Cooling System Mods

[vex]

Originally Posted by Barry Bordes

To minimize dissimilar metal corrosion we should stick with aluminum.

Barry

That's what I was curious about.

[classicauto]

Doing some housing mods for a current rebuild. Just setting up a bit to do the common jacket mod.

I was thinking about the fin idea......whats the thoughts on basically standing some AL sheets in the paths around the plugs? I'm thinking if they're sized properly the sandwiching of the engine oculd hold them in.....? Not entirely sure though, I certainly don't want the twisting around and clogging up a vein.

[Barry Bordes]

My best guess would be to oven braze two aluminum fins into slots cut into the main existing fin. Radiator type solder may work.
Barry

[Cp1]

Originally Posted by Herblenny

Very Interesting Barry! I would love to see the results of this mod. Maybe we could get one of the CNC guys to program this in and mass cut the housing... I also like the idea of parallel groves vs. the perpendicular grooves I've seen before.

Haha i would love to do this! i have already written a few programs for milling out rotors and some other things but if anyone wants to donate a set of useable housings i would be willing to program and machine them.

I dont like the parallel grooves. by observation, coolant flow is horizontal and those grooves seem like a great place to trap air. which would be counter productive to cooling. i would much rather see the parallel grooving.

[Barry Bordes]

Originally Posted by Cp1

Haha i would love to do this! i have already written a few programs for milling out rotors and some other things but if anyone wants to donate a set of useable housings i would be willing to program and machine them.

Cp1, how would you propose to fuse the new fins in? Could a piece of aluminum square tubing be used? (harder to machine two grooves but a lot more surface area!)
Barry

[Phoenix7]

can't wait to see the results fellas.

[nissanconvert]

subscribed

[Cp1]

Originally Posted by Barry Bordes

Cp1, how would you propose to fuse the new fins in? Could a piece of aluminum square tubing be used? (harder to machine two grooves but a lot more surface area!)
Barry

Sorry for the delay forgot which section this discussion was in and couldnt find it. but to answer your question i would just mill straight down the width of the housing, so longitudinally front to back if you would were looking at the motor built and in your car. i wouldnt add metal to the housing just take some away in logical places. ive been busy working on this for a little while so i should have something to show soon.

This weekend im going to the wrecker and ill see if i can grab some garbaged ones to use as an example.

[classicauto]

Attached a pic of one of the housings I did for my recent (and first entirely solo) rebuild.

I just did the common jacket mod, nothing super special. The only other thing I did thats neat is welded up the EGR holes in the exhaust sleeves and groudn them smooth. Take a good look at a housing next time you get the chance and take note of all the cavities that would be filled with (at WOT +1600F) HOT exhaust gas and soaking into the coolant as a result.

Don't know how effective that mod will be, but I'm giving it a shot nonetheless.

On the rebuild I'll do on the keg I'm swapping this one for, I plan to do similar jacket grooves (done with a dremel engraver bit on the drill press, nothing too special...) but with my newly found thin and LONG end mill I will add a piece of 1/8" AL to either side of the plug bore on a diagonal. I'll be cutting out a piece from center of the "divider/support" between the dowel bores and then notching the inside and outside edges to provide support for the piece. It will be a minor interferance fit and the sandwiching of the engine will also prevent it from uprooting afterwards.

Keep the discussion/thoughts going

[Barry Bordes]

Originally Posted by classicauto

On the rebuild I'll do on the keg I'm swapping this one for, I plan to do similar jacket grooves (done with a dremel engraver bit on the drill press, nothing too special...) but with my newly found thin and LONG end mill I will add a piece of 1/8" AL to either side of the plug bore on a diagonal. I'll be cutting out a piece from center of the "divider/support" between the dowel bores and then notching the inside and outside edges to provide support for the piece. It will be a minor interferance fit and the sandwiching of the engine will also prevent it from uprooting afterwards.

Keep the discussion/thoughts going

Sounds good. Can't wait to see a picture.

I wonder if you could fuse the 1/8" AL to the "divider/support" for better heat transfer?

Barry

[howard coleman]

congrats on an excellent thread. i see so many housings w plug hole cracks or carbon evidence of distortion at the plughole...

i really like the longitudinal (Cp1) grooves to add surface area. i also like the idea of welding the sleeveholes closed to help the coolant.

excuse me but i have got to go as i have some welding to do...

this thread is definitely heading in an important direction.

hc

[Barry Bordes]

Originally Posted by howard coleman

congrats on an excellent thread. i see so many housings w plug hole cracks or carbon evidence of distortion at the plughole...

hc

Glad to see you over here Howard. We can use your experience and expertise.

