Illegal Vette

Hello all, this is my first post to this board. My LS1 resides in an '82 Corvette, and one of the first things I discovered while preparing the engine for installation was a messy situation at the rear of the engine. The PCV system was a surprise and a disappointment, but a little googling revealed the solution, just install an LS6 valley pan and problem solved! So I ordered and installed it, and when reinstalling the intake noticed a clearance problem. Now my LS1 came out of a 2002 Trans Am, so it has an LS6 intake which I verified by the part number. I immediately googled "LS6 valley pan interference and got back nothing. I trimmed the ribs on the bottom of the intake manifold, but not carefully enough because on my first start I heard what appears to be a vacuum leak. I also show a misfire on my scanner, so off comes the intake manifold and I can't find any cracks. At this point I decided to trim ribs until I got an easy fit, and it now fits really well but I still have the sound of a leak and a misfire code. So the manifold will come off again and I'll look for cracks, which I hope I can repair if I find them. I'm posting this for 2 reasons: 1-So that others will be prepared to deal with this, and 2-because I can't believe (as google would have me believe) that I'm the only one in the world that this has happened to.

Darkman

iTrader: (2)

Can assume you using new gaskets/seals? Also the intake really needs to torqued down in sequence (starting in the middle and working alternatively to the front and back) in two passes (44 and 89 INCH pounds).

Undertow74

iTrader: (45)

A 2002 ls1 should have the rear coolant block offs not the coolant crossover pipes like the older models. With that said, if you have a ls6 manifold and out the new style valley pan in, you should have not had any problems with the manifold, unless you didn't uses button head bolts on the valley cover. If you uses standard head bolts on the valley cover it will cause the manifold to sit up higher. At the most depending on your block(non ls6)you may have had to notch a small piece out of it to get the valley cover to sit flush.

Paul Bell

iTrader: (9)

Welcome to LS1tech!

This how-to shows what you needed to do to convert a LS1 engine to a LS6 valley cover, including notching the block.

http://www.ls1howto.com/index.php?article=18

Illegal Vette

Thank you all for your replies! My valley pan came with new bolts, and I used them. They appeared to be the same height as the old ones, I'll look at them again when I take the intake off for the third time. I replaced the intake seals also. I read a very similar article to your how-to before I attempted this, and didn't expect any clearance problems. I really hope I won't have to buy another intake manifold because of this! Here's a picture of the engine in the car: [IMG][/IMG]

97FormulaWS-6

iTrader: (1)

Look at the link posted, did you clearance the block or check to verify that the block was already clearanced properly? If not, the valley cover my not be seated all the way down, which would cause your issues.

Illegal Vette

I didn't actually check for clearance because I knew it to be an LS6 block, and the valley pan fit without any problem. I'll take another look though when I take the intake off again, thanks for pointing that out.

Exidous

iTrader: (11)

You verified the P/N on the driver back of the block to ensure it is an LS6 block? I have an 02 ss motor and it's an LS1 not LS6 but it did come with the LS6 intake.

Illegal Vette

It was the first thing I checked when it arrived, made my day!

KCS

iTrader: (20)

You would know it if the block interfered with the valley cover. It leaves a huge gap and you probably wouldn't even get the bolts threaded.

What coolant tube are you using? Are the rear coolant vents blocked off or connected to the front vents?

Illegal Vette

It doesn't have any coolant pipes in the rear that I'm aware of, there's one in the front that connects to the throttle body.

KCS

iTrader: (20)

Then you shouldn't be having any issues. The LS6 manifold uses the stock bolts, the button head bolts are only needed on FAST intakes, so that shouldn't be a problem.

Darkman

iTrader: (2)

Milled heads?

Illegal Vette

It's an ummolested engine out of a really wrecked '02 T/A, I just pulled the intake off again, here's a pic:

and as long as the intake is off I took a pic of the block number:


I can't find any cracks in the intake, none at all between the runners and I don't see anything on the bottom. I'm scratching my head right now.

97FormulaWS-6

iTrader: (1)

How about some pictures of the valley cover area?

Illegal Vette

I'll post one when I get home. After going over everything with a fine tooth comb I now suspect that what I'm hearing is the fuel pulse muffler.(modulator?) there are no cracks and everything else looks good.

Illegal Vette

Here's the valley cover:

97FormulaWS-6

iTrader: (1)

Might want to throw some silly putty on those valley pan bolt heads and make sure those aren't hitting the intake, I thought (not 100% sure) that a different bolt head style is required.

LilJayV10

iTrader: (39)

Are you sure those are the right bolts for the valley cover? The reason I ask is my valley cover bolts are 10mm and from the pic it looks like those are bigger. If they are bigger I wonder if they are taller also.

I could be way off base here but that caught my attention when I looked at the pic.

LilJayV10

iTrader: (39)

Also, could the intake be interfering with the oil pressure adapter you are using?