Hemi head gaskets Cometic vs Felpro

I have a 572 World 4.50 bore aluminum Hemi with Edelbrock Victor heads and Cometic head gaskets that has a coolant leak into the valley after 2 summers of street/strip use.Tried retorqueing the head studs and it got worse.When I removed the heads the gaskets had coolant between the layers. I called Barton and he said he has seen the sleeves "settle"in aluminum blocks and allow coolant to weep up from the lower steam holes around the fire ring and down the exhaust pushrod reliefs.I measured the sleeves and they are 0.0005-0.001 below the deck. I was thinking of trying the Felpro 1104 or Edelbrock gaskets but i noticed in the picture they don't have the 2 steam holes in the outer corners.Has anyone had success using the Felpro"s

I'm thinking the sleeves on all aluminum blocks should be above(.002 to .0050 max ) the deck surfaces due to the increase height of those blocks when they get warmed up.
I would call World and ask them

The sleeves dropping is a common problem with the world, and other aluminum blocks. Fixing that is a bunch of work, but given how little they've dropped, I'd likely just work on the gasket. Take your cometics apart by removing the rivets. Clean all three parts, then spray them all, both sides with copper coat. Let the sheets dry for a couple hours, then stack them back together on the dowels, reassemble and see if that stops it.

In case you want to fix it. Make, or borrow a draw bar that pulls the sleeve down from the mains. While under pressure from the bar, beat the draw plate with a really heavy dead blow hammer until it would move a tenth. Measure all the sleeves to the deck, and use the lowest as your standard. Heat the block up ( I use a big kerosene torpedo heater) pull the sleeves, then deck the bare block to what you want for sleeve height.Then heat it up again, replace sleeves, let it cool, then use the draw bar and hammer again to positively seat them.

I've seen new blocks drop sleeves .01

I had a coolant leak on my World aluminum block as well , when using the Cometic gaskets. I found out that the World block with the three coolant holes on the bottom uses a different Cometic gasket. I switched to the correct Cometic gaskets and ended the problem. Does your block have the three holes on the bottom ? Also a smear of Hylomar around the coolant passages was applied. You can see in the picture where the standard coolant holes in the original gasket were below the bores . those are not present on the new gaskets. Also has better coverage at the main coolant passages IIRC.
The part # is H2807SP3051S for gaskets that are .051 thick and have the three large coolant holes across the bottom.

The last 3 digits determine the thickness, so 040S would be .040 thick.

Mark

It looks like your World block doesn't have steam holes and my 2014 vintage one does. The C5447-040 Cometic's I was using had the 3 steam holes around the bottom of the cylinder. I am leaning toward using the Felpro 1104's with Blue Hylomar this time but they are missing the 2 outer steam holes. Was thinking of drilling the outer holes in the gaskets.Any opinions on why they left them out and if they are required.

So your gasket blocks the main water holes and only uses the small holes around the cylinders? What do the ports look like on the heads?

Edelbrock Victor Jr. heads

Thanks, I have a cast iron set of stock heads and they do not have those larger water holes on the bottom of the chamber. But they have the smaller holes that do not go anywhere on a stock block. Makes me wonder what the cooling strategy is on these heads. Seems like you would short circuit the coolant flow across the top of the head depending on the design of the block/head and what gasket you use.

Hi all, I am Eric and I am a new member,

I have the same leaks using the C5447-40 Cometic gaskets. I am building a 528" Hemi with the 088515 4.500" bore World aluminum block and the Edelbrock Victor heads.

It is a 2018 block and has 2 steam holes per bank, near the sleeve at cylinders 1, 2, 7 and 8. I also have the FelPro 1104 gaskets and would drill them for the steam holes.
I think they will cure the leaks but they are 0.051" thick.

Anybody has infos about the Cometic C15620-040," Chrysler Gen-2 426 Hemi .040" MLS Cylinder Head Gasket, 4.500" Bore, World Products Block" ?

