What did you do to your NNBS GMT900 Tahoe/Yukon Today?

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89Suburban

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that they do. I have learned to polish clear pretty well thou from YouTube but it takes a long time.

my thoughts going in is if I'm not going to a body shop, then how much worse can I make it anyways. along as it seals enough to keep it from rusting, it was worth the try
My problem is the base color, I have hard a hard time finding it in touch up form.
 

j91z28d1

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you would have to try a automotive paint shop. they can mix it and put it on spray cans. for you.

there's also a site that will do it and ship it to you. if I remember right is was pricey thou. it's just based off you paint. code thou, so. might not be perfect.
 

j91z28d1

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I don't remember if this was the same one I had found before. but something like this.

 

89Suburban

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ahh that makes sense that you're in a totally different Realm than our stock trucks.

back in the day they used to sell weld into the exhaust collectors big like 3/4in vac ports, so the Venturi effect or whatever it's called would cause a vac at high rpm and suck the crank case pressure out of the engine. helps the rings seal have read. but yeah.


I've seen race cars with 2 big catch cans inline to catch all the oil and then vented to atmosphere, I guess big boost and especially alcohol fuels cause a ton of blow by and thin the oil quickly. so it's ******* cans.
I can right a book on this stuff with the different things I did 20 years ago when first supercharging my mustang, from open breathers on the valve covers, one way check valves in the PCV lines, those crankcase Evac valves you weld into the exhaust, etc.

I finally settled with a mechanical vacuum pump that's pulley driven (now there are many, affordable electric vac pumps that I would probably use). I have a - 10an hose running from the pcv port on the lower intake at the rear running to the vac pump. That port on the lower intake is baffled, has a metal plate that runs on the underside almost up to the front, so basically the oil spray in the valley is entirely blocked from the underside of the lower intake and doesn't get to the port. The oil fill on the valve cover is capped off, as well as any ports or openings so it creates a sealed system.

The vac pump has a pulley that's sized to keep the pump from spinning too fast with high motor rpms and within its operating rpm specs. On the sides of the vac pump is 2 ports. The intake port is "T'd" and has an adjustable relief valve and I have it adjusted to allow only about 10-12in max of vac in the crankcase. The out port runs to a vented (3" filter on top) catch can with baffle plates inside and a drain valve at the bottom. It doesn't collect much oil at all, but there is always a light oil mist running through the system, it lubricates the wipers in the vac pump.

With the crankcase being under a constant vacuum, it helps with ring seal/blowby and also with any gasket leaks and has been dyno proven to make/free up some horsepower.
 

Just Fishing

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you would have to try a automotive paint shop. they can mix it and put it on spray cans. for you.

there's also a site that will do it and ship it to you. if I remember right is was pricey thou. it's just based off you paint. code thou, so. might not be perfect.

To clarify, an automotive paint supply shop.

I have one not too far away from me, if you get a good counter person they can help.
Usually, they have a machine that can find a color that's really close to the current faded color, but in my experience it's best to go with the oem paint code.
 

Doubeleive

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To clarify, an automotive paint supply shop.

I have one not too far away from me, if you get a good counter person they can help.
Usually, they have a machine that can find a color that's really close to the current faded color, but in my experience it's best to go with the oem paint code.
the one here just uses a scanner and then the computer shows the mix needed. I went in there to get something to match the spohn control arms and they just said here let me scan it and that was that...
 

j91z28d1

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I can right a book on this stuff with the different things I did 20 years ago when first supercharging my mustang, from open breathers on the valve covers, one way check valves in the PCV lines, those crankcase Evac valves you weld into the exhaust, etc.

I finally settled with a mechanical vacuum pump that's pulley driven (now there are many, affordable electric vac pumps that I would probably use). I have a - 10an hose running from the pcv port on the lower intake at the rear running to the vac pump. That port on the lower intake is baffled, has a metal plate that runs on the underside almost up to the front, so basically the oil spray in the valley is entirely blocked from the underside of the lower intake and doesn't get to the port. The oil fill on the valve cover is capped off, as well as any ports or openings so it creates a sealed system.

