Jb weld

[Little Mouse]

Will jb weld steel stick epoxy last in an iron heads intake ports for a high strung mostly street engine ? Was watching vizard use an epoxy to do a floor in a bbc aluminum head he drilled 4 good sized holes through the the floor and beveled it at the bottom, claimed this is what was needed to hold it.

[nhrastocker]

Will jb weld steel stick epoxy last in an iron heads intake ports for a high strung mostly street engine ? Was watching vizard use an epoxy to do a floor in a bbc aluminum head he drilled 4 good sized holes through the the floor and beveled it at the bottom, claimed this is what was needed to hold it.

The preferred epoxy is A-788 Splash Zone.

[mag2555]

I have used Moroso A/B type in a iron head to reform almost the complete floor from the mid point of the short turn all the way back to the flange.

I ruffed the floor up a good amount with a Aluminum Burr and then epoxy stayed in place fine for a full season of weekend drag races.

I have used JB to repair a whole 1/2” pipe temp sender fitting on a aluminum intake and that held up for years, so I can’t see why the far lower expansion and contraction rate of using it on a iron head would be any issue.

[tjs44]

The advantage of Splashzone is you mix the 2 parts wet.I usually get a 5 gal bucket of water and do a golfball size of the 2 equal parts.I put my hand under water and work it until it becomes the green color.Remember it is a marine epoxy made to setup underwater.It is very EZ to form and smooth with wet hands.FWIW,Tom

[n2omike]

I used JB weld to repair a cracked intake port in a 289 head. Cleaned/Sanded the crack really well, then drilled a hole between the valve springs to get to the crack from the other side. Cleaned the crack through that hole, and used JB on the water side of the crack as well as the inside of the port. Threaded the hole and installed a pipe plug. Ran the heads as a part time daily driver for around 10 years after that! I believe fixing the crack from the water side where the pressure is coming from is key for a long lasting repair.

One major benefit to JB, is there is no peeling after a while like you will get with Splash Zone. Once it is there, it's THERE. Have not found another epoxy that holds up to gasoline, etc better than JB

I am NOT talking about JB STICK like mentioned by the OP, but the original JB Weld.

[Little Mouse]

Just looking at jb weld apears to be two types one is the more regular type used then there is the marine type that's recomened for aluminum and under water conditions.

[Little Mouse]

It seems like a combination of raising the roof and the floor of the intake port on a sbc should be a good thing. Still Hung up on using either a 200 or 180 dart iron head with the 49 cc chamber.

[swampbuggy]

What will be the cubic inches and estimated RPM little Mouse ?

[pcnsd]

I've posted this before here. You may or may not find it useful. I rejected the use the JB Weld steel stick because it has much lower useful properties for the price. I typically use original JB weld, but it is a self leveling pastes and can have it own application issues as a result. I'll mention that cleanliness and general surface preparation are as important as the epoxy choice. Slashzone A-788 is very common in port work, but most of it's properties are unknown other than it is mostly...good enough.

Epoxy Compare.xls

[n2omike]

As far as exposure to gasoline... Cannot beat JB Weld. The before mentioned port stood up for 10+ years. I've also repaired gas tanks that stood up for just as long. If using it on a port, may be a good ides to give it something to stick to by running screws up through the bottom of the port floor. And like paint... preparation, preparation, preparation. Not sure how thick you're supposed to make it, cure time for thick applications... or even if there is a max recommended thickness. Good Luck

[Little Mouse]

What will be the cubic inches and estimated RPM little Mouse ?

it should end up at 337 I'm highly consideing starting out with there 180 head. Raising the roof on the intake port, raising the floor. Then wallace calculator says I need a minimum 2.46 at the rpm I want to run so i may well need to open the push rod pinch width some. I plan to use the regular jb weld you mix together by hand to raise the floor. Was also thinking I may cut a few side ways groves in the floor before I put in the jb weld to help it get some more grip on the iron head.

[Old School]

As far as exposure to gasoline... Cannot beat JB Weld. The before mentioned port stood up for 10+ years. I've also repaired gas tanks that stood up for just as long. If using it on a port, may be a good ides to give it something to stick to by running screws up through the bottom of the port floor. And like paint... preparation, preparation, preparation. Not sure how thick you're supposed to make it, cure time for thick applications... or even if there is a max recommended thickness. Good Luck

How will the JB weld do with methanol? Unless coated with a hard epoxy splash zone will erode quickly with methanol. Just wondering if JB weld will hold up longer. I know coating it will also help.

[1980RS]

Will jb weld steel stick epoxy last in an iron heads intake ports for a high strung mostly street engine ? Was watching vizard use an epoxy to do a floor in a bbc aluminum head he drilled 4 good sized holes through the the floor and beveled it at the bottom, claimed this is what was needed to hold it.

The preferred epoxy is A-788 Splash Zone.

This is the stuff to use otherwise I use A/B epoxy also with good results, that stuff stays where you put it. Kind of like using clay in a head.

[swampbuggy]

LittleMouse, have you figured out what your Intake Port Airspeed will be when it is making the turn to get to the Valve ? Mark H.

[Little Mouse]

LittleMouse, have you figured out what your Intake Port Airspeed will be when it is making the turn to get to the Valve ? Mark H.

Probably will have no clue. I'm assuming three things, raising both the floor and roof will do a better job of getting air more around the curcumfrence of the vavle, the raising of the floor would speed up the velocity, then making the cross section bigger at the pushrod pinch would slow velocity down.