Finally had a little time to look over a newly rebuilt 355 I install and broke in around December. After seeing this I basically got disgusted and closed the hood until today. Just too many things aggrevating a simple rebuild beginning the POS machine shop I went to. Besides taking forever, screwing me on prices.

Anyway, I've built plenty of motors and never had this happen. See picture down below. Heads were milled, block was fully machined, except it wasn't decked. Machine shop said it was flat, I was tired of waiting from June 03 until November 03 to get it back. I feeler gauged it and it was fine. 193 heads, that I cut swirls out, ported, polished, intake gasket matched, springs, valves, valve guides, seals, screw ins and lightly surface milled. Used .018 steel shims, copper coat on both sides of head gasket. Used Locktite PST. Mind you I didn't retorque the head bolts yet, but still. I reused the head bolts from the 84 sb instead of using the bolts from 87 that I swiped the heads from. It's basically the same on both sides of the block. Without runnning out to the garage and checking all my sheets on the motor, it's calcualted around 9.3-1 CR. Motor runs strong, no smoke, no mixing of fluids and temp stays at 180. However, I'm not comfortable with the seepage at all (red arrows in pic.).

Any suggestions besides ripping it apart? I bought a set of head bolt washers and a new set of head bolts. Was contemplating swapping them out, one at a time. Maybe the bolts are bottoming out (just a guess)? Never had a set stretched that much. Not looking to dump some coolant stop leak junk into it. Especially not with a new heater core, water pump and radiator. Learned that when I was teenager and had a heater core explode at 60 mph into my interior. Fogs up, burns and makes a mess quick. Never had this happen with any motor that needed a re-torque or not.
TIA
John

 

I usually advise against those.... for just such reasons.

Also, if that's Dexcool, its molecule is real small. It will find its way through places even water can't go. Try getting rid of that, flushing it REAL GOOD, and put the green stuff back in. Dexcool will seep through every gasket it touches just about; the worst are paper ones, like the back cover of the water pump, or typical thermostat cheapies.

 

Nah, that's the copper spray coat getting squished out and taking some paint with it. The anti-freeze isn't visible anymore, but does seep out. It seems to have run along the perforation of the gasket. I've used steel shims on plenty of motors, where nothing else was available without any problems. You're definitely right though, it would've just saved time and frustration to just use a set of composites and ditched the quench.

 

Did you put new thread sealant on the head bolts??

Hmmm.. Although it doesn't look like it is running down from there...

 

Yeah, I used Locktite PTS with teflon. The coolant isn't making it to the head of the head bolts. It's seeping out from under the gasket to the outside of the block. Basically under the "little runners" in the gasket, for lack of a better word right now.

 

After searching/ reading some archives found this at...


https://www.thirdgen.org/techbb2/sho...hreadid=146253

Then I went to take a look again at the heads. Much like RB83L69 explained in his post, in the above link about the light weight cut outs. Which is exactly where the seepage is. Don't know how I missed that, during assembly. The head gaskets I used must had been for the heavy castings.

Oh well, looks like I'll be tearing it apart during the week.

 

OK, maybe you made a mistake during assembly, but why did the machine shop sell you those gaskets? Whenever you use steel shim you really need to make sure the head/block is flat. But, again, the mac/shop should have clued you in if they were on the ball.