Anyone trying the LT1 intake swap has probably noticed that the egr port doesn't exist on the LT1 intake where the TPI egr port was. The casting on the LT1 intake is smaller there and the gasket doesn't seal off the egr port completely. It will allow exhaust from the cyl. head egr port to be pumped in the lifter valley.

John's site doesn't mention anything about this. The alum. heads he uses probably don't have the egr port.

Any ideas?

Thanks,
J

 

I always block mine off anyway, usually by filling up the port.

 

Block off the EGR port on the head. Use intake gaskets without EGR holes or use the metal block off pieces that come with stock gaskets.
Another option is to build up that part of the intake on the bottom so it covers the EGR ports on the head.

 

Thanks for the replies. The only option I see is filling in the egr port on the head OR build up the bottom of the LT1 intake in that area. Simply using intake gaskets that don't have the egr hole (or using the tin block off plates) won't work. That is because there is nothing on the back of the intake side holding the gasket to the head.
Looks like it time to tig a piece of alum. in that area.
Thanks,
J

 

I wonder how many people have put on an LT1 intake with GM heads and are now blowing exhaust directly into the engine without knowing it?
J

 

I didnt do anything to correct for this. It it a problem to have exhaust going into the crank case? What affect would this have on the engine?

If it is a problem Im going to start thinking about a stealth ram, because honestly, I'm not super crazy about how my lt1 intake turned out anyway. The stealth ram is within my price rance, espicially if it turns out you can use stock fuel rails.

 

You cannot use stock rails with the Stealth Ram intake.

 

John, could you please respond to the egr problem??

 

Well, let's see,
1. John, Holley says you might be able to use the stock rails on the stealth ram with some fabrication. But no one's tried it yet so it's still an unknown.
2. Exhaust gas pumping into the lifter valley is BAD. Think about all those combustion chamber and exhaust pipe deposits ending up inside your crank case and mixed with your oil.
3. The way I'd fix it is the way Joe Mondello reccomends modifying Oldsmobile cylinder heads. He fills the exhaust crossover on the heads with an aluminum allow. I think they have the instructions for this on 442.com. It's not very difficult

 

Seems like that website has a problem right now. I'll try again later. Does it require removing the cyl. heads from the engine.
I whimpped out an ordered a Holley Stealth Ram. The cost is about equal to a finished LT1 intake (w/ hoses, fittings, etc). And like John's site says.......the LT1 intake cost under $200 so what is there to lose. Maybe I will have it tig welded this summer and put it on one of my other rigs.
Thanks,
J

 

I just bolted a '461 gm head to my LT1 intake and the part of the EGR port that is not covered is about a 1/4 to 1/2 inch wide. Looks like the intake is CA legal cause the EGR port is always on.......just not putting exhaust where it is supposed to be.
Cheers,
J

 

I just said you can't use the stock fuel rails because another member has the intake and mentioned right off the bat that they would not fit. I do agree though anything is possible.
Here's the link.
https://www.thirdgen.org/techbb2/sho...threadid=96559

 

To be absolutely honest I never even noticed the problem in the beginning. My TF heads have the EGR ports and I just bolted the intake on. No thoughts till lately. I planned on pulling the intake anyway again and doing some upgrades like the angled distributor spacer and hard mounting it. Mine is just floating back there and leaking. It was the first.

I will block off that EGR port somehow. Most likely extend the intake in that area and use gaskets without the port. I would hate to fill the aluminum head it would hurt re-sale.

So far no problems with the exhaust going into the lifter valley but it doesn't take a genius to see it can't be real good though.

 

how about drilling and tapping the egr port for a pipe plug?

 

John,
I still think the intake swap is an excellent idea. I have been slowly modifying one over the past few weeks. When I drilled the bolt I didn't even notice the EGR problem. It occured to me while marking out the coolant fittings.
I have a set of Chevy Trick Flow G2 heads lying around and I checked them for the EGR problem. Although the EGR hole is only about 1/2" in diameter, it is still a problem. You could probably just tap it and put in a pipe plug if you don't want to weld up the intake.
As for my set-up, I am running heavily ported/machined 461 castings. The GM EGR holes are very large and require the intake to be welded. No big deal, only a few smalls pieces of aluminum need to be made.
I am getting a Holley Stealth Ram too. I am going to try them both........probably not for another 2 months. I'll post the performance diffs then.

Sorry to be the bearer of bad news. Wow, figures are tired.
J

 

Don't be sorry. I just thank you for bringing it to the boards attention. We are all here to help each other and come up with joint solutions. That's the spirt of hotrodding.

 

So I lined up my intake with the egr ports on my AFR heads and I believe that the intake will block the exhaust gas. I have holes drilled instead of the square ports. Comments?

