Author Topic: GT350R replica 289 heads Valley Head Service waterports  (Read 3917 times)

98SVT - was 06GT

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Re: GT350R replica 289 heads Valley Head Service waterports
« Reply #15 on: March 29, 2022, 02:05:26 PM »
"Now" I use 10 additional ft lbs on the upper row of head bolts
I used a healthy dose of Copper Coat and and 5 pounds over the max - standard parts store head gaskets (Fel Pro probably). I did order a set of the thinner Ford head gaskets but by the time they arrived I had gotten impatient and put it together with the aftermarket ones.
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sg66

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Re: GT350R replica 289 heads Valley Head Service waterports
« Reply #16 on: March 29, 2022, 02:28:07 PM »
    Steve ,
      I tried all kinds of bolt torques and bolt manufacturers in the '60s. I will say it was "MY" lack of experience that caused my gasket failures. Too much compression , timing , and lack of fuel quality ( even though we had 100 octane leaded gas). As I look back on my approach , I was lifting the head off of the block by detonation that I caused. My "seat of the pants dyno" was out of calibration and I was out of control. The good thing is the early failures showed me the limits and strengths of most of the engine parts. I went as far as 100 ft lbs tq on the heads with no improvement on sealing. I also O ringed the heads which helped some and finally tried solid copper head gaskets as a last resort.
     "Now" I use 10 additional ft lbs on the upper row of head bolts as "I" believe the intake manifold torque does play a role against upper head bolt torque. With "modern" head gaskets and 50 years of tuning experience , I no longer lose head gaskets.
    Randy
Now that you mention it, I think the recommendation was for an additional 10 ft/lbs for the upper row. Whatever the root cause was/is, I'm with you that the additional 10 ft/lbs solves the problem.

pbf777

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Re: GT350R replica 289 heads Valley Head Service waterports
« Reply #17 on: March 29, 2022, 02:50:09 PM »
Back in the mid to late 80's, ............more likely Fel-Pro was recommending to increase the head bolt torque by 10 ft/lbs to prevent head gasket failure.


Now that you mention it, I think the recommendation was for an additional 10 ft/lbs for the upper row. Whatever the root cause was/is, I'm with you that the additional 10 ft/lbs solves the problem.

      Though there is a wedging effect in the torquing of the intake manifold on the S.B.F. that does attempt to pry the heads off the block (therefore one should be only tightening the intake retention fasteners as required to hold the intake on, not attempting to hold the engine together!  ::) ), the main reasoning for the recommended greater staggered torquing values is due to the greater elasticity presented in the longer fastener on the intake side, this otherwise giving a lesser clamp-load if torquing equally to the shorter.   ;)

      Generally, and particularly as stated by ARP Fastener, the torque value listed is in a range of approximately 80% of the yield value, so it is permissible to increase this torquing sum, 'some', for greater clamping loads.  Just be aware you'll be testing the fastener manufactures consistency of production quality, and of the capability of the structures involved and that they will tolerate such force.   :-\

      Scott.
« Last Edit: March 29, 2022, 03:04:59 PM by pbf777 »

shelbydoug

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Re: GT350R replica 289 heads Valley Head Service waterports
« Reply #18 on: March 29, 2022, 03:40:02 PM »
Back in the mid to late 80's, ............more likely Fel-Pro was recommending to increase the head bolt torque by 10 ft/lbs to prevent head gasket failure.


Now that you mention it, I think the recommendation was for an additional 10 ft/lbs for the upper row. Whatever the root cause was/is, I'm with you that the additional 10 ft/lbs solves the problem.

      Though there is a wedging effect in the torquing of the intake manifold on the S.B.F. that does attempt to pry the heads off the block (therefore one should be only tightening the intake retention fasteners as required to hold the intake on, not attempting to hold the engine together!  ::) ), the main reasoning for the recommended greater staggered torquing values is due to the greater elasticity presented in the longer fastener on the intake side, this otherwise giving a lesser clamp-load if torquing equally to the shorter.   ;)

      Generally, and particularly as stated by ARP Fastener, the torque value listed is in a range of approximately 80% of the yield value, so it is permissible to increase this torquing sum, 'some', for greater clamping loads.  Just be aware you'll be testing the fastener manufactures consistency of production quality, and of the capability of the structures involved and that they will tolerate such force.   :-\

      Scott.

