DIY_EFI Digest Monday, 11 January 1999 Volume 04 : Number 027 In this issue: Re: Non-linear fuel pressure reg - #2 Re: Heat sink compound Re: Fp regulator mods Re: carbide cylinder bore conversion (Bore Tech) Re: Fp regulator mods Re: carbide cylinder bore conversion (Bore Tech) Re: carbide cylinder bore conversion (Bore Tech) See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: bearbvd@xxx.net (Greg Hermann) Date: Sun, 10 Jan 1999 19:30:45 -0700 Subject: Re: Non-linear fuel pressure reg - #2 >> But then it occured to me, the diaphram surface area on which >> the fuel presses against, and the surface area of the vacuum >> side of the diaphram is equal. So the vacuum is probably just >> acting as a delta to the fuel pressure only, not the spring, and >> the spring is probably just setting the base pressure. In other >> words, a faster rate spring will simply compress more from the >> fuel pressure alone, then the delta created by vacuum will remain >> the same. So I guess there's a good chance that using a spring >> of a different rate won't make any difference. > >consider the vacuum to be a 2nd spring >the 1st spring is a constant source >the vacuum is a variable source >a diff rate spring will make a change in the variable generated >the base height of the spring sets the initial pressure But, to get a regulator that will give something approaching a constant output pressure vs. load, you need a spring that is of a soft enough rate to give pretty constant force over the travel of the regulator valve. It would be a grave mistake to try to get a rising rate out of regulator offset!! Regards, Greg > >Clive ------------------------------ From: KD6JDJ@xxx.com Date: Sun, 10 Jan 1999 23:08:58 EST Subject: Re: Heat sink compound Randy I realize that you are not seeking my guidance when you wrote::So on the CS-130 alternators the neg side of the diode pack is mounted to the case with HSC and has no screws to ground it. The screws are all insulated. On my last rebuild I used T & B"copper kote" on the ends where the positive bolt goes thru it and on the other end where I added an 8-32 nut and bolt to hold it tight and ground it. the middle I put standard HSC. Maybe the silver stuff should be used on the whole thing? Looked like a major flaw in the design to me, as I have fixed about four of these all with dead neg side diodes. But I have had a lot of experience with Delco designed alternators, and I suggest that you consider your design fix very carefully before you conclude that 'they' have a design flaw. The CS 130 alternator does not have the reputation ( in my experience ) for damaging negative diodes . It was my understanding that they are avalanch diodes , expected to minimize the bad effects of transient voltage spikes . I can get some very technical information if we need it But, for now , I wanted to submit to you that there may be another reason for the negative diode failures that you have experienced. Also , how is the negative diode in your alternator connected to ground? I understand that you have no screws to ground it , except the 8-32 that you have added. I am certain that Delco intended to provide a GOOD connection between the negative diodes and ground --- in a negative ground alternator. Or -- Have I misunderstood something here?? Jerry ------------------------------ From: "Mike Pitts" Date: Sun, 10 Jan 1999 23:37:06 -0500 Subject: Re: Fp regulator mods >--but how (and to what) are you venting the rest of the diaphragm >area on the fuel side of it?? Ahhh, good question! This one is easy. But to understand it, you may need to have a cut open Bosch regulator in hand. On the fuel side, the fuel from the rail forces the diaphram up, which opens a puck that seals a pipe which leads to the fuel return line. Around this puck is a rather large diameter "slug". If I braze a pipe into the bottom half of the regulator of the same diameter as this "slug", and at the proper height (critical), the "slug" should act as a new seal. Nothing fancy. Just a brazed pipe about 0.95" O.D. in diameter and 0.80" in height. This will remove 0.70 sq/in of fuel pressure exposed surface from the bottom side of the diaphram. This new surface area is approx. 57% of the original area. There are other concerns, like, will the slug act as a proper seal? This can be easily remedied by micropolishing its surface (2000 grit paper on glass) In answer to your question above, the "venting" is to the fuel return line, if you can even call it venting. It's more like a differential of pressure between the inside the regulator and the inside of the fuel return line. I do believe this will require a lighter spring -or- a ring of precise thickness made to act as a shim to raise the top of the regulator since the original spring will now overpower the diaphram and cause the base pressure to skyrocket given the reduction of force coming from the fuel side of the diaphram. I prefer the ring method so I don't have to go hunting down a perfect spring. Making the regulator adjustable will help with