Oil cooler..........round two, AKA fun with foam! Options

[mrdezyne]

QUOTE (maf914 @ Feb 21 2006, 08:30 AM)

Eastcoaster, Do you use a mold release on the styrofoam plug before laying up the fiberglass? Or do you lay it up directly on dry foam? (IMG:http://www.914world.com/bbs2/html/emoticons/idea.gif) Thanks for posting this process. Your installation looks great. (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif)

I was wondering the same thing. Looks like its directly on the foam since he had to cut away the core once it was cured. I've heard of wraping your core in aluminum foil and glassing on top of that before, just FYI...

[URY914]

Wrapping the plug with something does help when it comes to pulling the plug out. I used wide clear shipping tape because f/g won't stick to it and it leaves a nice smooth finish on the 'glass.

I'm not going to say anything about the line size, but that glass work it top notch (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif)

P (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

[spunone]

Line size ?? if the pump holes are 3/8 inch won't an8 work just as well it's same id ?? Just askin (IMG:http://www.914world.com/bbs2/html/emoticons/screwy.gif)

[Dr Evil]

Just freaking cool! I know how to FG, but I never thought to attempt what you did with such success. Nice (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif)

What resin did you use?

Trekkor,
Are you using an oil cooler on a 2.7?

[East coaster]

I layed up the glass right over the foam. I did a small test piece first and the impact was minimial, so I decided to go that route. I had planned on sealing the foam plug prior to lay up, but then said screw it. This was intended to be a "one off" sacrificial plug with no intent on producing more than one finished part. With that said, sorry to those who've asked, but there's no plan to produce these parts.

I did hope by posting these pics that someone could make these or any fiberglass parts they desired in the same sort of fashion. The whole process took 3 days of part time work. It's not really that difficult....Really! It's more like a third grade paste and glue project. People on this site have "mad" skills and this is an easy project. It requires no special tools (hacksaw blade, razorblade, paint brush, sand paper) and about 30 bucks in materials.

Most of my previous experience has been with more "finished" parts, where the plug is created and worked to a near perfect finish and then a female mold is created. The female mold is then used to create the actual part. This requires more work upfront, but lots less work on the tail end of the process and allows multiple pieces to be produced. This was actually the first sacrificial piece I ever made.

The plug could've been sealed with bondo, drywall joint compound, clay or any number of things to make the plug more finished and help to protect it during layup. I actually like the idea of the clear packing tape or aluminum tape (real duct tape). I've used both in other fiberglass project and they work great and are simple to deal with.

[maf914]

QUOTE (URY914 @ Feb 21 2006, 09:44 AM)

but that glass work it top notch (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif)

It does look good. It reminds me of the exposed bare fiberglass in the old Porsche race cars like the 908 and 917. Bare fiberglass ducts, engine shrouds, cooling fan, intake horns.... Cool!

Now everything is black carbon fiber. That's okay, too. (IMG:http://www.914world.com/bbs2/html/emoticons/laugh.gif)

[tdgray]

(IMG:http://www.914world.com/bbs2/html/emoticons/agree.gif) Top Notch work my man (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/boldblue.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/clap56.gif)

[fiid]

The glasswork looks awesome!! Great job. (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif)

I do have to ask a stupid question though:

How come it's okay (encouraged?) to use braided oil lines and not brake lines? Is it just because the breaklines have to flex with every bump in the road? What makes this so different?

Thanks for the education (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/beerchug.gif)

[Dr Evil]

I have not heard that you shouldn't use braded brake lines, I have heard that you shouldn't use braded anywhere wher you can not inspect it often as it is like a slow moving file. If you use braded oil line it is possible to have it rub through things in tunnels and such, but if you have it properly immobilized it should be a non issue.

AFAIK, braded brake lines are better (stiffer). I have them, but then again I only use the parking brake....since it is on jack stands (IMG:http://www.914world.com/bbs2/html/emoticons/dry.gif)

[ArtechnikA]

QUOTE (fiid @ Feb 21 2006, 03:50 PM)

How come it's okay (encouraged?) to use braided oil lines and not brake lines? Is it just because the brakelines have to flex with every bump in the road? What makes this so different?

the types of hose and their fittings are *completely* different, although they do both have an exterior woven stainless steel wire braid sheath.

the lines commonly used for fluid transfer (oil and fuel) are a nitrile rubber inner hose with various layers of reinforcement until you get out to the final outer braided sheath. most hose ends for this type of hose use a cutter to split the rubber hose (annular) and form a positive, high-retention seal.

