Ok folks, here's the story. When I first installed the Edelbrock Hi-Flow base on my '91 L98, stock heads, stock runners (back in '93), I had an oil leak from the rear china wall (base-to-block seal area). I used Fel-Pro gaskets on the heads, and a bead of sealant (I think from Fel-Pro..) on both front and rear china walls. I disassembled, re-installed the base just like I did the first time (maybe using a little more caution), and was leak free for years. In the past month I installed AFR heads, and when I was finished, I had (have) an oil leak from the rear china wall So, I'm getting ready to R&R the base to fix the oil leak. ALL SUGGESTIONS are highly appreciated, so keep those posts coming, PLEASE. Thanx in advance.
Bill

 

"The Right Stuff" gasket maker from Permatex works great in place of silicone on the china walls. Friends who had leaks with silcone fixed the problem using this product. I've done two intake installs personally using it and had no leaks either time.

 

Mark, thanks for the reply. Lately I've been hearing about "The Right Stuff" but have never seen it. If it's made by Permatex I assume it is available in auto parts stores, or , where do you get it?
Bill

 

I've noticed with AFR heads that they sit the intake up higher off the china walls than stock heads do. One of the many subtle ways that AFR "moves stuff around" vs. a stock head. I think they do this as a cheap way to raise the intake ports slightly for better approach to the valve.

Anywho... a thicker bead of RTV is usually called for and you'll be fine. Don't worry about over-doing it, not much harm in a bead that's a little too fat.

I usually run the beads on the china walls first, making sure that you get in the corners real good. Then while that's setting up I put paper-thin smears around the water port openings in the gaskets (both holes, both sides of both gaskets). Put the gaskets in place making sure they stay put where they are supposed do. Then a quick finger-smear of the china wall RTV beads up to mate with the ends of the intake gaskets so it's like one continuous bead of RTV from one gasket to the other across the china wall. By the time you're done the RTV has set up enough that you're ready to drop the intake on. And I don't mean DROP. I mean PLACE CARERFULLY AND ACCURATELY. You want to hit it dead on right from the first time it touches home. Little or no sliding it around to get things to line up properly- that's how gaskets get moved out of position and RTV beads break seal. Look though the bolt holes or whatever you have to do to make sure it's as close to dead-on the first time it touches.

 

Not sure if it was mentioned but make sure the surface areas are clean. I use carb cleaner myself to prep the surfaces.

 

Yep, I've found it at a number of local auto parts stores like O'Reilly and Auto Zone.

Nice writeup and excellent points Damon.

 

OK, thanks. Yes, Damon's reply sounds like what I did all 3 times I installed the manifold. This time it'll get an extra fat bead of sealant.
Installing an intake manifold seems to most people to be a no-brainer, until an experienced and, dare I say, skilled and talented, mechnical technician installs one and the SOB leaks.
Bill

 

It's on and it doesn't leak! I used the cork gaskets that come with the Fel-Pro 1205 intake set. With the Eliminator 195 heads and Edelbrock intake base, the gap between the block an intake was .05 inch to .07 inch. I installed the gaskets, and used RTV sealant on top of them to achieve a leak-free installation. Bill

 

Hi Bill (Burnout91), This question is NOT related to the Edelbrock Base Sealing issue, although I am installing one that's matched up with a Mega bored plenum and mega bored runners-
What I'm hoping you'll be willing to expound on is your choice of headers. I've been mulling over my exhaust design the past six months while my new 355 engine is being built. I did run a 'Search' for more info on Dyno-Don's headers and even sent him an E-mail asking after some specifics. His only response was a date when another set would be available. Can you share ANY information as to what's better about his design, or if it has a longer collector length, better for either torque or upper horsepower, etc????? And do you have any contact info that gives specifics of his design?

From looking at your modification list, we have most of the same set-up, except I havn't researched what the use is for LCA relocation brackets; and I'm running a 2200 stall with a 3.27 rear gear. You must have done a ton of research to arrive at your package. Any info would be EXTREMEMLY Welcome!!! Nitro-Nicky

 

neagan- Search the exhaust forum for the 1 3/4 header options thread for more details on Dyno Don's headers. Mine fit well and have no leaks. They also accomodate the exhaust port opening on the new AFR heads. And, the price was right. I hope to have some dyno numbers to post soon. Bill

 

I'll try another search and see if something different comes up. I did read that his creation seems to install easier, with less clearance issues. Was that the same for you? Also, did you have yours coated?? Nitro

 

...see exhaust forum, page 3. There are also other threads about DD's headers. See also Southern California area forum, Third Gen Friendly Shops. Bill