fine tuning. I liked the idea of adding larger or multiple diaphrams, but that's too complicated for this home project and frankly, beyond my skillset. Thanks for the input and questions, keep 'em coming! - -Mike ========================================== Mike Pitts Delray Beach, FL mpitts@xxx.net ========================================== ------------------------------ From: Alain Toussaint Date: Mon, 11 Jan 1999 00:24:29 -0500 (EST) Subject: Re: carbide cylinder bore conversion (Bore Tech) is there any website for the company,i just tried www.boretech.com and got what look like a firearm company !!! Alain T. > My impression was that it would be between $35 and $85 per hole, depending > on size, etc. > > Regards, Greg > >> > > > >Just out of curiosity, what's the boretech treatment cost? > >=========================================================== > > David Cooley N5XMT Internet: N5XMT@xxx.net > > Packet: N5XMT@xxx. Member #7068 > > I am Pentium of Borg...division is futile...you will be approximated. > >=========================================================== > > > ------------------------------ From: bearbvd@xxx.net (Greg Hermann) Date: Sun, 10 Jan 1999 23:32:18 -0700 Subject: Re: Fp regulator mods >Around this puck is a rather large diameter "slug". If I braze a pipe >into the bottom half of the regulator of the same diameter as this >"slug", and at the proper height (critical), the "slug" should act as >a new seal. Nothing fancy. Just a brazed pipe about 0.95" O.D. in >diameter and 0.80" in height. This will remove 0.70 sq/in of fuel >pressure exposed surface from the bottom side of the diaphram. >This new surface area is approx. 57% of the original area. > >There are other concerns, like, will the slug act as a proper seal? >This can be easily remedied by micropolishing its surface (2000 >grit paper on glass) > >In answer to your question above, the "venting" is to the fuel return >line, if you can even call it venting. It's more like a differential of >pressure between the inside the regulator and the inside of the >fuel return line. OK, but that should work well enough. But the one thing that still is of concern--you are right, it is kinda hard to tell from remote--is that it sounds as if you might be greatly increasing the effective area of the relief port. If this is true, the modified regulator's response would be VERY jumpy--all over the place. Not what you want at all. Like trying to drive a small finish nail with a three pound single-jack. Greg ------------------------------ From: bearbvd@xxx.net (Greg Hermann) Date: Sun, 10 Jan 1999 23:39:34 -0700 Subject: Re: carbide cylinder bore conversion (Bore Tech) >is there any website for the company,i just tried www.boretech.com and got >what look like a firearm company !!! > >Alain T. Dunno, but I sorta doubt it. Address and phone were in my first post the other day. If they have a URL, I spect they would be happy to give it to you! 'Twas in Batavia, OH, area code 513. Greg > >> My impression was that it would be between $35 and $85 per hole, depending >> on size, etc. >> >> Regards, Greg >> >> >> > >> >Just out of curiosity, what's the boretech treatment cost? >> >=========================================================== >> > David Cooley N5XMT Internet: N5XMT@xxx.net >> > Packet: N5XMT@xxx. Member #7068 >> > I am Pentium of Borg...division is futile...you will be approximated. >> >=========================================================== >> >> >> ------------------------------ From: FHPREMACH@xxx.com Date: Mon, 11 Jan 1999 02:58:01 EST Subject: Re: carbide cylinder bore conversion (Bore Tech) In a message dated 1/10/99 1:24:00 PM Pacific Standard Time, bearbvd@xxx.net writes: << Not really so when dealing with an 8 u inch polished finish. If the bores are the same diameter (within a couple of ten thousandths, and all straight, no prob. I thought about lapping each set of rings to its own hole, but decided that the extra block clean-up was a nightmare (not to mention stray lapping compound) waiting to happen. (Lapping compound in this case would be more like jewelers' rouge than what you are used to thinking of for lapping valves. WAY finer.) Lots of serious HP boat motors are pre-seated this way. It works. Also saves a LOT of break in debris from floating around insside the engine. Regards, Greg >> You might try using your cylinder sleeve with a bit of Diamond Lapping Compound. We used to use it on solid laps for very fine finishing on aluminum and andodized surfaces for Hydraulic actuators. These were lapped for finish and size and fitted with 0.0001-0.0002 slip fits. you might think about making air cylinder operated vertical lap if you want to get it done quickly, also no side load on the pistons that way. Fred ------------------------------ End of DIY_EFI Digest V4 #27 **************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. A non-digest (direct mail) version of this list is also available; to subscribe to that instead, replace "diy_efi-digest" in the command above with "diy_efi".