The vac pump has a pulley that's sized to keep the pump from spinning too fast with high motor rpms and within its operating rpm specs. On the sides of the vac pump is 2 ports. The intake port is "T'd" and has an adjustable relief valve and I have it adjusted to allow only about 10-12in max of vac in the crankcase. The out port runs to a vented (3" filter on top) catch can with baffle plates inside and a drain valve at the bottom. It doesn't collect much oil at all, but there is always a light oil mist running through the system, it lubricates the wipers in the vac pump.

With the crankcase being under a constant vacuum, it helps with ring seal/blowby and also with any gasket leaks and has been dyno proven to make/free up some horsepower.


that sounds like what I've read, much more detailed since you've actually done it. back when I had a supercharged car for a bit, I just had the old school stock pvc valve in one cover and a small k&n shoved in the other. it was a map car so it didn't care as long as the pvc valve was there. but it didn't have any oil spray issues that I remember but it wasn't making today's power or on today's fuels.


I see that people have crank case pressure sensors these days. sounds like it would have been helpful.


on a side note of stock cars, it does make me wonder why manufacturers ditched the pvc valve. it seemed to do a good job of nothing sucking in tons of oil and gunking up the rings or valves in the di engines. even the older ls engine before they ditched the pvc wasn't bad. I beat on a ls1 all weekend and it never used any oil, my ls3 used to eat almost half qt a day. I gotta think it's pvc routing running full bore vacuum at high rpm decel.

once you start looking around, it's a issue in almost every newer engine. my neighbor has a gm with a ecotec, like 80k miles on it and shop told him it needed a motor, at first I was like no way, and then I pulled the oil cap while idling and the damn thing blew an inch in the air. I was like well crap, must have broken a ring land or something.. later that night did some Googling and nope, very common. no pvc valve, all the pvc runs thru the intake manifold to a port in the head and it gets clogged up. has no way to release crank case pressure. junk.. the fix is either pull the intake ever so often, which is a job or some guys drill and tap the plastic intake for a catch can then drill the oil cap out to run it to.

the failure is weird.
 
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that sounds like what I've read, much more detailed since you've actually done it. back when I had a supercharged car for a bit, I just had the old school stock pvc valve in one cover and a small k&n shoved in the other. it was a map car so it didn't care as long as the pvc valve was there. but it didn't have any oil spray issues that I remember but it wasn't making today's power or on today's fuels.


I see that people have crank case pressure sensors these days. sounds like it would have been helpful.


on a side note of stock cars, it does make me wonder why manufacturers ditched the pvc valve. it seemed to do a good job of nothing sucking in tons of oil and gunking up the rings or valves in the di engines. even the older ls engine before they ditched the pvc wasn't bad. I beat on a ls1 all weekend and it never used any oil, my ls3 used to eat almost half qt a day. I gotta think it's pvc routing running full bore vacuum at high rpm decel.

once you start looking around, it's a issue in almost every newer engine. my neighbor has a gm with a ecotec, like 80k miles on it and shop told him it needed a motor, at first I was like no way, and then I pulled the oil cap while idling and the damn thing blew an inch in the air. I was like well crap, must have broken a ring land or something.. later that night did some Googling and nope, very common. no pvc valve, all the pvc runs thru the intake manifold to a port in the head and it gets clogged up. has no way to release crank case pressure. junk.. the fix is either pull the intake ever so often, which is a job or some guys drill and tap the plastic intake for a catch can then drill the oil cap out to run it to.

the failure is weird.
I also had decent results by just using a good pcv valve or check valve in the pcv line and also putting a filter/breather on the oil filler port. With a mass air system this would cause unmetered air and idle problems but if you had a tuning device (moates, tweecer, sct, etc) you could tune for it and get by.
 

j91z28d1

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it's funny gm started maf and went map, Ford started. map and went maf.

always had to be different lol. at first I had the old fmu that didn't do anything but lock up injectors and burn a piston and then I found someone had ported over the os from if you remember the syclone and typhoons, boost code. they turned it into a 3 bar code and it would load and run on the stock ecm that cam in my car. so I ran thsy for a bit worked much better. but broke the nose of the crank shaft off one night leaving a car show haha. any time that thing when near my car it broke something I couldn't afford to fix. Eventually it just sat in the shelf and I went back to playing with small nitrous kit. was so much eaiser and didn't break stuff, well it did drive line, but I could fix that cheaply
 

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