Boat anchor or matched case

So, I have been reading and rereading the wiki on porting and case matching. I would like a little more advice. Specifically about the file size people have used to successfully grind and match a case. Or anything else that may help. Any personal experience tips would help. I just feel the more info i get the better.

Re: Boat anchor or matched case

Shit, I forgot to include that I got an E50 with a 65cc metra kit. Thanks in advanced....

Re: Boat anchor or matched case

ask chris paz of the creatures of the loin he is a master of case matching, use a dremil

Re: Boat anchor or matched case

I just did my first case. Its pretty easy and fun. Kind of hard to fuck up really. Just draw it out for yourself before you go at it.

The cylinder is where you can fuck up easily and make a boat anchor.

Re: Boat anchor or matched case

Use a rotary type grinder like the dremel. I like to use 'A'

to cut into aluminum the teeth don't load as much and it cuts a lot faster. Depending on how aggressive I get I can port match a case in as little as 15min with it.

For best results use a gasket to trace the ports onto the case. There is a slight issue with the metra 65 kits, the ports are a bit lopsided on the kits but not on the gaskets. I just ported my first 65 metra case a few weeks ago and I matched the gasket (aluminum one) to the kit and then the case to the gasket to the case.

As for the actual case grinding, it depends. From the feedback I have received from the cases I have done the more of the original material you leave the better your mid range will be. If you profile the ports all the way to the back of the case you will improve the flow but it will show up more on the top end.

Get comfortable with dremeling first I really like the extension, holding a something shaped like a pencil vs something shaped like a brick has a lot to do with what the final product will look like.

When you are ready to attack the case I like to hold the dremel so that I will make a 45 degree cut into the case. I go around the whole port window and open it up to within about 1-2mm of the final dimension. This will allow you to clean up the port without going oversized. After you go around the port at a 45 degree angle you will be left with a steep transition. I then go back and round over that sharp angle and smooth it into the original port shape.

After you are done smoothing the port go back and open it up to the final dimension.

Little sanding and your done.

Thanks for the props Elliot!

I need to film the next case I port...

Re: Boat anchor or matched case

That would be an excellent teaching tool Paz. I just walked in from comparing the ports on my Moby case with those on the Malossi kit. There's a pretty good amount of material I need to take off the case, and I've never used a dremel for cutting aluminum like this.

I may go find Peter and see if he will mentor that little project.

Dumb question, but I assume you do all this when the case is cracked, correct? Wouldn't want all those nice shards of aluminum dropping down in the crankcase - no?

I also have a 65cc Metrakit to put on my son's Puch, so I'll be checking that out over the holiday break.

Re: Boat anchor or matched case

Here is a shot of the Malossi kit with the gasket laying on it.

Here is the gasket on the Moby case (parts of the old gasket show on the right - a little confusing)

So Professor Paz, do I want to take any additional material off the kit, since the gasket is a little bigger, or jsut leave that and match the case to the kit (primarily at the triangular areas at the top)?

Re: Boat anchor or matched case

Looking at the pictures now that they're posted, most of the gasket area seems to match pretty well already - it appeasrs that most to the work would be focused on those "ears" at the top - no?

Re: Boat anchor or matched case

You want to kit to match the case as close as possible, the gasket is the best way to do that. I you notice obvious differences with the gasket and the kit then take those into account. I would just leave the sides of the case alone since it looks like there is a little hang over on the case and the kit.

I would go alter the upper part of the case and leave the rest of it mostly alone.

Oh i forgot to mention originally that after you trace the gasket take the studs out of the case and keep the case halves together. You can access the case from any angle without the studs and you will end p with a smooth transition between halves if you leave them together. Learned that the first time, ported each half separately and when they were put back together the profiles did not match.

Re: Boat anchor or matched case

How do you prevent all of the crap you've ground off from dropping into the case? I know you couls stuff a rag in there, but will that really catch everything? Seems like there would be a great opportunity for catastrophic failure.

I'm in agreement on what needs to be removed in this example.

Also, the kit did not come with intake studs. Are those items that you can source locally? What would I be looking for?

Re: Boat anchor or matched case

I video would be PRIMO chris.

Thanks for all the info already.

Re: Boat anchor or matched case

Bert- you shouldn't have anything in your case. Do your work, and clean everything before you re-assemble it.

For short studs, try a hardware store that has a good metric section. If there is a place that specializes in old VW's around you they would have them too.

