Slant Six Forum :: Head Off, best way to attack the Intake/Exhaust

1970 Valiant . I am more then a capable Wrencher to pull the Head. The s6 is new to me so I'm not sure what the best way to handle the disassembly of the manifolds.
Drop the exhaust pipe then , what, pull the intake and exhaust off as a single unit?

What about reassembly? I know there is a gasket between the intake and exhaust under the carb( heat stove?)

I gapped it to .016 and now I get 30 lbs. I hope it's just the Valve.

As of 5 minutes ago I have a book (from a friend) that covers up to '68. My guess is that the gaps will be OK from that book.

Quote:

I gapped it to .016 and now I get 30 lbs. I hope it's just the Valve.

Still too tight for an exhaust valve. (if you've got a stock cam grind) Good chance the valve is still burnt, but don't want to see you messing up the new head with improper valve lash.

POO-POO! Mine are set @ .008 intake and exhaust cold. They close just fine

.008 lash for the exhaust, wouldnt that be a good way to burn an exhuast valve?

Author:	tony h [ Thu Apr 26, 2007 5:05 am ]
Post subject:	Head Off, best way to attack the Intake/Exhaust
1970 Valiant . I am more then a capable Wrencher to pull the Head. The s6 is new to me so I'm not sure what the best way to handle the disassembly of the manifolds. Drop the exhaust pipe then , what, pull the intake and exhaust off as a single unit? What about reassembly? I know there is a gasket between the intake and exhaust under the carb( heat stove?) . Is it best to put the manifolds together loose then fit it to the Head ..then what to tighten? the Heat Stove then the manifold to Head bolts? I'm sure I have a burnt exhaust valve on #6 due to the P.O. overtightening the Rocker....it wasn't fully closing 0lbs of compression. I gapped it to .016 and now I get 30 lbs. I hope it's just the Valve.

Author:	dakight [ Thu Apr 26, 2007 5:26 am ]
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There is a manifold installation article that addresses all these questions. Just go to the home page then click "Articles." The article in question is about halfway down the list.

Author:	Rug_Trucker [ Thu Apr 26, 2007 6:19 am ]
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I had the machine shop clean up the port mounting surface before I installed my head. I didn't have them do the intake and exhaust as I installed a NOS M-1 intake and a set of headers.

Author:	tony h [ Thu Apr 26, 2007 7:34 am ]
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Found it , got it THANKS Kinda new to the site..haven't done much surfing and clicking within.

Author:	Rug_Trucker [ Thu Apr 26, 2007 8:16 am ]
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Have them skin some metal off the bottom of the head while you're in there.

Slant Six Forum https://www.slantsix.org/forum/

Head Off, best way to attack the Intake/Exhaust https://www.slantsix.org/forum/viewtopic.php?t=22899	Page 1 of 2

Author:	SlantSixDan [ Thu Apr 26, 2007 8:30 am ]
Post subject:	Re: Head Off, best way to attack the Intake/Exhaust
Quote: 1970 Valiant . I am more then a capable Wrencher to pull the Head. The s6 is new to me so I'm not sure what the best way to handle the disassembly of the manifolds. Drop the exhaust pipe then , what, pull the intake and exhaust off as a single unit? Yep! Exactly right. Quote: What about reassembly? I know there is a gasket between the intake and exhaust under the carb( heat stove?) What you might not have known is that most of the gaskets available for this junction will never seal for you. It is very much worth your while to get the good gaskets for the manifolds-to-head and the intake-to-exhaust (heat riser/hotbox) junctions, even though they are mail-order from halfway round the world. As for manifold prep and installation, see this tech article.

Author:	Slant6Ram [ Thu Apr 26, 2007 12:03 pm ]
Post subject:	Lash is still incorrect
Quote: I gapped it to .016 and now I get 30 lbs. I hope it's just the Valve. Still too tight for an exhaust valve. (if you've got a stock cam grind) Good chance the valve is still burnt, but don't want to see you messing up the new head with improper valve lash.

Author:	tony h [ Thu Apr 26, 2007 12:54 pm ]
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Thanks for the Gap tip. I didn't have a book on the motor, I was just temporarily winging it to see if the Compression and motor idle gets better after knowing that the Valves were closing. As of 5 minutes ago I have a book (from a friend) that covers up to '68. My guess is that the gaps will be OK from that book. I have yet to read anything. I'm hoping I will be able to Lap in an exhaust valve myself put the motor back together and get on with the other car issues that this fix'r upperhas to offer my son and me.

Author:	SlantSixDan [ Thu Apr 26, 2007 1:24 pm ]
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Quote: As of 5 minutes ago I have a book (from a friend) that covers up to '68. My guess is that the gaps will be OK from that book. The multi-year aftermarket books are risky at best. The correct spec for all '60-'80 slant-6s is 0.010" intake, 0.020" exhaust, set hot and running per the valve adjustment procedure. It will definitely pay you to get a factory service manual as described in this post.

Author:	Rug_Trucker [ Thu Apr 26, 2007 1:35 pm ]
Post subject:	Re: Lash is still incorrect
Quote: Quote: I gapped it to .016 and now I get 30 lbs. I hope it's just the Valve. Still too tight for an exhaust valve. (if you've got a stock cam grind) Good chance the valve is still burnt, but don't want to see you messing up the new head with improper valve lash. POO-POO! Mine are set @ .008 intake and exhaust cold. They close just fine

Author:	SlantSixDan [ Thu Apr 26, 2007 1:43 pm ]
Post subject:	Re: Lash is still incorrect
Quote: POO-POO! Mine are set @ .008 intake and exhaust cold. They close just fine Mmm...nope! You're measuring incorrectly, or you're running some funky non-stock cam, or there's something else you're not telling us, or you're simply having a joke with us. But your valves, especially your exhaust valves, are not closing "just fine" if you have anything even reasonably close to a stock cam and you've got the lash set at 0.008 cold.

Author:	icaneat50eggs [ Thu Apr 26, 2007 1:44 pm ]
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.008 lash for the exhaust, wouldnt that be a good way to burn an exhuast valve?

Author:	SlantSixDan [ Thu Apr 26, 2007 1:46 pm ]
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Quote: .008 lash for the exhaust, wouldnt that be a good way to burn an exhuast valve? It is indeed a terrific recipe for crispy fried valve, especially since that's 0.008" cold, and the valves are supposed to be adjusted hot. Recipe serves one to six, depending on how many valves are misadjusted this way.

Author:	tony h [ Fri Apr 27, 2007 10:37 am ]
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The book I have has them at .010 and .020 hot. I'll set them there, If they are a bit noisey...so be it. I'm hoping I only have a burnt Valve. 1970 Head, how hard were the Seats? It was before Lead free gas...nuts I bet they were "soft"

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Author:	Rug_Trucker [ Fri Apr 27, 2007 4:42 pm ]
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Quote: .008 lash for the exhaust, wouldnt that be a good way to burn an exhuast valve? How many degrees of the circle does it need to be closed? Stock cam. Been setting that way for 26K since that head was put on there. Sounds sweet and idles smooth. Not my spec. Howard from Ha-Ha Racing in Smyrna TN's spec. He was racing Mopars when lots of us were in diapers. Also the flame induction seats started in 72. I do worry as the head I have is a 69. The 72 is in the shed.