Weight reduction: Running out of ideas.

[69427]

Lithium battery

I've heard a lot of good things about the Battery Tender/Deltran lithium batteries. I think I'm going to order their 4# 480 CCA model. That will be 12# lighter than my current 16# garden tractor battery.

It ain't weight off the front, but it's still mass that won't have to be accelerated or decelerated anymore.

 

[OZgreen69]

Please keep us posted if you like it or not.

 

[phantomjock]

Always looking to help you spend money$$$.

I was "on the hunt" for a mechanism for the gull-wings, and came across these:

https://picclick.com/C3-Corvette-68-82-Electric-headlight-motor-conversion-kit-321689148631.html

I'd post a pic - but my page is full and won't take anymore!

With an electric motor conversion (sorry more amps for the new battery) you could dump the vacuum tube behind the rear bumper and all the associated apparatus. Ought to be worth a few pounds. I seem to recall the tube was maybe over 30 pounds!
Somewhere around $25 per pound there...:idea:

Cheers - Jim

 

[69427]

Always looking to help you spend money$$$.

I was "on the hunt" for a mechanism for the gull-wings, and came across these:

https://picclick.com/C3-Corvette-68-82-Electric-headlight-motor-conversion-kit-321689148631.html

I'd post a pic - but my page is full and won't take anymore!

With an electric motor conversion (sorry more amps for the new battery) you could dump the vacuum tube behind the rear bumper and all the associated apparatus. Ought to be worth a few pounds. I seem to recall the tube was maybe over 30 pounds!
Somewhere around $25 per pound there...:idea:

Cheers - Jim

Vacuum tube behind the rear bumper???

 

[phantomjock]

That huge tube behind the front --oops maybe only on the rubber bumper cars?
On my '78 it had a fitting that tied to the headlights - so my assumption was vacuum receiver.

Maybe not. Anyway on my car --its gone!

Cheers - Jim

 

[vette427sbc]

the tube is only on rubber bumper cars... '69s had a steel vacuum tank in the drivers fender... Which leads me to think it could be replaced with a junkyard-found plastic one from a newer car

 

[69427]

the tube is only on rubber bumper cars... '69s had a steel vacuum tank in the drivers fender... Which leads me to think it could be replaced with a junkyard-found plastic one from a newer car

I agree. While I had things apart swapping out the pb booster for the lighter C4 piece, I took the vacuum tank out. IIRC it was about five pounds. Haven't taken the time to look for a replacement tank yet.

 

[Kacyc3]

That huge tube behind the front --oops maybe only on the rubber bumper cars?
On my '78 it had a fitting that tied to the headlights - so my assumption was vacuum receiver.

Maybe not. Anyway on my car --its gone!

Cheers - Jim

Isn't this part of the bumper for these cars?

 

[phantomjock]

I didn't look at the chassis manual when I pulled it years ago. If you want the 5mph "safety" prescribed by the fed, it might have some utility. Mine is a track and sometime street (when finished) and therefore not "required." And, with major front chassis/body mods, not "needed."

Your mileage may vary.

Cheers - Jim

 

[Kacyc3]

I didn't look at the chassis manual when I pulled it years ago. If you want the 5mph "safety" prescribed by the fed, it might have some utility. Mine is a track and sometime street (when finished) and therefore not "required." And, with major front chassis/body mods, not "needed."

Your mileage may vary.

Cheers - Jim

I thought it was welded into the frame.

 

[Kacyc3]

I kno wyou are looking for ways to reduce the weight of your car but have you done anything with the gas tank? I know with my 79 the tank sits on top of the frame and believe this is the same for your car also. Lowering the tank to be flush with the top of the frame would help your center of gravity and allow you to carry more speed through the turns.

Yeah, I've been trying to figure out my options with the fuel tank. I'm running stock location rear mufflers, so that gums up the works when trying to lower the fuel tank. So far the only decent option I've figured out is to fabricate a custom tank of about 8-10 gallon capacity versus the stock tank capacity (16-18 gallon range IIRC). The next thing I haven't figured out yet is if it would be better to make the smaller tank full height but narrow, and place it over to the right side to help get weight off the left side, or make the tank full width but shorter height to drop the c/g of the tank downward.

