New Engine Build

[69volunteer 84]

I started tearing down a motor that I built a few years ago and then moth balled. I never got it running and while trouble shooting, other projects got in the way. I thought there might be an issue with the timing chain so I started taking it apart over the weekend.

Years ago, I had a machine shop do the machine work including hot tanking the block and heads. Everything is new: pistons, valves, springs, lifters, pushrods, bearings, cam.

The head gasket must have blown in a couple of spots because I had water in one of the cylinders. When I took the head gaskets off, the coolant passages on the heads are full of gunk and some were semi solid. This leads me to believe that the block/heads were not flushed very well if at all.

Again, the motor never really ran so not sure how the head gasket would have blown given the blockage of the coolant passages.

After checking the timing gear, I am to the point of putting it back together but now need to deal with this. I ran a hose through the water pump passages of the short block and a ton of brown/rusty water poured out. I need to do the same to the heads. Should I completely disassemble the heads before I do? Should I just take these back to the machine shop and ask them to re-tank? I don’t think they do the tanking anymore because of the chemicals and think it is just baking.

Thoughts on how to proceed?

[JET 445 43]

First thing you need to do is check the straightness of the head and block surfaces, there has to be a reason for the gasket to leak. If they were not machined last time you may need to get them done.

[lanky 44]

On a seasoned motor I had a head gasket fail due to crud that had built up in the coolant passages. The engine wasn't even overheating if you can believe it, but water was seeping into oil slowly... When the block and heads were cleaned I was told all kinds of sediment had come out of the cooling passages. If you plug the bottom most passages and pour regular old vinegar and let it sit in there that can help. The hard part is keeping the vinegar topped off without having it leaking out, which is tricky...

[1969_Mach1 333]

20 hours ago, JET 445 said:

First thing you need to do is check the straightness of the head and block surfaces, there has to be a reason for the gasket to leak. If they were not machined last time you may need to get them done.

+1, Check the surfaces first.  If they are good, then try flushing the coolant passages yourself.  Dry the heads and block and oil everything as quickly as you can after washing them.  If you have a valve spring compressor, you can easily disassemble the heads, just keep everything in order.  Lanky's vinegar trick sounds like a good idea.  CLR also comes to mind.  If you go the flushing route, don't forget to replace all the freeze plugs again.

When you reassemble, I'd replace the stock head bolts with ARP head bolts, ARP head studs if you want to spend the extra money.  Especially if it's a 302 motor.  The 302 motors use small 7/16" diameter head bolts so leaking head gaskets are more problematic.

[69volunteer 84]

Thanks guys. They decked the block so it should be straight. The heads I need to look at. I assume they were.

ARP bolts on everything. The cylinder that had the leak also has some rust in the head combustion chamber.

The heads are probably were the issue was. I’ll look into the vinegar idea, 

 

[barnett468 418]

289 and 302 engines do NOT have a head bolt or head gasket problem period.

stock bolts are fine for a moderate performance build.

vinegar is a waste of time on heavy rust. buy some oxalic acid powder and mix 6 ounces by volume per i gallon of water and soak the heads in this for 3 days after cleaning all the rust you can get out.

 

[69volunteer 84]

Thanks Barnett. I flushed plain water through the intake passages and watched a ton of crap come out. It ran clear after awhile. I dug a screw driver in there to loosen things up.

I am toying with the idea of striping them down and finding a place to 'tank' them. The places I have used in the past just bake them and then supposedly flush them--or maybe I was supposed to do it.

I am concerned that if I re-install them and once they heat up, more crap will get dislodged and I will be back where I started.

 

 

[Rsanter 152]

I had an engine that was rebuilt, ran for about 20k miles and then sat for about 15 years.

the water rusted the passages and gunked then up but good

i removed the intake and the freeze plugs and dug as much cramp out as I could and then hit it with the pressure washer. Tons of crap came out.

put it all back together and I was constantly getting the water in the cooling system turn to rusty solar immediately.

i changed the water several times and even tried the off the shelf flushes. Did not do as well as I would have liked.

i ended up putting some oxolic acid mix in the system several times and it has cleaned it up a bunch.

i also put a filter in the upper hose and it was constantly catching little flakes

[barnett468 418]

3 hours ago, 69volunteer said:

Thanks Barnett. I flushed plain water through the intake passages and watched a ton of crap come out. It ran clear after awhile. I dug a screw driver in there to loosen things up.

I am toying with the idea of striping them down and finding a place to 'tank' them. The places I have used in the past just bake them and then supposedly flush them--or maybe I was supposed to do it.

I am concerned that if I re-install them and once they heat up, more crap will get dislodged and I will be back where I started.

 

 

just do what i suggested if no one has caustic soda or something else that will clean the rust . you can but plastic tubs from walmart and home depot for around $6.00.