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  #21 (permalink)  
Old 12-16-2019, 04:55 PM
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Default intake gaskets

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Originally Posted by cycleguy55 View Post
Had similar oil consumption problems with mild 460. I replaced my valve stem seals as well, but that had little effect.

Turns out the root cause was the intake manifold gaskets weren't properly sealed, allowing oil to be sucked from the valley into intake ports. Drain coolant, pull the intake manifold and carefully inspect the gaskets for signs of leakage.
Done that drill lke 5 times now, finally ended up with flatout 0.120 gaskets, trimmed the tops so that the inward taper on the upper part of the heads didn't force the gaskets down, maximized the area on the bottom where the intake bears...Think thats a problem with these big port head there isn't but like 3/8" of gasket area at the bottoms of the intake ports...
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Old 12-16-2019, 06:44 PM
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Originally Posted by tortuga View Post
Alameda

I am down in Gilroy, about 70 miles south of Alameda. You might want to check out some of the shops that are in closer to you first. If you don't find anything you like, I'll introduce you to the shop down here in Gilroy that I use.

They do both big and small block Ford and GM n/a stuff along with blown alcohol Chrysler and Rat motor platforms. I've used them for 20+ years on both blown and n/a projects with excellent results.

Let me know (PM is fine) what you decide.



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Old 12-16-2019, 08:35 PM
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Originally Posted by tortuga View Post
Done that drill lke 5 times now, finally ended up with flatout 0.120 gaskets, trimmed the tops so that the inward taper on the upper part of the heads didn't force the gaskets down, maximized the area on the bottom where the intake bears...Think thats a problem with these big port head there isn't but like 3/8" of gasket area at the bottoms of the intake ports...
Did you smear a thin layer of RTV on gaskets? Re-torque after 24 hours? Then re-torque AGAIN after engine run and heated to operating temperature?

It took ALL of the above to finally get mine to seal.
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Old 12-17-2019, 04:23 AM
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You simply can't put any of these engines together reliably without using sealant on both sides of the intake gaskets. Every engine I build, whether it's a Windsor, Cleveland, FE, etc., gets the gaskets glued to the heads, and sealant between the gasket and the intake.
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Old 12-17-2019, 06:26 AM
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Default Interesting

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Originally Posted by blykins View Post
You simply can't put any of these engines together reliably without using sealant on both sides of the intake gaskets. Every engine I build, whether it's a Windsor, Cleveland, FE, etc., gets the gaskets glued to the heads, and sealant between the gasket and the intake.
All the gasket makers say to go commando...but I’m getting so quick at swapping out the manifold these days I may have another go...interestingly enough I read a review on summit where a guy does the same: glues (permatex aviation sealant) the gasket to the head, sets it by snugging down the intake, waits, then checks and then glues the intake to the gasket.

Another thing, whatever is going on seems equal in all holes as the plugs all look the same...

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Old 12-17-2019, 07:29 AM
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When you pull the intake this time, look for oil on top of the intake valves. If there is oil there, look for oil in the intake runner, especially on the bottom. By look I mean feel.

Since you will have the valve covers off, you can squirt oil right on the valves (through the springs). See if you can prove the valves are leaking or rule them out.

PS
While the intake and gaskets are off, you should check the intake angle. When people mill heads down, they also need to mill the angle on the intake.

Blykins can better describe the best way to do this check, but here's my attempt. Set the intake on with the old gasket on one side. No gasket the other side. Snug up the side with a gasket. Then use feeler gauges to measure the gap between the head and intake on the non gasket side. Check at the top and bottom on both ends (gap should be the same top and bottom). Everything should be clean, so if the old gasket has RTV ect on it use a new gasket.

I have heard of other methods, that I cannot recall. I think there should be a way to use silly putty, but I have not done this. You would need to be careful not to let any drop into the oil drains, so maybe not a good idea.
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Last edited by olddog; 12-17-2019 at 07:50 AM.. Reason: PS
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Old 12-17-2019, 02:44 PM
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Quote:
Originally Posted by tortuga View Post
All the gasket makers say to go commando...
Agreed - that's what they recommend / require. I followed Edelbrock's instructions the first time and it didn't seal. When I did it again I used a thin smear of RTV (Ultra Black, not Right Stuff - it sets too fast, particularly when spread thin) on both sides of the gaskets, plus the China wall, of course. The instructions I found also had me torquing 5 ft lbs higher than Ford's spec, plus added the additional 24 hour and after running torque steps. Made all the difference.

p.s. I didn't add coolant until after the 24 hour torquing.
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Old 12-17-2019, 07:48 PM
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Steve,

Do the gaskets come off dry when disassembled, point of concern is around the intake port opening of the gasket.

You say all spark plugs look identical.

Dark from fuel or oil?

What colour is this "puff" of smoke you notice?
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Old 12-18-2019, 06:07 AM
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Default Answers

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Steve,

Do the gaskets come off dry when disassembled, point of concern is around the intake port opening of the gasket.

You say all spark plugs look identical.

Dark from fuel or oil?

What colour is this "puff" of smoke you notice?
Come off somewhat wet

Plugs are dark but not oily/wet

Puff is blue
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Old 12-18-2019, 02:35 PM
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Originally Posted by tortuga View Post
Come off somewhat wet

Plugs are dark but not oily/wet

Puff is blue
That tells me the oil is from the valley area.

