BB Head Gaskets

I've noticed on my low deck motor that the FelPro head gaskets have a restrictive slot where the coolant flows from the block into the heads. Does a factory head gasket have the same slot? Any harm done to open it up and get more flow? Or maybe there is a reason for it? Someone smarter than me must have designed it that way.

I cannot explain why or the engineering behind it, but I just know I have read that it was designed on purpose like that. But, not sure if that statement I had read was substantiated.

Which slots are you talking about? Pictures are worth a 1000 words
If your talking about the narrow short slits in the middle of the block and heads the factory did that for allowing a small amount of coolant to transfer from the block into the heads instead of making all the coolant go all the way back to the rear of the block to transfer into the heads through the big hole at the top rear of both sides of the blocks and heads

Yes Cab the slits that you mentioned are what I was looking at. Mostly just curious, I haven't had any heating issues, so probably will just leave them as is. As far as pictures, I haven't had any luck trying to post pictures to this forum. As I remember, it was somewhat complicated.

Your question of concern is common.

Head gaskets are designed to control the flow pattern and volume of coolant between the block and the head. Yes, some casting holes are blocked and/or restricted... again, to control the flow pattern and volume of coolant.

DO NOT EVER modify the head gasket's holes or you will encounter problems with engine temp at areas of the engine that you can't see. These patterns are designed by the OE developer.

I'm a former long-term applications engineer for a major gasket company.

Thanks for the good info Mitch.

The slots prevent air pockets and allow a limited amount of coolant flow to help equalize the cylinder head temperatures. The majority of coolant is forced to flow from the front of the block to the back of the block, then up through the back of the cylinder head to the front of the cylinder head.
Enlarging the gasket holes will reduce the amount of coolant going to the rear cylinders and cylinder head.
There is a misconception that making the holes larger makes the engine run cooler because the front of the engine where the temp sender is will be running cooler than the rear part of the engine.

Twice per month call at the Tech Line.

Another was "I set it dot to dot and turned it around and around, then after I turned it #1 wasn't at TDC firing anymore when it was dot to dot, then I kept turning it
round and round and couldn't figure it out, so your parts are junk"

Furthermore, the extra casting holes, as well as extra large size, are primarily intended to extract sand from the casting process... on all blocks and heads from any mfgr.

LOL! Probably why most people called the .528 MP cam junk. After degreeing in, mine was 8* retarded when installed "dot to dot". Try to convince the masses that even the most mundane builds need degreed, though.

#1 vs #6 piston and valve activity seemed to be beyond alot of folks.

Attitudes are: Head gaskets must all be made in China, because they have restricted coolant flow to some holes.

That kind of stuff is the ridiculous waste of time kind of material people will call up and complain about to anyone who will listen,
and is just the everyday stuff faced by a Tech Guy.

Spring relocation kit discussions were usually pretty entertaining. Plenty of others.

The reason the 528 cam was called junk by so many is because it idled like a garbage truck and made a bunch of torque,
and we can't have that! If you don't have to have a 5 grand converter and 4.88s, clearly it can't be any good. That's the attitude....