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I may be changing the head gaskets on my BBC. What type of gaskets (brand and type) should I use? There are many out there and it's confusing. Some are like $30 each and some are like $75 each - made from different materials. My motor is for street/strip use, about 500 HP, has 10:1 compression, no nitrous, no supercharger. The heads are oval port - iron.

thanks

Lee

What size bore is it? I have been using the FelPro 1017 gaskets on my engines. I used a different p/n in my 540 but I can't remember what it is. But I do know it's the same makeup as the 1017 just a larger bore size.

What size bore is it? I have been using the FelPro 1017 gaskets on my engines. I used a different p/n in my 540 but I can't remember what it is. But I do know it's the same makeup as the 1017 just a larger bore size.

I don't know the size of the bore at this moment. I know it's a 1979 454 block with a .060 overbore. I can lookup the casting number and add .060" to the bore size unless somebody out there knows.

Lee

4.25 + .060= 4.310" bore.

Cast Iron or aluminum heads? Yes, it makes a difference.

Put a set of Cometics on it and be done. They are $160 for the set.

Do you have series cooling; or parallel cooling.

If you have series cooling, you might consider drilling a few holes in the block deck and converting to parallel cooling.

Series cooling uses a different head gasket than parallel cooling. Note the holes at each end; and the added hole between each of the cylinders:

http://www.hbassociates.us/gaskets.html

Stock type, .020" thick steel shims just like GM put in them.

Check out what Mr. Gasket sell's and right about the two types of deck cooling hole arrangements.

pdq67

Stock type, .020" thick steel shims just like GM put in them.

Check out what Mr. Gasket sell's and right about the two types of deck cooling hole arrangements.

pdq67

The Mr. Gasket shims are for SERIES cooling. The (now discontinued) GM shims would accommodate either system, based on photos I've seen. I don't have one to inspect.

It "might" be possible to stab three holes in the Mr Gasket shims so as to use them with PARALLEL-cooled blocks--I'd have to see how they're rolling the beads into the shim stock. If the areas where the holes need to go has a nice bead around it, it shouldn't be an issue to convert the gaskets. I HAVE NOT DONE THIS YET--you take your chances.

Hi Lee, I would have a shop pressure test ALL 3 pieces while they are "down".

If you don't find the issue BEFORE you put it back together you will be out much more "time & money" and maybe right back where you are now, have a shop pressure test all the parts now!!

Thanks, Gary in N.Y.

P.S. Just to confirm my recommendation on the gaskets (8180's) somewhat further, the photo below has a 427" BB, 13:1, solid roller, 990 (iron) heads AND those particular gaskets "sandwiched" between the "non-O-ringed" cast iron block. The car just made a number of passes at 134+ MPH, and not a single issue with those gaskets.

http://thumb8.webshots.net/t/64/564/4/4/80/2700404800044112208CjmQCp_th.jpg (http://good-times.webshots.com/photo/2700404800044112208CjmQCp)

Heck, drill/cut the cooling holes in a set of .020" thick shims and then install them w/ good old Permatex, "Indianhead Shellac Gasket Cement" daubed thick wet on each side of your gaskets AND ALL head-bolt threads!!

Then re-torque three time's over three days of heat/cooling cycles DD her!!

You will be fine, imho!!

I've stacked two .020" thick shim headgaskets on my 11.5 to 1 CR .060" over, 409 "W" engine as well as have reworked .020" thick steel 350 shims on my 406 using the darn sticky stuff fine!!

pdq67

leejoy you have a Mark 4 engine you have no need to worry about parallel or series just always use a gasket intended for a Mark 4. The FelPro 1037 at 4.370" @ .039" compressed will work fine,the 1017 has a much larger bore at 4.540 @ .039" you don't need it.
Mike

leejoy you have a Mark 4 engine you have no need to worry about parallel or series just always use a gasket intended for a Mark 4. The FelPro 1037 at 4.370" @ .039" compressed will work fine,the 1017 has a much larger bore at 4.540 @ .039" you don't need it.
Mike
Nope. There are both series and parallel cooled Mk IV blocks. MOST are series-cooled; a few are parallel. The worst possible combination would be to use a "parallel-cooled" gasket like the one in the link in my previous post on a series-cooled block. There'd be no way to eliminate the overheating until you changed gaskets or converted the block to parallel cooling.

Converting from series to parallel on a Mk IV block involves drilling five or six holes; and using the correct gaskets. The block I have, has a hole "near" where it needs to be; a little bit of oblonging on that hole with a die grinder, and drilling five more is all it took.

Far as I can tell, ALL Gen 5/6 blocks are parallel-cooled.

