Well I thought "it would never happen to me", but it did. The engine only has about 10 hrs on it, and I already lost a freeze plug at the wheel to wheel school. I'm pretty bummed because I think there may be more damage than just a freeze plug.

First off, what is a popular remedy for this? It seems this is a fairly common problem. I was thinking of making up some round plates with a hole saw, and taping them into the block.

Second, and kind of a can of worms, I tried to keep an eye on the temp gauge, and I never did see it get above 210, but now I wonder if this was a false reading since I had lost all my coolant. When I came into the pits, the motor wouldn't go below about 3k (air getting in?), and it looks as if a good amount of oil came out of the headgasket/cam feed area. My guess is the head is pretty warped. Do you think I should just pull the head, have it checked for straightness and leave it at that?

 

Were they new freeze plugs or the old rusty stock ones? It would just be interesting to know.

Just replace the plug that came out with a good steel or brass one. They should be commonly available at most autoparts store.

Could be a false reading. I am old enough and driven enough crap cars to have lost all coolant due to one kind of failure or another and kept driving them to the point of seizing (many times). After cooling off, the motors loosen up a little and turn over once again. At times it has seemed to me the gauge didn't register overly hot too and I suspect this is because there is no coolant to transfer heat to the sensor.

The last time this happened to me was in my '91 V6 explorer. The heads were toast but a new set of heads and a water pump only and the motor is running great once again.

One thing that may not be obvious though is cast iron rings may have lost their tension due to the over heating and may need to be replaced. I suppose a compression check will show that problem.

If you can replace the freeze plug without taking the motor out, I would just take care of the head issues and call it good until you can check the compression again.

 

Thanks for the reply John,

They were brand new steel, and to the best of my knowledge the 2nd time they've been replaced.

I'm afraid that just replacing them will not correct the problem, although I gather brass may be a little less prone to loss. I've seen alot of road race cars with elaborate freeze plugs (o-ringed, etc.), and up until now, I thought they were a bit overkill. It seems to me that for the most part this is not a problem in autocrossing or drag, but only in road racing due to the higher stresses.

Hopefully I won't have to replace the head, this particular one has been ported. I was a little worried about the water pump too.

 

<Just get the plugs installed and do the tests. Then proceed with any additional repairs. You might do the plugs and fill the coolant. Then do the coolant pressure test. You could also do a cold leak down with the coolant tester in place. If the 80psi goes past the head to the 14psi coolant passage it will show up on the radiator pressure tester like the test I first described.

Good luck,
Alan

 

Hey Alan,

Good to hear from you again. I'm glad to have the "just take a breath and relax" feedback...was ready to pull the motor this weekend. I will most definetly try the tests first.

So with the JB weld, you have never lost a freeze plug?

Phil

 

Sometimes it helps to take a step back and relax. We lost one back in the 80's. It was a NAPA part. Lost it on the way to the track, during a pretty high speed run though.

After that I have only used the factory plugs. Haven't lost one since. Not to say it is impossible, but I tend to go with what works until it really fails.

Hang in there,

Alan

 

Another thing you can do as a quick check for head/head gasket problems, Remove the plugs and shoot some compressed air in the plug holes. Listen/feel for air thru the radiator and adjacent plug holes. If you can't detect any leaks, proceed to more elaborate leak diagnostics, but if you can detect any leaks that way, you know the heads gotta come off before you do anything else.

 

So what did you find in your testing of the coolant system?

Alan

 

I've been procrastinating a little bit, but I have plenty of time too. By not completing the school, I won't be doing any racing until the after next one in spring. Also the tow vehicle has had problems. It seems since I started using the enclosed trailer and pushing the truck a little harder, things have been failing, water pump, brakes, etc. I'm also ashamed to admit I didn't have a leakdown tester, but it should be in within the next few days. Hope to check it out this weekend and will post my results asap.

 

I know how the days can be stretched into longer periods of time.

One thing I tell folks just starting out in Motorsports:

"Motorsports is a study in desire and problem solving. If you don't desire to solve problems, this may not be the program for you."

Keeping that in mind can help keep an objective point of view while working through the tough parts.

Hang in there and keep us posted,

Alan

 

Here are the results!!! The only problem was I had a real heck of a time trying to get the freeze plug back in. It was the front left (driver’s side), and I ended up having to take the carbs and exhaust off, so I tested it cold. The test was at 75 psi per the instructions, which also said you could do it at 90 or 100. Throughout the test, the coolant pressure gauge did not show any additional pressure, but the results did not look good:

1-62 psi, 18% loss, not sure where air is going.
2-62, can feel air coming out the intake port, proper rocker clearance, burnt valve?
3-72, 4% loss
4- 62, air out of intake port again
5- 74, 1.5% loss
6-72

The tool is from Total Seal, and they have values for their gapless (0-2%) vs. conventional (8-10%). If this is true, then cylinders 3,5, and 6 are much higher than they should be. The rings were gapped correctly, any thoughts?

 

You can use a screw driver or something to slightly prop open the throttle plates while doing the test. You may want to spin the engine over to get rid of the gas from the pump jet to prevent false reading from the liquid sealing the rings. This would be for the folks that have the carb system in place of course.

Then while the cylinder is under pressure you can listen through a tube or stethoscope in the carb throat. Air heard hear as you are correctly suspecting would be the intake leaking. You also want to check the tail pipe, and the breather tube on the side of the block.

Tail pipe noise would be the exhaust valve. Breather is the rings.

Some rings leakage is normal. You really want the vales totally sealed. If the valve is leaking it may not be "burned" with a full chunk out of the edge, however it will sooner rather than later.

Has this engine had an over rev? A slightly bent valve can leak too.

