2 HEAD GASKETS BLOWN.....WHAT GIVES??

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leon_reynolds

Founding Member

Apr 24, 2002

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Sep 7, 2006

#1

• Sep 7, 2006

• #1

I have just removed my top end again only to find both head gaskets completely destroyed. The space between each cylinder was not only blown on every one but on several it was destroyed leaving metal ring parts stuck in valves or just floating in top of the piston. I upgraded to world heads with a 60cc chamber (non-oringed) and blew my first set in 1 day. Upgraded to a hegher end felpro and it lasted 3 weeks before it was toast. Is there any gasket that is designed to be able to withstand this type of pressure? I just want to make sure that if I put it back together again I will actually be able to enjoy it! Any suggestions......

 

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R2D2

Sep 7, 2006

#2

• Sep 7, 2006

• #2

Your using arp studs correct? One of the biggest problems with the 302 is only 10 tiny 7/16th head bolts. First step is studs, second step may be o-ringing the heads and using the appropriate fel-pro head gasket

 

thehueypilot

Active Member

Feb 25, 2004

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Medina,Tennessee

Sep 7, 2006

#3

• Sep 7, 2006

• #3

Sounds like you are running way too lean. How much boost and how high are you running the rpm's? Timing too high? It's trying to tell you something before it breaks the pistons and rings.

 

88Stang331

New Member

Mar 30, 2006

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Sep 7, 2006

#4

• Sep 7, 2006

• #4

What size injectors are you running? I'd say at least run 36, but preferrably 42.

 

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R2D2

Sep 7, 2006

#5

• Sep 7, 2006

• #5

the things you read on forums

 

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seijirou

Founding Member

Aug 15, 2002

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DFW

Sep 7, 2006

#6

• Sep 7, 2006

• #6

sbftech said:

Your using arp studs correct? One of the biggest problems with the 302 is only 10 tiny 7/16th head bolts. First step is studs, second step may be o-ringing the heads and using the appropriate fel-pro head gasket

Click to expand...

+1

 

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leon_reynolds

Founding Member

Apr 24, 2002

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Sep 7, 2006

#7

• Sep 7, 2006

• #7

Could you define using the arp head bolts correctly? I have been doing everything to recommended procedures/proper torque.

 

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leon_reynolds

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Apr 24, 2002

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Sep 7, 2006

#8

• Sep 7, 2006

• #8

I am also running 42# injectors with a wideband so I can monitor air/fuel and car is dialed in pretty good with a tweecer to keep enough fuel moving.

 

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R2D2

Sep 7, 2006

#9

• Sep 7, 2006

• #9

ya go to arp studs first off, the clamping capability is by far more than a bolt

 

ninety15.0

New Member

Mar 10, 2004

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Sep 7, 2006

#10

• Sep 7, 2006

• #10

which fel-pro's are you running?

 

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leon_reynolds

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Apr 24, 2002

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Sep 7, 2006

#11

• Sep 7, 2006

• #11

what is the main differences between the factory head bolts and the arp bolts? We are talking about the bolts that go directly into the block and not the rocker arm bolts right.......I was unaware that there was a stronger system out there to hold heads in place. my first set of gaskets were the recommended felpro 1011-2 and then the second time I went for the higher quality 9333pt-1.

 

2000xp8

SN Certified Technician

Aug 8, 2003

8,024

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NJ

Sep 7, 2006

#12

• Sep 7, 2006

• #12

With the minimum boost you are running, it's not the HG's themselves that are the problem. Don't know for sure what your prob is, but it's not them. Buying more expensive HG's with just result in losing expensive ones.

Factory head bolts stretch, they are NOT meant to be re-used, in fact if you did which it sounds like you did, that's probably the problem.
Arp's can be cranked down and re-used because they are alot stronger.

 

QUIKSVT

New Member

May 19, 2006

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Sep 7, 2006

#13

• Sep 7, 2006

• #13

I think some of you missed the point sbftech made. He did not say to run better head bolts, he said run head STUDS...

 

90lxcoupe

20+ Year Stangneter

Oct 7, 2003

3,596

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Sep 7, 2006

#14

• Sep 7, 2006

• #14

If your using those world heads i assume your using the correct washers that go into where the head bolts go... if not that could be your problem. Aftermarket heads are set up to use 1/2 inch head bolts and the 302 blocks use 7/16 inch bolts.

ARP makes a stud kit that comes with the 1/2'' to 7/16'' washers i'd definitly go with those and it was said before if your blowing gaskets its for a reason, check if the block and heads are warped and make sure your tune is right on and the motor isnt detonating.

 

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wicked84gt350

New Member

Aug 20, 2006

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West palm bech florida

Sep 7, 2006

#15

• Sep 7, 2006

• #15

Hate to break it to you guys but arp head studs are no better than head bolts when compared with the same tensile strengh there is no better sealing factor. The real reasons that engine builders use studs is it helps line up everything correctly and idealy the stress will be put on the threads and shaft of the stud rather than the head of the bolt. Which would realive fatigue But it would have no difference in weather he blows heads gaskets or not provided they are installed correctly. Yes I agree run the studs when ever possible but they will not keep you from blowing head gaskets. The other stuff you hear is a sales gimic if you dont believe me ask your local engine builder. So, I would say that the deck is warped and needs to machined. And the heads should be checked for square. And if you can run the o ring head gaskets that would be even better. Also years ago after you installed the head gaskets and torgued the head ran it to temp retorqued then went 1000 miles you would retorque again because of the bolt stretch. Most dont do that today because the new fasterners are "supreme to the older ones" but its a good idea to follow that procedure. Hell it cant hurt and it seems to work.

 

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leon_reynolds

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Apr 24, 2002

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Sep 8, 2006

#16

• Sep 8, 2006

• #16

ok, so I just got schooled......I installed the new heads with the original head bolts, torqued them down and called it good. Sounds like that was the wrong way to go. I guess I need to make sure I am using the proper size (1/2 compared to 7/16) and get the right equipment. So if you do head work on a car, is it customary to replace head bolts every time? I was unaware that this could be an issue and maybe I got lucky before and it finally caught up to me. I took the heads to get them checked out and am going to strait edge the deck to see if it is all good.

 

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seijirou

Founding Member

Aug 15, 2002

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DFW

Sep 8, 2006

#17

• Sep 8, 2006

• #17

leon_reynolds said:

ok, so I just got schooled..... So if you do head work on a car, is it customary to replace head bolts every time?

Click to expand...

that's fine nobody popped out knowing this stuff, so everybody here that knows was schooled at some point.

Yes, it is customary.

 

ninety15.0

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Mar 10, 2004

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Sep 8, 2006

#18

• Sep 8, 2006

• #18

you need to find out even more specifically what type of bolts you are using. The stock head bolts are called Torque-to-yield (TTY). this means that the bolts are torqued until the start to deform and stretch. It is the stretching action and the fact that the steel is actually quite elastic that the tensile load holds the head on the block. These bolts are actually ment to be installed with an angle gauge...tighten to a specific torque setting then to a specific angle to preload (stretch) the bolt. TTY are not 'supposed' to be reused. ARP head bolt have a higher tensile capability but i believe they are still TTY...studs are not TTY however. And those washers are a must if you have .5 inch head bolt holes in the heads. ARP makes a stepped and undercut washer for that application. I got my set for 80$ on ebay