Plastic B230F/B230FT Valve Cover Project - Input Wanted

[blockgabe]

You should consider designing it to use press in metal spacers/ unthreaded inserts in the bolt holes to avoid issues with plastic creep. They're pretty commonly used on OEM plastic parts and without them you'll have to tighten the mounting bolts periodically as the plastic deforms under the mounting hardware.

Definitely on the list, thank you.

 

[blockgabe]

And how much blow-by pressure does it hold?

Crankcase pressure really doesn't fluctuate that much (+/- a few percent from atmospheric) but eventually if I finish this project, I'll have some tests done to validate that it's strong enough. Glass fiber reinforced nylon is strong enough to withstand actual turbo boost pressure in an intake manifold at ~4-6mm thickness. The current design is 4.5mm thick. The main concerns are going to be mitigating cracking from vibrations/heat/oil exposure as well as sealing issues due to warping. All issues that are hopefully going to be solvable and worth it due to the weight/space savings as well as the improved feature set. An ideal future for me is when all of the parts for old classic cars have been reverse engineered by the community so we don't have to rely on large aftermarket companies to spoon feed us access to the privilege of owning old shitboxes.

 

[blockgabe]

How hot does the valve cover normally get on a stock redblock?

I haven't measured yet but I'd assume at most 300F. The low end operating range of the low end quality glass reinforced nylon is ~320F. But with high quality nylon and some post processing, that can be as high as 500F.

 

[Cwazywazy]

gf Pa66/nylon would be fine, I think that's what they make oil pans and stuff out of.

 

[culberro]

I haven't measured yet but I'd assume at most 300F. The low end operating range of the low end quality glass reinforced nylon is ~320F. But with high quality nylon and some post processing, that can be as high as 500F.

SLS glass reinforced nylon or MJF should be fine. Might need to epoxy coat the surface so it doesn’t get oil soaked/saturated.

I’ve done plenty of 3d printed development and production parts for intake and cooling systems.

This is a cool project!

 

[blockgabe]

SLS glass reinforced nylon or MJF should be fine. Might need to epoxy coat the surface so it doesn’t get oil soaked/saturated.

I’ve done plenty of 3d printed development and production parts for intake and cooling systems.

This is a cool project!

If you've got experience AND input, I'll take it any day.

 

[culberro]

If you've got experience AND input, I'll take it any day.

You seem to be on the right track.

Steel inserts for bolt holes so the print doesn’t get crushed, as was previously mentioned. Make them a flange style for extra protection.

You will 100% want an epoxy sealer of some sort to be used. SLS is very porous, and is only liquid tight due to the probability of the pores being blocked and not a continuous path after a certain thickness.

 

[cwdodson88]

Also best to water temper nylon SLS. Then throughly dry, we use a large filament drier. Water bath at 205f for 6-12 hours depending on thickness. Force dry at 70c in the drier for 1 hour, then increase to 95c for 4 hours with desiccant packs prior to epoxy seal.

 

[pinguin]

I think for venting, an LS style grommet hole at the back with a baffle might be the way to go. Lots of options for pcv hookups that way. Use a standard valve, or an AN fitting. Also, no risk from directly tightening anything to the plastic.