jamez74

iTrader: (1)

Hi I am putting an lt1 intake on my car and was looking at some Patriot heads for it. The only thing is the heads are sized for a 1206 gasket and I have heard the LT1's dont like to seal properly with anything bigger than a 1205.

So, I was wondering if anyone has gotten them to seal and how they did it.



P.s I apologize for bringing up another LT1 intake question but I could not find anything deffinative in my searches.

Chris89GTA

iTrader: (2)

I did not, and 89GTA383 did not. We both had issues w/ internal vacuum leaks (meaning it has almost 0 vacuum at idle) and coolant port (front) leaks.

KrisW

iTrader: (5)

I am not too familiar with this problem on Chevy engines, so I am a fresh set of eyes with a different perspective...

Back in the day we used to put big block Olds cylinder heads on small block Olds engines. There was no intake that could seal with those big ports. We used to flip the aluminum intake upside down on the bench and tig or mig aluminum on the edges of the port mating flanges until they were taller than the gasket height. Then, you grind out the modified flange to gasket match the bigger ports. It takes time and trial and error, but works good. It stops coolant and internal vacuum leaks as well if you take the time to do it right.

Sometimes you have to have the excess mig'd on first, then sit down with the die grinder to make it match. Then, if you broke through somewhere, you tig up the brake-throughs and re-fit. When you are done, you are done...

Just my two cents...

scuzz

I think you'd want to find a LT4 intake for the 1206 gasket.
I ran into that with vortec head and tpi. I called TPIS and bought a TPIS miniram III. They said the III fit LT4 head, fastburn GM, and vortec if you redrilled to old boltpattern, which I did.

LB9GTA

iTrader: (1)

I made my own.

https://www.thirdgen.org/forums/alte...tml?highlight=

Pocket

iTrader: (24)

Im running 1206 gaskets on mine right now
No issues

Just be sure to get gaskets or heads that lack the EGR passages

Orr89RocZ

iTrader: (20)

Can the LT1 intake ports be safely opend up to 1206 without adding material around the intake ports for more sealing surface?

jamez74

iTrader: (1)

Great, now I am really confused lol . I had just about talked my self out of getting the 1206 heads then I see people who have gotten it to work.

What exactly causes the problems putting the lt1 on a 1206 port? Is it because the ports don't match up or is it just because there is not a proper gasket for it?

If its just because of the gasket then making a paper gasket should work in most cases right? I have never heard of anyone using paper gaskets for the base of an intake though, are there any concerns with this?

Orr89RocZ

iTrader: (20)

i'm not sure its an issue with ports matching up or no proper gaskets for it. I think its more of the fact that porting the LT1 manifold will leave little material on the intake to seal to the heads. there will be very little gasket surface, but i'm not sure.
1206 port is pretty tall so i'm not sure how much material there will be left on that intake once fully port matched.

jamez74

iTrader: (1)

Ok so what if I did not fully port the intake to match the heads. Would that eliminate any of the issues?

jamez74

iTrader: (1)

I just talked to the guy that sells the heads and he said that a 1266 intake gasket would work. I checked summit and the gasket is twice as thick as a 1206 gasket.

Does anyone think this would work?

http://store.summitracing.com/partde...6&autoview=sku

Orr89RocZ

iTrader: (20)

yeah you dont have to perfectly match the intake to the heads, but its nice to beable to fully use that 1206 port.

Chris89GTA

iTrader: (2)

My heads are a 1206 port, due to my attempt at the LT1 intake I had that was already ported that way. I ended up installing a as cast HSR which is a 1205 on the heads... seems to be working great. I'm not too worried about it. I'll pull the intake one day and port it out anyways, so...