: dloch - &others swapping intakes...



eldorado1
04-16-04, 05:30 PM
I haven't received my 96 intake yet, so bear with me :) I noticed the heads have holes already partly drilled in them on my 94 northstar... I'm including a pic of the locations... Are these the spots I need to drill completely through/tap for the 96 intake? If so, GM sure made it easy on me... :rolleyes2

Another thing I wanted to note, the EGR ports are FILTHY! They all had huge buildups, some had 1/2" carbon stalagtites (sp)... Granted, emissions are good to keep down, but this must have affected the lifespan of engines, sucking in all that sooty carbon and all...

BeelzeBob
04-16-04, 11:01 PM
Any exhaust passage will build the sooty deposits. You are overreacting to the condition of the EGR passages. Keep in mind that the amount of buildup is the result of a 100K or more...???....it is really very little. Running EGR has no impact on the durability of the engine......

There has been a lot of work done on investigating the deposit formation in the EGR systems of IC engines. The depostis for in a specific temperature range as the exhaust gas coming from the exhaust manifold cools before it enters the intake ports. The idea is to force the EGR gases thru that temperature transistion range where the depostis form in an area where there is plenty of room for the deposits to build up without clogging the system. If you want to see deposits take the plugs out of the water crossover castings...THAT is the area where the deposits form...by design. The water crossover casting area has a very large cross section passage that goes across and back simply to cool the exhaust gas and force the deposit formantion in the passage where there is plenty of room..... Must be working as we have never had an EGR system plug up in that cross passage where the bulk of the deposits form. This was no accident....LOL.

eldorado1
04-16-04, 11:18 PM
Running EGR has no impact on the durability of the engine......

I've got 80k on my engine, which I consider to be 'just broken in' :) My concern would be one of those deposits breaking loose, and being ingested by a cylinder... Some of it was really flakey and hard at the same time. I would imagine that assuming it made it past the valves without being 'crunched', that it would end up scoring the cylinder walls over some amount of time.

dloch
04-17-04, 09:50 PM
I haven't received my 96 intake yet, so bear with me :) I noticed the heads have holes already partly drilled in them on my 94 northstar... I'm including a pic of the locations... Are these the spots I need to drill completely through/tap for the 96 intake? If so, GM sure made it easy on me... :rolleyes2


Yes thoses are the holes you need to tap. I also think you will need to open the two end registration holes so the gasket locating pins of register will line up with the intake face correctly. I haven't gotten my new gaskets yet so I don't know the size. Soon as I find that out I'll let you know... maybe Bbob may know that size.

I drilled through the locations above the coolant passages and will install studs there. You will also need to block the mouse holes going into each intake passage because the EGR gases on a 96/97 go into the intake just behind the TB. I can send you pictures if you like. I'll provide a complete writ-up once i have everthing done.

eldorado1
04-17-04, 10:40 PM
Yes thoses are the holes you need to tap. I also think you will need to open the two end registration holes so the gasket locating pins of register will line up with the intake face correctly. I haven't gotten my new gaskets yet so I don't know the size. Soon as I find that out I'll let you know... maybe Bbob may know that size.

I drilled through the locations above the coolant passages and will install studs there. You will also need to block the mouse holes going into each intake passage because the EGR gases on a 96/97 go into the intake just behind the TB. I can send you pictures if you like. I'll provide a complete writ-up once i have everthing done.
Excellent! That's almost too easy -haha! Now, I wasn't planning on using the EGR. Do the 96 gaskets cover up the milled EGR slots?

dloch
04-18-04, 09:21 PM
Excellent! That's almost too easy -haha! Now, I wasn't planning on using the EGR. Do the 96 gaskets cover up the milled EGR slots?
Not the gaskets don't cover the EGR slots... You will need to fill them with something, I'm going to use JB Weld. I am going to plug the EGR holes at the back of the head with a 1/4 NPT pipe plug.