Weight reduction: Running out of ideas.

[vette427sbc]

Not a fan of aluminum tube fuel lines. The marginal weight reduction doesn't make up for the compromised safety, IMHO.

Which brings to mind this recent scary event. A friend, who has just finished his experimental airplane build, suddenly lost power at about 3k ft altitude. After going through proper protocol, he looked down and saw an old airfield with big yellow X's on the runway below him. He immediately dead sticked the plane down, successfully landing with no damage. He left a trail of fuel the length of his landing. Turns out he had a broken aluminum AN coupler in the fuel line. Looking at it, it appeared to this EE to be a fatigued aluminum tube within a swivel female to female coupling.

I told him not to bother buying a lottery ticket in the future, because his luck is all used up.

Depending on the useage of aluminum it can be just as safe as steel. In a non-moving, low vibration application, aluminum has no reason to fatigue (ie: frame rail runs) Flex lines are used in appropriate locations. The AN fittings are not lifetime items. In an aircraft there should be a lifespan limit dictated by runtime hours or number of times the fitting has been on/off. I think I can speak for all of us in this thread that giving a modified car a regular look-over is an important step in maintaining vehicle safety and reliability... Your friend is lucky for sure... Good piloting skills as well :drink:

 

[rtj]

Not a fan of aluminum tube fuel lines. The marginal weight reduction doesn't make up for the compromised safety, IMHO.

Which brings to mind this recent scary event. A friend, who has just finished his experimental airplane build, suddenly lost power at about 3k ft altitude. After going through proper protocol, he looked down and saw an old airfield with big yellow X's on the runway below him. He immediately dead sticked the plane down, successfully landing with no damage. He left a trail of fuel the length of his landing. Turns out he had a broken aluminum AN coupler in the fuel line. Looking at it, it appeared to this EE to be a fatigued aluminum tube within a swivel female to female coupling.

I told him not to bother buying a lottery ticket in the future, because his luck is all used up.

Depending on the useage of aluminum it can be just as safe as steel. In a non-moving, low vibration application, aluminum has no reason to fatigue (ie: frame rail runs) Flex lines are used in appropriate locations. The AN fittings are not lifetime items. In an aircraft there should be a lifespan limit dictated by runtime hours or number of times the fitting has been on/off. I think I can speak for all of us in this thread that giving a modified car a regular look-over is an important step in maintaining vehicle safety and reliability... Your friend is lucky for sure... Good piloting skills as well :drink:

Yeah, should be lower vibes than a light aircraft. But, if you hit a resonant frequency (drive a resonant frequency) all bets are off. Think tuning fork. You might want to have a few extra rubber clamps in order to make sure there is lots of damping.

 

[stingray composites]

Not sure if your interested but I do have lift off carbon fiber hoods that are 7.5lbs. my second version I should be able to get down to 6lbs. most factory hoods I've weighed are 30lbs not including brackets. the bolt on hoods should be 10-11lbs. good deal of weight off the top of the car. I also am making a way to use the lift off hood as a normal functioning hinge style hood. T-tops are about 14lbs each for the early style fully assembled so if you can half 28 lbs that's a good deal weight off the top with carbon versions. carbon fiber rocker panels look cool and save some weight over the aluminum ones. I will be doing full functioning doors sometime, one piece targa top from carbon and a race weight one piece skin up top, carbon flares which you can throw a hammer at. Lots of plans just no money to do it all yet.

 

[vette427sbc]

Do you have any pictures of the assembled t tops? Id like to see the internal braces if possible

 

[COLE SWEAT]

Do you have any rear belly pans?

 

[stingray composites]

Do you have any pictures of the assembled t tops? Id like to see the internal braces if possible

i havent made them yet, but they will be based off early 77 tops with the dual latches since those were the lightest design for the tops, I also may get the latches made in machined aluminum to shed further weight.

