Milky oil after 1984 K10 305 top end rebuild.

bucket said:

Looks to me like coolant was leaking between the head and intake, at the rear port on the driver's side. It looks like evidence of rusty coolant leaking past the gasket.

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I was reading to see if anyone else was going to suggest that. I see it too. It seems to run from the bolt hole to under the water jacket and down into the valley.

And BTW, that's looks like A LOT of water in that valley. It's not even mayonaise like and churned up with the engine oil yet. Soooo, pull your dipstick and compare. You're probably going to find there's not near that ratio of water in the oil pan yet. With all that water in the valley, you can just about be certain it leaked there from the intake and has laid there and didn't make it to the drain back holes yet and get into the engine oil system. Certainly some did already but with that much water laying there at that ratio of oil/coolant I'd say that's where the problem is. And it does appear to be at #7 water jacket if I had to guess based on the pics.

Looking even closer at another pic, it appears it's leaking on both sides at the rear #7 and #8 cylinders and the water is traveling closer to the intake ports before it drops into the valley. That also coincides with where the water is laying in the valley. Notice where the water the begins at the back of the block. Then go straight up to the head from that point, and follow the path back to the water jackets.

All great observations!

I also believe it was an intake leak from the beginning.

First top end assembly with the felpro had a massive leak due to either incorrect installation, clearance or lack of sealant (only a smear), Second intake sealing with Mr Gasket and " the right stuff" reduced the leak but was still substantial.

Condensation by not having a pcv and short runs (10-20min) also added to the moisture.

And now Im here.

Hope to get this corrected with the recently installed pcv and the to be installed fel pro .120" intake gasket.

I am a journeyman machinist, so after looking at the posts, I have a few questions.
1) Bore size: 3.736 is the bore size for a 1994 265, an uncommon engine, I believe made only one year.
2) or a 305 1976- 86, I am guessing the latter.
3) 3.736 + .03 for the overbore = 3.766 the actual bore size now.
4) It is a well known fact that the # 8 cylinder can run hotter as the coolant on a gen one cools the cylinders first, then the heads # 8 being the last to cool, hence already heated coolant. This creates steam pockets. This is where the Gen 2 (LT1) got it right, reverse flow, heads first, then block, with the steam hoses on the back of the heads.
5) The machine shop that did the work should have recorded the amt. taken off the heads, which corresponds to how much needs to come off the intake. Only my opinion, but the intake should be machined to match the block, and ALWAYS pay the money to have the heads checked for cracks, usually around the exhaust seat.
6) As stated earlier, since the H2O contamination was significantly reduced after the second go around, it is possible that the intake is the problem. My opinion again, only real way to have piece of mind is the go back to the machine shop and have them mill the appropriate amount off the manifold, (there is a chart how much to mill off the intake which is related to how much was milled from the heads.) They should have informed you that this would be necessary. General rule is around .707. Here is an example: .020 (amt. heads machined) multiply by the constant, .707 = .0141, which equates to how much to mill off the manifold.

A bit lengthy but I sure feel for you having to do all that work and have things not work again. I would trial fit the intake as stated before and look at it. Is the bottom hitting first? Is there side to side play between the heads? How much, use a feeler gauge push manifold against one head and measure the gap on the other head. Is it the same front to back. If you have a straight edge, (tri square blade) see if you can see daylight under it or use a thin feeler gauge, like .001-.005. any more would make me nervous. Hope this helpes, keep us informed.

Thanks Craig,

All valid points you mentioned.

Actually the 305 is a 1984 and pistons are stamped "040" so it would be 3.736 + .04 for the overbore = 3.776 the actual bore.

Assuming stock crank and rods, what would be the displacement now?

What you mention about the #8 getting hotter coincides with the reason why I removed the heads the first time (early last year), water in cyl 8.

Then I had the heads milled to resurface the "surface" and was told by the machine shop that what they took off was just to clean them since it warpage was minimal. No, they did not mention how much warpage and how much they took off then and I didn't ask either. However, by what they said "only a cleaning pass" I assume it was as little as possible to get an even cut.