brake (and clutch, where it's used) is a Teflon inner hose with a single braided stainless sheath. the hose end is completely different and may in some cases separate from the hose. could be manufacturing defect, could be installation defect, could be abuse. but it *has* happened.

in addition, non-DOT-rated hose has no outer nonpermeable sheath, so sand and grit can theoretically penetrate the braid and exacerbate abrasion of the Teflon inner tube. Teflon doesn't like to be kinked, os if that ever happens, for any reason, you should consider the hose toast. hanging a caliper from the brake hose is an especially bad thing.

many consider them an expensive, high-risk item with marginal to imperceptible gain. aircraft use them, and race cars use them. aircraft are *completely* inspected by certified inspectors at least annually. race cars, if they last longer than a season, are at least inspected and usually rebuilt and replumbed *very* frequently. and they DO NOT use adapter fittings like we do - they are AN-3 all the way from the MC to the caliper...

i plan to use DOT-rated lines on my car, as I have had good results with them in the past and i'm committed to a regular inspection program.

the technical differences between nitrile and Teflon hose are very well spelled out on the Earls site - and probably Aeroquip and Goodridge and everybody else that makes hose. Hose ends for Teflon braided-steel lines are *very* expensive...

Still - when i replumb the 911's fuel system, i plan to do it in braided Teflon hose, because there are so many oxygenates in contemporary fuels that I do not trust nitrile in this application any more for cars that are not subject to re-plumbing on a regular basis. it will cost a small fortune but i will be done with it once and for all...

[Dr. Roger]

how on earth did i miss this thread??? very classy solution. (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif)

i'm thinking a similar FG thing for my radiator on a V8 car. i already have a space saver tire but want to put more stuff up front if possible.


by any chance do you know how high the temperature can go on the FG?

[Trekkor]

QUOTE (Dr Evil @ Feb 21 2006, 10:20 AM)

Trekkor, Are you using an oil cooler on a 2.7?

I run a 2.0 with a *BIG* Setrab cooler.


KT

[East coaster]

Roger, Fiberglass would have no problem dealing with radiator range of temps.

[davep]

Since I deal with heat exchange, air and fluid flow as part of my job, I thought I'd add just a little bit here.
Heat exchangers depend on velocity of the air as much as volume to do the job efficiently. A car at speed with the HX fully exposed will see sufficient velocity. At rest there, obviously, is no velocity. As you restrict the inlet, both volume and velocity decrease. Similarly, on the outlet side any restrictions will reduce volume and velocity. Pressure differences will also have a significant effect on both.
One way of designing a system is to start by measuring the cross-sectional area of the heat exchanger. By rights you should consider only the open area of the rad, that area through which the air actually flows, and of course that means subtracting the area of the tubes. So, if you have a 4" x 20" rad for a total area of 80 sq inches you may find the open area to be 40 to 50 sq inches. Then you can plan the inlet area to be at least this size, and slightly larger if there are lots of sharp edges as opposed to a nicely contoured duct. Generally the inlet is very short and unrestricted. On the outlet side of the rad, paths tend to be a little longer and may not be straight, thus the cross-sectional area of the outlet is generally larger than the inlet. The rule of thumb however is to try to keep the duct cross-section constant even while it is changing shape. The idea is to try to keep the velocity constant. Sharp bends should be avoided.
Placing booster fans in the system can be a real problem. When the car is at rest, and there is no other airflow, then they become a necessity. At speed they are usually a restriction. In this particular design I'd place the two fans in front of the rad and between the ducts in the front; you have three duct opennings, and two spaces between the duct opennings. By placing the fans out of the direct incoming airflow you reduce the restriction to airflow at speed, yet at rest the fans will easily draw air from the opennings on either side of it. I'd place the fans directly on the rad itself. My choice of fans for this would be a pair of 120mm x 38mm high speed units with ball bearings. I have some Panasonic models of this type.

Similar to the airflow design, the oil lines and other parts should be matched. It would be useless, almost, to have -16 lines and a -8 openning into the rad or into the thermostat. I too would place the thermostat close to the engine. I might even have two thermostats, one at the engine and the other at the rad. If the rad does not have a pressure relief valve in it, or with it, then the second thermostat would help. This would stage the cooling, and allow faster engine warmup. It may also prevent over-cooling of the oil on cool days. My friend with the GT always warmed the car up to ensure the hot oil was flowing through the rad before taking the car onto the track. Too many of his friends blew their rads halfway around on the first lap because they did not warm things up properly. He suggests synthetic oil to reduce the problems.

Your system sure is elegant, and that is a good sign. Perhaps this thread should be in the Classics section soon.