Head gasket direction question

I can't say for sure how it's supposed to be but mine were the way you described, one blocked in the from one in the back. Also the gaskets I ordered definitely had a top and a bottom and so I assumed that the design and the way they were before the water passages were blocked on different sides. For both water channels to be blocked in either the from or back one of the gaskets would have had to have been upside down, but maybe that is correct

Okay, no-one else piped up, so I went to PCM. According to them, the port side head is supposed to be blocked at the front, and the starboard head is supposed to be blocked at the rear. So the way it was on my boat as well as what Justin saw on his boat is correct (and SKIDIM is incorrect).

So did I. :-)   Only thing I can think of is that the GT40 requires it for some reason. I only asked PCM about a stock GT40, not a stock 351. At least I finally got some direction so was able to torque down the heads last night. :-)

Justin, by the way, what did you use to scribe marks on the push rods while setting your preload? And did you need to use shims on all of them? Thanks.

I don't know that engine, but the heads are typically identical only turned 180 degrees.

OK Straight answer coming up...unofficial of course, but you are getting bad information, place the gaskets on the block so the imprint that says FRONT is facing wait for it.... the FRONT. Yes one appears upside down but that is correct. I can't explain why but greater minds than mine designed it.   I've personally put together 3- 351 based engines this way and they are all still running with no overheat problems. This issue has been discussed here in detail over the years and all place front to front so have faith brotha.

There is also no difference in the short block of a 351 or a GT40, main difference being the heads and induction system.

You're doing fine Gordon, relax and finish assembling that thing. Don't overthink the rocker shims eiher.

Looks like Alan and skidim agree, and I'd be listening to Alan.

The dealer I called was not the one who replaced my starboard head under warranty; it was the old west coast distributor of CC, and they are the ones who called PCM and got the wrong answer. I also did get an email back from PCM today that essentially said that if it was backwards, it's Ford's fault, but again said that both should be front as SKIDIM says (funny SKIDIM knows more about it than PCM, which says a lot about SKIDIM, and not so much about PCM). Anyway, I'm following your and SKIDIM's advise and the starboard gasket will get flipped to the front tonight or tomorrow night, followed by rocker arm preload adjustments and putting as much as I can back together over the weekend (won't complete it since my boss is flying into town Sunday). A very long process when you haven't done it before and only have a couple of hours at a time to work on it.

What would be interesting to hear, is the rationale for the blocked passages.

I'm wondering if it's anything like the exhaust riser gasket blocked passage reasoning?

Jllogan wrote: yup, gordon my starboard head is coming off and Im gonna flip. Oy, well, I am an expert now right, haha. I talked to skidim yesterday and I trust their official answer over pcm honestly. They know these engines. Its no big deal to untorque and flip, it will take a half hour tops, my intake manifold was on and torqued as well. Oh well thats called doing stuff yourself, if thats the worst mistake I make then hooray!! Obviously the other way may work but it most not be optimal. I dont want any issues when it comes time to ski.

Hey Justin,

I hear you (I'm trying to get my boat back on the water ASAP since I ski year around--having to buy rides the last two weeks). I just pulled the starboard head, flipped the gasket, and re-torqued this evening.

Before you did your preload measurements, did you pull and clean the valve lifters? If so, how'd you clean them? Did you put them in oil to "fill" them up before reinstalling?

Did you follow the CompCam instructions (top of compression stroke, wait a few minutes for the lifters to bleed down, then back off the rocker, wait for the lifter to settle, then measure?

You mentioned that you used shims for most of the rockers. Where'd you order them? I went to the local auto parts store (with machine shop, etc.), and they had no idea where to get shims, etc. I suspect they just want me to buy pushrods, but it seems that shims will be much faster, etc.

By the way, where did you get your heads? I got them from Clearwater, and am curious what thickness shims you ended up using on most of them.

Would it be possible to email you off line or possibly even schedule a quick call? I'd love to talk to you since you've just completed this and I can hopefully get this done!   gordon.jensen@comcast.net

Let me know.

Thanks,

tim is right thats what I did, I didnt have to use 2 shims on any so between .030 and .060.

I just sprayed the lifters and wiped them off, didnt really clean, didnt soak in oil. I did not get my heads from clearwater.

Also just because I did it doesnt mean its right, my first time too. Also mine is back in and running yet so jury is still out.

hahah I wish bro its still winter in ohio, probably be a month before I hit the water. Also I just hit a snag with my strut that may hold me up. If it wasnt 30 out right now I probably would try to have it in the water next weekend. You will probably beat me to that.

Justin, just a heads up (no pun intended). A friend of mine this morning said that since I had already torqued down the starboard head with the gasket facing the rear, since I needed to change the orientation and the gasket had already been torqued, that I should probably get a new gasket. The auto parts place also suggested it (of course they are since they get to sell another gasket). But I don't want to risk it, so I bought a new one. I was able to get just one Feltpro head gasket (as opposed to two, or a whole gasket kit). It was $22, but cheap peace of mind. Just thought I'd mention it if you hadn't pulled and swapped yours yet (or maybe you did use a new one).

Gordon, it's been a while since I put on a marine head but I remember it being a special stainless steel head gasket for the marine environment. Are the felpros you get at the car parts place suitable for a boat engine?

If you only run in fresh water do you even need marine head gaskets?

I agree,I ran regular Fel-pro for years with no problems.In the case of the older motors like mine do you think Ford,who most likely put the basic block together used special gaskets? Heck they didn't even put marine carbs,distributors or starters on them either!

Gary S wrote: I agree,I ran regular Fel-pro for years with no problems.In the case of the older motors like mine do you think Ford,who most likely put the basic block together used special gaskets? Heck they didn't even put marine carbs,distributors or starters on them either!

Yup!! In that era, the basic block came in and the "marinization" was bolting on the exhaust manifolds!