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spiff

3D printed sr20 cas pedestal for the l/z engines

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spiff    0

I have a Z20E engine in my 720 pickup that's been turbocharged and ecu has been swapped to a megasquirt based ecu. It's running fuel only for now but for ignition I'm gonna be running coil on plug triggered by a SR20 CAS with a diyautotune triggerwheel. Inspired by the Japanese running the rb efi stuff on the l6 engines I designed a similar pedestal to swap the distributor for a cas and had a guy 3d print a prototype so when I'm back from vacation I'm gonna swap it into my running engine and try it out.

Photobucket is being a bitch so here's a link to a Google photo album

https://photos.app.goo.gl/E8OL4PZljwr0dqqp1

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jacky4566    1

Neat! Ya i would also ask what material. PLA does not have the same heat tolerance as ABS. In a covered environment you shouldn't need to worry about UV too much so thats good.

 

Also, be sure to check out mu writeup for the Jeep CAS sensor if anyone else wants a CAS.

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spiff    0

What are filets? I'm not experienced with 3d printing or even designing stuff like this, this is the first one I did.

I found a guy in my hometown through 3dhubs.com who printed it for me, this one I think melts at like 100 degrees Celsius, which isn't a lot considering the temperatures I measured on the timing cover and flange and distributor where in the 65-75 range with the engine idling at about 17 degrees ambient temperature. I'm thinking if you suddenly get some hot sunny weather like today with temps at 25-30 it's gonna get real hot under the hood.

 

He could order some plastic that had a melting point of 120 degrees c but I'm still not sure if that's enough what do you think?

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Filets are a radiused curve usually found on corners. So instead of your part meeting at 90* they would meet the corners gradually. It helps to add structure in parts, in 3D printing it helps prevent separation from objects since it forces your cutting program to make that area more top layers.

 

If this is a prototype for something you are having machined out of billet then no real worries as it is one piece. If it is a prototype for something that will be made out of several pieces, once again no worries as you would most likely be welding the pieces which in and of themselves would act like fillets. If you are printing then fillets will be your friend to help support shapes.

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spiff    0

Thanks, I found this article which also explained it and had a few other tips as well http://support.3dverkstan.se/article/38-designing-for-3d-printing

 

Of course billet would be pimp as f... but in the end i have to consider the cost of this and having something printed may be cheaper and just as good for the work intended. With sintered plastics, fiber reinforced and you could even have it printed in metal (but that's probably insanely expensive :-P)

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spiff    0

The oil pump shaft doesn't even reach up to the spacer, from the face of the flange down to the shaft the distance is 65mm, if you look at this picture( https://photos.app.goo.gl/EbhlMDl34KjKTMJX2) you can see the end of the cas axle where it slots in to the oil pump shaft just like the standard distributor does. And the cas axle is supported internally like the distributor is too.

I don't understand why you would want a bearing in the spacer?

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Those tips were very good. 

 

My concern would be the heat involved. 

 

I did see this thing on cold casting. Basically you print the part, then you make a mold using silicone, then you cast the part by using iron added to resin or JB weld. Fairly low buck compared to say a sintered print. Although the sintered print would be much more direct.

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spiff    0

Those tips were very good. 

 

My concern would be the heat involved. 

 

I did see this thing on cold casting. Basically you print the part, then you make a mold using silicone, then you cast the part by using iron added to resin or JB weld. Fairly low buck compared to say a sintered print. Although the sintered print would be much more direct.

 

Smart, are we talking iron particles or how big wold the iron added be?

 

My main concern also is heat, hopefully there will still be some sunny days left when I get back from vacation so I can get some more temperature readings. 

I see 3dhubs.com is also offering cnc services now so just for the heck of it I've sent a price quote for this part in 6061 aluminium. Less costly alternatives are ABS, Nylon and polycarbonate.

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The video I watched, the guy's goal was to impart rusting into his final piece so he just used iron powder that is commercially available to I think something like fiberglass resin.

 

Gun guys do something similar or you could just go out and buy devcon steel putty if I remember the name correctly which is a steel imbedded resin.

 

I did not not know 3d hubs offered CNC, that is pretty neat. I had some parts quoted, basically anything that can safely stand up to engine bay temps are going to be quite spendy. Remember that the radiator is going to be pumping air through a matrix heated to near boiling, not to mention the engine especially with the exhaust on the same side is going to be hot to start with. 

