Preparation for metal headgasket?

[redline19]

i gotta take of the head to do a timing chain along with all correlating parts and was going to put in a 86mm bore 1.1mm thickness apexi metal head gasket along with arp studs along with them while everything was out.

just out of curiousity i was searching to see what everyone was saying about headgasket installs and some say you really need to surface the head and block to have an exact mating surface while others have installed cosmetic head gaskets with some copper spray and its been running fine for now.

My question is if I properly installed the 1.1mm apexi and have a properly tuned ecu, say by enthalpy, should i really have to worry about anything?

set up is basically mild - S14 SR, fmic, tubular mani, and stock fuel system, running at 13lbs. I don't plan on runing much more, maybe 14 lbs at most but i don't forsee much problems with a properly tuned/chipped ecu with a metal head gasket.

Anybody have any useful input on my situation? thanks

[ILikeMy240sx]

I have apexi HG 1.1mm as well... I torqued and took it off about 4 different times and each time there was gunk from copper spray I just scuffed up the surface with some abrasive pads. But everytime I do HG install, I always spray with copper spray. It's been holding up fine.

[redline19]

so you're saying you didn't send the head and what not to the machine shop to get resurfaced or checked and just installed the hg with copper spray.

some people are pretty anal and say you HAVE to send it out for some machine work before you install a metal headgasket, but i don't think i'll be ripping out the entire engine just for this.

I'm sure most of the people buying aftermarket head gaskets have their engines already installed and can't afford to send it to a machine shop to have everything reworked.

anyway thanks for the input

[DrifterProdigy85]

ive always heard to resurface the head and clean the block as preperation.

[ILikeMy240sx]

so you're saying you didn't send the head and what not to the machine shop to get resurfaced or checked and just installed the hg with copper spray.

some people are pretty anal and say you HAVE to send it out for some machine work before you install a metal headgasket, but i don't think i'll be ripping out the entire engine just for this.

I'm sure most of the people buying aftermarket head gaskets have their engines already installed and can't afford to send it to a machine shop to have everything reworked.

anyway thanks for the input

Well ideally, you would want that done...

But for me, I have never done it and it has been working pretty well for me. Now if your head or blck is warped for some reason then thats a different story.

[95lstegman]

i've built lots of engines in my time (and i'm ASE Certified for building engines, incidentally, though don't let me be a discredit to certified mechanics everywhere!), and i almost never go to a machine shop JUST to have a head or block machined flat again. if it's within 0.001" or so on a straight edge in each direction, you're good to go. just make sure you get ALL of the old gasket off. and i wouldn't rough up the surfaces, although that combined with copper spray is interesting. i wouldn't, but it's interesting that you're boosting pretty high and it's doing fine.

personally i think copper spray is bogus, just like putting something in your engine OTHER than oil (like Z-max, Lucas, x-brand engine smoke stopper, etc.). i'm sure people that use it think it's great, but at least in my experience, the head gasket will be fine if you install it right anyways, so there is no need for such a thing.

[xero1]

i have 5 ase certifiication too, including engine building; when you're replacing a metal head gasket you alway get the head resuface. you want the head and the block as smooth as you can. why do you think subaru blow head gaskets so ofter on their ej25shoc engines. on of the reason is the machining process of the head. ask anyone on iatn.net about head gasket replacement and they will tell you always have the head resurface when replacing a head gasket. never use copper spray on a aluminum head and block, this is just wrong. use copper spay on an old american iron block and head engine.

[DrifterProdigy85]

if the head checks out with a straight edge with no problems and is totally cleaned, why would it need machined? Piece of mind perhaps?

[xero1]

if the head checks out with a straight edge with no problems and is totally cleaned, why would it need machined? Piece of mind perhaps?

this would be ok if you're were using the stock head gasket and not building a lot of hp (+270rwhp), but a metal head gasket requires a mirror finish on the head and block for a proper seal. even if the head is clean and strainght(using a machinest straight edge) there might still be imperfections on the head that you cannnot measure with a straight edge and a fleer gauge.

[xero1]

i've built lots of engines in my time (and i'm ASE Certified for building engines, incidentally, though don't let me be a discredit to certified mechanics everywhere!), and i almost never go to a machine shop JUST to have a head or block machined flat again. if it's within 0.001" or so on a straight edge in each direction, you're good to go. just make sure you get ALL of the old gasket off. and i wouldn't rough up the surfaces, although that combined with copper spray is interesting. i wouldn't, but it's interesting that you're boosting pretty high and it's doing fine.

personally i think copper spray is bogus, just like putting something in your engine OTHER than oil (like Z-max, Lucas, x-brand engine smoke stopper, etc.). i'm sure people that use it think it's great, but at least in my experience, the head gasket will be fine if you install it right anyways, so there is no need for such a thing.

what kind of cars do you work on?

