The Stovebolt Site Forums The Shop Area Engine Shop 261 headgasket, sealer or not?

Ever since I built the modified 261 in my 37 truck 6 years ago, it's always leaked alittle oil from the headgasket on the pushrod side of the engine.Not a gusher, but enough to make a mess that needs to be wiped down once a month.Both the head and block were milled ,I installed the headgasket dry like on my other 261-235's.
I just finally pulled the head to fix the leak,all the bolts were torqued properly, a check with a machinists straight engine shows the block and head surfaces are perfectly flat in all directions. The engine leaked absolutley no coolant or compression, just seeped oil.
I have the new gasket in hand,Detroit brand ,like on my other engines,soft material on both sides, metal in the middle.These 261 headgaskets are the type requiring a re torque.The soft material is factory covered with something slippery like a graphite paint.
So, do I paint the gasket with Permatex Copper head gasket sealer or?

Felpro? Only one i have used that does not seep . Copper ones make for nice shiny art on the garage wall. PCV system?

I used the copper gasket with the copper spray. The way it deforms when torqued would seem to make it hard to leak.

I've never tried used a sealer with the newer gaskets. About all I know there is the manufacturers say not to.

Whenever I had a leaker, I did like Tony M and used the old copper gasket with copper spray. Back when I turned wrenches for a living that was all that the boss would let us use.

D8,yes it has a PCV system,no crankcase breathing problems I've used Detroit gaskets before, no problem.I wonder with the low volume of 261 gaskets, maybe there're made by the same company anyway.One nice thing about solid copper gaskets, they need no scrapping, just peel em off hang em on wall
I'm gonna spray several coats of Permatex copper sealer on the headgasket,see what happens.

Make sre you check that the dowel pins that align the head to the block are not bottoming out not allowing the proper amount of squish on the gasket. It happened to me on a Corsica after milling the head. Just a thought.

I think the felpro gasket is diff . The copper head gaskets gives away too much compression. They do come off real nice? I dont think you will want to put any sealer on the gasket unless you use a copper one. My 235 leaks with a copper gasket. and my 261 has the felpro with a PVC valve from a 292 and a good breather cap and it has been dry as a bone for 1 years now. Your head gasket black or blue?

D8, The gasket is black, Felpro no longer lists a head gasket for the 261 engine according to all sources I checked.
48bigtruck,no locating dowels these old Stovebolt heads.

Ok, I won't be using the head gasket I had,the guy helping me position the 80 lbs lump of cast iron, while leaning over the fenders of the 37, dropped his end of the head a few inches.Dented the gasket,garbage.I called the local machine shop,he said the parts warehouse has one Felpro 261 head gasket left in stock.I'll use a stronger helper next time,lol.

Tony,
are they really that rare where you are ? I am talking about the gaskets with the thin metallic rings around everthing important and the black squishy stuff in between. There is a guy in Hamilton, calls himself Gasket City, and I would think that he would have fifty, anyways.

Fred,261 head gaskets aren't rare,there just seems to be a limited choice of brands and designs.
The style you mention is what was in the engine and the replacement gasket that got ruined.Why it was seeping oil on the sparkplug side of the engine is a mystery to me.The block and head were machined, they are flat as Paris Hilton's chest and again no leakage of coolant or compression.When I built my other 261, a light smear of Hylomar sealant was used on the edge of the gasket on right side, absolutely no oil seepage on that engine.
I run the 37 truck pretty hard,maybe a slight oil leak is because of this, and maybe the seepage might not bother some one else.It never leaks on the ground, just gets all over the engine ,makes a mess.

Tony,
that is very weird. My 216, which looks like a 235, leaked in the same place when I got it, but it had a blown head gasket. I mention the 235 because the Canadian 216s in the later years had the same type of side cover as the 235s.

Paris Hilton's chest?? Yuck!!

Guess I'm lucky cuz I thought Paris Hilton was a hotel. I assume she must be on tv, but all I watch anymore is history and discovery channels and local news.

Fred, you gotta get out more often,lol. Paris Hilton is 20 something rich girl, she and another girl were on one of those stupid reality shows on Fox.The two rich LA brats spend a month on a working farm, saw a little of one show, total garbage,that's why I don't hardly watch TV.Anyway,they play up Paris like she's some hottie,she's got as much sex appeal as the 261 head gasket.

But you are right. Paris Hilton owns Paris Hilton. Or she will, some day.

Back to head gaskets,I emailed Detroit Gasket, got back a friendly reply with some info.It appears the Detroit parent company,Corteco, makes some or all gaskets for the Fel-pro brand name.The sales rep said the Felpro #7782 is a 261 gasket,.040 compressed thickness.He seemed to actually have experience on these old engines as he said you can simply use a Felpro 235 gasket #7619, punch the steam holes and bush them with small brass eyelets.The 7619 gaskets is .060 compressed if you want a head gasket factory coated with the blue stuff.

Tony thanks for the info. Here is another tid bit of info you may or may not know. Detroit Gasket was the ONLY company to make a head gasket for the Oldsmobile Quad 4 motor of the early to mid 80's.

I always use the Pematex copper spray , even on modern composite head gaskets , so far not one leak .

I hang the head gasket up and spray it , allow to tack up then spray it again , allow to dry for several hours before installation .

paris hilton is a carpenters dream flat as a board and easy to lay! dont knck it or her knockers for that matter

The tech rep at Corteco,the parent company of Detroit gasket and Felpro said it's ok to use gasket sealer on these retorque gaskets used on older engines.Copper spray on fibrous head gaskets, and aluminum paint on sandwich styles having metal on both sides.

With an all metal gasket like the copper ones I can't think of any disadvantages of using the copper spray as well. It would have to be a pretty bad fit to leak after several coats of that stuff.

I have also heard of people having to shorten their bolts because of crud in the bottom of the holes and or height removed from the deck.

That is another nice thing about the copper ones, after removal you can see if the gasket was flattened equally all the way around.

I have allways run a tap through the head bolt holes and used the non hard premtex sealer on the bolts and silver paint on copper gaskets with pretty good results. My 235 does weep some with the copper gasket but i can live with it. I may change it because it does loose some compression. I did not know the felpro was a detroit gasket. Oh well i will keep using them.What works for one guy may not for another.

Just dont go crazy with the copper spray. It'll squish out like silicon if you use too much. I install the blue coated gaskets dry, the copper ones get a light coating of copper spray on both sides of gasket and block & head. I've never used a steel shim gasket or one of the fiber ones. Sounds like the 7782 is the one to use. Did the rep say anything about what to coat it with??

chip

The Felpro is not made by Detroit,both are made by Corteco I guess, maybe to different specs. The UPS guy just dropped off the Felpro 261 gasket,it's coated with the blue stuff,looks like the Detroit gasket that is coated with black stuff, except the Felpro sealing rings around the cylinders look better.i get my burley neighbor to help me with the head and that's the end of this story,lol.