What size headgasket should I use? Bore/thickness

[newdude1]

Im still in the process of learning these motors but Im looking at replacing my head gasket with an Apexi headgasket and some arp head studs. But I have no idea what bore or thickness I should use. I need some info on these.

Also I have heard that sometimes is hard to get a good seal on the head gasket with out decking the block or the head. Is this true? Because I was just planning on removing the head and installing the new headgasket.

[240life]

Thickness is a preference, if you have not upgraded pistons or had to deck the block or head I would go with a stock thickness to keep the compression numbers accurate. If I didn't overheat I would have the head checked to make sure it is level at a minimum before installing a new head gasket...Apexi is a good choice many people have had good experiences with them, but they are pretty expensive. G/l with your build!

[Justin35ll]

Well yes since the sr is a cast aluminum block and head the metals can warp easier then say a cast iron block or head.

You shouldn't have a problem unless you can really see the warpage we're talking 1000's of an inch here, but even a small amount of warpage can put the decks out of spec.

You just need to make sure you pay close attention while taking the cams out and the head studs. You need to look it up in the sr fsm and take the bolts out in sequence to prevent warping, cracking, or damaging any parts.

Once the head is off you can carefully razor blade the excess headgasket material off the decks. Then what I did was used scotch 3m bright pad (the red one) and smoothed down the surfaces. This obviously isn't as good as getting the decks resurfaced, but it was good enough for my garage job.

Then place the new head gasket on and when installing the arp studs make sure to lube the studs, nuts, and washers with the supplied arp assembly lube and not oil. Then torque down in sequence as the ARP directions will tell you (about 35, 70, and final 105ft/lbs of torque) But it is extremly important you do it in order. Then place the cams in and also check the fsm for reinstallation instructions and you shouldn't have a problem.It's really not that hard to do just make sure you keep all your bolts in order and don't mix any of the cam cap bolts up or anything else.

Here is how my block looked after using the scotch bright pad

After I get my engine running hopefully this upcoming week I'm going to flush the engine with water before putting in the coolant and capping it off because when I used the bright pad some fuzz and stuff got down in the coolant passages and I don't want that circulating through the engine so I will first flush it

[newdude1]

Thanks for the quick response. So on the bore should I get the 86 or 86.5?

[240life]

are you using stock pistons? If so use the stock size, if it isn't available a .5 larger will not hurt...my CP pistons are 86.5 and my tomei H/g is 87mm I run 17psi of boost and have no issues, perfect oil pressure and temp

[newdude1]

Ya Im running stock. Noob question but whats stock size? lol

[newdude1]

Never mind figured it out. THanks for all the help guys.