Shurkey can you show me the two FelPro part numbers for the parallel and series cooled Mark 4 engine? Are you including the marine engine?
Mike
I found reference material supporting your info. It would be nice to know what engines in the Mark4 series this applies to. Anyone have any information about that.

Coolant Routing Mk IV/Gen 5/Gen 6
There are two different ways that coolant can be routed through the engine: series flow and parallel flow. Both ways work just fine. There may be a slight preference for parallel flow, but it is not a big deal. Series flow has the water exiting the water pump, flowing through the block to the rear, it then transfers through the head gasket and into the cylinder head through two large passages on each cylinder bank at the rear of the block. The coolant then travels from the rear of the head, forward to the front of the head, into the intake manifold water passage and out past the thermostat and thermostat housing. The water cools the block first, then it cools the head. The coldest water (coming out of the water pump) is directly below the hottest water (having already picked up the heat of the block and the head) as the hot water transfers into the intake manifold. By contrast, parallel flow has the water exiting from the water pump into the block, where a portion "geysers" up into the head between the first and second cylinder, another portion "geysers" up to the head between the second and third cylinders, another portion geysers up to the head between the third and fourth cylinder, and the remainder transfers to the head at the rear of the block. The coolant temperature inside the engine is more even that way. The differences in coolant routing is having (or not having) the three additional coolant transfer holes in each block deck, and three matching holes in the head gasket. The heads have passages for either system, and are not different based on coolant flow.

Be aware that gaskets that DO have the three extra holes between the cylinders often have restricted coolant flow at the rear--instead of having two large coolant transfer holes at the rear, there is only one, and it's the smaller of the two holes that remains. This is important because if you use a parallel flow head gasket on a series flow block, you can have massive overheating and there's NOTHING that will cure the problem except to replace the head gaskets with ones that don't restrict flow at the rear of the block, or to drill the block decks to allow the coolant to flow into the head between the cylinders. Here's why they can overheat: A series-flow block doesn't have the openings between the cylinders, no coolant can flow up to the head there. The gasket may only have the single, smaller opening at the rear, so the amount of water that gets through that opening is greatly reduced from what the block designers intended. The result is that the coolant flow through the engine is only a fraction of what is needed.

Most, but NOT all Mk IV engines are Series Flow. ALL Gen 5 and Gen 6 engines are Parallel Flow. A series flow block can be converted to parallel flow by drilling 3 holes in each deck surface, and then use parallel flow head gaskets. You can use the parallel flow gaskets as templates for locating the additional holes. It's really easy: Put the parallel flow gaskets on the block, mark the location and size of the three extra holes. Remove the gasket. Grab a 1/2" drill and a drill bit of the correct size, and pop the extra holes in the block. There is NO modification needed on the head castings. Some blocks have one of the holes already, but it needs to be ground oblong to properly match the gasket. Again, very easy with a hand held die grinder and rotary file.

Shurkey can you show me the two FelPro part numbers for the parallel and series cooled Mark 4 engine?
Not instantly--sorry. I have those photos in the link supplied; but I don't have part numbers.

LATER EDIT:
IF the photos supplied on the Summit site are accurate depictions of the actual gaskets;
Fel-Pro
1017 = both parallel and series
1037 = Parallel only
1027 = parallel only
1047 = Parallel only
1067 = Parallel only
8180PT-2 = Series only
5823PT-2 = Parallel only
17046 = Parallel only
Mr. Gasket
5802 = both parallel and series
1131 = Series only
3156G = Both parallel and series

There's lots more gaskets listed, but that should give you some examples.

Are you including the marine engine?
Yes--some of the Mk IV 427 tall-deck blocks I have use parallel cooling. Those engine have "TRUCK" and "MAR" or "MARINE" cast into them.

I found reference material supporting your info.
Sort of. I wrote that article. So it's not like it's an independent source...

I do give you points for researching this, though! :yes:

Funny thing--I thought I was really onto something when I discovered the two cooling system routings by comparing gaskets. (I was installing Gen 6 heads on a Mk IV block, and needed to know what was different, and if it could be done.) Then I find out that Fel-Pro (and no doubt others) are including an installation note in certain head gasket packages telling the installer to drill three holes in each deck if the block doesn't already have 'em. So this is "old" information, but few people seem to know about it.

It would be nice to know what engines in the Mark4 series this applies to. Anyone have any information about that.
Aside from what I've said about at least some of the tall decks, no, I don't have that info but would love to find out. I have suspected that the LS-6 engines (and, I suppose, any other that used the same block) had parallel-flow cooling; but I've no actual proof.

Very interesting info thanks for going to the trouble. I will have to remember the FelPro 1017 number so I can stay out of trouble with either block. Thanks.
Mike