[Sabot]

Is simple you get yourself and straightedge a feeler gauge make sure the surface is cleaned and check your block and head to be within spec. If is not get it resurface if it is then you don't need to. You can only resurface but so much so is not something you just want to do for fun or peice of mind. Ok I know your normal SR owner is not going to be taking the head off & on alot but somebody like me that my s14 is my weekend warrior might. Now I'm not ASE cert. or hold a PHD but I do have alot of experience on 4cyl. b16,4g63T and now SR so I hope my info helps somebody.

[95lstegman]

hey, there are a lot of people with an ASE cert. that don't really know what works well, they just studied and did some hands on and passed, and LOTS of people who could easily get one that either never bothered or never knew they could pass.

in any case, to answer your q, i mostly work on hondas, but since i've been a nissan guy for almost a year now i've gotten to know my way around nissans as well. but i've also done all sorts of cars for money; i just focus on imports. they're all not that different from each other, it's just a matter of how well the engineers have designed it and how good their quality control is. hence, i like imports a lot.

and yes, you need a good straightedge and a feeler gauge. just b/c you have a metal head gasket, be it copper or MLS, it will still crush some. EVERYTHING deforms under any load, no matter how small, it's just a matter of whether or not your brain/eyes/hands can pick up on the deformation.

[xero1]

if i was doing a headgasket upgrade on a sr20det, i would spend the extra $50 to get the head resurface, reason 1, i'm getting paid 12 or more hours of labor, and i don't want to put another head gasket on for free if it blows. 2 i work at japanese motor works, inc in athens, ga and the shop offers a 12,000 miles or 1 year warranty on all work done. 3 the customer is paying to get the head resurface.

[DrifterProdigy85]

its definitly worth getting the head resurfaced then. but what about the block? chances are if the head has imperfections, so will the block.

[VitaminT]

When everyone says head resurfaced, how much are we talking about. I have heard of people getting it milled to 0.000mm just to take the crap off. I don't mind sending mine to the shop it is the fact that they will more than likely mill more than 0mm. I guess I just don't have expert machine shops around here as this one seems to get a lot of jobs from dealers and stuff where people don't ask questions.

I sent a CA head to this shop to have it check for bent valves and they milled it.... but when I asked how much the guy at the counter didn't know and told me "enough to make it flat". Well that could have been 2mm or something and now that car has 10:1 compression. Ok rambling done.

[xero1]

it depends whats being done to the engine, if its just a normal(the block is straight and in good shape) head gasket upgrade with the engine still in the car then only the head gets send to the machine shop, but if its a complete rebuild then the block, crankshaft, rods, and pistons gets send to the machine shop. the crank, and the new rods and pistons need to be balance. the block needs to bored to match the new pistons and also honed and resurface.

[180fan]

I've built my SR without any need for the copper spray on my head gasket. Do get the head and block decked though. It's cost is very low for the peace of mind it gives.

[95lstegman]

if i was doing a headgasket upgrade on a sr20det, i would spend the extra $50 to get the head resurface, reason 1, i'm getting paid 12 or more hours of labor, and i don't want to put another head gasket on for free if it blows. 2 i work at japanese motor works, inc in athens, ga and the shop offers a 12,000 miles or 1 year warranty on all work done. 3 the customer is paying to get the head resurface.

if i'm being paid to do it, OF COURSE i have it machined. i don't want to be doing it again for ANY reason. and the person is paying for it.

its definitly worth getting the head resurfaced then. but what about the block? chances are if the head has imperfections, so will the block.

the imperfections are tiny tiny. enough that torquing it down onto a new gasket will take care of them. unless you overheated the crap out of it or something and warped the aluminum.

When everyone says head resurfaced, how much are we talking about. I have heard of people getting it milled to 0.000mm just to take the crap off. I don't mind sending mine to the shop it is the fact that they will more than likely mill more than 0mm. I guess I just don't have expert machine shops around here as this one seems to get a lot of jobs from dealers and stuff where people don't ask questions.

I sent a CA head to this shop to have it check for bent valves and they milled it.... but when I asked how much the guy at the counter didn't know and told me "enough to make it flat". Well that could have been 2mm or something and now that car has 10:1 compression. Ok rambling done.

that's the main reason i refuse to do it on a turbo motor. i seriously don't want higher compression, and they ALWAYS take off some material, even if just enough to make sure it's flat. they NEVER take off 0.0000mm. and since i will probably take the head off at least 1 more time after upgrading (maybe to do valvetrain, or whatever), i won't want this procedure twice. i've had motors that i just cleaned the block and head and replaced the gasket every time and done it as many as 4 times and not had problems. no turbos, but it's good experience.