[65nss4spdGTO]

We've been working on a solution for Tiger headed engines that have had problems with head gasket sealing between the center exhaust ports. Glenn Sedig, (Vintage Mechanical Works) and myself have come up with a special alloy insert to add stability in the high heat area's between the center exhaust valves. The insert is going on two engines for testing and we feel the upgrade should improve sealing and prolong head gasket life.

The cost for this upgrade is $500.00 for the pair of heads. For more information contact me or Glen Sedig.

http://vintagemechanicalworks.com/

http://www.hillperformance.com/

Calvin Hill
Hill Performance
708-250-7420

[Half-Inch Stud]

Have to say, by observation: clever, and potentially effective. Ever done before? Wonder if it needs IP protection?

[60man]

Interesting Calvin....by all means keep results posted..

[john marcella]

I hope it works for you. But boy i dont know, 2 dissimilar metals on the deck at the highest temp spot????
Why not just machine a pocket out of the deck , like you did, and fill it up with a hard welding rod and peen the hell out of it?

Have you done this before? If not Good luck!

[60man]

Originally Posted by john marcella

I hope it works for you. But boy i dont know, 2 dissimilar metals on the deck at the highest temp spot????
Why not just machine a pocket out of the deck , like you did, and fill it up with a hard welding rod and peen the hell out of it?

Have you done this before? If not Good luck!

OK..Speaking of dissimilar metals....which combo would tend to seal better....a aluminum block & heads ....or a iron block & aluminum heads ??? Always wondered if there was advantage (not including less weight) to going with aluminum block ??

[john marcella]

Originally Posted by 60man

OK..Speaking of dissimilar metals....which combo would tend to seal better....a aluminum block & heads ....or a iron block & aluminum heads ??? Always wondered if there was advantage (not including less weight) to going with aluminum block ??

I dont think that would mater that much.But i dont know. I would have to say iron block.
My concern is the 2 metals on the same surface, same plane. I think that piece is coming out, but i have been wrong before. If it works that would be pretty cool.

[Brian Baker]

Clever idea indeed. What keeps the insert from separating from the head due to the disimilar metals? Same processes as a valve seat?

[65nss4spdGTO]

Originally Posted by john marcella

I hope it works for you. But boy i dont know, 2 dissimilar metals on the deck at the highest temp spot????
Why not just machine a pocket out of the deck , like you did, and fill it up with a hard welding rod and peen the hell out of it?

Have you done this before? If not Good luck!

This has been done before, just our first attempt with the Tiger head. The thermal properties of the materials have been taken into consideration in the machining process.

This alloy will resist heat much greater than the aluminum.

Calvin Hill
Hill Performance
708-250-7420

[65nss4spdGTO]

Originally Posted by john marcella

I dont think that would mater that much.But i dont know. I would have to say iron block.
My concern is the 2 metals on the same surface, same plane. I think that piece is coming out, but i have been wrong before. If it works that would be pretty cool.

The insert has been machined in a key type fashion, the alloy material will not burn up and fall out. The rest of the head with have to collapse or completely burn away for that to happen.

Calvin Hill
Hill Performance
708-250-7420

[john marcella]

Originally Posted by 65nss4spdGTO

The insert has been machined in a key type fashion, the alloy material will not burn up and fall out. The rest of the head with have to collapse or completely burn away for that to happen.

Calvin Hill
Hill Performance
708-250-7420

I didnt think it would burn up or fall out. I think you are going to take it out.
How deep does the key go? how much press? It definitely has the potential to work.
Its not a dumb idea.
Have you checked the Rockwell of the head in that spot? Have you tried a different heat treat?

[twinturrbo406]

Originally Posted by john marcella

I didnt think it would burn up or fall out. I think you are going to take it out.
How deep does the key go? how much press? It definitely has the potential to work.
Its not a dumb idea.
Have you checked the Rockwell of the head in that spot? Have you tried a different heat treat?

... we did have a set of ProStock Ford heads in the shop a little while ago, and they had many runs on them, and i myself was surprised to see that piece in there, but it has held up very well ...

[aaronman]

Very innovative. Love to hear more after a many cycles of use/abuse.

[Scott Roberts]

Dave Wilcox did the very same thing on the tigers on the dirty bird.... it definitely helps!

[Elarson]

Originally Posted by 60man

OK..Speaking of dissimilar metals....which combo would tend to seal better....a aluminum block & heads ....or a iron block & aluminum heads ??? Always wondered if there was advantage (not including less weight) to going with aluminum block ??

I would expect the iron head/alum block to work better, (theoretically) for a couple of reasons:

1) iron head is stiffer and would bridge across the head bolts better.

2) the head runs hotter than the block. Iron has a lower coefficient of thermal expansion. So....that mix would tend to equalize the thermal expansion of the two and minimize the movement along the deck surface.

But if someone has actually tried it and it didn't work well, that would override theroy.

FWIW,
Eric

[Elarson]

"One test is worth a thousand expert opinions"

author unknown but that's been a favorite of mine for years.

Eric

[GTO Dan]

Originally Posted by Elarson

"One test is worth a thousand expert opinions"

author unknown but that's been a favorite of mine for years.

Eric

Dude, keep that quote to yourself, if that gets around the only postings left on the internet will be porn.

[BruceWilkie]

So... better cooling of the center head bolt area isnt as good a fix? Seems Rex and Langer have had huge improvement in head gasket life by creating a water passage where there wasnt one, and directing a separate cooling line to it. Not knocking what your doin there Calvin. Perhaps doing both would be even better?

Fwiw there are lots of lessons to learn from the original 55-59 rev cool factory setup that could be applied to our modern stuff. Those gusher tubes directing coolant to valve guide areas is one of them. No room in modern heads for gusher tube...however their is certainly room to build an external water rail with probably 9 feeds just below the valve cover.(8 holes directed toward guides 1 hole toward center head area)
Keep in mind heat rises and cool sinks... its key to why early system works so well. I'll also add that most liquid cooled 2 strokes have water jackets around the cylinders yet there is NO return flow path outside of gravity, convection, and vibration! Water pumps thru head and water simply "falls" out of head into cylinder jackets. The 55-59 Pontiac only uses two 1/2" holes on block face for circulation to pump. Mainly its the bypass for when the thermostat is closed. Majority of water flow went thru heads via the gusher tube. Very little can actually "flow" thru the block.

Yep I've been studying closely!

Good explanation/pics of 55-59 rev cool and changes made in 1960 for conventional cooling can be found here... http://www.pontiacsafari.com/EngineCooling/index.htm

My bet is, dry deck or not, we arent cooling as well/evenly as we could/should and that siamesed center ex port lets the center bolt expand/stretch much further than the rest.

[twooldgoats]

Originally Posted by GTO Dan

Dude, keep that quote to yourself, if that gets around the only postings left on the internet will be porn.

Even then..........

[Mike Kasparian,Sr.]

Has the cometic been surviving with this mod? Seems like the raised sealing embossment in that area flattens out with the heat then you just end up with 3 flat layers in that area. Good idea, hope it works out. MK

[John Langer]

Originally Posted by john marcella

Why not just machine a pocket out of the deck , like you did, and fill it up with a hard welding rod and peen the hell out of it?

That wont work. Want to know how I know... Knowing what I know from first hand experiences with n/a Pontiac engines, I wouldnt be brave enough to try that. Just sayin'. I fixed the problem but I guess there is more than 1 way to skin a cat. I didn't really have problems until I started making over 1025-1050 hp.