 

What kind (part number) gaskets are you using on the intake manifold?
J

 

i think a fel pro 1256. why would that matter?

 

It matters because you want to know if you are going to blow exhaust into your engine. I don't have any AFR heads, but most heads I know of will suffer from the problem of the egr port blowing exhaust into the lifter valley.
There is no way a stock gasket or any gasket with or without the metal egr block off plates. Some say that Chevy has a gasket without the egr port hole. I personally have never seen one.

If what you claim is true that the intake does block the hole, then you could use the gaskets without the egr hole. But again, I don't know the part number.

If I were you I would make a template out of this cardboard of the head and look at how it fits the intake.

J

 

Does the intake not cover the hole on both sides or one. When I put mine back together, I'd swear that the intake covered it. I'm running TFS G1s, btw.

 

The intake does not cover the bottom part of the gasket. It does cover the metal egr block off plate. But the plate does not seal, it is just a block off. The bottom part of the gasket does not seal this area. Therefore, the egr gases are allowed to enter the lifter valley area. I have Trick Flow heads and yes it is NOT sealed off correctly. It is easy to miss this. I think most people on this board has.
J

 

So if you use gaskets that have no egr hole?? What happens then??

 

Please list the part number for the gaskets without the EGR holes. I have heard of these only on this website, but have never seen any in real life. Every one talks about them, but can never provide a part number. Please post it if you have it.

As far as I know, all chevy heads (and gaskets) had the egr hole because it used to function as the choke activation mechanism.

If you are talking out the gaskets with the metal block off plate. They won't work either(they have the egr hole and it is just block with metal and not a real gasket type material).

Thanks,
J

 

It effects both sides of the manifold. I have Trick Flow heads and they have this problem. I am guessing yours do to.

J

 

I ordered gaskets from jegs, should be here today. I will let you guys know

 

Care to share the part number?
Thanks,
J

 

yeah, i don't know it. when I get them I will tell it. also, I am not sure if jegs will send the correct ones.

 

does anyone know off hand if the world products heads ( sportsman II )have the egr hole? i know i should call to find out, but i am at work so no accessiible number right now? these are the heads i plan on using, and wondered if i was gonna have a problem as well.

 

I am not sure about the World Heads. My simple solution was to buy a piece of alum. angle stock and have it welded to the intake in the area where there is not enough meat. Now it works on all heads.
J

 

Here's a pic from when I first started. Didn't even dawn on me



This is a stock felpro gasket lined up. Obviously it doesn't cover the egr. Doh!!

 

Yeah, every one ignored what I was saying at first cause they didn't understand. I am glad you see it now.

J

 

if you go to http://www.airflowresearch.com/ and go to the parts and accessories section. Scroll down to the felpro gaskets picture. the gasket the has no EGR provisions, just saw this in passing a remembered that a few people were asking about these gaskets.

 

I don't know how well the ports would line up but..., the 1205 Felpro intake gasket does NOT have any holes for the EGR.

 

Thanks for the repies. I have a set of Fel-Pro 1205s and they do have the egr hole. It is blocked with a tin plate. What I mean be 'no egr hole' is that gasket material is in place where the hole would normally be. This is the only type of material that would seal properly. RTV could be used to seal the tin plate. Unfortunately a lot of RTV would be required and I don't like using large gobs of it on engines. I have seen a number of oil pumps with chunks of it stuck to the pick-up screen.

J

 

Maybe they sell FelPro 1205's both ways. I've used two sets in the last year and neither had ANY holes where the EGR hole in my heads (TFS 23 degree) are at. I bought them at the local speed shop and had to punch a hole in one side when I installed my Accel TPI intake. Bought another set when I installed the Holley Stealth Ram a few weeks ago. No holes at all in it. Also, there's a picture of a Mr. Gasket intake gasket in another recent thread that's supposed to be a match for a 1205 and it doesn't look like it has any holes in it either.

Just trying to help solve the "needs no holes" problem . . .

 

https://www.thirdgen.org/techbb2/sho...hreadid=102779


Here is the thread.


Also, do you guys think the exhaust gas would burn through the paper gaskets????

 

I am not sure about burning up the gaskets. I wanted to be on the safe side so I welded a piece of angle alum. to each side of the intake.
The cost of a roll of alum. wire + 2 foot bottle of Argon gas is approx. $35. That is, if you already have a mig welder. I'd rather err on the safe side.
J

 

Junk, I think we understand the welding part, thanks.

 

Ill try to post some pics in a few weeks. Been so busy that I haven't even opened the box for my new Holley Stealth Ram I got the other day.
J

 

I have confirmed that my LT1 intake will cover the egr ports in my AFR heads.