Cracked Block????

[wilcom]

Just replaced the intake manifold gasket. Had a problem with one I replaced first and didnt seat right...drove it and the temp went up to about 270 deg or so and I shut it down. Checked the oil and found water in it. Towed home and replaced the intake manifold gasket again. Started up and got setam out of the left exhaust (I have dual exhaust). Replace the intake gasket again and got water out the right side not the left. Replaced it again and got water pressure spraying water out the overflow but no water out the exhaust or in the crank.

Here are things done;

Have a new radiator cap..I worked fing through all gasket replacemnts execpt the last one with water spraying out the overflow within 30 seconds after starting. 12-14 lb version.

First set of gaskets were edlebrock with gaskasinch applied per specs and torqued to specs. started up and got steam out of right exhaust. Pulled plugs on that side and found water in cylinder but still firing.

Second were Felpro and done same as above. Started up and got steam out of left side of exhaust. Pulled plugs on that side and got water on one plug but still firing.

Thrid set was Felpro special type, top of the line $40. Started up and got water squirting out of the overflow withing 60 second.

All gaskets were installed per specs, caulked around the water jacket inlets etc.

Torqued to specs with a torqure wrench.

Removed both heads and had them magnafluxed and the surface checked.....no cracks or problems.

Visually checked cylinders when heads were off and didnt see any cracks in cylindders or head surface.

I cant believe I cracked the block when running it the first time, but maybe. The fact that each time I put a intake gasket on it, it does something different has got me guessing. I figure that if there is pressure getting into the water system it has to be coming from the exhaust since that is a pumping pressure and everything on the manifold is a vaccume.

Ok guys.....who has the answer?? <_<

 

[Crude dude]

If I was in your situation I would not invest in another set of intake gaskets yet. Go to Carquest and buy a cooling system pressure tester and read the directions on how to use it. It is a very handy tool to have and it can help you locate where the coolant is escaping other than obviously the overflow tank. Have you ever had this intake on a running engine? If not, there are some other things to check after youve done a cooling system compression test with the intake bolted on. Some machine shops will mill heads at an angle for compression and better flow. With all the gasket surfaces clean, set the intake back on the engine.Feeler gauge and a flashlight. Check for gaps that you think a gasket would not seal,between the head and the intake. If you install the intake again, only use a thin layer of silicone around the water ports on both sides of the gasket and follow the torque pattern to keep the intake from snugging to one side of the engine and not the other. By chance are these 351 heads on the 302?

 

[Crude dude]

Also get 4 5/16 bolts about 5 inches long. Cut the heads off of them and ***** them into the four corners of the cylinder heads. This will help the intake sit flat and evenly on the heads so you can check the gasket gap. If the intake does not go over all of the headless bolts without some help from a hammer then you have found your problem, the cylinder heads are not straight on the engine (machined wrong?) or the intake is not straight. The reason I asked about the 351 heads is the bolt sizes for the heads. If you did not use some aftermarket bolts with shoulders to center the 351 heads on the 302, that would also make the intake not seat. I believe the 351 uses 1/2" bolts while the 302 uses 7/16" bolts.

 

[wilcom]

If I was in your situation I would not invest in another set of intake gaskets yet. Go to Carquest and buy a cooling system pressure tester and read the directions on how to use it. It is a very handy tool to have and it can help you locate where the coolant is escaping other than obviously the overflow tank. Have you ever had this intake on a running engine? If not, there are some other things to check after youve done a cooling system compression test with the intake bolted on. Some machine shops will mill heads at an angle for compression and better flow. With all the gasket surfaces clean, set the intake back on the engine.Feeler gauge and a flashlight. Check for gaps that you think a gasket would not seal,between the head and the intake. If you install the intake again, only use a thin layer of silicone around the water ports on both sides of the gasket and follow the torque pattern to keep the intake from snugging to one side of the engine and not the other. By chance are these 351 heads on the 302?

