Here's a question from a first time engine builder so it may sound stupid. I had my 1970 Riviera 455 bored .030 over, decked, and otherwise flattened where it may have been curved. I also bought a new aluminum Edelbrock Performer intake manifold. So as I was reassembaling the block after the heads, pushrods, rockers, oil pickup, and oilpan, I put on the intake manifold tightened the bolts in the required sequence to the specified torque, and low and behold there's a quarter inch gap between the block and the intake manifold. There is only that crappy metal gasket between the heads and the intake manifold but the sudden appearance of the .25 inch gap, which oil will just pour out of, is a total mystery to me. Does anyone know why this happened or how to fix it?
There are 2 rubber gaskets that come with the metal intake gasket set. They should go there. Did you use them? 1/4" sounds excessive, but who am I to say thato No:
The steel gasket should have had a pr of rubber ends for that BUT I never use them I use Ultra black RTV as my gasket sealer for the intake/ block gap.
How much was removed when decked? Did the heads get re-surfaced also? You may need to get the intake machined down a bit to fit properly.:gt: With the performer, I had Jim Weise install his oil splash sheild to the bottom of the intake. Then bought the TA gaskets for alum intake and bolt kit (your stock bolts are a tad short). Also had Jim polish and seal the intake so dirt doesn't stick. Looks great!:TU:
You decked the block and some material was also removed from the heads to true them up. A stock intake manifold will no longer fit. Take the intake to the machinist that did the block and heads. He will know how much material to remove from the mating surfaces of your new intake, to make it fit.
I'd like to thank everyone who responded to my message. There were a lot of good answers to my question. I'm thinking I'll have the intake machined if possible and I found out my felpro rebuild gasket kit lacked an intake gasket set so if the gap is still a little large or the intake material is too thin to be machined I'll get those gaskets, silicone the thing, and hope that fixes it. But if the guy with a 830 HP engine just filled the gap with silicone I feel better about how I don't have to go crazy with the seal between the block and intake and still keep the oil IN the engine. Thanks for you knowledge and time guys.
I'd like to add that Mike T. suggested after laying the bead across the front and back of the block...smear a line across the bottom surface of the intake where it'll meet the beads you put on the block. That'll give it something sticky to grab onto. He oughtta know!