Re: Boat anchor or matched case

i feel like case matching should be easier than porting. Is it just as simple as putting the new gasket on yer case, and grinding away until they are flush? This idea seems friendlier, because you just open the case as close as possible to match the ports on the cylinder, and the amount of material and places you are supposed to remove material from are clearly highlighted by the gasket.

Porting seems harder and scarrier cause there isnt a friendly guide to help you, like the gasket. You have to do it and do it right the first time or your done.

is there any truth to that?

Re: Boat anchor or matched case

yeah best results are done to pre-cleaned case halves, then re-cleaned post porting. there are tricks to doing it without cracking the case but i'm not going to mention anymore about it, if your crafty you can figure it out, but its not reccomended for a solid build, since 100% shaving removal is not garenteed.

Re: Boat anchor or matched case

Mike, that's why I was wondering what Paz was referring to -is he taking the case halves with everything removed, and just putting them together to do the matching - then taking them apart to clean it all out?

That makes a lot more sense - I couldn't imagine doing that grinding with the crank still in there!

Since I'll just be doing the transfer ports I think I'll do it while the hlaves are apart - no profile to match.

Re: Boat anchor or matched case

If you want to do it on a uncracked case put the rod in it's lowest postion and then pack the space into the case hole at the crank halves with modeling clay. After you are done grinding douch it out good and then remove the clay

Re: Boat anchor or matched case

clay thats interesting. i have used socks and tape personally with no problems.

Re: Boat anchor or matched case

With internals still in the case "shudders". I have never gotten a grinder close to a motor that was anything but fully stripped. Well there was this one time at band camp... Im not saying it won't work but why risk it? The other option is to use paraffin wax, you stuff some cloth into the crankcase and create a chip resistant layer with melted wax.

I don't actually have any cases that are un-ported to do a quick how to video with. I'll see if I can find a junker e50 case or if someone in the city needs a port match...

I port match my cases (and others) when I am in the process of building a motor. I pull all the internals out and give the case a good once over to get the oil and dirt off of it. Then I mount it in my vice and get to porting. After all the porting is done I bring it up stairs and give it a good bath in hot soapy water to get every last metal chip out.

A few other recommendations:

Full face mask

https://www.amazon.com/dp/B000BO6RIE/

">like this one is a great thing to have. The dremel is running at 25k rpm and tosses chips all over the place. It's kind of distracting to have em hitting you in the mouth when you are trying to see what you are doing.

A good light source makes life a hell of a lot easier too. Depending on how you need to hold the tool to get the cuts you want you might be casting a shadow across the piece and having a light that you can move around it a great asset.

Re: Boat anchor or matched case

i did 3 with the case together no problems so far

1196845734_cr85expert03.jpg

Re: Boat anchor or matched case

this is my 65cc metrakit ,i use duct puddy from ace hardware,it is very tacky .i use it like a spong to mop up the gindings . works great for pellet gun trap to stop pellets.

Re: Boat anchor or matched case

hey chris,

well I need to case match my metra kit as well as rebuilding the engine. Maybe when I come out to SF we can videotape the whole process for everyone, what do you think, a total engine rebuilding case matching tutorial! I have a couple of split cases ready to go....

Re: Boat anchor or matched case

I dunno Coco - after seeing that picture I think I'll take mine apart before doing all that grinding - that's a LOT of little pieces to make sure you sponge up!

Re: Boat anchor or matched case

i know it looks scary but it cleans up real easy ,only part thats hard to get it out of the stud holes but i should have removed the studs and pluged them holes.

1196872282_cr85expert06.jpg

Re: Boat anchor or matched case

Re: Boat anchor or matched case

paz i got e50 halves that need matched to polini. i'll call ya wen its ready if u want to do a vid

Re: Boat anchor or matched case

stop stealing my thunder bella! I want to make a video with Paz! A sexy video!

Re: Boat anchor or matched case

Ha, I have shot some pellets and 22s into that stuff too. Interesting mushrooming patterns

Re: Boat anchor or matched case

if you're going to put a kit on, you should be disassembling everything anyways to make sure your shaft seals and bearings, etc, are all in perfect condition. The other advantage to porting with it disassembled is you can get at it a lot better to smooth it out, etc. If you are gonna spend a couple hundred bucks, you might as well take the 2 hours or so it takes to dis-and-reassemble the engine.

Re: Boat anchor or matched case

Great info. The pictures really help me understand what to expect.

Re: Boat anchor or matched case

I'll do a sexy video and port Elliot's case (that's not Bella) too.

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