The AFR heads I just used recommended the 10 # greater on the top bolts as well as recommending ARP bolts. They have the thickest of the decks that I have come across and am sure that helps the situation considerably. 5/8" thick decks I believe.

I had to shave the heads .020 and used a thin head Cometic head gasket to get the chambers to 53cc's.

I wound up going through three sets of intake gaskets on the C6OA intake with a continued water leak at the back near #8. The Fel-pro's couldn't deal with it well and the solution was a Mr.Gasket intake gasket with silicone on the "S's". They are the thickest of the group and the softest compound so they squish up nicely.

That back intake manifold bolt is the outboard one that you need to be careful of not breaking the manifold too.



All is well now. I was coming off of Clevelands which do not have those issues so I had to relearn the SB peculiarities...which they definitely do have.



My 427 aluminum heads were having issues in that exact same corner as well. Leaking water AND OIL from the drain back hole. In that case it was the aluminum squirming around and not enough material on the head gasket itself which also were Felpros. Hum? Coincidence?  ::)

On the 427 aluminum head you need to dial down the torque, NOT increase it  to keep the head from turning into silly putty. I believe the most I could safely do on the bolts was 92#?


So much "tadue" over nothing. Something that should have NEVER been an issue at all.  ;)
« Last Edit: March 29, 2022, 03:48:30 PM by shelbydoug »
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gt350hr

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Re: GT350R replica 289 heads Valley Head Service waterports
« Reply #19 on: March 29, 2022, 04:21:49 PM »
 Doug ,
      Make SURE you re torque the small block intake every week until they don't need it. Non metal core gaskets "settle" more than metal core versions and you will spring a leak if you don't re torque. Guess how I know.
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shelbydoug

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Re: GT350R replica 289 heads Valley Head Service waterports
« Reply #20 on: March 29, 2022, 04:38:39 PM »
Doug ,
      Make SURE you re torque the small block intake every week until they don't need it. Non metal core gaskets "settle" more than metal core versions and you will spring a leak if you don't re torque. Guess how I know.

I don't use a torque wrench on the intakes. I took advice from Ollie Morris at Offenhauser almost 50 years ago now, to just use a box wrench and snug the bolts up when necessary. So far that has worked well as a "fused link" and haven't broken anything YET.

The Mr.Gaskets work the best of all. As Bond found out, "sometimes the old ways are the best ways?" 8)
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CSX2259

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Re: GT350R replica 289 heads Valley Head Service waterports
« Reply #21 on: March 30, 2022, 08:04:48 PM »
From the SAI catalog. Interesting to note that the “Drag Racing” heads do not have welded in banana ports.....

98SVT - was 06GT

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Re: GT350R replica 289 heads Valley Head Service waterports
« Reply #22 on: March 30, 2022, 09:32:35 PM »
From the SAI catalog. Interesting to note that the “Drag Racing” heads do not have welded in banana ports.....
They didn't run long enough to present an overheating problem.
Previous owner 6S843 - GT350H & 68 GT500 Convert #135.
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CSX2259

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Re: GT350R replica 289 heads Valley Head Service waterports
« Reply #23 on: March 31, 2022, 01:20:53 AM »

Maybe they didn’t run long enough but the head would still flex and cause loss of compression into the cooling system.

gt350hr

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Re: GT350R replica 289 heads Valley Head Service waterports
« Reply #24 on: March 31, 2022, 10:30:25 AM »
 The FACT is NHRA did NOT ALLOW welding on cylinder heads! It's as simple as that.
 No guesswork.
    Randy
Celebrating 46 years of drag racing 6S477 and no end in sight.