I will go get the pressure tester today and try it and let you know. This intake is a new aluminum Eldebrock Truck Perfromer. I have not tried the feeler gauge test yet but did do the bead of sealant and torqued to the Edlebrock specs and pattern everytime I changed the gaskets. The heads are from a 1975 or 76 302 that were put on way back 15 years ago in order to convert the engine to burn unleaded gas. I have only put about 12, 000 miles on it since then and its been prefect.

The block and heads were milled and matched together at a machine shop back then. I reciently removed the heads thinking this was the problem of them being cracked but I had them boiled out and magnafluxed and all were good. I put back on with premium head gaskets and they mounted perfectly with the normal round metal dowels that are there to line up the heads when you put them on. Torqued to mfg specs....all is good I suspect.

I will try the pressure pump and the 5/16 bolts and get back to you probably saturday night

Thanks Curde dude

 

[wilcom]

I will go get the pressure tester today and try it and let you know. This intake is a new aluminum Eldebrock Truck Perfromer. I have not tried the feeler gauge test yet but did do the bead of sealant and torqued to the Edlebrock specs and pattern everytime I changed the gaskets. The heads are from a 1975 or 76 302 that were put on way back 15 years ago in order to convert the engine to burn unleaded gas. I have only put about 12, 000 miles on it since then and its been prefect.
The block and heads were milled and matched together at a machine shop back then. I reciently removed the heads thinking this was the problem of them being cracked but I had them boiled out and magnafluxed and all were good. I put back on with premium head gaskets and they mounted perfectly with the normal round metal dowels that are there to line up the heads when you put them on. Torqued to mfg specs....all is good I suspect.

I will try the pressure pump and the 5/16 bolts and get back to you probably saturday night

Thanks Curde dude

Ok here are the results;

Pressure tested the the supposed new cap (16lb type) and it was releasing at 12lb, so I replaced it with a 13lb that the specs said, tested it and check out OK. Cycled the engine (with remote starter) with the pressure tester on the radiator and the coil disconneted. I did not see any quick presure build up other than the small 5 lb you would expect for just cycling the engine. Just wanted to see if it was being pumped up by intake pressure. Checked each cylinder with pressure tester and found them all to be at 150 lbs....nice. I guess if the cylinder wall(s) were cracked, I would see the pressure leak. So, this means the heads and block are good and not cracked?????

I paid attention to the plugs to see if there was water on them and found only one with water on the plug. It was the 3rd cyclinder back from the front on the left side if you are standning in front of the vehicle .

I guess if I run the engine a bit longer I would see steam coming from the exhaust again like before on the same side but I shut it down quickly when I saw the water shooting out of the overflow.

I have not tried to run the engine yet because I didnt have the timinig set exactly right when I ran it the first time but I will do so when I do. I figure I will leave the radiator pressure tester hooked up and run the engine to see if it builds up quickly (exhaust leak into water system) or slowley and/or if it surges in pressure (itake manifold leak??). I checked the oil again and it is clean.....no water.

I thought about your suggestion about removing the manifold and place 5/16" studs in the four corners and then lower the manifold down to see if it needs a hammer to line it up. When I originally placed it down on the heads I have four manifold bolts in the four corners and I lowered the manifold down and they lined up and fit perfect and started threading right away.

anything else you can thing of to try before I take downe the manifold again??

 

[Crude dude]

Everything sounds good so far. I think you are right about letting the engine run until it warms up to see what happens. Maybe for 4-5 minutes. Check the coolant pressure tester for pulses in pressure and then the oil again for cream. When you say that you have steam coming from the exhaust, is it right after you start the engine or a a couple of minutes after? Most engines will produce steam from the exhaust a couple of minutes after starting, and even some water drops. I have been told that this is from compression of oxygen in the cylinder which creates h2o. Dont know how true that is because not every car does it. If you are worried about starting the engine with a coolant leak internally, you could also pump up the coolant system and let it sit for a few hours with the spark plugs out. Then if the pressure has dropped quite a bit, turn the engine over and look for some water in the cylinders, or even a wet piston with a flash light. Before you turn the engine over, check the oil dipstick for water. It may show up as beads on the stick. Also, do not use a hammer to install the intake manifold, that was just an example. The manifold should easily slide over the four bolts by hand.

