Description: My cases mating surfaces are not perfect and tend to drip alittle.
My cases mating surfaces are not perfect and tend to drip a little.
how much can be taken off here ? can this be done at the home shop somehow, or who can be trusted to do this out there?
Also what is the best sealer to use here?
Thanks guys ???
Case mating
-
- Senior Member
- Posts: 6937
- Joined: Sun Feb 10, 2002 2:30 am
- Bikes: -
- Location: Central Illinois
- Has thanked: 112 times
- Been thanked: 310 times
Re: Case mating
Rammy!
I often encountered distorted and weld-repaired cases that need attention, but could not justify the tangled chain of expenses involved in re-machining. Each one required its own approach.
Please start with carefull inspection.
One method is to ink one side's mating surface with a broad felt-tip pen, and then attempt a rubbing upon the opposite case to determine gaps and blemishes that otherwise may escape notice.
If there is very minor "daylight", and only handling knicks, the cases may be improved by simple lapping of the two together with a coarse compound.
More likely, you will immediately discover highspots and knarfs. A repeated inking and scrapeing of just the highspots (with a decent machinist's scraper) will eventually bring the cases significantly closer to a mate, given enough diligence and attention to detail.
This is time consuming of course. But there will be a minimum of metal removed, and alignment will hopefully not be affected (beyond what a line-hone can correct when fitted for oversize rollers.) Machine set-up would have inherent errors that then require.....more machine set-ups!
If a lot of meat must be removed, then be prepared to grind some thin thrustwashers. I just finished a SportScout where extensive hand-scraping brought the cases together a whopping .020+" (.5mm); I hope the cylinders will go over the studs!
....Cotten
PS: Oh yeah, sealers....I avoid silicones, traditional Permatex, Yamabond4, and anything that gets hard.
I'm sure there are some excellent ones out there, but I use 3M #800 Industrial Adhesive.
I often encountered distorted and weld-repaired cases that need attention, but could not justify the tangled chain of expenses involved in re-machining. Each one required its own approach.
Please start with carefull inspection.
One method is to ink one side's mating surface with a broad felt-tip pen, and then attempt a rubbing upon the opposite case to determine gaps and blemishes that otherwise may escape notice.
If there is very minor "daylight", and only handling knicks, the cases may be improved by simple lapping of the two together with a coarse compound.
More likely, you will immediately discover highspots and knarfs. A repeated inking and scrapeing of just the highspots (with a decent machinist's scraper) will eventually bring the cases significantly closer to a mate, given enough diligence and attention to detail.
This is time consuming of course. But there will be a minimum of metal removed, and alignment will hopefully not be affected (beyond what a line-hone can correct when fitted for oversize rollers.) Machine set-up would have inherent errors that then require.....more machine set-ups!
If a lot of meat must be removed, then be prepared to grind some thin thrustwashers. I just finished a SportScout where extensive hand-scraping brought the cases together a whopping .020+" (.5mm); I hope the cylinders will go over the studs!
....Cotten
PS: Oh yeah, sealers....I avoid silicones, traditional Permatex, Yamabond4, and anything that gets hard.
I'm sure there are some excellent ones out there, but I use 3M #800 Industrial Adhesive.
-
- Former member
- Member
- Posts: 119
- Joined: Wed Sep 03, 2003 6:24 am
- Bikes: -
- Been thanked: 1 time
Re: Case mating
Thanks Cotton,
I will try thease things. Have you ever heard of a product called Gortex I think it is called , I got a sample of it , neet stuff , comes on a roll kind of like teflon tape.
They say it`s good for machined surfaces . ???
I will try thease things. Have you ever heard of a product called Gortex I think it is called , I got a sample of it , neet stuff , comes on a roll kind of like teflon tape.
They say it`s good for machined surfaces . ???
-
- Member
- Posts: 88
- Joined: Fri Jan 14, 2005 3:35 am
- Bikes: 1955 FL on a 54 frame
2012 Heritage Softail Classic - Location: Inola, Oklahoma
- Has thanked: 1 time
- Been thanked: 1 time
Re: Case mating
Rammy
Gortex is a good product for sealing wide flanged surfaces. I use it in several places on oilfield equipment.
I would not use it to try to seal the cases as it will extrude into the crankcase and end up in a lot of places in the engine that you really don't want it to be.
Red
Gortex is a good product for sealing wide flanged surfaces. I use it in several places on oilfield equipment.
I would not use it to try to seal the cases as it will extrude into the crankcase and end up in a lot of places in the engine that you really don't want it to be.
Red