The Stovebolt Site Forums The Shop Area Engine Shop '54 261 Engine questions

Hi All,

I got my '54 261 engine back from the machine shop last week, and I'm now in the process of putting it back together. , but I've got a couple questions for the "experts".

1. Is the head gasket the same for all 261 engines from '54 to 62? The gasket I have covers up a couple water jacket holes in the block and the head, a 235 "848". I don't like the idea of punching holes in a head gasket.

2. I have two different thermostat housings, one of them is quite large, with a thermostat that looks like a small sink strainer basket. The part number is 3764748. Is this a correct 261 housing and thermostat? The other one looks just like the 235 housing. Which is correct?

Thanks!
Steve

Steve:
You may have a 235 head gasket. When I rebuilt my 261, the "extra" holes were already in the head gasket. I had to drill out the corresponding holes in the 235 "848" head. I think the 261 head gasket is different. Others may remember this with more clarity. I also remember a 261 rebuild article, either on this site's tech tips or the Inliners site. The article I believe talks about the extra holes.

Steve,

1. As Donsz said, you have a 235 head and 235 head gasket, Both have to be drilled to match the holes for a 261 block.

2. The larger thermostat and housing are for a 261; however, you may use either the 261 or 235 thermosta/housing on either a 235 or 261 head.

If you search this forum on "261 holes" you will find more information about the extra holes in the 261 block/head.

Also, look at the 261 thermostat and see if there is a small hole in it. This allows a little fluid to always circulate through the head, even with the thermostat closed. Many people drill a similar hole in a 235 thermostat.

Tim

hmm....interesting.

I'm starting to wonder what I've got. The gasket kit says its for a '55-62 261, so I don't think its for a 235 either. Besides, it covers up a couple holes in the head as well. All of the bolt holes line up though.

Can I punch holes in the gasket without wreaking havoc? All of the other cutouts in the gasket have metal reinforcements around the holes. Or should I just try to find a '54 261 head gasket? None of the regular parts suppliers seem to have one.

Thanks,
Steve

There are severl 261 head gaskets,seems the blocks that are all the same ain't all the same.The "universal" gasket has severa; large ringed coolant holes on the manifold side.Some gaskets have only one large hole on the manifold side.The Felpro has several holes, the Victor generally has one hole.When you drop on the head,use 2 guide bolts, you can cut off the heads of cheap 1/2 carriage bolts.Drop the gasket onto the bolts, push it over towards the manifold side as much as posible,then lower the head down and keep it over to the spark plug side.It's been my experience the gasket coverage on edge of the spark plug side is mariginal at best.

You are right TC!!

I just got back from the auto parts store with a "universal" head gasket by fel-pro. It has all the holes needed and then some. The one I had was a Victor and it only had the one hole. I'm happy now!!

Now, about that weird sink basket-like thermostat. Are they available anymore? The folks at NAPA said that they can't get it. Does anybody else have it?

Thanks
Steve

You can use the housing off a 235. I did that on two engines, no problems.

Steve,

I have not been able to find a replacement for the 261 thermostat and have used a 235 housing and thermostat on my 261.

Have you tested your thermostat? This can be easily done in hot water with a thermometer (to tell you at what temperature the thermostat starts to open). http://www.markl.f9.co.uk/howto/electrical/cooling/cooling.htm

Tim