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TR4/4A TR4 Head Seeping Water Through Intake Casting

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JCL TR4

JCL TR4

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I am rebuilding my TR4 race car which my brother and I have owned since 1965. I was a day or so away from starting the new engine up when I installed the radiator and new hoses and filled it with water. I noticed a drop of water in the #2 intake throat which I assumed I splashed it on there when I added water to the radiator. So I wiped it off and it came back a few minutes later. So I wiped it off again. Maybe 10 times before I thought WTF?

So after a good long while looking at this drop of water which kept reemerging, I finally came to the conclusion that it is seeping through the casting. It had quit at one point since the water level in the radiator had dropped. I filled it back up and it started seeping again. I have never seen anything like that, especially on this head. We've been using this same head since the mid 60's. It is shaved down to a dangerous level, and apparently the intake had been reamed out just a little too much:smile:

I need to figure out what to do with it. I know it can be welded, but I'm worried about striking an arc if the casting is that thin. I'm wondering if brazing it would do the trick. I used to be a welder many years ago and know it can be done but wonder what would be best. The blue dot is where it is seeping through.

I just thought I would share this crazy issue. Can you imagine if I had installed the exhaust and carbs already? I would have been changing out head gaskets until the cows come home trying to stop a suspected head gasket leak on that cylinder. I am so glad I hadn't installed them yet.
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So...it is the head casting?...and cast iron? If so, I would not consider it repairable. Sorry, as I know that's not what you wanted to hear. If it is an aluminum head, then it CAN be easily welded.

That said, you may be able to live with it for a short period if you can get epoxy into the crack. It might last a good while...or not.
 
Hi, Devcon epoxy was used on the intake ports the 70's by Nascar teams racing Ford 351 Cleveland's. The ports were way to big so they raised the bottom of the ports. Edelbrock and Moroso sell versions of the epoxy. That and Bar Leak, should work. It only works on the intakes, the exhaust is way to hot.

Do you have any flow numbers for the heads? I have wondered what a ported set of TR-4 heads flow.

Good luck, Roy
 
Yes, it is the casting that has become thin. The guy who did the head work just emailed me and said that he has repaired some like that by drilling and tapping the hole and using marine epoxy. There isn't much pressure from the water jacket, only 7 psi according to the cap. Might be worth a try.
 
TR-3rg said:
Hi, Devcon epoxy was used on the intake ports the 70's by Nascar teams racing Ford 351 Cleveland's. The ports were way to big so they raised the bottom of the ports. Edelbrock and Moroso sell versions of the epoxy. That and Bar Leak, should work. It only works on the intakes, the exhaust is way to hot.

Do you have any flow numbers for the heads? I have wondered what a ported set of TR-4 heads flow.

Good luck, Roy
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Thanks Roy. I don't have flow readings. This head was done in the 60's by somebody who was supposedly quite good at it. It doesn't have much meat left and has cracked a couple of times in between 2 and 3 but has been welded without any trouble.

It is a tiny leak, but would cause heck if I hadn't noticed it.
 
I would suggest that a stainless steel sleeve be fitted and set with sleeve sealer or metal bonding epoxy.
Do all 4 if you find the tubing to do it.The epoxy is good to 300deg as is the sleeve sealer. should make a
race worthy repair.
Mad dog
 
Apart from Mad dog's suggestion, I think it is time for another cylinder head as it is only going to deteriorate.
 
Casrt iron is weldable.Why not a small drop of brass /bronze alloy,applied with either tig or gas welding?
Tom
 
True, cast iron is weldable. Very few welders are capable, though. The entire casting must be brought up to, and maintained at cherry red as you weld. Then it must be cooled slowly over 24 hours...in a kiln, not one of those blankets. Then you have repair all the guides and seats for the valves. Chances are good it will warp during the procedure, so the sides will have to be milled straight...and there is a good chance that, after doing everything perfectly, it will crack in the end. If you do anything wrong, you are guaranteed a crack.

I don't think TR4 heads are expensive enough to warrant all the work. But...give it a shot if you have the time.
 
Marv on the forum here might have a head he will sell you. When I bought one from him, he had a couple, but that was a while ago.

Steve
 
CJD said:
True, cast iron is weldable. Very few welders are capable, though. The entire casting must be brought up to, and maintained at cherry red as you weld. Then it must be cooled slowly over 24 hours...in a kiln, not one of those blankets. Then you have repair all the guides and seats for the valves. Chances are good it will warp during the procedure, so the sides will have to be milled straight...and there is a good chance that, after doing everything perfectly, it will crack in the end. If you do anything wrong, you are guaranteed a crack.

I don't think TR4 heads are expensive enough to warrant all the work. But...give it a shot if you have the time.
Click to expand...
I have to disagree.Heating the entire casting cherry red isn't necessary.I have welded a lot of cast iron and most repairs I don't even preheat with Nickel steel alloy arc welding rods.
to gas weld,since the casting is very thin,the spot should be able to be heated red for drop of brass alloy quickly without any distortion.
For this ,if it was mine,to arc weld I would put a piece of scrap right next to the hole,then strike the arc on the scrap,get the rod burning and then drag quickly to give a tack over the hole.no pre or post heat,I would also do it in place with head torqued down.
If you want see some expert cast iron welding on big cracks,something I try to avoid ,watch some YouTube vids of guys in India or Pakistan repairing blocks and heads with oxycetlene torch,cast iron bar and flux.preheated on a bed of coals,usually in the dirt on the side of the road in pretty primitive settings,but with amazing results.I do agree that alot of welders would just say no,and replacement head may be best.
Tom
 
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If you did that and did not get a crack, you were exceedingly lucky. With an arc on cold cast iron, you super cool the weld material, forming a martensite that is hard as rock. Not to mention the rapid cooling pulls the adjacent iron in at great tensile stress. Not saying you can't do it...but I am saying that 99% chance that you will eventually get a crack doing it. I have watched those (cringe worthy) youtubes of 3rd world repairs to all sorts of equipment. They never show how long the parts last in service. Honestly, if you ordered a part that arrived saying it was from Pakistan, would you trust it, LOL?

As I always say...it's your car. If you have the time and desire, give it a shot...you may be a 1 percenter! I have a degree in Engineering materials and have been welding since I was 12. I am proficient in MIG, TIG, ARC, Gas, Soldering, Brazing...if it can be done with metal I have done it. I personally would not waste time on a modified, too thin, casting...unless it is a super rare, unobtanium.

I would epoxy it if you have to use it.
 
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