RPU, bodywork underway.

I read somewhere the Fel Pro gaskets were too hard to use with aluminum heads or intakes, but I've never had any problems with them sealing.

Yeah, everything I read on line suggested using these gaskets if you have an aluminum intake, so this is what I ordered:

https://www.summitracing.com/parts/fel-1256

Here is what is driving me nuts about this thing, I have installed intakes on a lot of engines over the years, bolt them on and no issues. On my 23 with the sbc, I used an aftermarket aluminum intake and then put two Rochesters on it on a Vintage Speed setup. Ran like a clock right out of the box ! Why is this one giving me fits ?

Clean the intake and heads mating surfaces then set the intake on the engine without gaskets and see if it touches both heads correctly. Sometimes the intakes mating surface to the block is too tight, won't let the intake drop down far enough and will need some material removed to get it to touch the heads.
You may already be doing this but, just use a bead of silicon between the intake and block mating surface without any of the rubber gaskets.

I did exactly that, OI, and it fit very tight against the heads. I also always throw away those rubber end seals and use The Right Stuff sealant in a thin bead.

I think what I may have done wrong was overseal the last time, I really gooped the sealant on and maybe it was keeping the intake from seating all the way. Tomorrow I am calling FelPro and getting their best advice on what to do because the internet has so much conflicting info.

Ok, I called FelPro and got a very helpful guy there. I told him all the details and what I have bought so far, and he recommended a gasket set that I had not ordered yet.

He asked me if I needed the heat crossover to be open for the choke, and I said no, I have the choke locked up and I am in Florida. So he recommended set number 1205S3 which is a steel backed set. He said it has the Print O Seal feature so that when the engine warms up it sort of melts and acts as a sealant around all the ports.

He said to put them on dry, except for using The Right Stuff instead of the rubber end seals. He said nothing additional needs to be done.

So, now I have the new (but opened) set of FelPro 90314-2 gaskets, a new set (but opened) set of Mr Gasket gaskets, and, coming via UPS are the Fel Pros I ordered yesterday, that I can return to Summit.

What hurts my head is that this should be the most simple engine gasket set to install, and everything is brand new. I am no master mechanic, but I have put a lot of intakes on over the years, never had a leakage issue at all. Why this one has done this is nuts. But, hopefully, this will be the fix when this set comes on Wednesday.

Just thought I would pass this info and these part numbers along to maybe save someone else any problems.

Are these factory cast iron heads or aftermarket?

This may be way off the mark, but has the block been decked or the heads shaved? That can cause an alignment problem between the manifold and heads. I'm assuming they are GM iron heads, not an unusual intake port shape...

Ooops, Old Iron beat me to it

They are factory cast iron heads and brand new. So there should be no problem with them sealing.

Like I said earlier, in my 23 I pulled an engine out of a boat, rebuilt it, and put on an aluminum intake and it sealed perfectly. Why this one did this is probably because I did the install some time ago and I really gooped the heck out of the gasket with sealant.

The reason I asked is, the manifold bolt holes may have not gotten drilled all the way through if they were aftermarket cast or aluminum like the factory does and the bolts at that point will bottom out and not tighten.
All but the ends on factory go into the oil valley on stock SBC heads.

Yep, you are right, and the middle ones need some sealant on them so the oil will not wick up the threads and escape.

One thing I am going to change is the stainless AN washers I had under each intake bolt. I did it for cosmetics originally, but when I removed the bolts I found each washer was deformed into a slightly concave shape, so it was sinking down a little into each manifold bolt hole. I am going to replace those with thicker washers of a slightly larger diameter.

Such a simple motor to become so confusing. But hopefully, the changes I am making will put this all behind me.

The only time I have had an intake manifold vacuum leak was when using a set of Bowties heads (Chevy over the counter racing heads) with raised intake ports. I didn't realize there is a dedicated manifold for those heads. I can't imagine that your heads have been milled enough or the decks on your block have been cut enough to cause a mismatch that would result in a massive vacuum leak, especially if the intake bolts and holes lined up.

Did the engine ever backfire while you were getting it running? If it did it might have pushed part of the intake gasket out, or into the valley.

Yep Bob, it backfired a few times........good point. You may also be right because in the beginning, when I first got it running, it ran better than it has recently, so probably the gasket has gotten worse and worse. Hopefully, this new one should cure the problem.

