Should we Re-torque small block heads? Yes or NO
automotive breath said:I agree it's the details that make the difference. Abnormal combustion will kill
a head gasket quicker than anything; light ping cycle after cycle, pre-ignition,
high combustion temperatures and pressure spikes. I spent all the time
it takes to eliminate these completely. We race every weekend and run our
engines two to three years before freshening up, never find loose bolts
or blown gaskets.
My brother has had one of his back tires pass him going down the street, turn left into a neighborhood hit the edging around one of the houses garden and go in through a front window landing about a foot away from someone sitting there watching TV...cusz28 said:I can wholeheartedly agree with the head bolts staying torqued. I just like making sure they stay there after a few miles. It's just like aluminum rims. they say to retorque after 100 miles or so, but it's really to cover their butts if it does come off. I've never seen any fall off.
While I don't go out of my way to retorque after a few heat cycles, and don't really believe that it does any good, but I usually try to work things so I'm putting on the top end of the engine (heads/intake) at the end of the day so when I come back the next day I check the torque on all the bolts before slapping on the valve covers, carb/FI, emissions stuff... the head bolts don't usually move, but the intake bolts almost always do, and whether it does any good or not, it makes me feel better that at the very least I know that I didn't miss torquing any of them...If it's my pocket the money comes out of, i'll retorque only to check and varify. if not, screw it.
SEE! The one time you don't do it, it happens. GOD I hate carma. Good point though, thanks for bringing it up. The chance, no matter how infantecimal, for a head (or rim in this case) to loose it's fastener's retention is there, but most people either do not fall into the category to neccesitate retorquing, or it doesn't matter due to application, fastener, head material, etc. Some people do fall into the category, and for them, it sucks to see them cut corners and have something catastrophic happen. I've always stuck to: TTY, torque once. NON-TTY, torque and check.Silverback said:My brother has had one of his back tires pass him going down the street, turn left into a neighborhood hit the edging around one of the houses garden and go in through a front window landing about a foot away from someone sitting there watching TV...
What PTFE dope do you usually use? I used to swear by the stuff but the last few years I've had notoriously bad luck with any of the ones that I can get easily over the counter... I would love to find something that I can trust again.Duntov said:Exactly Silverback!
I'm sure a whole lot of people were waiting to hear that said, because it's been true for fifty years.
That's why we use the PTFE pipe dope from a professional plumbing supply outfit. Learned it from a hydraulics engineer in the Eighties. It acts like a medium grease on first torque. to 65 ftlbs. but will hold 3500 psi of hot hydraulic fluid, on a half inch pipe thread.backhoes ect.
I've been having a heck of a time getting the good stuff. Seems like all of it is runny and inconsistent for a couple of years. We have about four cans in the engine room and some on the paint shelf. we leave the lids loose half off on the ones we don't like and after a while you get a really good one for several engines and then you have to go to another "seasoned can".. I hate to admit that to the world but it seems the truth goes a long way here abouts. I'll check the brand name on the one good can we have in the clean room. Post tomorrow night. DuntovSilverback said:What PTFE dope do you usually use? I used to swear by the stuff but the last few years I've had notoriously bad luck with any of the ones that I can get easily over the counter... I would love to find something that I can trust again.
Secondly, do you guys use something different on cars with O2 sensors? As far as I can tell, no PTFE pipe dope is "sensor safe."
It seems like i try something different on my own stuff every time, and if it's someone else's it's usually whatever they want or sensor safe RTV (which I hate if you have to mess with it later)
So, where the heck is TI.Duntov said:it's getting down to the details
you are absolutly right, an open poll should be open to those that votedcobalt327 said:I don't like the fact that after you vote you can't see who else voted and what they voted for.
Not gonna tell us?a1supersport said:Naw you just have to click on the number...it'll show.
P.S. I'm surprised no one uses the thread sealer I use. Oh well...it's a secret anyway...HAH!! :mwink:
Okay. Tell you what...multiple choice:Duntov said:Not gonna tell us?
a1supersport said:Okay. Tell you what...multiple choice:
1. "Just put spit...YEAH!!!"
2. Bubble Gum
3. Two-part epoxy (well, at least the bolts won't come loose...EVER)
4. Red or Blue RTV (if they had White...you could use all three. All-American engine)
5. Ear wax (and when you run out of ear wax...use boogers)
6. Grease (hey, it's a water repellent...)
7. Sugar (the heat will caramelize it...right?)
8. Talcum powder (so you don't chafe your bolts)
I figure it doesn't cost me anything at any time I do it; The extra time of course, but the peace of mind is well worth it to me. Besides we aren't adding torque are we? Aren't we just checking to be sure it is still holding the torque we were intending according to the specs? Book says 65 or 70 so I think they want it to be there next month also....... Actually never had a failure from not re-torquing but in 40 years you couldn't believe how many customer engines came in loose and leaking...Deeavi said:Never have re-torqued with the modern gaskets. I am considering doing it on my current build because motor will be under boost after getting some miles on it. Also Tony Mamo from AFR says that he always does it. That is enough to convince me to do it this time.
I like that process but it only works on what it is designed for. I had sbc on my mind when I started the poll and I might should have kept the question to that but it is good that these other applications come up. SBC has short bolts on lower row what tty wouldn't work for; at least I don't imagine they would have that spring in a short length.latech said:I do A LOT of engine work and some of the ones i repair have two smaller torque steps and then back off completeley and then retorque to a third and then + 90 degrees. (TTY) Insane. Many auto manufacturers have there own ideas and even for the sake of argument follow the manufacturers standard unless using a non oem design and it specifies differently.Reality is stranger than fiction.