cylinder head install
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=2170
Printed Date: November-23-2024 at 4:01am
Topic: cylinder head install
Posted By: '72 mustang
Subject: cylinder head install
Date Posted: July-29-2005 at 2:56pm
I am getting my heads back from the machine shop today and am getting ready to put the engine back together. I have 302 heads on a 351 block. Anyone know which torque specifications I should use, 302 or 351? Any other helpful hints are apprreciated as well. Thanks.
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72 CC mustang
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Replies:
Posted By: GottaSki
Date Posted: July-29-2005 at 4:48pm
351...
The shop opened up the bolt holes to 1/2", right?
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"There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing."
River Rat to Mole
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Posted By: Siveck
Date Posted: July-29-2005 at 5:13pm
The torque specification is in relation to the diameter size of the bolt. Being that you are using the bolts for a 351 (larger size than 302 bolts possibly), then you should use the 351 specification.
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1975 Ski Nautique
"Small Letter Boat"
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Posted By: '72 mustang
Date Posted: July-29-2005 at 6:24pm
Yeah, the head bolts are 1/2" diameter. Thanks guys.
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72 CC mustang
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Posted By: 64 Skier
Date Posted: August-01-2005 at 11:09am
50 then 60 then 75 ft-lbs.
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64 Skier
66" HO VTX and 67" HO Triumph
http://www.correctcraftfan.com/diaries/details.asp?ID=1071&sort=&pagenum=3&yrstart=1971&yrend=1975 - 71CC
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Posted By: GottaSki
Date Posted: August-01-2005 at 6:10pm
finish @ 90-100-112 for a 351.
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"There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing."
River Rat to Mole
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Posted By: captan1
Date Posted: August-01-2005 at 8:33pm
Did we get GT40P heads off an Explorer, and new bolts?
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http://www.correctcraftfan.com/diaries/details.asp?ID=452&sort=&pagenum=1&yrstart=1978&yrend=1978 - 1978 Ski Nautique
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Posted By: Jim_In_Houston
Date Posted: August-01-2005 at 11:19pm
Yes we did.
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Happy owner of a '66 and a '68 Mustang
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Posted By: 64 Skier
Date Posted: August-02-2005 at 11:08am
Sorry....had 302 on the brain....Gotta Ski is correct on the torque.
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64 Skier
66" HO VTX and 67" HO Triumph
http://www.correctcraftfan.com/diaries/details.asp?ID=1071&sort=&pagenum=3&yrstart=1971&yrend=1975 - 71CC
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Posted By: captan1
Date Posted: August-02-2005 at 1:33pm
I love my gt40p heads. Jim, have you installed the heads yet? I think I'd do that again if I bought another boat.
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http://www.correctcraftfan.com/diaries/details.asp?ID=452&sort=&pagenum=1&yrstart=1978&yrend=1978 - 1978 Ski Nautique
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Posted By: reidp
Date Posted: August-03-2005 at 12:36am
Hey, since '72 Mustang didn't reply after the good info, is it possible that he meant to say 351 heads on a 302? Most all of the 4V Ford powered Mustangs of that '71-76 or so vintage were 302's with 351 heads as part of the Ford factory supplied marine long block package. This also included the 351 cam and firing order as did later models.
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ReidP
/diaries/details.asp?ID=231&yrstart=1971&yrend=1975 - 1973 Mustang
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Posted By: Jim_In_Houston
Date Posted: August-03-2005 at 1:36am
Yes, I install my GT40Ps on my '68 with a 289. I'm happy with them. I know that any lack of performanc is not due to flow restriction. I run up to about 5500 RPM at about 48MPH (with no head wind).. Fast enough for that old hull imho.
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Happy owner of a '66 and a '68 Mustang
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Posted By: Guests
Date Posted: August-03-2005 at 12:20pm
Jim,
Is this the engine with the Speed Pro cam? If so, you could probably gain some speed and most definitely fuel economy if you brought the rpms back down to 5000-5200. When I've run a Fed 12x13 prop with the similar engine combo, I would turn about 5500 but lost about 2 mph, compared to 5200 with a 12x14 Fed.
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Posted By: Guests
Date Posted: August-03-2005 at 12:21pm
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I guess I didn't log in correctly or something on that last post.
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Posted By: reidp
Date Posted: August-03-2005 at 12:23pm
You'd think by now I'd have this figured out. Sorry.
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ReidP
/diaries/details.asp?ID=231&yrstart=1971&yrend=1975 - 1973 Mustang
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Posted By: '72 mustang
Date Posted: August-03-2005 at 1:59pm
Hey guys, sorry I didn't reply sooner. Got confused with two different torque specs and the GT40P talk. Anyways I just got the boat and already had to tear into to it(seller left out part about blown head gaskets), but it is a 351 going by the half inch diameter head bolts (and the 351 casting in the valley) and they are 302 heads. I went with the torque specs out of the book for a 351 since those are the bolts I used. I appreciate you guys helping me out. Are these valve adjustable or do I just tighten all the way down? Thanks again.
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72 CC mustang
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Posted By: Jim_In_Houston
Date Posted: August-03-2005 at 11:43pm
Yeh Reid. I installed the SpeedPro cam. I am very happy with it too. I have learned to control myself and seldom run over 4500RPMs, (unless some kid in a shiny new boat tries to pass).
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Happy owner of a '66 and a '68 Mustang
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Posted By: captan1
Date Posted: August-04-2005 at 1:25pm
Here's the website for the cam spec's
http://engineparts.com/motorhead/techstuff/2003marine/Camshafts_Lifters_TimingComponents.pdf - http://engineparts.com/motorhead/techstuff/2003marine/Camshafts_Lifters_TimingComponents.pdf
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http://www.correctcraftfan.com/diaries/details.asp?ID=452&sort=&pagenum=1&yrstart=1978&yrend=1978 - 1978 Ski Nautique
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Posted By: Bob's2001
Date Posted: August-06-2005 at 6:06pm
If the heads have the original pedestal rockers they are not adjustable.
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Bob Ed
83 2001
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Posted By: '72 mustang
Date Posted: August-08-2005 at 2:53pm
Thanks, Bob's2001
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72 CC mustang
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