They should look dry, or at least look the same as when you reassembled.
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Old 12-19-2019, 03:15 AM
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Had this problem and I found out it was oil wicking from improperly sealed intake rocker studs. The last 408 I built I paid particular attention to this and the cleaning and drying process of the studs and threaded holes. "Brake cleaner"
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Old 12-29-2019, 12:03 PM
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Default Here we go again

Pulled the intake, sure as hell the back (head) side of the intake was wet. Also as I’ve noticed, the bottom of the ports had minimal gasket coverage. I am thinking that I’ve been over compressing the gasket causing the thing to creep down exacerbating the problem. This time I’ve marked the gaskets by putting them on the manifold and heads alternately to get the best vertical position.

After a good cleaning I coated the head side of new ford Motorsport gaskets and put them on to my marks,

I then put Saran Wrap on the manifold side and installed the manifold,

Then maneuvered the gaskets perfectly to my marks and snugged down the manifold,

Going to wait about 6 hrs, then remove the manifold from the Saran Wrap, remove the Saran Wrap clean any goo from the ports, apply the sealant to the intake and assemble. Think I will again just snug it down, wait another 6 plus hos then torque it down

This time I think I’ll only go to maybe 15 ft-lb or so?
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Old 12-29-2019, 12:24 PM
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Yeah, I don’t care what the gasket makers say. Use sealant or you’ll be doing it again.

Glue the gaskets to the heads, set the intake on overnight to mash the gaskets down, then come back with another layer of sealant, lay beads for china walls, then bolt it down.

Tightening the intake down isn’t causing your problems.
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Old 12-29-2019, 12:24 PM
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When you take the manifold off again from the saran wrap, place the manifold n a flat surface and see if it rocks back and forth or from side to side. I was having trouble with into manifold gaskets leaking and it turned out that the intake manifold was a bad casting and it was not flat; there was a slight twist to it. Ordered a new intake manifold and the problem was solved.
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Old 12-29-2019, 02:20 PM
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Default Second manifold already...

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Originally Posted by blykins View Post
Yeah, I don’t care what the gasket makers say. Use sealant or you’ll be doing it again.

Glue the gaskets to the heads, set the intake on overnight to mash the gaskets down, then come back with another layer of sealant, lay beads for china walls, then bolt it down.

Tightening the intake down isn’t causing your problems.
I’m also going to grind off the raised portion of the manifold Where it meets the China walls (raised when upside down). It does rock a very little when set on the engine without gaskets, ford instructions say there should be .040” at China walls with manifold on engine sans gaskets...

P.S. man this permatex aviation gasket maker is some really messy $hit...
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Old 12-29-2019, 10:53 PM
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Any V8 should have a measurable gap between the bottom of the manifold and the block, with gaskets in place.

I like to aim for for .040, .060 is generally ok.

If the manifold touches the block, it cannot be fitted to the heads correctly, and then oil consumption is the result.

What were you sealing the manifold to block junction with?
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Old 01-06-2020, 07:39 AM
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Quote:
Originally Posted by blykins View Post
You simply can't put any of these engines together reliably without using sealant on both sides of the intake gaskets. Every engine I build, whether it's a Windsor, Cleveland, FE, etc., gets the gaskets glued to the heads, and sealant between the gasket and the intake.
Which glue/sealant are you recommending at heads, intake, and china wall?
Thanks,
Mark

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Old 01-13-2020, 01:46 PM
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Default Update

I re-fitted the intake using .070 ford racing gaskets, sealed on both sides with permatex aviation sealer (Absolute mess).

still eats oil.

Tried some restore engine restorer, (which has quite a few favorable reviews), the oil consumption has slowed dramatically...Which was another FRP 427/535 owners fix.

Ill keep using the restore, and at some point pull this thing and go through it top to bottom.

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Old 01-15-2020, 09:57 AM
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It sounds like the oil consumption may be somewhere else.

When you do pull the engine, it would be interesting to place a bright light in the lifter gallery. Leave the gaskets out between the intake and block, front and back, to allow the electric cord to fit, or whatever it takes. Then snug down the intake with new gaskets. No sealers. Now run a camera down the intake ports and see if there is light shining into the ports on the bottom. You would need to check all ports. If there is no light shinning then the intake is sealing up and that is not the problem. If there is light, then I suspect there is an angle wrong, and it will never seal until it is corrected.

In the mean time, maybe a new set of valve stem seals should be attempted. That might be the sources of your problems.
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Old 09-24-2020, 10:45 AM
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Default Update

Soooo
I got a smoking deal on some bare Z304"P" heads, ported with slightly larger intake valves. Had Valley Head in Northridge assemble, went with some very gourmet bits putting them together.

STILL ate oil...Had my intake machined to match head angles, no joy. Took apart and followed Mr. Blykin's instructions to the tee, no luck, pulled all of the intake studs and noted that several seemed to not care much about the sealant i installed with them (Nod to RetCop). I Cleaned them up and this time used plain old Teflon plumbers tape which is rated for service up to 500 degrees...Suddenly plugs are cleaning up! I Hope Hope Hope ive finally slain this dragon, not much confidence given the hours and hours of time and literally thousands of dollars ive spent chasing it...Fingers and Toes crossed.

Next step if its not cured, as i keep threatening to do, is to pull the mill and have a pro go through it admitting defeat-which i hate to do)...

Sure appreciate all the help on the site!

Steve H
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