 

[wilcom]

Everything sounds good so far. I think you are right about letting the engine run until it warms up to see what happens. Maybe for 4-5 minutes. Check the coolant pressure tester for pulses in pressure and then the oil again for cream. When you say that you have steam coming from the exhaust, is it right after you start the engine or a a couple of minutes after? Most engines will produce steam from the exhaust a couple of minutes after starting, and even some water drops. I have been told that this is from compression of oxygen in the cylinder which creates h2o. Dont know how true that is because not every car does it. If you are worried about starting the engine with a coolant leak internally, you could also pump up the coolant system and let it sit for a few hours with the spark plugs out. Then if the pressure has dropped quite a bit, turn the engine over and look for some water in the cylinders, or even a wet piston with a flash light. Before you turn the engine over, check the oil dipstick for water. It may show up as beads on the stick. Also, do not use a hammer to install the intake manifold, that was just an example. The manifold should easily slide over the four bolts by hand.

I know about the hammer.....just wanted to let you know the manifold slippped down perfectly with the 4 manifold bolts so I dont think it is warped. The steam coming from the exhaut startes immediatley. I can pull the plug on that one cylinder and see it is wet pretty good....this seem to be the only cylinder that was wet when I pulled all the plugs to do the cylinder pressure test.

I think I will go steam clean my stock cast iron manifold and get it ready to be put back on. If it works then I guess the Edlebrock is not matched to these heads.

Thanks

 

[Mike G]

I sure you've done this but have you looked at how the gaskets lay on both the head and intake? I good eye balling to make sure there is nothing not covered by the gasket surface as it should be.

 

[wilcom]

I sure you've done this but have you looked at how the gaskets lay on both the head and intake? I good eye balling to make sure there is nothing not covered by the gasket surface as it should be.

Belive me, after 4 times replacing them I scrape them with a razor blade and steele wool them with fine wool, prep and clean each surface.

I just thinking here...but what about putting double gaskets down??? If the match up between my new Edlebrock manifold and my heads is slighly off in the rear, maybe two gakset would work.

I also just just cleaned up my old cast iron manifold and will be painting it up just in case I cant get the Edlebrock to work.

 

[Crude dude]

Theres a term for that kind of work, and it wouldnt be polite to name it on this site. That would be something some would do if they were selling the car. Do you have the intake off of the motor right now? Try the alignment studs and see if there is a bad gap between the heads and intake. If there is, try your cast iron manifold and check the gap. Still a gap, then it must be the machine work on the heads. No gap, then its your aluminum intake. You do not need to install the gaskets to check the gap or even torque the manifold. Should be obvious if the two surfaces are not on the same angle.

 

[wilcom]

Theres a term for that kind of work, and it wouldnt be polite to name it on this site. That would be something some would do if they were selling the car. Do you have the intake off of the motor right now? Try the alignment studs and see if there is a bad gap between the heads and intake. If there is, try your cast iron manifold and check the gap. Still a gap, then it must be the machine work on the heads. No gap, then its your aluminum intake. You do not need to install the gaskets to check the gap or even torque the manifold. Should be obvious if the two surfaces are not on the same angle.

I agree on the gasket option, but I figured if it worked then I would know for sure there was a miss match.

I am going to pull the distriutor and retime it first before pulling the manifold off just to make sure in my own mind I did everything right. When I pull the manifold I will check again. I did this the first and second time I pulled the manifold to replace the gaskets and could not find a spot to put a feeler gauge. The only place I couldnt check real well was the very back rear which will have to check better with a mirror and bright light.

Any way I painted the cast iron manifold today just in case I have to put it back on. I probably wont be able to get to it until this weekend and will let you know.

