I dont know if I could just get a rebuild kit and a cam or look for an ls1 motor and harness?

 

[Aloicious]

the 'vortecs' that are prone to piston slap are the gen III vortecs (5.3's and 6.0's, etc), not really the gen Ie SBC vortecs....more than likely the ticking you're hearing is a lifter or something that has bled down and takes a second to pump back up with oil...like was mentioned, if it goes away within a couple seconds, you're probably okay, if not you'll probably want to look at a rebuild sooner rather than later...although if you've got a decent oil leak, which it kindof sounds like, make sure you are frequently checking the oil level, if it gets too low then you can oil starve the valvetrain and it'll make a similar knocking/tapping noise which will take alot longer to go away, and if the oil is extremely low, it won't go away...

to answer the questions in your original post, the only headers that will work as a bolt on without modifying the exhaust are shorites, but they won't provide much gain, so for their cost, its not really worth it IMO. Long tubes are good, but they will require a good amount of fabrication to work. Thorttle body spacers are completely worthless for performance on any 96+ truck since our engines are port injected. they do absolutely nothing unless you're trying to use them for fabrication purposes (i.e. tapping them for nitrous or using them for clearance or something). The stock air ducting from the filter box to the throttle body is perfectly fine for your setup, it can supply a good amount of air without a problem, much more than the stock intake manifold can use effectively. personally I'd ditch the K&N, there is no conclusive evidence that they give any power gains, and from my experience, they are piss poor at filtering, so they let a LOT more contaminants into the engine. If you want to read a little bit on the subject, here's a test I did of various air filters, the K&N was the second worse filter in regards to letting contaminants through :http://www.gmtruckcentral.com/articles/air-filter-study.html

personally if you know you're going to be pulling the motor somewhat soon, I'd say save your money to use good parts for the rebuild/swap and build the engine the way you want it...but if you really want a little performance gain until you get a rebuild or engine swap or something, then really the only thing I'd suggest is to get a PCM tune.