Roco71

Here’s the story and then the problem. When I bought my 1971 350 home (on a trailer) the engine was just basically setting in the car. It is a 75 L-48 yea I know lucky me. The goal was just to get it running and replace it with a crate motor a year or so later while I worked on the rest of the car. First thing was to drain the block so I removed the drain plugs on the side of the block drained the coolant it was not as bad as I expected yellow in color. So I pulled the heads cleaned them and the valves and replaced valve seals. The cylinders did not look bad at all. I replaced the head gaskets put the heads back on. I went ahead and replaced the intake and carburetor with Edelbrock that I had from another car. New water pump alternator HEI distributor fuel pump. When it came time to start it, it started right up it idled a little rich but ran ok. Now I did not have a radiator so I could not mess around with tuning it I ran it for 30 to 45 seconds at a time and that's it. Last week I got the radiator in it and started it up did a little tweaking with the timing and let the car idle for about three minutes or so never reaching operating temp. I wanted to make sure that there was coolant in the manifold and that the thermostat was working so I took the thermostat housing off and now for the problem. I have a frothing foam caused by what I assume is oil it had not worked itself to the radiator as the thermostat had barely opened before shutting the engine off. I have check the dip stick and there is no water there. Usually my first thought would be blown head gasket but I just replaced them. The coolant I drained from the car before working on it did not have any oil in it what have a screwed up?

P.S. The partial rubber fuel line is a temporary fix so go easy on me.

jimboscarbs

A compression check will ease your mind and tell the tale, consistent bubbles in the radiator is usually a sign of compression leaking from the cylinder into the radiatior. If you did not use sealent you may have to go back and put sealent on the bolts that enter the coolant passages. Bolts/studs that enter coolant passages should be coated with a thread sealant such as Permatex. I would do a compression check first if no leaks are found do a coolant system pressure test if it passes no worries! (A creative mind and a bicycle tube cut in half and a gauge will make short work of this) If it does not pass go back and remove the bolts that enter the coolant passages one by one and coat them so you do not disturb your gasket seal.

Jim

P.S nice job on the installation!
What carb are you running and what height air cleaner is that? I have a reason for asking.

snoopykissedlucy

My guesstimate is that you might have a crack in the block somewhere near an oil passage. At first, no problems but as soon as the block expanded due to heat, it started foaming.

7T1vette

A leaky head gasket that was just done is MORE likely to leak than one that has been running OK. There are lots of opportunities to generate a non-seal when installing a new gasket. You may also have a cracked block that leaks oil into a water jacket. You probably should have used some Magnaflux Spot-Check on the head-surface of the engine block to check for cracks before you put the heads on.

My advice would be to use low pressure (around 5-10 psi) to pressurize the coolant system (after draining the coolant) to see if you get any leakage [plumb air line, with a gage, into the coolant system; pressurize and let stabilize for a minute; then shut valve to close the air supply and look for loss of pressure on the gage]. If is drops pressure quickly, you have a leak path somewhere; if it leaks down very slowly, it is probably fine. If you find it to leak, pull the heads and use the Magnaflux Spot-Check on it. The crack/leak should show up. You may be able to weld and grind smooth if the crack is small and not too near a cylinder.

Roco71

I did use sealant but perhaps not enough. That was one thought that I had. I will check the compression this weekend and we will see where we go from there. The manifold and carburetor are Edelbrock Performers 600cfm the Air cleaner is a 4 x14 K&N all just left over from another car. I have a L88 hood so there is plenty of room.

Thanks, Scott

Manuel Azevedo

Looks like a nice job there. You say no oil in the radiator so thats good, there is no oil pressure on the deck of your engine so not likely anything there. Oil pressure is much higher that water pressure so that puts the possible problem on an oil line. There is one on the back of the block that runs up to the cam along side the water jacket but this is very unlikely there is a problem there though. Does this engine have an oil cooler on it? GM had a crazy one that was between the oil filter and the block that leaked this way, it's not original to your car but thats an old car. Also by the look of that engine to begin with I would not be surprised that oil was in the water jackets before you started. I think that is the most likely problem. Probably if you had an oil galley leaking oil to water you would of put a lot of oil in the water and lost enough to show on the dip stick. Try flushing the water system and try again, I think thats what I would try first.

KapsSA

Stick a garden hose in the radiator and disconnect the upper hose so it runs on the ground for a while. Divert an occasional bit of water into a bucket so you can take a close look at it.

Roco71

Today I did the simplest thing first and that was to flush the system with fresh water. I flushed it and button it back up and ran it for a few minutes very little foam in the thermostat housing this time. I flushed it again and let it run longer this time no foam just orange water. I have done these five times each time letting the car run longer the water gets a paler orange. I do not seem to get it totally clear yet but maybe I need to get and flush additive. I do not see any signs of oil and I do not see any sings of water on the dip stick. When I got the car the intake manifold was setting on the car with four bolts finger tight. I wonder if oil somehow spild into the water passages that way. Anyway I will flush it a few more times run a pressure test and compression on the cylinders and see what happens.

jimboscarbs

you can't go wrong with what you are doing, good luck

birdsmith

Just out of curiosity...looking at your before/after fotos...just what the hell did you do to get that engine bay so clean and shiny?? VERY impressive!!

AvRog

Same question, looks like a different car.

Roco71

I thank you for the complements. A lot of work but no magic. The first thing I did was use engine degreaser (a couple of times) everything was pretty much replaced. Power brake booster, master cylinder, alternator, water pump, fuel pump, belts, hoses, manifold and valve covers. I cleaned all the brackets and painted them. I took the heads off and cleaned and painted them before installing them. With everything off it was easier to clean the bay and lightly sand with 220 and paint it satin black. Its just a driver but I want it clean.
Thanks again Scott