Author Topic: esr350 coolant leak (Read 15214 times)

patman13mia · « **on:** June 23, 2014, 02:11:35 PM »

heres some pics of my topend from this past weeknd. i didnt even put an hour on it do to alot of individual issues. but one main issue was coolant leak thru the head bolts. i dont know if the oring was sealed correctly cause after 10 mins of riding i had to re toghten the head studs. maybe the oring slipped out of its groove then i tightened it down. also does it seem like the clearence from piston to cylimder wall is larger on the intake side than exhaust or am i just seeing things? i also had some black stringy things floatin around in the coolant passages. looks as if its from the orings. this is my first oring head. tony said there is some sealent or lube to put on these. what are you guys using? i have some more pics coming with the cylinder off so we can see whats goin on down there too. hope yall can help

patman13mia · « **Reply #1 on:** June 23, 2014, 02:53:17 PM »

here are some more photos of the piston and bottom end spacer that i filed by hand. i went a lil to far and the divet into the cases is showing. does that make any difference in performance or hurt anything? i am waiting on the correct size gaskets and spacer to get here hopefully by this weekend. also my piston seems to have some cracks in it. it did have an air leak pretty bad at the end of the day which i think is from the unseated oring. the cracks are at the exhaust and intake sides.. what do you guys think? theres also a pic of the head as soon as i took it off.. does that look ok? there is coolant in there for sure

Tbone07 · « **Reply #2 on:** June 23, 2014, 03:05:59 PM »

I put a liberal amount of white lithium grease om the o-rings before installation and haven't had any leaks on my sphynx or PC2000

That piston looks like it has some type of crack/dent above the top ring, on both sides

Bowtie316 · « **Reply #3 on:** June 23, 2014, 03:38:53 PM »

What do the o-rings themselves look like? Are they cut up at all? I suspect that is what is on your finger in the first post.

Is the top of the piston just scratched from ring installation? Clean everything up and take more pictures with it clean.

Bio86 · « **Reply #4 on:** June 23, 2014, 03:59:48 PM »

What clearance do you have piston to cylinder? That piston looks cracked in several places. Looks like the compression o-ring was sealing from that one pic? Cant see any blowout area at least.

patman13mia · « **Reply #5 on:** June 23, 2014, 04:58:41 PM »

ok when i get home i can take pics of everything cleaned up. as for clearance im not to sure. neil did all the work on it. i can find out though. the only way coolant could leak through would be cause of the orings correct?

Bio86 · « **Reply #6 on:** June 23, 2014, 05:23:13 PM »

Other than a cracked sleeve I dunno where else it'd come from? Unless your deck surface isn't flat or sleeve is lower and the dome never really seated well.

patman13mia · « **Reply #7 on:** June 23, 2014, 05:58:18 PM »

oh i never actually got a kick out of it without the spacer. it was caught up with the top ribg. i homestly think my problem was the head wasnt torqued down right and then when i went to torque it down the oring may have popped out. thats just my guess though

Pumashine · « **Reply #8 on:** June 23, 2014, 06:24:33 PM »

It kind of looks like the water o-ring was sheared when you put it back together. The o-rings usually last a year or two before needing replacement. The cracks in the piston are unusual.

Coolant leaks through the head bolts happens cause there is no seal on any cylinder between the 2 o-rings. Your acorn head nuts will seal at about 20 ft-lbs

Jerry Hall · « **Reply #9 on:** June 23, 2014, 08:13:13 PM »

It looks like you have a dome for a 330. It looks like the piston is hitting the head. I can see a witness mark about 1 to 2 mm wide around the circumference of the piston and head dome where contact is being made.

An 0-ring head should not need to be re-torqued. If the head nuts were loose it is probably due to the piston tickling the head. A piston that is tickling the head will also overload, collapse and break the skirts.

Detonation will often occur when the piston is close enough to make contact with the head. Detonation will also erode the inner edge of the o-ring. If the detonation continues long enough it will eat all the way through the o-ring.

Jerry Hall · « **Reply #10 on:** June 23, 2014, 08:14:19 PM »

It looks like you have a dome for a 330. It looks like the piston is hitting the head. I can see a witness mark about 1 to 2 mm wide around the circumference of the piston and head dome where contact is being made.

An 0-ring head should not need to be re-torqued. If the head nuts were loose it is probably due to the piston tickling the head. A piston that is tickling the head will also collapse and break the skirts.

Detonation will often occur when the piston is close enough to make contact with the head. Detonation will also erode the inner edge of the o-ring.

Pumashine · « **Reply #11 on:** June 23, 2014, 08:43:56 PM »

Quote from: Jerry Hall;37362

It looks like you have a dome for a 330. It looks like the piston is hitting the head. I can see a witness mark about 1 to 2 mm wide around the circumference of the piston and head dome where contact is being made.

Good eye Jerry. If the piston does not fit into the groove cut into the dome you will be able to tell by putting the two together. If it is hitting like Jerry says then you will want the correct dome.

patman13mia · « **Reply #12 on:** June 23, 2014, 09:05:42 PM »

i dont know how to upload a video but i put everything together and paid more attention to what i was doing when installing. it doesnt leak out of the top of the head at all. i also performed a leak down test before installing pipe and carb and it was good. now when it runs it is making a loud noise as if it is hitting the head just like jerry said..how do i tell if i have the correct dome? i took the dome out to clean it and it is scribed 350 race dome.. it looks to have the diameter of the piston.. what should i do to fix this issue? maybe beed a thicker spacer plate?? please help!!

rk88r · « **Reply #13 on:** June 23, 2014, 09:14:13 PM »

Hopefully its the spacer plate. If its apart check the rod bearing also.

Pumashine · « **Reply #14 on:** June 23, 2014, 09:15:11 PM »

If you were to have everything disassembled you just put the dome on the piston to see that the piston does in fact fit inside the small step that is machined into the dome. If it fits then you may need thicker base gaskets! Myself just use a calipers and measure the piston and compare to the step cut into the dome. There should be some clearance.

Did you use the 3mm or 5mm spacer?