I have decided to name this car Christine II..........I swear it is haunted ! Tonight I went to the shop to do a few things and while there I decided to put an intake bolt into the rear most hole on the head to see how deep it went. As I was taking it out, it went PLOP and fell out of my fingers and went straight down the hole in the lifter valley where the distributor goes !!!!!!!!!!!!!!!!!!!!

I could see it deep down in there, but my longest pair of needle nose pliers would not fit into the hole, and I couldn't use a magnet because the bolt is stainless steel, non magnetic. I considered putting JB WELD on a dowel and putting it down into the hole to rest on the bolt and to let it harden over night.

Finally, out of desperation, I took my big 5 gallon shop vac and made an adapter out of Gorilla Tape to shrink it down to fit a small hose of about 7/16 ID diameter. I slid that down into the hole, touched the bolt, and turned on the shop vac. After moving the hose around a little I heard it make a noise like it sucked up the bolt, and when I slowly removed the hose the bolt was stuck to the end of it.

So I came home, and after I eat I am going to bed and stay there. Like I said, I think this car is possessed !

Don, that's how it went for me all summer. Everything I did, I had to redo.
If the corner intake bolts are too long they will bottom out and not clamp the manifold tight enough. If the middle two on each side are too long they can contact the push rods and interfere with their operation.

Don: look at it this way. Once you you get past these stumbling blocks it will be like walking down easy street. Great idea on bolt retrieval.

Don, I know this sounds crazy but are you running a power brake booster? When I was building my Ford PU I had a vacuum leak that drove me cray & after messing with it way too long I took it to a mechanic shop down the street & they found out it was a leak in the brand new booster. I replaced it... problem solved! I would have *never* thought of that in a million years!

BoB

kenny c said:

Don: look at it this way. Once you you get past these stumbling blocks it will be like walking down easy street. Great idea on bolt retrieval.

Click to expand...

I thought it sucked. [ddd

The last SB chev I did was for my Rat55 project and I had lots of gasket problems. I've put lots of SB's together and figured it would be a no brainer but I made the mistake of using a cheapo fleabay "offshore" kit. Never again! The head gaskets leaked, as did the intake gaskets, even the water pump gaskets leaked - I made some quickie gaskets from a Cheerios box and
they worked perfectly - how bad was that material that cereal box cardboard works better?? The fun didn't stop there, the cam from the same country went flat and the "bargain" intake manifold with 1/2" NPT pipe fittings on all 4 corners leaked when I put in 1/2" brass pipe plugs also from China. I learned the hard way that you get what you pay for...:
I'm sure you'll get yours sorted out, it sure is looking good
[cl[P(

Thanks guys. Bob, I am going to use shorter bolts for sure, and will run them down into the holes first to make sure they do not bottom out and the do not contact any pushrods, good point.

Kenny and Skip, haha, more than the vacuum has sucked on this project so far.

Tripper, no, it has manual brakes. The goofy thing is, this engine could not have less places as potential leaks, it has no accessories, and very few fittings going into the intake area. It could not be more simple, and I feel weird that it has been kicking my butt.

zz, whoa, is that a cool hot rod you have or what !!!!!!! Love it. I agree with you about buying bargain basement parts. I realize most stuff is now made overseas, but there are good overseas parts and then there are crappy overseas parts. For example, the Mr Gasket gaskets I bought were really cheap looking, and I wouldn't use them on a car I was flipping.

One thing for sure, I will have rags down inside the engine to catch anything I might drop again until I put the intake on. Now, if I just remember to remove the rags first !!!!!

"One thing for sure, I will have rags down inside the engine to catch anything I might drop again until I put the intake on. Now, if I just remember to remove the rags first !!!!!"
I was thinking the same thing as I was reading your post cause, a friend of mine did exactly that, with a bath towel, while building a engine for his race car. He was even a seasoned mechanic too [ddd[cl
He called me over and asked why the push rods felt so spongy, thank God he never tried to fire it up.

Old Iron said:

"One thing for sure, I will have rags down inside the engine to catch anything I might drop again until I put the intake on. Now, if I just remember to remove the rags first !!!!!"
I was thinking the same thing as I was reading your post cause, a friend of mine did exactly that, with a bath towel, while building a engine for his race car. He was even a seasoned mechanic too [ddd[cl
He called me over and asked why the push rods felt so spongy, thank God he never tried to fire it up.

Click to expand...

Lol.
I got a frantic call from a from a friend the other day telling me he sucked a paper towel down into his flathead by accident . He had the carb off and the towel laying on the intake and had cranked the motor over for some reason. He ended up using the shop vac to suck it back out.
Must be the phase of the moon��
Torchie