 

[69427]

Not sure if your interested but I do have lift off carbon fiber hoods that are 7.5lbs. my second version I should be able to get down to 6lbs. most factory hoods I've weighed are 30lbs not including brackets. the bolt on hoods should be 10-11lbs. good deal of weight off the top of the car. I also am making a way to use the lift off hood as a normal functioning hinge style hood. T-tops are about 14lbs each for the early style fully assembled so if you can half 28 lbs that's a good deal weight off the top with carbon versions. carbon fiber rocker panels look cool and save some weight over the aluminum ones. I will be doing full functioning doors sometime, one piece targa top from carbon and a race weight one piece skin up top, carbon flares which you can throw a hammer at. Lots of plans just no money to do it all yet.

I'm always interested in any weight loss options. I like the thought of lighter weight body components (as I believe Duntov said, that the body of a Corvette only serves to keep the wind and rain off the driver, and doesn't really contribute to the structural strength of the car). My frustration/concern with changing body panels/parts is, in addition to paint color matching, that the bodies of these antiques are so varied in build quality/tolerances that I don't know what difficulties arise when trying to fit an aftermarket part onto these cars.

 

[69427]

I'm still looking into additional areas to cut weight. I'm massaging a few of the present fabricated parts to pull off a few ounces here and there. My objective several years ago was to get something to work and be reliable. I'm now taking a closer look at stuff from a force/vector standpoint to see where I've overbuilt stuff.

I'm looking around for a lighter radiator/coolant volume combination. I have an aluminum DeWitts radiator on it presently. It's a very high quality piece that keeps the engine cool (I run a 195* thermostat) on 95* days. (I presently have most of the front grill area blocked off for less aero drag/lift, and have absolutely no cooling problems.) I'd like to experiment with a radiator with a touch less coolant volume to take a few pounds of coolant weight off ahead of the front axle.

Would love to run a lightweight Lithium battery in the car, but I still haven't found one that I don't have concerns about the possibility of a battery fire. Any helpful advice on this matter is welcomed.

 

[redvetracr]

how about a polycarbonate front windshield, fiberglass bumpers, lightweight hood & t-tops, triple disc clutch w/reverse drive starter (not only lighter but lowers your moment of inertia), EDM lighten your ring gear...have I spent enough of your money yet?

 

[rtj]

The front wheel wells look heavy. I’ll pull one off a junk front clip and weigh it.

Sheet alum wheel well world be light.

 

[vette427sbc]

the Porsche GT_ cars had a Lithium battery option... I would have to imagine of all batteries those would be the least likely to cause fire? They pop up for sale once in a while... $$$

 

[69427]

Going to swap out the intake manifold next week. I'm currently running an old Edelbrock C396 manifold (for the stock/sleeper look), but I've got a spare that had been gathering dust over the years. Several guys over at the Chevelle website (where there's still a large group who run these antique BB engines) have had good results bumping up their higher RPM power by removing the plenum divider from their intake manifolds. I've got more bottom end power in the engine than I can use, so I spent some time with a carbide grinding wheel and removed the divider, and then noticed a few other bits of casting on the manifold that wasn't doing any productive work (the exhaust crossover under the plenum was the biggest chunk). I got about 1.5-2 pounds of aluminum ground off the manifold so far, but will end up putting a couple ounces back on when I weld up the center crossover ports on the gasket flange.

Last fall I replaced the trouble-prone/demon-possessed Holley 850 with one of the newer aluminum body models. This carb is about 4 pounds lighter.

Not a lot of weight removed, but it's from up front and up high.

 

[vette427sbc]

Nice! 1-2lbs that high up and forward is pretty significant in my book... And it was free? Cant beat that! That might have a similar loss to 3-4 lbs dead center and under the car.

Is there a term for that? "dynamic weight loss" maybe? Weight further from points of rotation that has more of an effect compared to weight that is closer to the point of rotation?

 

[69427]

Nice! 1-2lbs that high up and forward is pretty significant in my book... And it was free? Cant beat that! That might have a similar loss to 3-4 lbs dead center and under the car.

Is there a term for that? "dynamic weight loss" maybe? Weight further from points of rotation that has more of an effect compared to weight that is closer to the point of rotation?

