Head Gasket Coolant Holes-No Match2Head

[johnl]

I am looking at a head gasket that has a single small hole that appears to BLOCK coolant flow through the larger matching coolant passages in the cylinder head and block.

I mean the four wide arcing passages/holes that arc around each bore/combustion chamber on the front side of the block/head.

Are there gaskets that are matched to the stock castings?

If not, is it a good idea to match the gasket to the castings? Or cut/punch a couple of more holes to improve coolant flow - while preserving the integrity of the gasket as much as possible?

I assume, generally, that Chrysler knows a lot more than I do. Did they discover that coolant flow should be limited in that area, contrary to their thinking when the patterns for the head castings were built?

Is the single small hole optimal for stock engines and not so optimal for high HP engines?

[puppet]

From what I understand the size of those holes made it easier to get the sand out of the cooled casting. In that case, the size of the holes in the HG is proper for cooling.

[turbovanman]

The blocked holes are there to help coolant get blocked so it can pick up more heat, keep coolant velocity up, blah blah. Thats what I seem to have read about other cars, trucks? anyone else?

I deburred all the coolant holes in the block and waterpump mounting pad to streamline and stop foaming, air pockets etc!

[johnl]

Quote:

Originally Posted by puppet From what I understand the size of those holes made it easier to get the sand out of the cooled casting. In that case, the size of the holes in the HG is proper for cooling.

OK, that makes sense. Since # 4 combustion chamber overheats, maybe the modifiication of drilling/tapping and adding a coolant line to the side of the head at #4 could be avoided by opening up the hole(s) in the gasket in the vicinity of # 4 only?

This is a 1st grade question, which direction does the coolant flow? Is it up the passenger side of the block from the water pump and then across to the driver's side, and then out the water box?

I'll try to post some pics; gotta figure that out.

[turbovanman]

It comes up the right side of the block-#1 cylinder, moves up and over across the block to the thermostat housing, then out to the rad, down and back to the pump. Thats why #4 overheats, its the last one to get flow and its hot by then!

[johnl]

So, does the coolant move, sort of indiscriminately through the block from passenger side to drivers side, and along the way, some of it flows up - via those little holes in the head gasket - and into the head, and then - again generally from passenger side to driver side in the head and then on to return to the radiator via the the thermostat/coolant box?

Assuming that path, it would seem that making the gasket holes around #4 larger would get more of the coolant to # 4 sooner - and thereby cooler. Presumably, the coolant, moving more directly to #4 will not pick up as much heat along the way, and would be cooler.

[turbovanman]

I think the biggest problem with #4 is the coolant stagnates in that area due to the thermohousing being between 3 and 4. So that coolant gets superheated hence the coolant bypass or moving the thermostat over to the end to eliminate that problem.

I don't think enlarging the holes will do anything otherwise Gary D and the other fast cars would modify them plus it makes them more prone to cracking.

[johnl]

''I don't think enlarging the holes will do anything otherwise Gary D and the other fast cars would modify them plus it makes them more prone to cracking.

Simon - Good point, the thermohousing - outlet is between 3 & 4 and so, leaves 4's coolant flow to stagnate.

Just so we are clear, I am asking about enlarging the holes IN THE GASKET in the area of # 4; I am not saying that the head's coolant holes should be enlarged, or that the gasket be matched to the coolant holes in the head but only that the holes could be enlarged at the # 4 end to promote more flow at that end.

Are you saying that an increase in the size of the gasket holes would overcool the #4 area and so increase the probability of head cracking in the #3 and #4 area?

Help me think this through, if a greater % of total coolant flow is diverted to the vicinity of #4 by opening up the holes in the gasket near #4 by say .040" than all of the others, then why wouldn't #4's higher operating temperature issue be helped by alleviating the stagnation of coolant in the # 4 area?

[turbovanman]

Quote:

Originally Posted by johnl ''I don't think enlarging the holes will do anything otherwise Gary D and the other fast cars would modify them plus it makes them more prone to cracking. Simon - Good point, the thermohousing - outlet is between 3 & 4 and so, leaves 4's coolant flow to stagnate. Just so we are clear, I am asking about enlarging the holes IN THE GASKET in the area of # 4; I am not saying that the head's coolant holes should be enlarged, or that the gasket be matched to the coolant holes in the head but only that the holes could be enlarged at the # 4 end to promote more flow at that end. Are you saying that an increase in the size of the gasket holes would overcool the #4 area and so increase the probability of head cracking in the #3 and #4 area? Help me think this through, if a greater % of total coolant flow is diverted to the vicinity of #4 by opening up the holes in the gasket near #4 by say .040" than all of the others, then why wouldn't #4's higher operating temperature issue be helped by alleviating the stagnation of coolant in the # 4 area?

That I don't know, but remember, the manufacterer spend alot on R@D so if it really worked, they would have done it already. Granted the #4 is a problem but Dodge never knew we would be pushing them so hard. I have never read ever of anyone modifying head gasket holes on any type of engine so there must be a good reason.

[puppet]

I know what your getting at John but the bottomline is that the t-stat return is still between 3 & 4. Coolant is still going to have the tendency to be drawn away from the rear corner to the t-stat return. Larger holes won't direct water away from the "drain".

The two mods either (a) pull water from the end of the head or (b) flow cool water to the end of the head. Both of them force flow past #4 ... to the rad (a) or to the t-stat return (b). Either is fool proof.

[johnl]

OK. Thanks. I guess if someone has tried it, it didn't work, and they went on to the develop the mods that are known to be effective.

[Phreakish]

would also squeeze the HG more in that area if you grind anything out... which could cause premature failure...

[johnl]

Quote:

Originally Posted by Phreakish would also squeeze the HG more in that area if you grind anything out... which could cause premature failure...

Words fail. No grinding. Just saying - What if the coolant holes in the gasket only, NOT in either the block or head castings, were slightly enlarged around # 4 only. This, presumably, would divert a greater proportion of the coolant to #4 head/block from the #1, 2, & 3 head/block. It could better balance the flow and allow the stock thermostat block to pull a greater proportion of total coolant flow from the #4 area of the head.

My problem is basic ignorance of the exact path of coolant flow through the block and head. Does it just dump into the block and then randomly find its way up into the head (through the small holes in the head gasket) and then randomly work over to the thermostat block, leaving flow in the #4 area (thanks Simon) stagnant?

[igotaneed4speed]

get an electric water pump remove the core plugs at each end of the head, made fiitins to run -10 an lines to the head and y them together and run that to the outlet of ur electric pump..

the pump feed comes from the lower hose and the old water pump location was fitted with a hose barb and water is diverted to the upper hose on rad..


reverse cooling like the ls1's..... cooling the head first an equaly from the sides in....


has work wonders for my head gasket problems...

[turbovanman]

Quote:

Originally Posted by johnl . My problem is basic ignorance of the exact path of coolant flow through the block and head. Does it just dump into the block and then randomly find its way up into the head (through the small holes in the head gasket) and then randomly work over to the thermostat block, leaving flow in the #4 area (thanks Simon) stagnant?

Yes, it starts at the passenger side block and gets pushed up and over to the thermostat housing. Due to the housing being over and not at the end, the coolant stagnates and overheats. Hence the bypass or moving the thermostat over.
Funnily enough, every stock car with a 2.2 or 2.5 has had the gasket blow on #1 cylinder????? funny really!