Regards,

welcome to the board Eric !
my name is Eric as well. [not sure if that is good or not ! ]

i can't help you with your question, but glad you are here.

Yes my name is Eric too, many thanks to welcoming me! I will try to post some pictures of the engine build in a new thread.

Hi again, i finally found the reason of the leak. The sleeves are supposed to be dry, not exposed to coolant.

Coolant leak from exhaust pushrod holes #4 and #8

The front steam hole of bank 2 is drilled too close to the sleeve, no more block material between them. So the pressurized coolant follow the empty spaces between the upper parts of the sleeves and block deck up to the exhaust pushrod holes where there is no aluminum wall left (cylinders 4 and 8 in my case).

So my idea is to plug these steam holes with a threaded plug or a some sort of a metal bonding. I am thinking of drilling the 2 lower steam holes of each cylinder on the block. I will update my post about my findings... Any help is welcome!

With that hole touching the sleeve, I'd be reluctant to thread it. I'd make a press fit aluminum plug, put some locktite on it, and press it in.

Did you have anyone pressure check the block. If you have coolant in the valley its usually from over tightening the intake bolts on a Hemi. The bolts pull the intake straight down so it starts to lift the heads in the corners if over tightened.

Hi and thanks for the replies.

There is no intake manifold installed, just a Torque Plate and a 1104 FelPro gasket. The block was pressurized with the AR engineering tool, no leaks on Bank 1 with 20 psi with the head. On Bank 2, there is a leak with less than 10 psi applied,
with the cylinder head or torque plate on, Felpro or Cometic Gasket and sealant around the coolant holes.

Maybe I'm misunderstanding the procedure but what prevents the sleeves from moving downward again?

The bottom of the sleeve should be seated against the machine lip in the block for the sleeve to sit and seal against

Enjoyed this older thread just for education purposes.

Never know, might get one of those blocks someday.

Hasn't really been any closure, though.

So I'm going to ask...how have you guys repaired this?

I'm thinking maybe lightly press in a plug with a smaller steam hole drilled off center to get it away from the sleeve, or thread the hole and install a homemade "jet" with a similar hole, or something like that.

Maybe he will chime in, but its still sitting in his garage in pieces last I saw it around the holidays.

Good info Randy. I really like that Coronet alot and was looking forward to seeing more of it.

Call Cometic's, They will get you the correct gasket for your application, they were great to work with and got me the correct gasket for my KB alum hemi with the steam holes in the proper location.

They have my head gasket on file, always great to work with. But the HEMI is going top fuel hoops.

The first blown pump gas KB street Hemi block I assembled and dyno tested years ago leak water into the motor due to the sleeves being a tad bit too high , .005/.006 instead of .003 to .004 at room temps. It was a 4.375 bore with a Mopar brand 8 bolt 4.150 stroker crank.
Long story short I ended up working with SCE gaskets to get a custom set of their ICS Titan head soft copper head gaskets made to cure all the gasket sealing issues I had with that project
I'm getting ready to start making a 4.500 bore new KB street wedge 572 C.I. B1 race motor for myself and I bought a set of the SCE Titan head gasket with the Teflon sealant rings around all the water passages ,
That type of gasket worked really well for me on the last KB aluminum block I built: up:
I've also use them on other cast iron blocks high compression builds and roots blower motor builds with really good success IHTHs

My question is how much torque on the inside bolts -M1 heads? How much on the others also?

That is one super super nicest 9.85 street cars you will ever see...Rob has like OCD for these things....And he goes all out when trying things. I think he has tried ever carb/intake combo available on that car I think except an SV1 which I tried on mine.... If you ever get to talk with him, he has a lot of knowledge locked away up there of what works and what doesn't....We call him Mr. Sixpack.....He really has a thing for those.

Yeah from the few pictures he's posted here, that car has got the attitude and the performance.

I can tell by the pics it's real close to my target with the GTX but in many ways it seems a couple notches above where it'll end up.