1970 LT-1 Radiator ID

[Jeremy D.]

I wam tracking down a cooling problem that I have and I'm wondering if my car has the right radiator. On the lower output tube of the radiator, there is a "Dent" in the tube....right above and perfectly matching the curve of the swaybar. However, the swaybar comes nowhere really near the radiator output, there's a lot of room. It looks like somebody dropped the radiator smack dab on the swaybar when installing it....but the dent is so perfect, I don't know if it is the case. Looking at the Dewitt aluminum replacement, there is a similar "dent" in the lower tube, but it's not nearly as large. It just looks to me like this would restrict coolant flow, and it kinda bugs me.....is it supposed to be there?
Also, has anyone used Evans Racing Coolant? I've heard nothing but good things, but I'd like to hear more before I shell out the cash. Thanks In Advance!

Jeremy

[Michael W.]

Re: 1970 LT-1 Radiator ID

$25 for a jug of coolant? What benefits do you expect it to have?

[Scott Sims]

Re: 1970 LT-1 Radiator ID

Jeremy, the "dent" is factory correct as I have the same set up on my LS-5 lower radiator. I'm only guessing but it appears that there may have been some rubbing issues if there was a rubber hose there instead of the metal tube.

Scott

[John H.]

Re: 1970 LT-1 Radiator ID

The Evans coolant ranks right up there with the "miracle rare-earth magnetic gasoline molecule straighteners" that clamp on your fuel line

[Scott Sims]

Re: 1970 LT-1 Radiator ID

Or snake oil refrigerant. Sign me up for some of each! I personally prefer the store brand coolants. Lesser expensive. Read the labels and see who supplies the stuff. Read the labels and you'll see the same ingredients in the same amounts.

Scott

[Joe L.]

Re: 1970 LT-1 Radiator ID

Jeremy------

For the most part, if not exclusively, 1970 Corvettes with LT-1 used a copper brass radiator of GM #3018803. This radiator has a core width of 26". Most importantly, it has an integral filler on the top of the right side tank, so it does not use an external supply tank.

I would not rule out the possibility that some 1970 LT-1s, particularly very early ones, might have been originally equipped with the GM #3155316 aluminum radiator which does use an external supply tank. I've heard of this possibility, but I've never confirmed it.

[Jeremy D.]

Ok, Evans sucks. But....

My car still runs quite warm. I have 4:11's, and at highway speeds, it gets pretty hot. My shroud is in great shape, I installed a new thermostat, hoses are new, and the water pump is in great shape. I am using the original fan clutch restored by Fred Oliva last year with a 7 blade big block fan.I've narrowed things down to the radiator,or the temp. sending unit/gauge. The sending unit is the one that Lectric Limited brags about being right all the time, even put on the new repro connector, and the gauge seems to work ok(meaning: it moves smooth, and does go up and down in relation to runnning the car hard vs. tooling around)Soooooo....any ideas? Would swapping to a Dewitt radiator make enough difference to justify the price?

[Mark #28455]

is the radiator clean?

I have a 427 with 4.10 rear and totally stock cooling system - it runs 180 to 210 degrees all the time. The factory designed these cars for routine driving (except the L88 or ZL1) so all the stock parts should work fine.

Does the radiator have solder bloom from corrosion? Are bugs stuck in the radiator or too thick a coat of paint? Are all the foam seals present on the core support and shroud? Are they sealing? Are the sheet rubber seals present at the bumper supports and the front valence to core support? Is your engine timing set right? Is the vacuum advance working? Is the plastic air dam on your car? They are frequently damaged and removed and are VERY important in cooling the engine.

Good luck,
Mark

[Patrick H.]

Re: Ok, Evans sucks. But....

You still haven't verified you actual temperature. I don't care how much Lectric Limited or any other company brags about their temp sender calibration, the truth is that the track record for these parts is poor.

Find (or buy) an IR temp gun, and verify your temps by shooting a part such as the thermostat housing. See if the real temp matches the gauge before you go any further. You'd hate to spend a lot more time and money on the project when it turns out it's running at the right temp, and it's the equipment that is faulty.

Patrick

[Gary S.]

Re: Ok, Evans sucks. But....

I am in Patrick's court on this one - you don't have an overtemp issue until you verify the actual temperature of the radiator. IIRC, IR guns are widely available for around $65.

[Erik S.]

Re: Ok, Evans does not suck.

I have a 1968 L71 with 4.11 gears and do use Evans - works perfectly well for me! It is worth every penny because before Evans things got messy as I had water overflow issues (even in the cold city of Amsterdam, the Netherlands were I live).

Erik

http://www.heartbeatcorvette.nl

[Michael W.]

Re: Ok, Evans does not suck.

Would have been a lot less expensive to just stop overfilling the surge tank- this is the number 1 cause of 'boil over'.