That's where I'm at currently. I appreciate your input here. :thumbs:

OBTW, anyone here know the weight of the early C3 fuel tanks?

Like this, would that leave you enough room for your exhaust? May have to wrap them to keep them from warming the tank.

http://www.vettemod.com/forum/showpost.php?p=132036&postcount=615

 

[69427]

Rear spring hanger bolts.

I've been kicking around changing the rear hanger bolts. I'm presently using half inch diameter parts, but it looks like I could swap them out for 3/8" bolts, at a half pound weight reduction for the pair. Doing the math for the rear corner weight/stress (vehicle, driver, and full bumpstop suspension/spring compression), it looks like a grade five bolt would have a 4.8x tensile strength "safety" margin, and a grade eight bolt would have a 7.8x margin.

I don't know how easy it is to find 10" bolts in this size and grade, but I'd welcome any technical input while I'm looking for these things.

 

[rtj]

https://www.fastenal.com/products/details/15133

Problem is they get some bending loads. Two different arcs, so not in line all the time. Maybe use a spherical bearing to reduce any bending. Just a thought.

 

[Housegarage]

Small bending from cushions loading. Tension loaded. Use cables?

 

[rtj]

Cables, that is interesting.

The reason I think there is bolt bending is I used 1/4 inch grade 8 bolts on my rear sway bar (with a spacer tube between the TA and the sway bar). The bolt was always bent when disassembled. Sort of similar, two arcs of motion at either end.

 

[69427]

https://www.fastenal.com/products/details/15133

Problem is they get some bending loads. Two different arcs, so not in line all the time. Maybe use a spherical bearing to reduce any bending. Just a thought.

I gave the angularity thing some thought the other day (it's a C4 suspension on the car, but there is some fore/aft movement of the knuckle with travel) and
the smaller diameter bolts should be able to pivot about (with less bind than the present half inch bolts) in the spring and cushion holes. Theoretically, at least. :wink:

The spherical bearing is a clever idea :thumbs:, but it might cancel the weight reduction of the smaller bolts.

 

[69427]

Small bending from cushions loading. Tension loaded. Use cables?

Cables is an interesting thing to contemplate in that application. :thumbs:

 

[rtj]

Cable would give some indication of wear too. You’d would see broken individual strands before failure. Probably available in very high tensile strength steel. Just have to figure out how to secure the ends. Great suggestion House garage.

Might have to ensure it won’t touch the tire when unloaded. I have cable travel limiters on my spc a-arms and was careful about that.

 

[69427]

Big block radiator dimensions?

Tied up at the relatives. I visited a local junkyard for a break in the action. I saw a radiator that might let me take a couple pounds off the car, but I don't recall the height and width of the stock radiator. Anyone able to help me out here? Thanks.

 

[BBShark]

31 1/2" wide x 18" tall.

 

[69427]

31 1/2" wide x 18" tall.

Thank you, sir!

 

[69427]

Well, I found a radiator that will package pretty easily onto the radiator support, with just the addition of some simple custom brackets, but I noticed an item I'm not comfortable with.

First, the upside of why I picked this radiator: The lengthwise dimension to fit our antiques is getting harder to find. Most decent candidates are too long. This radiator is just right, and the height was acceptable (another inch or two higher would have been perfect, though). The weight of this is 4# lighter than my current aluminum radiator (which is about 13# lighter than the stock radiator). I'm also trying to reduce the water weight of the full radiator, as a second tube row adds 100% more water weight, but only adds a small amount of extra cooling capacity (25%, according to the manufacturer of my current radiator). My measurements/guesstimates are that this "new" radiator will hold 5.5# of water, while the current radiator holds about 12#. So, weight wise, this "new" radiator is in the 10# range of additional weight reduction. Additionally, like the stock radiator, this radiator doesn't have a fill/cap neck, but has a vent line that can connect to the expansion tank.

Now, the downsides: Will it cool sufficiently? I don't know, but the price I paid was cheap enough to take a gamble/try. No butchering needed to install this.

The inlet/outlet tubes are slightly smaller, so I would have to figure out how to adapt hoses that fit the thermostat housing and w/p to fit this radiator.

