[joes455]

Okay so I broke through short turn radius I'm able to get to backside of hole through water jacket I've sandblasted it, this will allow me to use epoxy on both sides of repair.Would this hold up with very low concentration of antifreeze?

[Mike Davis]

What type of head?
One set of my E-Heads has epoxy in them with no issue street or track.
I have used Splash Zone and Moroso A/B with no problems.

[joes455]

Thanks Mike,6x-4

[taff2]

My previous iron race heads were fine with JB epoxy as long as water temp didn't go over 200f.

[Scott Stoneburg]

I have a set of iron D-ports that have had A-B epoxy in the intake ports for 20 years. No issues. I have heard good things about Splash Zone epoxy too.

[joes455]

Scott were the heads repair epoxy under pressure with water / antifreeze?

[Scott Stoneburg]

Originally Posted by joes455

Scott were the heads repair epoxy under pressure with water / antifreeze?

No, mine were just in the intake ports to raise the port roof and floor up. Filled the floor aprox 7/16" and the roof. The head porter broke through the roof into the area under the valve cover.

[joes455]

So scott your post is totally useless for me.re read op.

[Mike Davis]

Joe, one set of mine goes into water. After the epoxy I used Moroso Ceramic seal in the engine. No leaks or issues after 6+ years of racing and some street driving. I only use water with Royal Purple, Purple Ice so cannot confirm about the antifreeze. I had a set of 7F6 heads years ago (in the 90's) on a 76 TA with a 455 that were full of A/B epoxy from breaking through to water. Same deal, used Moroso Ceramic Seal. These were ran on a 455 with a 250HP N2O shot that was street raced. No issues after about 3 very hard years and a few N2O backfires.

[Scott Stoneburg]

Ok....just saying that the AB holds up to heat, oil and fuel.

[steve25]

I have never had to grind thru the short turn on a 6X head to even get them to flow 280 cfm, so the fact that you ground thru the floor tells me that your port shape is way the Hell off and you will likely be very unhappy with the motors performance once you do fix the head and get the motor running!

What increased size valve bowl throat are working with?

When you have the port shape right the only place I have ever broke thru when max porting a 6X head is on the roof between the Intake flange and the rocker stud, and this was due to the factory cast in numbers and such.

If it where me and I wanted to fix this hole ( and also reshape the short turns as they need to be) I would spend the money to get a Tub of Balzona 1111 epoxy.

Note that this 2 part epoxy is mixed by weight, not by volume, but the amount you get it a lot so you can play around with it first and get the feel for how much volume is right as opposed to going by weight.

You can cure this expoxy in your oven and it will be even more durable then it already is!

As a added safety I would also get a bottle of Goodson supply SEAL ALL to add into the head and then have a shop that can pressure test test heads pressurize the head to spread it around and pack it in so to speak, and then then take it home and once again bake it in your oven.

This sealer will coat the inside of the head and fill in any pin holes that you may have in the epoxy or else where from your porting work.

If you do not reshape the floor I hope you will get a couple of your Intake ports flow tested to see what going on that's good or bad!

When all these items are bought and the work done your looking at like a 400 buck expense If you want to throw in some flow testing.

[joes455]

Thanks Steve I got greedy and cut through apex of the short turn radius.Had issue with port stall ,and when laying port back it got better

[steve25]

There is another way that’ needs to be implemented in conjunction with laying back the short turn to slow down the too high port velocity that takes place over the short turn so you go thru the casting .

Below your bottom cut I f you make a Straight section on the short turn this will not accelerate the flow, but help to slow it down.

This straight section needs to be parallel with the 14 degree valve inclination angle of the head and be .100” to .150”tall and that should get the job done for you.

Allow me to ask again, what throat size are you up to?

With that head and a stock 30 degree seat once you get up to like 230 cfm @28” with only a 1.67” throat then without the right width and shape of the short turn the head will start to display turbulence issues like that!

[Jay S]

I use the epoxy the others mentioned, that last one Steve mentioned sounds interesting, have not tried it. I am not afraid of epoxy, but fwiw, for cast iron heads on street engines I use an arc welding rod called Muggy 77. For areas on the exhaust where the carbon is burnt out I use the 72 rod and use 77 for the surface finish. The 77’s stretching and crack resistant properties are impressive.

https://www.muggyweld.com/product/77...n-welding-rod/

Photo is of an exhaust port of a 6x-4 that I welded. I raised the center ports nearly a 1/2” by welding a 1/2” thick spacer at the center head bolt, and did a lot of work in the bowl. Went though below where the sharpie marks are. Could stick 2-3 fingers into the hole. I was about 3/4 done welding when I shot the picture. Takes some grinding and welding to pull the impurities out. I can look to see if I have the finished photo, but when my machinist and I were looking we had a hard time picking out which ports had the welding, pretty please with how it turned out.