Any other ideas on cooling the sparkplug boss area?

Barry

[classicauto]

Originally Posted by Barry Bordes

Sounds good. Can't wait to see a picture.

I wonder if you could fuse the 1/8" AL to the "divider/support" for better heat transfer?

Barry

Didn't think about fusing them barry, but I suppose a tack on each corner wouldn't hurt.....just don't want to warp anything.

I'd imagine though, that a press/interferance fit would still have heat transfer through the contacting areas - but correct me if I'm wrong.


__________________________________________________ ______________
I'm getting ready to set this up here though.........and just wanted to pose the question to you guys on whether or not you think the AL used for the housings is anything super special? (in the areas we're talking about adding to)

Reason being, is it was brought up in a discusssion I had recently that some of the sheet AL I have around the shop, may expand at a higher rate then a cast aluminum part.......if this is the case, it would risky to do what I'm proposing if the piece expands too far and creates more problems then it fixes. If it does pose a problem - what grade of AL should I be looking to use?

Thoughts?

[vex]

Originally Posted by classicauto

Didn't think about fusing them barry, but I suppose a tack on each corner wouldn't hurt.....just don't want to warp anything.

I'd imagine though, that a press/interferance fit would still have heat transfer through the contacting areas - but correct me if I'm wrong.


__________________________________________________ ______________
I'm getting ready to set this up here though.........and just wanted to pose the question to you guys on whether or not you think the AL used for the housings is anything super special? (in the areas we're talking about adding to)

Reason being, is it was brought up in a discusssion I had recently that some of the sheet AL I have around the shop, may expand at a higher rate then a cast aluminum part.......if this is the case, it would risky to do what I'm proposing if the piece expands too far and creates more problems then it fixes. If it does pose a problem - what grade of AL should I be looking to use?

Thoughts?

You'd have to look at the metallurgy book to get the specifics of expansion rates for the cast and cold formed aluminum. I don't think it's anything significantly special as they are cast, and the different aluminum alloys would require more time and facilities than a mass produced cast would.

Also the difference in temperatures isn't going to significantly deform the material to cause interference/failure of the housing.

Using this list from Mechanics of Materials (5th Edition) we have:

Aluminum: Alloy 1100-H14 (99% Al)
Coefficient of Thermal Expansion (10^-6/F):13.1
" " " " (10^-6/C):23.6
Aluminum: Alloy 2014-T6
Coefficient of Thermal Expansion (10^-6/F):12.8
" " " " (10^-6/C):23.0

Aluminum: Alloy 2024-T4
Coefficient of Thermal Expansion (10^-6/F):12.9
" " " " (10^-6/C):23.2

Aluminum: Alloy 5456-H116
Coefficient of Thermal Expansion (10^-6/F):13.3
" " " " (10^-6/C):23.9

Others have similar Coefficients as the ones listed, so we can use it from there.

We'd need to know specifics about the dimensions of the piece being inserted, but looking at the formula of Alpha x DeltaT we would get (say for reference a Delta T= 167F(operating temperature)-75F(room temperature of the measured piece)=92F)
Biggest heat Coefficient of Aluminum Alloy is 5456-H116=13.3 x 10^-6 /F
Plug and chug we get EpsilonT=.001224
Multiple that number by the length of the piece (lets say .5 in) we have .000612 in increase in overall length. Now if we assume that the Housing as the just as high Coefficient and look at the piece directly across the O-ring (about 1/8 in estimate for example) we'd have another increase of .000153 in.
That means you'll have no stress or problems with thermal expansion unless you have the two edges of the piece within .000765 in of each other.

This is just a rough math crunch to work out the numbers and give you an idea of how little the thermal expansion is going to run. Since we don't normally see a DeltaT of magnitudes of order higher than this example I think we'd have the same/similar numbers for the actual piece.

[Barry Bordes]

Here is a product that may work for installing fins on sparkplug ribs.

Controlled Atmosphere Brazing was developed by Alcan, under their trade name NOCOLOK®, as a non-corrosive flux brazing process and is now established as the accepted process for brazing of aluminum heat exchangers.

Barry