1986 K-5 Exhaust and Injectors

[Ebrown]

I have a 86 k-5 with the 6.2. The engine has the j-code intake. I'm looking to do a exhaust job on it and want to go dual 2.50 with flowmasters and a cross over pipe. Should I use a cross over or not?? Next y injectors are leaking and i want to replace them with some better one ( Any ideas)? Pleas help

[john8662]

2.25 is the factory size of pipe if I'm not mistaken. The manifolds come out at 2", then immediatly upsize to 2.25.

If you need an exhaust system, go with the 2.5". The crossover isn't manditory (wasn't that way from factory) but will help balance out the sound and pressures in the system. In a blazer you don't really have that much room to do the crossover though, because of the extra length in tranny/case and short drive line going to the rear diff.

Question for you though? What are you referring to on the "y" injectors?

I think you're talking about the return lines that go from injector to injector right? If so you can get a fuel return line kit from several places, most of the venders on the main site offer a kit that comes with the lines and end caps.

www.kennedydiesel.com

www.heathdiesel.com

Although these guys are not a current vender, I use them:

www.dieselpage.com (Diesel Injection Service).

[Ebrown]

My injectors are making a funny sound. The Y was a typo.

[Ebrown]

My injectors are making a funny sound. the Injectors aren't leaking around the return line but lower closer to the block! The Y was a typo.

[john8662]

Again, the above mentioned venders will be able to supply you with injectors for your engine.

I'd just replace the injectors with what you already have.

You should have Fine thread long-body 6.2L injectors

The place where you're describing the leak sounds like the injector body is leaking, this does happen. Another common place (recent discovery myself here) is that they can leak at the line connection as well. Seems as though the washer underneath the injector nut can't seal to a pitted injector top (reman injectors that I purchased off ebay). If it's leaking at the line nut the inside of the nut (where the line enters) will hold fuel.

Get the return line kit when replacing the injectors while you're there.

[Ebrown]

IS there any special tricks to change the return lines? I might try this first before buying injectors?

[john8662]

If the return lines are leaking, you'll be able to find the leak pretty easily, just look for splits etc.

The fuel return lines will not require any special tools to change, just a pair of needle nose pliers to remove the original ones. The OEM return lines have small metal retainer clips on them which are REAL fun to put back on.

The return lines used in the "kits" don't require the use of the clips because they fit snug enough and are fabric wrapped to keep the tension (as well as protect the hose inside).

Just an FYI on the injectors, when you replace them you'll need a 30MM deep socket to remove the injectors from the heads. You can obtain one of these where impact sockets are sold. A deep 30MM socket is somewhat harder to find, but the impact sockets in a deep variety work great. There is also a special injector socket that Snap-on makes that makes removing the injector on the passenger's side rear easier to remove. I think there is one on ebay right now :)

Also, there is a wealth of information on this forum, feel free to perform a detailed search for some good reading. Click on the "Search" text in the bar above, then select "Advanced Search" and then select 6.2L forum (all forums are default) and then search for injectors, etc. only in the 6.2 forum.

P.S. Welcome to The Diesel Page Forums!

J

[Ebrown]

Thankyou for you info John.

[Craig M]

Dr. Lee has installed duall 3" exhaust with a crossover on his non turboed engine. I believe it is currently a 6.5. He likes his system. Others have discussed improved exhaust manifolds. Stray Cat did some performance testing a while back with a modified exhaust manifold and got some minor improvement over the factory exhaust.

[Ebrown]

I'm not sure if I want to go throught making a custom exhaust manifold! It looks like alot of work and I just don't have the time!

[DmaxMaverick]

If you intend on keeping the engine N/A, you can take advantage of headers. I haven't seen any in catalogs lately, but they are available. If you plan on a turbo, forget it. No point in scavenging the exhaust with a turbo.

IIRC, they weren't much more $ than SBC headers. Ebay may have a set.

[Ebrown]

At present I plan on keeping my Blazer as a N/A. I've look into buying headers
but, I haven't found any MFG yet! I think 4 Wheel Drive did a artical on a N/A 6.2 and got 165 hp and around 300 lbt with some minor work. I'm going to look up tonight!

[john8662]

For headers, look up "Stans Headers" they're somewhere on the 'net.

[Ebrown]

That alot of money for header at $450.00. Do you know what kind of performance number come along with them?

[Craig M]

The testing by Stray Cat on a dyno showed a 12% increase in torque and 13% on horsepower at 2000 rpm with just headers added. Graph and actual before and after test are in the old posts. Just put "stray cat headers" in the search option to find. Results are toward the end of the long posts (page 4 or so).

[john8662]

Another option for headers could also be from military hummers with the 6.2 in em. I see the headers from time to time showing up on ebay, or call some surplus military places.

I don't know what kind of gain you can expect from the headers, worth a try...

I went turbo, and it ain't all fun either.