The other shot is a hole from some bad core shift. I welded it to. It was a tiny hole to start out, but I found a large area was thin so I enlarged the hole until I found some thicker metal, then filled it in. When I am done I can run a bead anywhere in the area and it won’t burn through, sometimes I will weld a new piece of cast iron in from a junk head. The rod pulls the impurities to the surface. I use to braze spots like that on cast iron, and on aluminum we tig weld. We have one head for a super stock engine we brazed the short turn and blended it with epoxy. If you have some arc welding skills the 77 is a better repair IMO. It takes a little patients, but if your grinding on a Pontiac head you probably already have more patients than a normal person, a lot of work.

I went with 2.125” sbc valves with 45* intakes on the last 6x-4 I did. I was a little shocked how much bigger the bowl ended up being with the bigger valves and the 45 seats. Made the short side easier to work with

[lust4speed]

Getting back to the epoxy question, I built up areas in a timing cover that had pitting and hadn't failed yet but needed material. Applied JB Weld on a fully prepped surface and put the cover back into service on a daily driver with a mix of antifreeze. Was back in the engine five years later for a cam swap and was surprised that the epoxy had softened and had started pulling away from the cover around the edges. No failure but definitely didn't like what we found.

[steve25]

I don't nessaserally mean to relate cost with quality, but a tub of Balzona is over 200 dollars
And is in quite a different league then JB weld and others, plus its rated to over 400 degrees.

You folks who are interested should go to there site and check out its spec's.

I have seen the two type welding stick process on You tube fixing a Exh Manifold and if I was a welder or new someone who could do that for me then I would not hesitate to get that short turn closed back up that way!

Short turn height wise if you want to take things to the other extream then here's a picture of a Ford 2bbl Cleavlend head that I ported a few years ago.

On the Intake side it flows stock thru it's 2.05" valve 206 cfm.

I stuffed in 2.11" Pontiac Intake valves in the latter half of porting it and going for big flow numbers but I could not get them even with the bigger flow areas I had ground in, I found I could not top 250 cfm.

Once I got the balls to massively rearc the short turn I was rewarded with 286 cfm, this level of flow is just about as good as what the much larger 4 bbl Boss heads flow, but my mid lift flow numbers blew away the 4 bbl Boss C heads numbers!

Look at the difference in this picture between the stock left hand cylinders short turn and the right hand one, and yes I was sure risking breaking thru , lol!

Just to piss the Ford guys off even more I fitted the Exh side with custom 1.77" Pontiac valves, lol!

[Jay S]

That Ford Head looks awesome!

I will definitely try that Balzona epoxy, it looks better to me than the JB and Moroso AB. The muggy 77 rod is not cheap, usually about $80 to fix a hole like I posted, it is the best cast iron rod I have ever used though. I think it is as good or better than cast filler rods with the tig or torch. Sometimes I will preheat the head in a bbq grill. To do a proper job brazing it takes preheat. I will let the head warm up for 4 hrs and then slowly cool it. Most of the time I have not needed to do much of any preheating with that 77 rod. I have no plans to go back to the iron filler rods or brazing. Watched a video that someone weld up a cylinder with that 77 on the bottom of a block with it. That block was broken out up into the water jacket. I could never come close to making that work with the older nickel rods.

I did find a finished photo of the 6x bowl. I had to look through my pics for the sharpie marks, can’t really see where it was fixed now.

Here is a photo of the short turn on the intake of the 6x-4 with the 2.125” valves.

[Jay S]

If you can epoxy both the water jacket and int port side of the trouble area I would not be worried about the outsides of the epoxy lifting. I would be more concerned about the iron cracking on the chamber side of the fix, heat cycles will likely crack if eventually if it is to thin. Race engine could survive a long time like that with no issues, depends how thin it is.

[neill]

I did exactly what you did trying to gain height in the short turn. I cleaned it up as you did and took it to a friend at a rad shop. He used the torch on the port and fed the rod through the hole into the water jacket. unfortunately I went through on several ports before I caught myself. The heads are on the car running for more than a year. I did use some epoxy but the main repairs were done with solder. When I did get some leakage into #3 cylinder I used AC delco pucks in the cooling system and that fixed it. Do I trust it? I only put the heads on after the fact because I had so much time and money into them that I at least wanted to try them. The result is that the heads have over 3000 miles on them and the car has never performed so well. Good luck!