turbotime

Here is my conundrum:

I have a built engine, but i have no way of contacting the builder. I need to replace the headgasket, but i have no idea what thickness copper gasket i need, or what type to get. Moreover i dont know if i need a b18 or b16 headgasket. I was told a need a b16- but when i look on summitracing it says i need a b18.

I have a built b17a1 with 8.5:1cr, sleeved and oringed.

I need to know what thickness and bore(82.5mm = stock?) headgasket to get. Also, should the headgasket have orings if my block already has them?

I need a gurus help, im trying to rasie compression a lil to like 8.8 or something if thats possible...

PLEASE HELP

NJIN BUILDR

Measure the old one.B16 and B18c are the same gasket (as well as B17).The copper gasket will not have o-rings in it.There are many thicknesses of copper gaskets so you may be able to go thinner to raise your compression.You still want at least .035" piston to head clearance.Stock bore is 81mm.
Glenn

turbotime

cool good info- so i can use any b18 or b16 gasket? and just a plain copper gasket is all i need? What do you think about teh SCE copper gaskets on summitracing.com?

I am thinkin of getting like 0.43 thickness. If i want to measure the thickness of my current gasket how would i do that? is there a special tool?

NJIN BUILDR

You can measure it with a micrometer .Talk with a few of the gasket companys direct,even if you order thru Summit.Check with Flatout gaskets http://www.flatoutgroup.com Their tech line is 877-837-9200.They make coated gaskets that seal the water and oil better than plain copper.
Glenn

turbotime

is it possible to measure the thickness while the head is still on? Like measuring off the lil front left corner edge or something?

NJIN BUILDR

Yes.If you find a spot exposed enough.The next issue is the bore.If you are sure it is 82.5mm then order that size or even 83mm if that is the only one available.
Glenn

turbotime

im not an engine builder so im not completely sure on what oringed means- does it just mean the sleeves have rings machined into the tops?

Im not really sure of the bore i dont know if its stock or larger... can it be stock bore and still be oringed?

NJIN BUILDR

The sleeves have grooves cut in them that the o-ring sets in.This can be done in standard or oversize bores.Guessing as to what you have is not very productive.I take it the gasket is leaking and that is why your asking these questions.You are not going to be able to order what you need without knowing what you have.O-ringed blocks are very good when it is done correctly.Copper gaskets are very hard to seal for a long period of time and are rarely used outside of racecars.Take the head of and see what you have.
Glenn

turbotime

ok ill be pulling the head this thursday i was hoping i could have a gasket ready at that time to go on. The head is lifting under bost and leaking air into the coolant. Im not sure if its due to the headstuds or the gasket but im gonna replace both.

So how do i measure bore once the head is off? And if copper doesnt seal well or last a long time is there a better alternative?

NJIN BUILDR

A set of vernier calipers will get you close enough on the bore size.With o-rings copper is your only choice.The FLATOUT gaskets would be my choice.
Glenn

HiProfile

Here's what you do:

1) Buy ARP head studs, no way around that (*ANY* headgasket will 'blow' if the bolts allow lifting)

2) Take it apart, measure it, order it

3) Re-install it, spraying it with copper seal (metalic spray for headgaskets)

4) Wait for studs/HG, then install them. Enjoy boost.


Otherwise you can try dicking around w/o taking it apart. Either way you're going to have to take it off to take every measurement. As for o-rings, OEM headgaskets shouldn't have o-rings, although I only deal with the newer metal gaskets.

turbotime

damn flatout wont be availible in time, there is no way oem will work with an oringed block?

The leak only happens in boost so im not sure if the gasket is busted or the headstuds are stretched (i think they used stock ones).

I may just try pulling the studs and using ARP's and see if that fixes my issue..

NJIN BUILDR

The stock head gasket is to hard to use with o-rings.The o-rings will hold the gasket up and it will leak coolant externally.I'm sure it already has studs with all the outer mods.You could try to retorque the head studs and see if it seals.You may be detonating under boost and lifting the head.If this is the problem a new gasket won't help you.
Glenn

turbotime

wouldnt i notice some sort of hesitation or noise if it were detonating? The timing is very conservative and i hear no noises or gaps in power in boost.

At idle it sounds fine with the occasional "pup pup" im not sure what that is- but how would i know if its detonating?

Oh also i havent overheated yet either, which is weird

NJIN BUILDR

So its pushing fluid into the overflow tank?How do you know it is leaking compression into the coolant system under boost.
Glenn

turbotime

yup exactly its pushing coolant back into the overflow tank.

I tried replacing the tstat, i have a fludyne race radiator and a 16lb fluidyne cap...

I'm "pretty sure" its only leaking under boost becuase we had it on the dyno and it was fine as we brough it to thrid gear then as soon as he went WOT and hit boost i could see bubbles in the overflow tank and then it started slowly overfilling and squirting out the top....

NJIN BUILDR

Sounds like a good call on the head gasket.Did this have many miles since the build or did this happen right away?
Glenn

turbotime

well its got about 500miles on the build- or so i was told...

i didnt even notice it until i saw it on the dyno doing it (getting it tuned)

does the pup pup in my exhuast also point to a headgasket?

*edit* also the guy i bought it from didint know **** about cars- he had all the work done by shops, so he may not have retorqued the bolts after xx heat cycles, which is what i think your supposed to do with arp studs. Of course, i havent removed the cams to verify they even used arp/aftermarket studs...

but when the engine was swapped (i had a shop do it) they did verify it was built head and bottom end as far as they could tell (took oilpan off to weld oil line bungs)