Head Gasket

I am replacing the head gasket using a Felpro 7277 on my 8N. I have the torque sequence for the head but do you normally use new bolts? All mine are bolts, not studs. Thanks.

If you have the time, money, and a good bolt shop nearby, replacing 70 year old metal with a good new equivalent would seem like a reasonable exercise to me. If you don't have a good nut and bolt store nearby and the old is in decent shape, you can easily re-use them. Most probably do.

I don't use new head bolts on these engines unless they're rusty.
I make sure the bolts and the holes are squeaky clean and that
the bolts will thread all the way in easily. Then I use a small
amount of red RTV on the bolt threads.
Others may prefer a different sealer. No problem as long as it holds.

Thanks for the tips. Do you use any sealant on the head gasket or anything to help keep it in place while installing the head?

I just recently swapped an 8N head gasket.

Clean very well with a brush and some wd40 worked
well. In fact make sure to clean all of both
surfaces (bottom of head, top of engine block)
very well.

Sealer on the bolts can"t hurt, but it"s not a
requirement, I didn"t end up adding anything when
bolting down the head.

As a side note, I was suspect about running the
engine and needed to re-tighten the bolts (my hood
is a big pain to get off, and remember it"s heavy
with the gas tank), however I would highly
recommend doing it, it turns out the tensions
changed somewhat significantly.

(quoted from post at 15:49:55 07/13/14) I just recently swapped an 8N head gasket.

Clean very well with a brush and some wd40 worked
well. In fact make sure to clean all of both
surfaces (bottom of head, top of engine block)
very well.

Sealer on the bolts can"t hurt, but it"s not a
requirement, I didn"t end up adding anything when
bolting down the head.

As a side note, I was suspect about running the
engine and needed to re-tighten the bolts (my hood
is a big pain to get off, and remember it"s heavy
with the gas tank), however I would highly
recommend doing it, it turns out the tensions
changed somewhat significantly.

Click to expand...

Thanks. I plan on running it for 5 to 10 minutes and retorquing the bolts. I have an old lawn mower gas tank with a shutoff valve and rubber fuel line I use to run the tractor without putting the hood on. I just hang it with bungees from an overhead joist in my shed. I am trying to decide if I should get the head milled. I put a straightedge across the head and can see light under the middle of the head surface. When I put it on the block it rocks slightly across the diagonal. I checked the block with the straightedge and it was flat. I'll have to check around tomorrow to see if I can get it done locally. I could also just install the gasket and hope it seals.

I would definitely have the head milled. Just make sure the pistons do not hit it afterwards!

I typically do not use anything on the head gasket.
If I were going to, it would be a spray like copper coat.
I would have the head checked at least.
I can't remember the spec, but they can't be milled much
before the pistons hit them. When you get it back, lay it
on the block and see if the pistons push it up when you turn
the engine over by hand. If they do, you can relieve the head
with a die grinder to get enough clearance.
There are several posts in the archive on doing just that.
Best of luck!

The local machine shop here charges $40 per hour so
it wouldn't cost to much to have it milled. I use to
use #3 permatex brush on sealer.
Is your 8N a front or side mount distributor?

(quoted from post at 17:33:54 07/13/14) The local machine shop here charges $40 per hour so
it wouldn't cost to much to have it milled. I use to
use #3 permatex brush on sealer.
Is your 8N a front or side mount distributor?

Click to expand...

Mine is a front mount. I think it is a 49 model year. By the way there is a flat boss cast into the head at the base of the coolant neck. Was this for a temperature sensor? Just curious.

My impression is that heads get resurfaced far more often than is
necessary when inexperienced mechanics put a straight edge on
the bare head and get all alarmed that they are not perfectly flat.
But a flat head is not anywhere near as rigid as an OHV head so a
little distortion in inevitable when the head is not torqued down.

The life of a head is measured pretty much by how many times it
gets cut. . Why use it up unecessarily?

I seem to recall that Zane (who is considerably more creditable
that me) has made a similar point.

(quoted from post at 02:45:59 07/14/14) My impression is that heads get resurfaced far more often than is
necessary when inexperienced mechanics put a straight edge on
the bare head and get all alarmed that they are not perfectly flat.
But a flat head is not anywhere near as rigid as an OHV head so a
little distortion in inevitable when the head is not torqued down.

The life of a head is measured pretty much by how many times it
gets cut. . Why use it up unecessarily?

I seem to recall that Zane (who is considerably more creditable
that me) has made a similar point.

Click to expand...

Good info. I put a straightedge along my head and I could slide a 0.016 feeler gauge under the largest gap (in the middle). Would you get this shaved or try it with a new gasket and hope for the best?

Just replaced my head gasket last weekend. I also have a front mount dist. but have studs instead of bolts. 5 of the studs pulled out while removing the nuts. I had originally ordered 18 of the exact ford studs from MAC Ford in northern NY for a few about $2/stud as a precautionary measure. Wound up only replacing 5 of them. They were the exact shape and size as original.

Anyhow, I had my 15 yr old son chase out the 5 stud mounting holes in the block with a bottom tap that I removed prior. Also had him re-thread all of the remaining studs. You would be surprised at how much rust came off.

With the head off I placed a 10 inch narrow blade screw driver down through the water jacket holes of the block. About 3/4 of the way down the screwdriver felt like it was penetrating through muck which was really 60 yrs of rust and what ever. So I removed the block water drain cock as well as the lower radiator hose from the block. I connected a small restriction connector at the end of a garden hose ( found at the home depot. Creates high pressure from a garden hose) which fit perfect in side all of the water jacket holes and flushed the hell out of the block until everything came out. Yes water got all over. Most of the time my piston cylinders were filled of water up to the top but a rag dried them right up.