I guess at this point you might try one more thing before taking the head off. First take off the rockers and lash pads. Make sure to keep them in order. Then turn the engine to the point where all of the pistons are 1/2 way down in the cylinders. Then take your plastic hammer and a brass drift tap on the valve end. What you are doing is making sure the valve is fully seated.

Then rerun the test. If the results are the same, off to the machine shop you go. Repair and replace as necessary.

One more thing to think about.... those freeze plugs on the ends of the engine. Makes you want to go hmmmmm.........

Good luck.

Alan

 

Thanks for your help thus far Alan. As I stated earlier, the carbs/manifold and exhaust are off the motor, so it was pretty easy to tell where the air was comming from. The I was carefull not to pump the carbs either during removal, so no gas seeped in.

The motor has definetly not been over rev'd. I was trying to break it in as gently as possible, and it never saw over 7 to 7500. I will try your "tapping" test, sounds intreging.

I had the valve cover off to help find TDC, and during the cyl 1 test, it felt like the air was coming up the timing chain area, which leads me to beleive its rings, which really thows me for a loop. Maybe it was like that since day one?

Yeah, I thought I mentioned something about the front and rear...don't know if I want to go there. The back would be pretty easy, but the front, of course, only after a complete teardown.

 

One other thing, what's general concensus with total seal rings? If I end up having to re-reing it, I was thinking of possibly going this route.

 

Glad to hopefully help you out.

10 hrs. is not too much. The air coming up from the timing chain area is the same as the breather.... crankcase...... rings. It could be possible that the rings have not seated yet. Were the cylinders honed to size with a machine, or with a hand unit?

As for the Total Seal rings ... I have heard both ways. The folks that like them have had good success with them. I have heard of the rings flutering in the grooves on the pistons. If you have a good hone job and real round cylinders they should do pretty good.

On hi-po street engines I just use a factory ring. They got the cars pretty darn far up the road. We have put 100k on some fairly stout combinations and they still run great.

For race stuff we use 1mm thick ductile iron rings. These get replaced at about 10-15 hrs. of operation.

Bottom line on your deal .... Try the tapping on the valves and retest. If it improves then put it together and warm it up. Then retest again to see if the heat will help seal the rings up. If it passes that then run it. Just be aware that those freeze plugs will need replacing. At least you can try to make it until cold weather and get some fun while the weather is nice.

Alan

 

I tapped the valves like you said, and that seemed to do the trick, for cylinders 2 and 4, but 1 had no improvement.

1-still 62psi
2- 70
4-69

The cylinders were honed to size by hand (drill), but they were bored with a boring plate, but I think it's actually quite interesting, bad I know.

It looks like an all clear to start it up, but I'm real worried about one thing. It appears the head gasket was pushed out right where the oil feed is. I'm thinking that why I saw the oil all down that side of the block. I'm also worried that the oil feed to the head is now blocked. This setup is the o-ring (fire ring) set up. I know its crap, but I'm stuck with it until I start over with a new block.

I wish I could remember the material the rings are which came with the JE's, from Malvern. I believe chromoly and possibly ductile iron like you said. Man 10-15 hrs for a re-ring seems a bit extreme. Do you hone it every time too? I almost wonder if I'd be better off re-ringing it now too. Where would be a good supplier?

 

I guess that is some progress. If the gasket looks to be suspect then take the head off and do the right thing. That is a shame.

You might not need a new block. I would measure the bore while apart though. Do it at three places, top, middle, and bottom. Measure side to side and front to rear, making for six measurements for each cylinder.

If you have an old head you can cut it in two just behind the first two head bolt holes. Then cut an old cam right behind the first journal. Now you can bolt this unit on and mount the chain. This whole deal makes it so you can turn the engine with all of the timing in place.

Good pistons too. Damn. You can get new rings from JE direct I think. Let me know if you can't and we can get you hooked up.

Go get um',

Alan

 

I went ahead and pulled the head off; it wasn't as bad as I originally thought, but the oil passage was pretty close to being cut off. The gasket in that spot was deformed really weird. Wish I had digital camera.

Alan, one question I still have, when you re-ring the motor, do you hone every time? What's the general proportion of re-ringing to having to start over with a new block just from wear and tear?

I'll check with JE and see what I can find.

Phil

 

Slightly blocked is not good. What kind of gasket was it? I have seen Felpro do that.

Most of the time I have some scuffing on the bore that makes me hone. With the new 140mm rods I am hoping to cut down on that.

If there are no scratches or scuffing then I let the measurments tell me what to do. If the bore is out of round then it needs attention. The only time I had switch blocks so far has been when a wrist pin clip failed. I guess that block will be a 3.0.

I use a Pro-Stock drag motor guy to final hone with the plate torqued down. He has some super duper machine that does a great job. Bottom line ... new rings ... fresh hone.

Alan

 

The gasket is the Nismo 0-ring (fire ring), and you must use their gasket with the rings. I remember having this discussion a while back, when looking for a cheaper alternative.

Wow, 140mm! That's quite a difference in length when compared to the stock sizes and the L24 at 133mm. Kinda funny, a few years ago I thought I was slick when I thought of using the L24 rods, and came to find out that's the norm!

That's real interesting with the honing. In my mind, it wouldn't take much to go beyond spec after a couple of honings. I'll check out mine.

Thanks again for all your help.

Phil

 

I recall that gasket deal now. Oh well. I hope they still keep those in stock.

The 140mm seem to make things smoother. They are having a big discussion about rod stroke ratio over on the Hybrid board. I have stayed out of that one, but it is somewhat amusing to watch.

The hone provides as much of the seal as the rings do. When they use the big machine it has total control over final bore size. If the damage it not too bad then you can use the piston a couple of times if it has not been scuffed on the sides too.

I hope things work out.

Alan