 

[Crude dude]

It also would be easier to do with the distributor out since you are pulling it anyways. Good luck, let us know

 

[wilcom]

It also would be easier to do with the distributor out since you are pulling it anyways. Good luck, let us know

Ok, here we go. I put in the distributor and started her up. No overflow pressure coming out of the radiator overflow like before but I still have water coming out of the exhaust. This time more on one side than the other...this is first. Usually its on side or the other, but not both.

The long and the short of it is I just took off the Edlebrock and put on the cleaned up and painted stock cast iron manifold. I will wait until tomorrow and start her up to see if it fixes it and let you know.

Thanks again Crude Due

 

[wilcom]

Ok, here we go. I put in the distributor and started her up. No overflow pressure coming out of the radiator overflow like before but I still have water coming out of the exhaust. This time more on one side than the other...this is first. Usually its on side or the other, but not both. The long and the short of it is I just took off the Edlebrock and put on the cleaned up and painted stock cast iron manifold. I will wait until tomorrow and start her up to see if it fixes it and let you know.

Thanks again Crude Due

YAAAAAAA...HOOOOOOO! It worked!!!!!! I put on the original stock manifold, set the ditributor in and started her right up....no vapor, steam or water coming from either exhaust. I used a standard Felpro gasket as well. I guess it was the Edlebrock manifold after all and it appears that my original cast iron one was machined and matched to the heads way back went 15 yrs ago when I had it rebuilt.

I took some pictures this time so you can see the Edlebrock and the gaskets and then my cast iron one on the engine.

 

[wilcom]

YAAAAAAA...HOOOOOOO! It worked!!!!!! I put on the original stock manifold, set the ditributor in and started her right up....no vapor, steam or water coming from either exhaust. I used a standard Felpro gasket as well. I guess it was the Edlebrock manifold after all and it appears that my original cast iron one was machined and matched to the heads way back went 15 yrs ago when I had it rebuilt. I took some pictures this time so you can see the Edlebrock and the gaskets and then my cast iron one on the engine.

oooops, forgot to put in the picture of the Edlebrock and its Felpro gasket. As you can see the gasket holes are bigger than the ports on the manifold. Pretty strange since this is the manifold and gasket that they spec. The gasket has the correct size ports that match the original cast iron one, so the Edelbrack must be wrong but I called them to double check and they said I have the right one even if my intake ports are bigger than the manifolds. Im thinking way back 15 years ago the machine shop got heads from a 1975, 302 because of the leaded gas being the only thing to burn back then and they said the vales were hardened to unleaded gas use or something to that effect. Any way I wonder if these heads are different that the 1970 but according to Edlebrock it takes the same manifold. I think this was part of my problem with it not fitting properly and the ports being different.

Oh well, it works great now so no bid deal....

thanks again Cruded Dude

 

[Crude dude]

All the 302 heads that I have ever worked on had the same size intake ports on them. Except for the Boss 302. The differences in the years were the chamber size and designs, the valve sizes and the exhaust ports. And of course the emission changes. I think Edelbrock does this so that the owner can alter the manifold if they want. If the intake manifold ports are smaller than the gasket holes and the cylinder head intake runners this is ok. If they were bigger , then you run into a flow problem. Engine looks good! Hope you dont have to take the intake off for a while...you may go postal.

 

[wilcom]

All the 302 heads that I have ever worked on had the same size intake ports on them. Except for the Boss 302. The differences in the years were the chamber size and designs, the valve sizes and the exhaust ports. And of course the emission changes. I think Edelbrock does this so that the owner can alter the manifold if they want. If the intake manifold ports are smaller than the gasket holes and the cylinder head intake runners this is ok. If they were bigger , then you run into a flow problem. Engine looks good! Hope you dont have to take the intake off for a while...you may go postal.

All is good now....filled radiator with antifreeze and went for a long deserved ride with wife. No problems and she runs better than ever. thanks again