New engine, oring leaking coolant out exhaust port?Help

[lt1bird]

Ok ,got a 485 with power valves. New engine, I am real anal about assembly. Everything looks perfect...Went to fill the coolant and I saw some coolant dripping out the exhaust port right side. Wonderful! Took the head off, it all looks fine. How the hell could this leak? This is not even running yet! LOL, not like pressure is blowing past the oring, its leaking with no pressure so that means it must be pretty bad to do that. Now, the cyl oring looks fine, the dome looks good etc...It's a brand new engine... I dont see any major scratches on the dome surface....The domes stick down a little past the head surface...Guess I might assembly the head and make sure the domes sit flat just to make sure again...., again, with the orings im sure it would have to be pretty bad to leak. Guess im just venting and looking for anyone who might have had a similar thing happen... Thanks for the help!

[bansheesrtoys]

get a straight edge and go from one end of the jug to the other end on the other jug and make sure its flat.

[Larry's Shee]

What brand head do you have ? Did you find coolant actually in cyl ?

[lt1bird]

I checked the head surface and the cyl surface when I was assembling it..they were fine. Yes, a little coolant got into the cyl as it ran down the wall and out the port....did not come down the piston....I dont think much if any coolant got into the lower end...any easy way to tell?

 

The head is a trinity head with removable domes. You know, the only thing that was marginal might be the orings. The looked a bit odd as they were smushed a bit with some material squeezed out along the edge where the oring meets the cyl etc... Im wondering if something attached the orings... the outter ring looks fine, the two dome rings which do get compressed more look a bit smushed. Like flashing around the whole oring. I just put new orings on, gonna pull it off and see if it looks "flashed" now. If they do not, than Im going to have to go with something attached the dome orings where they meet the cyl... then ill try and see if it holds fluid again.

[BigRed350x]

If you had coolant coming out the exhaust port and had some inside the cylinder, it can only be coming from around your dome. I'd look at the dome o-ring and check to see that the dome is flat and that the dome seats to the head correctly. Sounds like trinity sold you some crap domes (no surprise) or you might have some gunk or something around where the o-ring seats.

 

If it turns out the domes are the issue, contact Tim at Titan and have him cut you a set of domes.

[sleeper06]

Before you fill next time pressure test it,air comes out rad cap something is up.Make sure the notch on the dome is positioned rite in the head.

[lt1bird]

Figured it out....Put my bore scope up the exhuast port,,,, coolant was coming down from the power valve port. Looks like a bad casting in the thin area around the power valve/water jacket. Called trinity, they will send me a new one. Thank god for bore scopes

 

I do have custom cut domes for proper squish angle

 

Thanks for the help boyz!

Edited November 20, 2010 by lt1bird