Epoxy closed deck

[benflynn]

Easy enough

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[benflynn]

No real guidance on the coolant holes so I am going to wing it. I’m not going to drill out the large holes to access the case bolts on the already assembled engine. Will drill them when I inevitably have to go back into the short block.

[benflynn]

Hardest part is drilling the holes.

[SoCoNoHa]

Cool. I've seen this done on BMW engines with great success.
I would assume you just use the head gasket as a rough guide for coolant holes?
What's the setup, ie internals, heads, etc?

[benflynn]

One is just a case, built one is Manley hbeams, CP pistons, stock w25 heads with bc1600 springs, going in 15’ w/35r.

[SoCoNoHa]

"35r" yeeeeee!

[benflynn]

Got to the rest of the blocks that have been to the machine shop already. I’ll drill the water ports once mine has proven the method.

[dScooby]

Was also looking into this. Which epoxy are you using chris boyette or did you source it from somewhere else?

[benflynn]

Epoxy54, guy from email was named Payton. My kit came with 2 cans and 2 bottles, ended up with enough for 3 complete engines. So have some extra blocks ready to not waste any. May of been able to do 4 as I didn’t have enough prepped to use all the first half.

[dScooby]

Originally Posted by benflynn

Epoxy54, guy from email was named Payton. My kit came with 2 cans and 2 bottles, ended up with enough for 3 complete engines. So have some extra blocks ready to not waste any. May of been able to do 4 as I didn’t have enough prepped to use all the first half.

Wow, perfect! I actually do have a couple blocks I can test with. Haha

[Fernandosf2000]

Hello, is there any update to the epoxy closed deck working??

[benflynn]

Should be finishing it this week, I need to order some 2.5i fuel rails and secondary air block offs. It will work fine I’m sure. I was told there are a couple shops doing these just none seems to be talking about it.

[Charlie-III]

Originally Posted by benflynn

No real guidance on the coolant holes so I am going to wing it. I’m not going to drill out the large holes to access the case bolts on the already assembled engine. Will drill them when I inevitably have to go back into the short block.

OK, I'll bite, why?
Are you trying to control coolant flow?
Is this to be additional "top of cylinder" support?
About how thick is the epoxy?
Does the epoxy have a compression rating?

[benflynn]

Epoxy was chosen to match the expansion rate of aluminum. We are probably not going to get the specs of the epoxy cause it’s this guy’s product.

I did it to support the cylinders like any other closed deck. If I was looking to fine control the coolant flow I would do it with a copper head gasket I think.

It’s about .5” to .75” thick.

There is a lot of info on this in the BMW world.

[BlueSTI4Me]

IN before, well.
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Element Tuning
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Project TBag

[cpreissner]

I applaud your pluck. Did you hone after the epoxy cure in (I don't think so because you needed to assemble the case house before pouring the epoxy)? There is very likely shrinkage associated with the curing of the epoxy this means there will be tension in the mass of epoxy which means the cylinders will be distorted.

Or, did you measure the bores after application. That would be telling about the distortion.

There will be some stiffness increase. However that epoxy is likely over a factor of 10 less stiff than aluminum. (Epoxy modulus ~5GPa, aluminum modulus ~70 GPa) It is more on the order of 15 times less stiff than aluminum.

Given the very likely bore distortion and the significantly less stiffness in skeptical those is worth doing.

Curt

[benflynn]

Originally Posted by cpreissner

I applaud your pluck. Did you hone after the epoxy cure in (I don't think so because you needed to assemble the case house before pouring the epoxy)? There is very likely shrinkage associated with the curing of the epoxy this means there will be tension in the mass of epoxy which means the cylinders will be distorted.

Or, did you measure the bores after application. That would be telling about the distortion.

There will be some stiffness increase. However that epoxy is likely over a factor of 10 less stiff than aluminum. (Epoxy modulus ~5GPa, aluminum modulus ~70 GPa) It is more on the order of 15 times less stiff than aluminum.

Given the very likely bore distortion and the significantly less stiffness in skeptical those is worth doing.

Curt

I’m not doing anything new, the process is straight from 1000hp open deck BMWs and Hondas. They have the process down it seems.
I do not believe it distorts the bores, part of the reason to not do the traditional closed deck(and 1000$ difference in price) is you don’t have to go to the next bore.
Any thing different for the subbies we will find out shortly.
I did both an assebled and 2 empty blocks. I did not check any of the bores.

[benflynn]

I don’t think I understand the lees stuff arfument. The epoxy is not facing the same force as the aluminum. The aluminum is not seeing the same force as the iron sleeve. I assume my epoxy supports the stronger alum the same way the aluminum supports the stronger iron. Now I really just took the operational examples as proof of concept.

There are subbie shops doing this I was told by the supplier. They surely have a bit more info for us, maybe they will chime in, maybe they were mentioned above.

I am sure enough this will work I did it to a forged short block and spares. The spares were fresh from machine shop being honed and cleaned up. Those would be the ones to check.

[cpreissner]

I have never used epoxy block filler. However, from talking to machinists who do the work, when used, the bores are honed or bored/honed afterwards. This is because curing of the epoxy will stress the bores and distort them.

In regard to stiffness, the material properties of the epoxy are different than that of aluminum. The parameter that quantifies that is the so-called Young's modulus. Epoxy has a modulus roughly 14.5 times less than aluminum.

This means that if you have a .75" thick epoxy ring, it is going to be less stiff than a .75" (or even a .5") thick aluminum insert.

I am not saying it will not do anything, just that the effect will not be as large as a shrink-fit aluminum insert.

I would for sure check those bores. I can't tell in your pictures if those are stock pistons or forged. The piston-to-wall (PTW) clearance for stock pistons is -.00039" to .00039", meaning even if there was only .0005" change in the bore diameter or roundness, that could be problematic. If they are forged, you might have a little more cushion depending on the PTW.
cheers,
Curt

[benflynn]

I’d put a decent amount of $$ that there are no distortion issues. (Mainly I feel like I recall the process of picking the epoxy was one that would not shrink during curing, not an issue with expansion, also that it has the same thermal expansion properties) And that it is not as strong as a real insert. Also considering the cost and labor I think it is beyond worth it tho I have never had the issues that this should help alleviate. Prob because of e85.i will throw a gauge in these just honed cases and see what’s up.

I feel the only issue is longevity. How long before erosion or heat cycles becomes an issue.

Lucky enough I will beat this engine hard hard hard.

Pretty sure it would of expanded up if anything