My biggest issue. The car was an auto trans model, and the radiator has a trans cooler in it. The cooler takes up so much of the end-tank volume, that it looks like there's an appreciable flow restriction for the water entering the radiator (I didn't notice the cooler size until I got the radiator hose segment removed so I could see straight into the tank). I don't have solid numbers of what gpm coolant flow is at higher RPMs, but I'm not comfortable with what I see. And, as much as I'd like to take the trans cooler weight out of the radiator, which would also help the flow problem, I don't believe the time, effort, and expense would be a wise use of my resources.

I may use this radiator for another project, and just rack up my time and money (thankfully, only twenty bucks) as a learning experience.

I may do some shopping on the interwebs looking for sizing info on radiators that fit different vehicles, and then focus on trying to find the applicable models at the junkyard again.

 

[vette427sbc]

Sounds interesting... Thats a great weight reduction, and ahead of the axle :clap:

I have heard the argument both ways about high flow water pumps & flow requirements to cool a motor. I have to imagine the "optimum flow rate" is a variable based on uncontrollable things like ambient temp, airflow through the core, inlet water temp and probably a few more...

I downsized my radiator bigtime. C&R claims it should be OK, provided I have ducting and airflow optimized. Mines a 55mm core, 27.5"x14.5". I am also hoping the oil cooler will help with overall engine temp.
Post some pictures of the rad and the trans cooler if you can :drink:

 

[phantomjock]

Seem to recall (edited):
2 sq inch per HP and that was maybe a 2 - or 3 core?

Get by with less if using a fan I know for sure. I'll look it up in the morning - its somewhere here, with a add/subtract area based on manual, auto etc. Oh yeah, Like this one:
(found it on the desktop--sorry for quality)

In/out tube size probably not too big a problem - unless drastic. Remember you want to keep some heat in (180-200F).

Maybe use the transmission cooler bits on the diff?

Hope that provides "some" comfort.

Cheers - Jim

 

[69427]

Okay, guys, I've pissed away more of my life than I want to think about just trying to post two simple damn pictures. The first isn't the size I want, and the second won't show up. Pardon my poor manners here, but it shouldn't be this damn frustrating to just post two freaking pictures.




Just a quick mockup on the original support, and the original radiator for a size comparison.

 

[BBShark]

Mike, I attached it

 

[vette427sbc]

Looks like it fits well enough in the rad support, although I wonder if the upper hose is going to give you an issue with the upper control arm. I know youve got C4 stuff, but it looks like it may come close? What car is this out of?

 

[69427]

Mike, I attached it

Thanks Larry.

I'm not sure what I'm doing wrong. Been a while since I last posted a picture here.

 

[69427]

Looks like it fits well enough in the rad support, although I wonder if the upper hose is going to give you an issue with the upper control arm. I know youve got C4 stuff, but it looks like it may come close? What car is this out of?

Nothing wrong with your eyesight there. :amused:

A rough measurement looks like the upper hose would run right under the UCA. I won't know exactly until I actually try to install the radiator.

The radiator came out of a 2001(?) Cavalier.

 

[69427]

Radiator hose size adapters

I think I'll try installing this radiator to see if it will package okay, and if it will keep the engine temps under control at speed. I don't have any track days scheduled yet, so this might be the best time to work on it. I believe new mounts can be fabricated pretty easily to adapt this radiator to the radiator support framework. What I don't know off the top of my head is how I'm going to adapt the differing hose sizes (2" ID on the old stuff, to 1 3/8" ID on the radiator) to fit together. Some aluminum tubing pieces welded together is easy enough, but I'd like something that has some barb type ends so that the hoses won't slip off once everything is up to pressure. If anybody has some ideas/suggestions, I'd appreciate hearing them.

Thanks,
Mike

Edit: Did some thinking (should have done that earlier). On my shelf of used parts I have a thermostat housing that uses the same size hose as the radiator (1 3/8"), so I can just use one size hose on the top. The bottom hose will need to be a transition size as the water pump intake (2") is larger than the radiator outlet. I did some math. If I run the whole length of the top hose in 1 3/8", and the majority of the length from the radiator outlet in 1 3/8" hose, making the size transition right near the water pump inlet, I can reduce the hose volume of non-productive water (water that's not picking up heat or dissipating heat) by about .2 gallons, or 1.7 pounds.