posbl blown head gasket?

[fabio420]

My friend blew his 240. Alright, it's not really blown, but it sputters. We checked the compression on his cylinders, and the first 2 read 125 and the 4th reads 30. He said he was boosting at half thottle and the after he went to rev again and he had the nsputtering. I put oit in the cylinder and took the compression again but nothing changed, which makes me believe that the pistons rings are fine. So I think it's the head gasket, but I want to be sure before pulling the head out. Anybody has ideas. Am I missing a way to find out for sure what my prblem is without pulling the head?

[Florida240sx]

goodbye head gasket.Check oil.Should be milky.timing to far advanced? boost spike?

[TheOne]

leakdown test i believe.

check for oil in coolant or viceversa, if it still runs and throws white smoke out the exhaust then sure it is the head gasket:(

[bruinbear714]

Is the car belching out smoke?

White smoke = coolant burningBlue smoke = oil burning

In either case, it's bad.

[fabio420]

Instead of wondering, we are just gonna speed up the build up process. I'm gonna build a new head and drop it in. Gonna put .5mm oversize nitrited valves , titanium dual valve springs, port and polish, 3 angle valve job. Was gonna do it in 3 months, but this just sped up the process. I know it's not the piston rings and he didn't overheat the engine, so the new head will fix the problem, whichever it it (head gasket, valve, valve seal, etc..)

[:: orion ::]

Chances are it's the ringlands...the stock HG will hold up under detonation...the same CANNOT be said for the ring lands on stock pistons.

So before you plan a big head rebuild and leave the bottom end alone, make sure it's the HG and not the rings.

- Brian

[:: orion ::]

...and the rings may be fine, but if the ring lans are cracked, the compresion WILL NOT go up.

Adding oil during a compression test can help seal a bad ring, but CANNOT help a piston with broken ring lands.

FYI...

[fabio420]

Thanks, I didn't know that. So the only way to check the ring lans is? Do I have to pull the piston out?

[:: orion ::]

Unfortunately, YES.

Pull the motor, remove the head (you have to either way), remove oil pan...push them up and out the top.

Most likely, it'll look like this:



My HG was fine...in fact, I reused it for a while (not reccomended)...still held up to 8-9psi.

- Brian

[fabio420]

So, if it's my ring lands, then i have to swap out the pistons? If so are there performance pistons with stock size? Or should I just go .20 over? G-d, Iwe don't have the money for all this!!!

[WDRacing]

Depends on how bad the compression is in that cylinder. You can always add boost to compensate while you save money for new pistons.

[S14MaN]

take ur rad cap off and if it keeps blowing air/ coolant then its blown