Just a thought Rick, had a fellow with the same problem on a Mopar 440. He changed heads several times and used the same bolts over and over. Kept blowing gaskets between the cylinders and finally channled out the block. I suggested he put in new bolts or studs like I run and that cured it. The stretch on those stock bolts, and even ARP's, etc. will only take so many torque's and that is what may be your problem is. If the bolts are stretched to the limit, the heavy load on compression and power stroke, may be lifting the head up and down a few thousands, and burning out the gasket. Had a lot of trouble on intake bolts before I went to grade 8 and good hardened washers. Maybe a lean condition with the NOS?????? Got pic's coming of the 347 I just finished yesterday, hope it lasts a couple of years like the 331 did. JMO
Forgot to mention that I have used nothing but 1011-2's on all my engines. 14.5 compression as well, rods always break first or the crank and block. Never used nitrous though.
Thanks for your input, Dave. I haven't run these heads with nitrous .... yet. The bolts were bought specifically for these heads (and used only once). They have the stepped shank from 7/16" to 1/2" (AFR 185's have holes the accept the 1/2" threaded holes for the 351 block). If anything, I might've over torqued these. From what I recall (and I will look again), I believe the torque on SBF Al heads are ~100 Ft/Lbs and ~90 Ft/Lbs on iron heads. (EDIT: SEE BELOW) It's not beyond me to give a "little extra". Who knows for sure though. I'll order a new set of stepped-shank ARP bolts and give it another go.
From AFR's site: "HEAD BOLT TORQUE: Apply moly-oil mixture to washers, and area around head bolt to prevent galling and improper torque readings. Torque to 70 ft/lbs. for 7/16" bolts or studs (289 or 302) or 100 ft/lbs. for 1/2" bolts or studs (351W) in three or four steps following the factory tightening sequence. Then tighten the long (upper) head bolts or studs to 80 ft/lbs. (7/16") or 110 ft/lbs. (1/2"). Actually, we could devote an entire thread to Torquing. Depending on what lube and its coefficient of friction, the 'recommended' torque is really a bogus number. You can torque a dry bolt and a lubed bolt to a specified amount and get different elongation and clamping force in each bolt.
You made me go check! I remember being told by a local builder to "bump" the numbers up a bit using a good lubricant. I think it might've been 90 on both upper and lower bolts. You have to remember, I have some-timers disease what were we talking about? :16suspect
i think it was about tail lights i better be careful i might end up becoming what my title is below my name in my avatar
Even the best manufacturers make a head just a little off from time to time. Rick, I'll guess that the heads were new and have never been checked for being true. Once you get them back from the machine shop (and I know you know this) don't cut corners on anything. Spend what you can now and save your money and labor later. If you are spraying then use the very best gasket you can afford. If you are runnig just a high dome piston then a 1011-2 should hold a true head. The AFR 185 shouldn't be giving you any problems and since you have a zero deck it had to be either a "bad gasket" or a head not completely true. One other thing that no one wants to think about is a micro crack in the head. Good luck and keep us all posted. Bossmav
Update: Dec 16 I took the Left Side head off and found MORE than what I thought I would. I knew the gasket would be blown from one cylinder to the next (zero compression in #6 & #7) but I wasn't prepared to see part of the seal ring pinched underneath the #6E valve. I clipped the seal ring off and took the heads to a local Performance Machine Shop to have the heads checked for flatness and to check that one valve. He could get a .002" feeler gauge underneath the center of the Left Side head. He assured me that was no big deal - pushing it - but still no biggie. Torquing the heads will easily close that gap. He then removed the #6E valve and inspected it and found it to be "fine". I will do a leak test (gasoline in each chamber to see if there is a leak). He also measured my spring 120 @ closed, 300 Lbs at valve open. The compressed height was .6?". He said that I could safely run a .550 lift cam without a problem. He also advised that if I want to turn high rpms (6.5K+), to go to a stronger spring (140/340) or use shims. He told me that he would tear down the heads, inspect everything thoroughly, check for cracks, relap the valves etc for around $150+ (depending on what he'd find) - but it's "not really necessary". The queue is a loooong one too. There must've been a hundert heads, blocks and cams in the "receiving" area alone. He suggested I clean the heads really good and reinstall as-is (if everything looks okay). I do have some pictures of carnage attached (everyone loves those). I've already added this set of gaskets to my "wall of shame" in the garage. Update: After a thorough cleaning, and using a loupe, I saw some pitting in the seal area - strangely enough - not on the cylinders that blew. I'll have the heads shaved.
DUDE!!! you scared me at first, when I thought it was your PISTON ring stuck in there. Took me a second to realize it was part of the gasket...
Ha Ha! So did I. After I woke up, changed underwear and had a beer, then went and looked at it again, I realized it was the metal seal in the gasket.
I told myself I was not going to do this and I told the crowd at our Christmas Breakfast this moring I wasn't going to do this, but, what the heck... Rick, what color was the pump handle you last used to fill this car up with fuel?
Kinda like a "Grabber Green". Why? Sumthin' wrong wi dat? (Ha! I learned my lesson from "Rattle Can Deisel-Dan" )
