How ironic, I bought these rods to do intake manifolds and possibly heads. I found that they didn't work at all on cast aluminum manifolds and haven't had the nerve to try them on heads.

I will say that if you do any sort of welding on your head, it must be thermally stress relieved. No, you can't do this in your kitchen oven. Find a reputable head shop and just have them add the weld where you want it and then stress relieve it for you. When you get it back, you can shape it the way you want and it'll be safe to bolt on.

Mike

 

Thanks Mike, guess I'll give those a miss. Hmmm, no kitchen oven... I worked at an aluminum extrusion place way back when, we stuck the channel sections in a huge oven to "age" them, 600F for 8 hours I think it was, not totally sure, is that the kind of thing we're talking about?

 

There is no epoxy that will stand up in exhaust ports for very long.

 

There is no epoxy that will stand up in exhaust ports for very long.

Yes, there is one.

 

Yes, there is one.

Then why :bash: don't you :bash: tell us :bash: what it is? :bash: .......





... oops, I mean pretty please with sugar on top would you be so kind as to educate us unworthy mortals as to the identity of this product?

 

The highest rated epoxy is about 1300 degrees. But if there is something, feel free to share.

 

The highest rated epoxy is about 1300 degrees. But if there is something, feel free to share.

I forgot to mention the only problem is you gotta travel into the future to get it!

 

Great, bring me back a spare flux capacitor while you're there. :rolleyes2

I was wondering if you could use the highest temp epoxy you could find, and then skinned it with 1/8th of muffler cement as a thermal barrier...... yeah, figure that's one for your last race of the season, not your daily driver.

 

i Know Stephane used JB weld in the exhasut port that broke into the cooling passage, it worked for 2 races, then again hes only running 1200 or so EGTs. for 8 seconds.

 

Hmmmmm it won't have to hold (much) pressure when used for building up, only has to withstand high surface temps, if it contacts the gases, metal it's sticking to is going to be nowhere near EGTs apart from maybe a thin line near the edge where you feather it out... so, if there's real (as opposed to makeshift like muffler cement) thermal barrier coatings that will stick to the epoxy, then if you coat the ports with it, it would probably hold...maybe...

 

Okay, I quit being subtle and picked up Google and used it a blunt instrument to beat the internet into submission, and before it passed out for the third time, it whispered to me this url....
http://www.cotronics.com/vo/cotr/rm_putties.htm
Durabond™ 7032 Stainless Putty, all hail the magic goop! Now to find out where to get it in Canada ...

 

There's another one, Mondello Pyro putty, still researching it.

 

"Rosebud..." lmao!

I'm gonna move to Canada someday, mark my words!

Can you explain to noobs like me what filling in the exhaust ports with putty will do for it?

 

There is no putty rated for the extreme temps in the exhaust ports. Turbos can run in the 1600 degree range, and some in the high 1900s. You use epoxy to shape the ports to correct bad spots and increase flow. Mondelle says 1400 which is very good and would be excellent to keep with you for a short term quick fix... I might have to get me some for the tool box.

The downside if it breaks loose due to high heat....I dont wanna go there.

 

It's to make the hole smaller so it flows better

Yeah, really!

Many heads take too sharp a turn coming out the exhaust valve, if you stick a wedge in there raising the floor, you can curve it round more gracefully and boost flow amazingly.

Found out the pyro-putty is actually by these guys
http://www.aremco.com/a15.html

Guess I could try this instead...
http://mpgheads.com/PortPlate/PortPlateDetail.htm

I thought about doing it like that, but it seemed a bit kludgy but if it can be got working for those engines...

Drag racing guys are also talking about something called the "D-Port exhaust plate" which seems to be something similar. Apparently there's a patent description for that somewhere, circa 1980 grant date.

Drag racers also mentioning covering high temp epoxies and putties with "silicone" or "red silicone" to protect them, though we're talking blowers, bottles and top fuel here I think.

 

Use playdough.

Idle at 450 degrees though to cure.

 

The "propper" way to do it is to preheat the head and weld up the ports to desired dimensions. Then reheattreat the head(stress relief), then deck the surfaces and line bore the cam journals.

Another way to do it is to cast wedges of the floor in the desired shape(obviously requiring the use of a donor head and epxoy on a flow bech to get this shape). Once the wedges are cast you can attatch them to the floor using a combination of epoxy and set screws either through the top of the cast, or the bottom of the head.

The last way to do it that *I* know of is the tongue thing that was listed above. I have a freind of mine that used that method on old Hemi engines that he used to race where modification ot the head was illegal in the class. He said it made a HUGE difference. If you made them out of high quality stainless I suppose it would work pretty well. I wold just be affraid of them trying to "curl" under the high heat and pressure...

 

Thanks Reaper1

Mmmkay, shade tree method....

Melt up a load of wax, plug the ports with it, carve 'em out, try something a little different in all 4, the winner is the one that drains a 5 gallon bucket of water the fastest. Slip the wax mold of the winner out, cast it in plaster of paris, make 4 the same in wax. (Maybe even put those back in all 4 ports and "tune them" and recast the winner of those if you've got the patience) Set up a sand box, put the wax casts in, set up for lost wax casting. (Put in inlet sprues..) Mix up a BIG batch of thermite (There's always a solution that involves thermite if you think hard enough ) set it off, enjoy the fireworks, and scrape the slag and pour it in your sandbox molds... Let 'em cool, clean them up, bolt them in place...

Hmmm, I'm thinking the plates would be a whole lot less hassle. Need to make me a dolly or jig or something to get a nice shape to the tongues though I think, even though I've heard that just flat wedge shapes get you an improvement on some heads.

This motor will be N/A so not too worried about melting or disintegrating plates. If it were a turbo, I guess I'd do the casting, or pay $$$$$ for a head.

 

I'd be interetsed to see if one of our head porters or suppliers could come up with a tongue plate to go along with a modded head that could yeild good improvements. I might go for that!

 

What, 175cfm on a stock valve not good enough

 

LOL...well...if ya can get more!! :thumb:

My big thing is that I think a slightly modded head(say a stage 2 type for argument's sake) could bennefit from something like that if it was designed right. I could be wrong, but I don't know anybody that's actually tried it to find out. It could be a good compromise between spending $1200-1500 on a race head or bolting on a $250 peice of stainless that yeilds say 70% of the gains...and could possibly yeild gains on the fully modded head as well.

You know how it goes..you get the taste of power and then you want more! The company makes money on the part, they gain a customer, the customer is happy, and most likely will return to spend even more money! It's a win-win here IMHO.

I'd like to hear thoughts on something like that...seriously. I've always thought that the floor would bennefit from being raised and we all know that welding them up is expensive and time consuming. If this can do the job well, then I'd like to know if it will work...

 

I'll take a head and put putty in it to mimic that part your talking about and flow before and after and tell you what it does., that will tell you alot for .05 cents of clay.

 

Thanks!!! I appreciate it! :thumb:

 

The exhaust ports on our heads are extremely restrictive for what we expect from them. To merely raise the floor will make them even more restrictive. If a raised floor were incorporated into an enlarged port, where flow is shifted from one area of the port to another, then I might see it as beneficial. Just putting the plate in there on a stock port would be counter productive (in my opinion).

Let's get somebody to try it and make a fool out of me.

Mike

 

Just went and put puddy in one. If you have it .310 thick at the head/manifold opening and run it straight back to the top of the hump you gain 7.4cfm (2.25%). So the expense of welding and shaping might be cost prohibitive for most. This is on a ported head with no valve so I had alot of flow.