Like I do with all of the heads I work on, I placed my cylinder head on a 1/2 think sheet of glass that protects my girl friends dinning room table. The best I was able to slip was a .002 guage under the largest gap. Good enough for me.I don't mill heads unless you really need to do so.

Put the new studs in with Aviation sealant (thanks TOH for hooking me on this stuff) and tightened to maybe 5 ft/lb. Yes only 5 ft/lb. Placed a drop of oil on each stud. Used a fel-pro gasket. Not metal. Metal gaskets only serves their purpose for new or completely milled heads and/or block surfaces. Sprayed copper gasket sealant to the gasket, block and head and tightened the heads to stud torque specs. Your bolt torque specs are slightly higher. I believe 65-70 ft/lbs. Finally replaced the hood.

Ran the engine for 30 minutes and re-torque the cylinder head nuts again to spec. My 18" 1/2 drive torque wrench fit perfectly under the gas tank when the tank and hood were permanently mounted.

.009 out of plane is one of the benchmarks calling for a resurfacing . . . at least on a thick OHV head.

Don't use any sealant on the gasket.
Felpro make great gaskets; Their motto used to be:
"where sealing is a science."

Some gasket including Felpro Perma Torque advertise that a retorque isn't necessary. While that may be so of Felpro ONLY, I wouldn't trust any other outfit's no retorque claim and have always ignored that regardless of the maker.

The reasoning behind clean threads lightly oiled as someone mentioned, is to keep your torque readings true. Felpro Grey Bolt Prep (GRA2) for any bolts extending into the water jacket.

If you did the rings too, then don't be letting your engine just idle before a proper run-in under load to seat the rings. Excessive idling can "polish up the cylinder walls, cause incomplete combustion and carbon up the valves".

Here's a good tutorial on installing head gaskets .
http://aftermarket.federalmogul.com/en-US/Technical/Documents/How%20To%20Prevent%20Head%20Gasket%20Failure%20-%20Low%20Clamping%20Force.pdf

(quoted from post at 16:51:20 07/14/14) .009 out of plane is one of the benchmarks calling for a resurfacing . . . at least on a thick OHV head.

Don't use any sealant on the gasket.
Felpro make great gaskets; Their motto used to be:
"where sealing is a science."

Some gasket including Felpro Perma Torque advertise that a retorque isn't necessary. While that may be so of Felpro ONLY, I wouldn't trust any other outfit's no retorque claim and have always ignored that regardless of the maker.

The reasoning behind clean threads lightly oiled as someone mentioned, is to keep your torque readings true. Felpro Grey Bolt Prep (GRA2) for any bolts extending into the water jacket.

If you did the rings too, then don't be letting your engine just idle before a proper run-in under load to seat the rings. Excessive idling can "polish up the cylinder walls, cause incomplete combustion and carbon up the valves".

Here's a good tutorial on installing head gaskets .
http://aftermarket.federalmogul.com/en-US/Technical/Documents/How%20To%20Prevent%20Head%20Gasket%20Failure%20-%20Low%20Clamping%20Force.pdf

Click to expand...

Thanks. At least the .009 guideline gives me an idea of what is acceptable. With min being .016 I might go ahead and get the head milled. I'll check on it today.

Here's a good tutorial on installing head gaskets .
http://aftermarket.federalmogul.com/en-US/Technical/Documents/How%20To%20Prevent%20Head%20Gasket%20Failure%20-%20Low%20Clamping%20Force.pdf[/quote]

Greg,

Check out point #7 on that Federal Mogul/Felpro pdf.
Felpro makes a copper shim to use in conjuction with the head gasket in order to restore head height if your resurfacing calls for that corrective measure.

Terry

Yes, that's the best place for the sending unit. If I were you I would
go ahead and drill and tap or or have the machine shop do it while
it's off

Thanks but I decided not to add a temperature sensor.

Greg maybe the warm milk and bourbon has made its mark tonight but....your pict shows the boss already tapped in the ideal spot for a sending unit. So why not?

You are passing up a nice upgrade... Its not hard to drill and tap it... You will not regret it...

On a side note if your fel-pro gasket is blue no sealer needed its pre coated with it from the factory.... I would slop some on the head bolt threads. :wink:

(quoted from post at 16:26:43 07/30/14)
You are passing up a nice upgrade... Its not hard to drill and tap it... You will not regret it...

On a side note if your fel-pro gasket is blue no sealer needed its pre coated with it from the factory.... I would slop some on the head bolt threads. :wink:

Click to expand...

Ok I might reconsider the temp sensor. What sensor and gauge do you suggest? Where did you mount your gauge?
And Yes my fel-pro is blue but I did put some Hi-Tack sticky to help hold it and I used a small amount of high temp red on the bolt threads. I have now removed the head because of an exhaust valve not sealing. I checked it by topping the valve with fluid and it seeped thru. I'll update this issue later. Thanks for your help.

I use a mechanical sunpro gauge from advance auto. I remove the useless amp meter and put the temp gauge there. You can mount the charging indicator anywere you want. BTW if its 12V it a good time to step up to a volt meter :wink: ... The temp gauge will come with 1/4", 3/8" and 1/2" bushing use the 3/8"... I will look for a pix to show you were to drill baby drill nuttin to it....

http://forums.yesterdaystractors.com/viewtopic.php?t=889616&highlight=gauge