The geek in me often envisions different moment arms (or leverage arms) and rotational axes in the car. The couple pounds I got off the intake manifold reduces (albeit in a smaller quantity than I wish) the nose dive effect under braking, and the roll effect during cornering. It's certainly not much, but it's directionally correct.

Your comment reminds me of an additional bit of "reward" for spending the time making the aluminum mufflers last year. The mufflers are located at the extreme rear of the car (great, if I drag raced the car, but I don't) which causes two detriments to handling. The extreme rearward weighting will induce oversteer (bad, of course), but the placement of that weight, due to the moment arm using the rear axle as the pivot, tries to lift the front wheels off the ground, causing understeer. It's a lose-lose situation. By making the lighter weight mufflers I (theoretically) reduced both the oversteer and the understeer, a win-win situation (plus acceleration and deceleration is improved due to the lower total vehicle mass).

(A few years back I made a muffler and packaged it under the passenger seat floor area, in an effort to reduce system weight and centralize the mass of the muffler closer to the car's cg/rotational axis. It worked fine on the track, but the loss of precious ground clearance during street driving just made life difficult, so I went back to the stock location for the mufflers, but reduced the weight as much as I could while still keeping the exhaust pretty quiet.)

 

[rtj]

Make yourself some NASCAR boom tubes. There are some good articles on these.

1-7/8″ High
8-1/2″ Wide
30″ Long

https://venomclassics.com/product/dr-gas-boom-tube-side-exit-mufflers-with-3-inlet-pair-oera7700123/

 

[69427]

Make yourself some NASCAR boom tubes. There are some good articles on these.

1-7/8″ High
8-1/2″ Wide
30″ Long

https://venomclassics.com/product/dr-gas-boom-tube-side-exit-mufflers-with-3-inlet-pair-oera7700123/

That's something to mull over. Two things I'd have to work out. A while back I had a similar size item under the passenger seat floor (an exhaust termination box), and the loud booming noise from the flat upper surface just penetrated the cabin. I'd have to figure out a way to dampen the noise transfer from the flat surface, and I'd have to make it out of aluminum for weight reasons.

 

[69427]

how about a polycarbonate front windshield, fiberglass bumpers, lightweight hood & t-tops, triple disc clutch w/reverse drive starter (not only lighter but lowers your moment of inertia), EDM lighten your ring gear...have I spent enough of your money yet?

Lots of good ideas there. My wallet may end up the lightest item in the list. :amused:

 

[69427]

Trying for a few ounces off the water pump.

I've got a old frozen bearing ZL1 aluminum water pump sitting on the shelf waiting for a rebuild, and I noticed how heavy the steel rear/impeller cover is (13.5 ounces). If I get bored some evening I think I'll cut a cover out of aluminum and see what weight I can trim off there. There's not a helluva lot of room ahead of the timing cover, so I'll have to see what thickness aluminum I can even sneak in there.

Again (if it works), it's not much, but it's up front on the car.

Edit1: I put the water pump on my old original engine sitting on my run stand. Looks like there's about 5/16 inch of usable space between the timing chain cover and the pump cover flange. However, if I use any cover material thicker than about an eighth inch I might not have room for the bolt heads unless I countersink them. Doing a bit of math on the cover area and thickness (giving me the volume of the cover material), I could figure out the weight of a new cover. A 3/16" thick cover would be five ounces lighter (directionally correct), and an eighth inch thick cover would be eight ounces lighter (hot damn, half a pound). For the first round I think I'll make and install an eighth inch cover for the broken pump, fill it with water, and then plumb the pump up to about 15-20# of air pressure to test/confirm the (burst) strength of the cover. Beforehand I'll try to find some material strength numbers and do some calculations, just to get a better warm and fuzzy feeling about this modification (and the pressure test!).

Edit2: After giving the issue a bit of thought I'm suspecting I'm being a bit too "worried". I got to thinking about the thinner material thickness of the expansion tank and the typical radiator. I gotta think that an eighth inch thick cover should be just fine. (I think I'll still do the pressure test anyway, just for amusement.)

