I need to retorqe the heads on my 462 it has been studded with ARP's. What is the proper procedure for retorquing? Do I back the nuts off first? 1 at a time , all at once? then retorque in sequence? I searched and can't find this info anywhere I've looked The reason I need to do this is they are seeping water into the valley. Will retorquing seal it. I have the intake off and when I pour water into the water jackets I can watch it weep out of the head gasket and into the lifter valley with no pressure applied. :ball: Or will I need to install new head gaskets first. The engine has about 3 hours on a fresh rebuild
Sounds like the gaskets are toast, but you have nothing to lose by trying a retorque! The retorque procedure is to do each nut, one at a time. Back off the nut 1/8th of a turn (this overcomes the static friction) and then torque to spec.
Yeah I'm hoping a retorque will do it If I must put new ones in, this engine has been bored .030 over do I use stock gasket size or are there different gaskets when it's been bored? The engine has Poston 10.5:1 pistons and a GS113 cam Thanks
pull em You can try a retorque and then add water and recheck the leak. I would pull the heads if it were mine. If they leak this bad then I don't think a retorque will do it, unless you find some loose studs. Beside you already have the intake off. Also try a cylinder leak down test after the retorque and before the intake goes back on, or at least a compression test. If you don't stop the leak completely then the water can cause more damage to some bearings. Head gaskets are cheaper than another rebuild!
You are right. I am picking up new gaskets in the morning. The intakes off so pulling the accy. brackets is no big deal. The local parts shop has a head gskt set in stock. Thanks
Yes, something seems wrong. What brand of gaskets are you using? I also say pull the heads and re-install.
I did not build the engine so I'm not sure what gaskets were used but they are blue so I'm guessing they are Fel-Pro. It's a 72 block and 73-74 heads. I'm going out there now to pull the heads so I'll soon know if it is a gasket problem or a cracked head. The block & heads should be compatable. I just love midnight wrenchfests
Well I pulled the head here are a few pictures of the Block, head and gasket. If you look the block has round water passages and the heads are oval passages. You can see the imprint of each on the gaskets but there is only a very small hole for the coolant to go thru. Is this right ? The head gasket part number is 8494PT it is a Fel-Pro gasket. The block # is1238861 and the heads are #1241860 Any thoughts would be appreciated
You are trying to use 73/74 heads on a 71/72 block as indicated by the casting #s, Those are double scallop heads. And not a double scallop block. You need to plug each head at the offending hole using either a 1/2" pipe plug or a 3/4" freeze plug with some JB Weld. This problem/solution is in the "Guide to Buick Performance" book Jim Burek from PAE Enterprises was involved with. You may want to give him a call. Just my 2 cents.
keen eye. I like it. it will now make me rember to check those scallops when i put my 71/2 (cant rember what) heads on my 75 block. :TU:
Hi Guys, Jay....."Beast" is right on the money! After reading your first post and what you described that's immediately what came to mind, your pic's then just confirmed it!:TU: Those center clean-out holes in the heads need to be plugged, at the very least...the one hole that has no corresponding scallop on the block below it. There is just no support for the head gasket to "crush" and seal up against...so that is where the seeping into the valley is coming from.:Smarty: A new set of Fel-Pro's along with plugging the heads and you'll be on your way!:TU: Good luck!
I had this same problem when I built my first 455. I had a '73 stage 1 engine and tried to run '70 steel shim headgaskets to raise the compression.
Should I plug both just to be on the safe side? I don't want to do this again. Which plug is the better option? These two holes were casting cleanouts and are not needed now correct? If my last statement is true why do the gaskets have that small 1/8 inch hole? I Thank all of you for all your help. :TU:
My 430 and 455 blocks look like yours. One scallop in the centre. And the heads inc. my alum. STG 2s have the one hole where yours has two for the centre scallop. So if you only plugged the one not being sealed against the block it would be the same as using an earlier head. I would go the pipe plug route myself. Some of my iron heads' holes are pretty crunchy, and have rust & corrosion. They look like they were not cast perfectly round anyway.This is just my opinion. I've never done it before. Good Luck!
I'll be doing the pipe plugs Sunday Morning. I'll post some pics of the process and finished plug. I'm going to use pipe dope on the threads then stake the thread to be sure it does not move. I also stopped by the GM dealer and got some of their Block sealer tablets to be sure.GM uses them in all new cars off the line now to be sure there are no coolant leaks. They say to put them in whenever you do a cooling system flush.