Yesterday I took the heads to be checked like you mentioned with a straight edge and feeler gauges. Told them not to mill anything, just to check. Same for the intake, they will check for warping and not mill. Will pick them back up today.

Since the engine has not overheated since I decked the heads last year, and no water was found in the cylinders , and when I removed the heads again a week ago all the gaskets and passages looked ok.. I don't expect to have warped heads again now.

I'm only having them checked because they are not installed and for good measure.

When I get them back in a torqued I will definitely do as you said and dry fit the intake and measure gaps to heads and china, then proceed depending on what I find.

Question
Assuming stock crank and rods, what would be the displacement now with 3.776 cylinders?

If I later (much later, not in budget right now with all the other stuff to do) buy an aluminum intake, do the intake runners get ported to match the heads or do the heads get ported to match the intake?

AlexK10 said:

Remove and clean the oil pan and lifters

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Make damn sure the lifters go back in the same hole. They are 'worn into the cam lobe' and MUST go back on the same lobe.

or...

buy new lifters..

OR....!

dump that fricken thing a drop a Big Block in!

I prefer the first option, make sure lifters go in the same hole .

Formula for any cylinder volume is as follows:
BORE X BORE X STROKE X .7854 (A CONSTANT), X NUMBER OF CYLINDERS
SO: 3.776 X 3.776 X 3.48 = 49.6184 x .8754 =38.9703 X 8 =311.7626 C.I.

Thanks!

I got out late from work yesterday and didn't make it to the machine shop. Hope to get the heads and intake back today.

Anyways, I will not use the end gaskets, but a bead of the right stuff and the .120 intake to head fel pro gaskets and more of the right stuff on the water ports.

Since the rear water ports are blocked by the intake... is it possible to weld a flush steel blocking plate in the rear water ports on the heads?

This way the intake gasket wont be doing all the work in keeping water out of the valley.

Can the same be done for the exhaust crossover, weld a block plate to the heads. (flush)?

I ordered a set of edelbrock alum (corrected to cast iron) plugs that block the exhaust crossover but was wondering if its better to weld a 1/16"-1/8" plate.

Yes on the Felpro 8510PT head gasket.

AlexK10 said:

is it possible to weld a flush steel blocking plate in the rear water ports on the heads?

Click to expand...

Bad idea... I just remembered heads are interchangeable and blocking the rear water ports on the heads will result in not being able to use that head on the other side in the future, which will be the front water port then.

Got the heads and intake back on Thursday, no work was done because all surfaces were found to be flat from the previous mill job. So now all I need to do is finish cleaning everything (lifters, threads, pan and crank) and prep to reinstall with the 8510 pt head gaskets, new Elgin bolts and the .120" felpro intake gasket with the right stuff.

I should be getting the edelbrock exhaust plugs in today.

Any better ideas with the exhaust crossovers? Like welding a flush plate to the heads instead of trimming the plugs to fit and still get gaps around them. I have all the tools and a wire feed flux core welder to tack them.

Anyone done this? Pros and Cons of each method?

Hi, I was able to remove and clean the lifters (kept in order), remove-clean and reinstall the oil pan and installed the heads.

Torqued the heads in correct pattern at 30, 45 and 65 ft/lbs with thread sealer and oil under the bolt heads.
Also gave the intake a fresh coat of paint.

Notice I also made some exhaust crossover blocking plates out of 1/16" +/- steel. Chamfered the ports with a dremel, press fit flush into the ports and a tack weld that was filed flush. Don't expect these to fall in since they do not fit all the way into the ports as they are held by the chamfer. Should have no problem with the gasket and "the right stuff" to further secure these from any movement.

The edelbrock plugs were huge and would have to grind the hell out of them to fit.

I lost a lifter plunger retaining clip when I was disassembling the guts of each one to clean. Had to buy a new lifter just for the clip.