 

[rtj]

Based on your comments, I may take a swipe at making aluminum side pipe mufflers. I’ve been thinking about doing them in steel, but found cheap intercooler alum. tubing last month. It might make good SP muffler material.

Wasn’t your car a 6 pack originally?

 

[69427]

Based on your comments, I may take a swipe at making aluminum side pipe mufflers. I’ve been thinking about doing them in steel, but found cheap intercooler alum. tubing last month. It might make good SP muffler material.

Wasn’t your car a 6 pack originally?

No, just a lowly 390 horse Quadrajet model.

 

[redvetracr]

Lots of good ideas there. My wallet may end up the lightest item in the list. :amused:[/QUOTE]

i can help with that if you are ready to let loose of your j-56 brake pistons...

 

[phantomjock]

Just did a quick search of the thread - you were/are looking at aluminum brake calipers.
How about Aluminum hats on the disks? Give you lower unsprung weight too!

Cheers - Jim

 

[69427]

Just did a quick search of the thread - you were/are looking at aluminum brake calipers.
How about Aluminum hats on the disks? Give you lower unsprung weight too!

Cheers - Jim

Got Wilwoods all around, and lightweight Wilwood rotors and aluminum hats up front. Rear rotors are stock 11.5"/.81" wide C4 rotors. Looked at two piece rotors for the rear a while back, but I've only seen 11.75" diameter pieces (I haven't looked yet to see if I can find correct offset hats, and what the weight would be). Due to rotor/caliper clearance issues if I had to bump up to 11.75" rotors, I'd have to fabricate another pair of rear caliper brackets. I'm trying to figure out if the net weight reduction is worth the cost/annoyance factor.

 

[69427]

Headlight actuator(s) weight?

Just curious what the weight of the actuators might be, and is it possible to just manually open and close the headlights if they're removed?

Running out of ideas, and this weight is way ahead of the front axle centerline.

Thanks for any help here.

 

[vette427sbc]

You can open and close them by hand, but I found at high speed the headlights will open by themselves if there is nothing holding them in the closed position. (This is even with similar grille block off plates to yours) Don't forget, you also get to remove the vacuum relay, tank and associated lines. If you were to get rid of the actuators, a simple aluminum or composite T-handle attached to the actuator pivot would make opening and closing much easier than reaching up through the radiator ducting up front

 

[69427]

You can open and close them by hand, but I found at high speed the headlights will open by themselves if there is nothing holding them in the closed position. (This is even with similar grille block off plates to yours) Don't forget, you also get to remove the vacuum relay, tank and associated lines. If you were to get rid of the actuators, a simple aluminum or composite T-handle attached to the actuator pivot would make opening and closing much easier than reaching up through the radiator ducting up front

I removed the storage tank a couple years ago when I swapped out the stock m/c and p/b booster for the C5 m/c and C4 booster. I left the rest of the vacuum system intact as I don't want to excessively strip the car for the next owner when the wife has to sell it after my funeral someday.

I thought that the lights were held up or down by some overcentering springs, but I apparently am wrong here. I'll have to stick my head in the actuator area and refresh my memory on how it all works.

I appreciate the feedback.

 

[OZgreen69]

I found out that the springs who hold the lights up or down are quite firm in their actuation, but I never drove the car at speed in that configuration, soooo...
And I love the endurance light look !

 

[vette427sbc]

The springs do hold the lights down, but there is no over center geometry in the lift direction, only the down position. FWIW the high speed numbers were 3 digit, and with my old splitter which likely pushed significantly more air through those lower ducts than a stock front lip would

What would be really great is if someone 3D modeled the headlight housing... a composite printed headlight housing could probably save 6+ lbs off the most forward part of the car

 

[COLE SWEAT]

Does the electric conversion do away with the springs? I believe this conversion is 5 lbs less than the original setup

 

[69427]

Does the electric conversion do away with the springs? I believe this conversion is 5 lbs less than the original setup

I'm not familiar with the details, but I'll look into it. Thanks.