B_Swapped93

bone stock y8 replaced some burnt valves with regular OE-Replacement valves reused my hg as I've always done with a d-series. However my compression is still **** 40-60-?? last time I did this my comp went back up to 180-180-180-180 reused the HG too. So my question in the od chance I crumped my HG would it cause over 100 PSI loss, I was careful like last the other 7 times I have done this for ppl. my winter car of 2 years selling it finally



OEM Honda head studs
reused OEM HG

NotARaCist

iTrader: (1)

Re-used head gasket

B_Swapped93

after 8 times with that routine you bet! on stock high millage d16 that gets used for the winter. If you look around on here that's not uncommon on a beater d16

NotARaCist

iTrader: (1)

"Not uncommon" and "a good idea" are rarely the same thing. It's ******* stupid. Head gaskets are cheap, and should never be re-used.

B_Swapped93

Again beater car you won't catch me doing that on any of my other vehicles all that is far from the point. Could it have bent or crumpled in such a way to net me a loss of 100+psi. this hg has only been reused once i'm referring to past beaters.



I'm trying to find out why it has no comp seeing as the car won't even start and it's blocking my garage

NotARaCist

iTrader: (1)

Yes. It pretty clearly isn't sealing correctly. This is a silly question, you should know better. Replace the head gasket. If you want absolute confirmation, do a leakdown test. Even just a partial leakdown (like what I did in my build thread) will tell you where the compression is being lost.

B_Swapped93

I took the cam girdle or what ever it's called off so all the valves would be "shut" still netted the same results. just seems so strange that this time it all goes to **** when I got away with it so many time, I don't endorse it had to mention it for the title tho.

NotARaCist

iTrader: (1)

It would net the same result if you have a bent or burnt valve, or a damaged valve stem seal, too. If you (or a friend, or a buddy at work, or...whatever) has an air compressor that can put out 75 PSI, it'd take you all of 30 minutes to verify that it's the head gasket. Better safe than sorry.

spAdam

iTrader: (1)

Do a leakdown and figure out where the compression is being lost. Anything else is just pointless speculation.

Burnt exhaust valves are typically a symptom of other issues, not a problem of their own. There's a good chance the seats are F'd.

I still can't think of any good reason to reuse a head gasket though.

B_Swapped93

Seats being where the valve meets the combustion chamber right? seemed fine when i installed them tbh i'm not even sure they were burnt but the low comp issue was what made me do it. I'm aware it's not good but it's a habit from my teens when i got the thing that worked. leakdown isn't an option no compressor/the car won't move i'll gave the new HG a shot if not it's a rolling shell sale.




thanks guys.

White_EG1

You reused the same head gasket on the same motor more than once?

NotARaCist

iTrader: (1)

Yes, that's the valve seat. Things can be wrong, and not look wrong. My head "looked" physically OK to the machine shop at first inspection, but had complete compression loss through a valve stem seal.

Can't afford to buy a $60 air compressor? Don't have a single friend who owns one?

3 gal. 1/3 HP 100 PSI Oilless Pancake Air Compressor

B_Swapped93

Sure didn't know better at 17 when all your buddies aren't into cars, never had an issue but for my F250 and several tegg projects they got more than just basic parts. i was carful and placed it on the tool cart pls keep in mind that was a beater.




we'll we don't have harbour freight but ill check Canadian tire, what hose do I need tho?

NotARaCist

iTrader: (1)

https://honda-tech.com/honda-civic-d.../#post50363409

Check that post in my build thread, it'll tell you exactly what you need to do.

tony_2018

So I think you had a good fair amount of re-uses for that headgasket. And if this happen after knowing that you had good compression before than yeah, its possible the headgasket couldn't survive this time. I know it might sound weird, all you did was put the headgasket flat back on and everything would be the norm.

spAdam

iTrader: (1)

Even for a quick backyard beater job, you need to at least inspect the seats and lap in your replacement valves. Did you adjust the lash at least?

W95civicEXcoupe

It's not a "good" reason but it is usually financial.

I had gone this route on my old Nissan 240SX. Would you believe me if I told you, that, every single time an old HG was re-used, the HG work needed to be done again?

Was the same thing.. Did not seal correctly.

B_Swapped93

Not in a technical manor I saw no gouges or rough areas and said "ok" lap slightly no on the lash. Pls remember im going by past experience and it was always ok thus why im all surprised everything is still ****/worse. maybe it's something else not the valves etc I comp tested it on day and had 120/100/80/40

joey1320

Buahahahahhahaaa...
Reused hg tsk tsk tsk

B_Swapped93

Removed the head again, only real thing I saw was the head studs bent the edges of the hg in 3 places this was the worst one. those aren't stripped threads rather what the HG cut into the bolt.

LSTurbo23

"hey guys my beater car isnt running right....i do shitty lazy maintenance on it but cant figure out why its running rough"

B_Swapped93

Everyone knows i'm more than capable of doing it right, i'm trying to move this stupid thing so I can get my 4RUNNER in the garage. I've got plenty of build threads to back that up F250 to tegg i'm well aware of what to do.

tony_2018

So compression was low and you replaced valves, or you replaced valves because they were burnt and then compression was low? It could be, as stated, that the valve seats are not done properly, whatever that process is called...lapping??

24TEN

iTrader: (2)

If you still have the head off turn it on its side and spray some brake cleaner into the ports that are facing up. Look at the corresponding valves on the combustion chamber side and see if the brake cleaner is seeping through. Dry is really good. Damp along the edge of the valve is still usable, wet/dripping is a weak sealing surface. Pouring right through is not sealing at all, typically it's a bent valve at that point.

LSTurbo23

but you posted a thread asking for help...o..ok