 

Overall it is a pretty simple shape. I don't know how the machine shops in Norway would work, but you could take some pieces to a machine shop or engine shop here and they could build it for you for a fairly reasonable cost if you supplied the right diameter material.

 

Then again this could all be overtly cautious. I honestly haven't even thought of trying to have anything made for inside the engine bay, maybe one of those materials would be happy. I mean there are plenty of plastics in there to start with.

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spiff    0

Here's an interesting story about the use of plastics in engine applications: http://www.assemblymag.com/articles/86440-plastics-under-the-hood
Seems Nylon might be the way to go for something like this. 

 

I got quoted this from 3dhubs:

 

Hi Tom,


Thank you for reaching out to 3D Hubs! I have taken a look at your model and would love to help.
 
The price for one unit in Aluminium will be around $550 USD with a 2-3 week lead time. Would this be within your budget?
 
I look forward to hearing fro you.
 

 

So yeah, expensive. I paid something of the equivalent of 120usd locally to have some bolt spacers for the 12mm diff center made up, so factor in the material needed for something like this and I guess it's just as expensive if not more here.

 

The family hauler is 2015 Peugeot 308 station wagon and it sure does have alot of plastic underneat the hood, and I also have a Z32 and if plastic can survive the scorching heat underneath that engine bay i'm sure it can survive the relatively drafty datsun engine bay but I need to find out the right material to use, I think that's the most vital clue.

Exiting stuff this, I've already started thinking about other uses for 3d printing like cold air intake ducts, intercooler ducting and stuff like that

Overall it is a pretty simple shape. I don't know how the machine shops in Norway would work, but you could take some pieces to a machine shop or engine shop here and they could build it for you for a fairly reasonable cost if you supplied the right diameter material.

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ZHoob2004    1

A lot of plastics under the modern car's hood are ABS, but it should be noted that ABS for 3D printing is formulated to soften at lower than normal temperatures, and is probably right on the edge of what would be tolerable in this application.

 

3D printed ABS should tolerate up to ~105c, which I think is a little low, but maybe passable for something in contact with the engine block. At the same time, it's on a corner of the block without a lot of material to move heat to it, so it might work as is. One workaround here is to use a spacer or gasket (distributor gasket?) to keep the heat from moving too readily to the adapter. I believe a higher infill percentage can also help with the strength in heat.

 

Nylon should work great in this application, with a melt temp typically higher than 200c (and no glass transition, so it doesn't get soft before then), but nylon sucks to print, so it's harder to find someone to make it for you. (requires all metal hot end, heated bed, saint-like patience)

 

 

If I get a chance this weekend I might print out a rough analog in PLA, ABS, and PETG and zip-tie them to my distributor and see if they melt. I can stuff a few under the hood of my honda as well and see how they fare. I've been meaning to try out 3d printed engine parts for a while, just haven't had a realistic enough application.

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spiff    0

I ordered a print in nylon, no hubs here in Norway but there where a couple in Sweden and Denmark, so I'm gonna have to wait a little bit longer on shipping but I'm on vacation anyway so...

 

Like I said earlier the guy I spoke to locally could order some plastic with a 120c melting point but I think that might be to close for comfort in this application. For intake ducting or something like that I'm sure it's OK

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HowlerMonkey    12
Posted (edited)

The oil pump shaft doesn't even reach up to the spacer, from the face of the flange down to the shaft the distance is 65mm, if you look at this picture( https://photos.app.goo.gl/EbhlMDl34KjKTMJX2) you can see the end of the cas axle where it slots in to the oil pump shaft just like the standard distributor does. And the cas axle is supported internally like the distributor is too.

I don't understand why you would want a bearing in the spacer?

 

You don't want the benefit of knowledge of someone who has already been there?

 

Isn't the CAS supported by a single bearing while the distributors have both a lower and upper bushing?

 

I'm just saying you might get more movement than is optimal which will prematurely wear parts.

Edited by HowlerMonkey

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spiff    0

You don't want the benefit of knowledge of someone who has already been there?

 

Isn't the CAS supported by a single bearing while the distributors have both a lower and upper bushing?

 

I'm just saying you might get more movement than is optimal which will prematurely wear parts.

Think I might have misunderstood what you initially meant. Good point, no I'm not sure how many bearings they have.

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