Re: [AMC-list] head studs for 195.6 ohv

[Frank Swygert <farna@xxxxxxx>]

If you don't use some type of sealant on the head gasket (even though new ones say it's not necessary) you will get a good bit of seepage from the gasket on these engines, especially from the narrow right side surfaces (which are only sealed against crank case pressure). I'm reasonably sure the sealing issues have to do with the design and type of metal used when casting. These engines were designed when retorquing the head was necessary due to gasket material. Even with modern head gasket material this particular engine still needs the head retorqued every other year or every 12-15K miles. You could probably go further, but will it blow at 18K or 25K? Don't know... but it will if you don't retorque at regular intervals. I drove one for 14 years and retorqued every other year, put no more than 18-20K on in the longest interval (maybe once!), averaged 12-14K between retorques. Everyone I know who has driven one for 3-4 years blows the head gasket, with the exception of a few w
ho probably haven't put 4K on in 4-5 years. I tell those guys to retorque the head anyway before driving much. I've bought a couple that I drove a bit before retorquing the head. Around town on short trips usually isn't a problem, but the last one I took on a 30 mile cruise and blew the head gasket after I'd driven on several 10-15 mile runs. Wanted to go somewhere, knew it was only around 30 miles round trip, figured it would be good for one more trip before retorquing the head. Blew at around 25 miles. 

The heads are hard to get, and will warp pretty easy if driven much after the head gasket blows -- mainly because it's been done a couple times already. Usually the first obvious sign that it's the head gasket is steam coming from under the hood -- already run hot. You don't loose much power, and most are already high mileage engines. A slight loss of power as it warms is expected. There are no real warning signs except the temp gauge, and it comes up rather fast. Unless you were watching it like a hawk you probably won't notice until you see the steam.

Studs might fix the problem, the L-head (from which the OHV was derived) has never been known for head gasket problems, just the OHV. 2/3 of the top of the block is the same, so it would stand to reason that studs might be the answer (the L-head uses studs). The only problem is how much do you risk your engine? Even if I installed studs I'd still retorque the head every other year, might risk three year intervals if I knew for sure I didn't put over 15K on it in those three years. I just wouldn't be willing to risk damaging a hard to replace head, even if I had a spare lying around. Even so, the studs will be good insurance since they should hold better. I don't think it's age of the bolts, studs just hold better. I've known one or two people who reported that they replaced the bolts with new and still blew the gaskets. 

------------
Date: Wed, 27 Jan 2010 16:16:48 -0800
From: tom jennings <tomj@xxxxxxx>
Subject: Re: [AMC-list] AMC-list Digest, Vol 10, Issue 42


On Wed, Jan 27, 2010 at 15:50, Andy&Tonja&Phoebe&Miles
<raysinvegas@xxxxxxx>wrote:

> Have you thought about, or tried, the copper spray on adhesive that is
> meant for head gaskets?
>
> Yeah, I think that's what I used last time, copper permatex. 

I don't want to go off the deep end on this. Leaking heads is what kills all
these motors in the end, but usually it's way end-of-life, after overhaul(s)
and who knows what maintenance. All I've ever seen is rust spray, water-only
coolant, water+oil, etc, all signs of abuse and neglect.

I mean, Nash then AMC ran these things for decades, they worked. It's hard
to believe good flat surfaces, good bolts or studs, and good sealant won't
do the job.

--
Frank Swygert
Publisher, "American Motors Cars" 
Magazine (AMC)
For all AMC enthusiasts
http://farna.home.att.net/AMC.html
(free download available!)


_______________________________________________
AMC-list mailing list
AMC-list@xxxxxxxxxxxx
http://list.amc-list.com/listinfo.cgi/amc-list-amc-list.com