Head Gasket replacement 351W

94' cobra 351

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Hey guy's,

Blew out the side of my head gasket on my 351w running nitrous, oops. Going to replace the head gaskets here soon and was just looking for advice/tips/tricks!

It all seems pretty straight forward, take everything off and put everything back on. I've done a head gasket job once on a little mazda 323 (OHC) Main thing I'm not sure of on this one is how to adjust the valves after replacing the gaskets.

Also, with the bigger head bolts of the 351, would it be alright if I just reused them? Anybody have any suggestions for a performance gasket that won't blow again?

Thanks!
 

rocket5979

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Replace with an MLS gasket, before installing gasket spray it with a coating of Permatex copper gasket sealant on both sides, install with new TTY head bolts. Or, I really suggest that since you are using nitrous on it that it may not be a bad idea to step up to ARP hardware. As long as you get a gasket of the same thickness as the one before then you shouldn't need to adjust your rocker height or pushrod length because the valvetrain geometry isn't changing.
 

Maniak

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make sure the deck of the block is flat and not warped. same goes for the heads.

what heads are you running?
 

Ear Rak

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Also, don't forget to use a good lube/water sealant on any headstuds/bolts that go into a water jacket.
 

rocket5979

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make sure the deck of the block is flat and not warped. same goes for the heads. as eric said, good idea to do both head gaskets.

what heads are you running?
It sounded like the OP already planned to replace both head gaskets according to his first post. :dunno:
 

blck10th

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If I remember correctly head bolts are torque to yield so you need to replace them since they stretch. I would do it with arp as mentioned earlier no point in not spending a little to save a bigger headache later
 

rocket5979

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If I remember correctly head bolts are torque to yield so you need to replace them since they stretch. I would do it with arp as mentioned earlier no point in not spending a little to save a bigger headache later
You are correct. Modern head bolts are TTY. Older ones weren't.
 

Ear Rak

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You sure the ol' 351's are tty?

Not that i would re-use bolts that have been involved in a nitrous induced head lift anyways.
 

rocket5979

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You sure the ol' 351's are tty?

Not that i would re-use bolts that have been involved in a nitrous induced head lift anyways.
I don't think the old 351's are TTY because it caught on after those were coming out of production and from what I understand they only have a tq value and not any final degree value like how you do a TTY. But like you said, it would not be a bad idea to get some new ones. ARP's would be a safe investment being that this is being used in a performance application instead of just a DD vehicle. Fixed my last post so as not to confuse.
 

batman

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Use standard gaskets(gives at the gasket , unless you have the money to replace an entire motor), arp studs not bolts...torq in three steps.
 

94' cobra 351

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The heads are GT40's and roller rocker arms.

TBH, I'm planning on selling the car after I get the head gasket fixed. And although I don't want to screw the next guy over, if it isn't necessary to replace the head bolts then I don't want to spend the extra dough.
 

Ear Rak

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Honestly, replace the head bolts. Chances are they are stretched (thus, your head lifting and the gasket blowing).

Don't need to get studs, just get a nice new set of head bolts and a good felpro head gasket...if you're just gonna sell the car.

I get what you're saying about not wanting to spend much to fix something you're just gonna sell but at the same time do it right so he's not calling you a week later ripping you a new one because coolant and oil are seaping out the side of the head.
 

zenriddles

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The heads are GT40's and roller rocker arms.

TBH, I'm planning on selling the car after I get the head gasket fixed. And although I don't want to screw the next guy over, if it isn't necessary to replace the head bolts then I don't want to spend the extra dough.
Pish.

If you're going to sell, the old bolts will hold fine, old guys like me have changed those shitty gaskets a hundred times with the original bolts. Put in MLS gaskets and worry no more.

TTY bolts are for aluminum engines (Which swell and shrink a LOT more than iron blocks and heads) and less than skilled mechanics. Those bad ass mofo's on your Windsor are not a worry, IMO.
If you are nervous, add another 5 or 10 pounds to the torque wrench, you're NOT going to hurt anything.
 

Ear Rak

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Pish.

If you're going to sell, the old bolts will hold fine, old guys like me have changed those shitty gaskets a hundred times with the original bolts. Put in MLS gaskets and worry no more.

TTY bolts are for aluminum engines (Which swell and shrink a LOT more than iron blocks and heads) and less than skilled mechanics. Those bad ass mofo's on your Windsor are not a worry, IMO.
If you are nervous, add another 5 or 10 pounds to the torque wrench, you're NOT going to hurt anything.
I've seen 5 or 10 ft lbs extra snap ISX cummins head bolts. What makes you think stretched head bolts from a nitrous car are gonna handle the extra torque? :dunno:
 

IZZy

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I've seen 5 or 10 ft lbs extra snap ISX cummins head bolts. What makes you think stretched head bolts from a nitrous car are gonna handle the extra torque? :dunno:
did you actually see that or you read it on a magazine?








sorry i had to:blowingup
 

zenriddles

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I've seen 5 or 10 ft lbs extra snap ISX cummins head bolts. What makes you think stretched head bolts from a nitrous car are gonna handle the extra torque? :dunno:
I've seen people forget to blow the old oil out of headbolt holes before assembly too.
 

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I wouldn't recommend MLS gaskets unless the block is going to be decked as well as the heads. They really need a perfectly smooth and flat surface to seal well.

As for head bolts, you may as well spend the little bit of money and fix it right. Even if the original bolts are fine, the added security of ARP bolts is worth it, and they can usually be had for less than $100 from Summit.
 

rocket5979

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I wouldn't recommend MLS gaskets unless the block is going to be decked as well as the heads. They really need a perfectly smooth and flat surface to seal well.

As for head bolts, you may as well spend the little bit of money and fix it right. Even if the original bolts are fine, the added security of ARP bolts is worth it, and they can usually be had for less than $100 from Summit.

He is selling the car immediately after fixing the HG. I think in light of that new information most of us would recommend that he just use a stock style non-MLS gasket and reuse his stock bolts if they are in good condition, or some new OEM ones. Doing ARP would be a waste of his money.
 

Aron

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I understand that and it doesn't change my opinion one bit. There's nothing wrong with a decent oem style head gasket like Mr. Gasket for a street/strip car, I have one on mine now and they hold up well. As for the head bolts, here's my thought - he's most likely going to tell any potential buyers that the head gaskets were just replaced. You also tell them the head bolts were also replaced with ARP, and if I was a potential buyer I'd be more at ease thinking that the job was done properly. It's a selling point, otherwise I hear the hg were just done before he put it up for sale and I think it was just slapped together to get it off his hands. For under $100, it will help him sell it, and maybe even help him make a couple hundred more off the sale.
 

94' cobra 351

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To be honest, I don't mind spending a little extra to replace the bolts and get a quality gasket. I don't want the gasket blowing on the next guy.

But I think that horse has been beat, haha my main question with the post though was adjusting the rockers/valves??
 

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