If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You may have to register
before you can post: click the register link above to proceed. To start viewing messages,
select the forum that you want to visit from the selection below.
Announcement
Collapse
No announcement yet.
*!Build of the year candidate!* Strange PNW Build: E30+Volvo
Vacuum pump. As I understand it, the valvetronic engines don't have manifold vacuum since the valve is the throttle body in normal use, so they need a mechanical pump for vacuum accessories (brakes).
Sent from my iPhone using Tapatalk Pro
How many miles on the engine? It might be good to replace the vacuum pump (Pierberg is about $160) proactively as they eventually leak / wear out. Replacement is pretty well documented here: https://www.youtube.com/watch?v=iD-_H03UyGM
This guy needs a special title. Can we get one of the mods to come up with something special and bestow it to him. Something like "Mechanical Wizard" or "Your 100 years to young to compare yourself to me", "Grease Monkey" just isn't cutting it.
I'm not usually into the concept of monarchy, King would be in order!
Alright, mold making time. First off, with the plug halves, I painted (random paint I had left over from my XC90 build) and clear coated them. Then I applied plenty (hopefully) of mold release wax.
When it comes to the mold itself I try to use polyethylene whenever possible cause of the natural mold release properties.
For secondary mold prep I like to use mold wax. It's a pain to get cause for some reason stateside everyone uses clay. The thing I don't like about clay is getting it out of the mold when that process is done. Another thing that's nice about wax is that it sticks to itself, so cleaning up the unused stuff is just a matter of taking a blob of wax and wiping up the residue. It also self releases and is pretty easy to get out of the mold.
First I'll roll the wax into a snake and press it into the crack.
Then I use these “ball on a stick” tools. I think they're just for sculpting, but they work great to just add radiuses where I want them. Radiuses (even small ones) help with the mold work cause sharp corners can break out when releasing plugs. I did a slightly bigger radius on the actual part and a smaller radius on the part-to-flange joint.
For adding wax to fill a gap or some place I need to keep the corner tight, I use an interior removal tool that I've added some custom edges to (one sharp and one tight radius).
That gets me to here. I need to add some flange locating features for the mold halves, then it's gel coat time.
When I'm making a two part mold, not only do I have bolts to hold the halves together, but I add locating features. These are easiest made out of wax. Basically just squish some wax to the flange and then use a razor blade to cut facets. Size doesn't really matter
Gel coat is next
I let this tack up until it prints when pushed, but doesn't lift on the glove.
The first layer is surface veil. It's the thinnest fiberglass cloth and is just meant to be an intermediate layer before chopped mat. Getting this on as smooth as possible will make for a good mold.
Some composite tips I wish someone had told me earlier on:
-Use good materials, and the right materials. Lay-up or structural resin is meant to stay tacky between layers. Finishing resin has surface curing agents in it so the surface gets hard
-Take your time. The better the mold, the better the final part. Heat is the enemy of a good mold. Too much catalyst, or too many layers at once will create too much heat and deform the mold
-I'm a cheap ass and will wipe out buckets to reuse them, but what I don't skimp on is gloves. I always put on more than one pair at a time. Sometimes more than two pair. Inevitably something will happen mid lay up and you'll need to take resin-ey gloves off. It's much easier to put a pair on over another set, than trying to get them on over damp hands
-Fiberglass mat uses binders that soften with resin. If you're having trouble getting mat to stay down, get some resin on it and wait. If it still won't stay down, rub the area with your fingers and it'll loosen the fibers.
One of the things I'm trying to deal with (it's a personal problem) is not having this engine look “too new” in the vintage body. The reason I painted the block that color and wrinkle black painted the valve cover. My attempt to change the look leads me down some really silly paths. Like making an N52 oil cap vintage-erator. 😛
One of the things I'm trying to deal with (it's a personal problem) is not having this engine look “too new” in the vintage body. The reason I painted the block that color and wrinkle black painted the valve cover. My attempt to change the look leads me down some really silly paths. Like making an N52 oil cap vintage-erator. 😛
That's a tough task, lots of plastic and complicated systems on a new engine.
Looks like you're making some good efforts towards it though.
Comment