[tayto]

I dealt with jasper 10 years ago only took 4 engine swaps (bad vibrations) in a mitsubishi mini van before we said **** this and got it built locally. I would at a minimum get it dyno'd before installing it. worth the few extra $100 dollars to not have to worry about breaking in a new motor or discovering an issue before all tha labour putting it between the fenders.

 

[SAH62]

Here's the intake manifold after degreasing:


After additional cleaning and installing replacement parts ( PCV valve, PCV hoses, injectors, EGR valve, fuel rail o-rings, etc):


if you're looking for something that does a really good job of cleaning raw, cast aluminum, I can recommend NAPA Aluminum Brightener. It contains multiple acids, so you need rubber gloves and ventilation while working. Spray it on, scrub the stubborn spots, and rinse it off with water.

 

[sherlock9c1]

You didn't polish the fuel rails? I know it's a nitpick, but man they're so close to being beautiful.

 

[SAH62]

I'm going for the "factory" look. I was just happy to be able to get all of the encrusted black stuff off. I don't know what it was, but it managed to pit the aluminum in spots.

 

[sherlock9c1]

One of the things I did with my block was to take a grinder and grind off all the casting flash and sharp edges. It was amazing how much of that there was on the stock block.

 

[95wagon]

Did you take the lower tray off and remove the big hex plugs to clean the idle passages ?
If so, great
If not, time to start over

 

[Marky Dissod]

Merely liking this post is not enough. The idlespider does NOT get enough attention.

Did you take the lower tray off and remove the big hex plugs to clean the idle passages?
If so, great.
If not, time to start over.

 

[95wagon]

As in not enough as in seen so much crap in them to destroy a new engine if not caught after porting or abrasive cleaning.
One first hand was from a highly regarded LT1 shop.
Don't ask won't tell. I'm sure it was an isolated mistake
It wasnt Karl

 

[sherlock9c1]

As in not enough as in seen so much crap in them to destroy a new engine if not caught after porting or abrasive cleaning.
One first hand was from a highly regarded LT1 shop.

I had an intake bead blasted at a local shop. Came back FULL of sand. I took it back to the shop and made them clean it out. Then I got it home and cleaned it out again myself with water and compressed air. Yes, absolutely remove those pipe plugs and clean out the ports and plenum. Clean the EGR the best you can.

I also discovered that #1 idle hole was not drilled to the same diameter as the others. I drilled it out to match, since a properly functioning LT1 throttle body is completely closed at idle.

 

[95wagon]

I had no way of real world testing flow through the idle ports vs main runners and figured GM knew something .
I left the one smaller idle ports as is .
Not sure which would be right or wrong, especially on an engine with modifcations.

 

[SAH62]

Did you take the lower tray off and remove the big hex plugs to clean the idle passages ?
If so, great
If not, time to start over

Yup, done.

 

[sherlock9c1]

I had no way of real world testing flow through the idle ports vs main runners and figured GM knew something .
I left the one smaller idle ports as is .
Not sure which would be right or wrong, especially on an engine with modifcations.

Only thing I wonder is if they were allowing for some leakage around the throttle blades at idle.

 

[95wagon]

Exactly, and #1 is as close to the blades as they get.
Add in idle individual fuel trims, who knows for sure