Took heads of: what now?

[bigboy]

Hi,

First i took the port side head of because there were 2 cyl with +- 106compression. All the 4 others had 117compression.

Seems like there is some scoring in all 3. Today I took the starboard head of and just the same. Also scoring at all 3 cylinders.

Does someone know what is the reason of this?
I added pics of the 3 cyl at starboard.

Thx

http://users.skynet.be/fa003940/cil1.JPG
http://users.skynet.be/fa003940/cil2.JPG
http://users.skynet.be/fa003940/cil3.JPG
http://users.skynet.be/fa003940/cil4.JPG
http://users.skynet.be/fa003940/cil5.JPG
http://users.skynet.be/fa003940/cil6.JPG

[Jay Smith]

I'm not observing any deep scoring or gouges . On most steel sleeved engines there are marks as the chrome ring wears and takes to top off the plateau of the hone. ( It hits the highs and misses the lows ). Quality and quanity of oil sometimes makes a ring tent to scuff also. IMO and from what I've learned the hard way I would NOT use any 100% syn oil on that steel sleeved engine for a long extent period after complete break-in. Stick with the thicker more lubrisity and higher film strength of the blends.

You might want to tear down, hone and re-ring now while you've caught the bores where a honing can bring it back to usable condition. Also I suggest the use of a dial bore gauge to check to see if the bores are truely ROUND not egged...If they are egged (more than .001" ) you may choose to bore to the next over bored size and go back with new pistons and rings . Then the motor's bore/ ring health is as new.. While you are down I would also go through the cooling system , completely..

Good luck, I mean gooday Mate ,
Jay

[bigboy]

So I assume this is a high hour motor and this "damage" is all normal in that case? In some cylinders you can feel the scars but it's quite hard to feel them.

I was thinking the same: hone & rering! I hope I can stick with the stock pistons if not that will be much €€€. It will depend on how much they will have to be honed.

Previous owner used merc racing oil and mixed 1:33 ....
Yes I've been thinking about going through the cooling system... I will use the boat also for skiing so it has to be at a good temperature at all RPM ranges. Not only for going fast...

Thx again for your help Jay!

[T-REX]

I would hit dat bad boy wit a hone and put new ringz and rock an roll!!!.....A ridid hone will show if ya cyls are out enuff to rebore...If it ain't way out ov specs, U good ta go......A steel bo fish'in mota iz a tuff'n, and kan take stuff ya won't want ta put it thru.....Tha cool'in system iz tha key to tha longtivity ov a steel bo fish'in mota....Juss my unprofessional opinion

PS, U kan rering dat dude, and take one trip down tha river, kum back and pull tha heds, and U will already start see'in them lil scuff lines...Purdy normal...

[bigboy]

Thx guys!

What would I do without s&f:p

[j_martin]

Thx guys!

What would I do without s&f:p

Ya'd probably get talked into about a 6 grand overhaul. With T-rex, the scrap pile wizard as an advisor, you'll get by for a buck two ninety eight.
You'll lose some speed though, cuz yer wallet's too heavy.:D

just my 02
John

[T-REX]

Dammit Boy........So datz my problem???:eek::D:D

[Ted Stryker]

I'll copycat what everyone else said and say that the bores look OK to Me, and plenty of steel bore engines will have some markings and streaks even after the 1 hour idle time after a re-ring.re-hone job... As far as the low compression on 1 cylinder, I'd try putting a leakdown tester on all 6 to see if they all hold pressure well... If the "low" cylinder held pressure as well as the other 5 I'd put the spark plugs back in and let it ride...