Too Hot

[Stingray74CC]

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AAAAAAAAAAGGGGGGGGGHHHHHHHHHH!!!!!!!!!

ok...had to get that off my chest. I spent just over four hours taking out the old radiator, fan and shroud. The stuff was not too bad to take out. There were a couple issues with the "previously mounted fans". They were about 1.5" to far left. Then I thought the I'd have to modify the upper hose connection like 69MyWay did....luckily it went on. So all in all, the radiator was a drop in...no modifications.
The previous owner had everything taken out and cleaned...so that was good. All said and done, with the fans wired to come on at 195 degrees or manually if I wanted, I started the car. I left the cap off the surge tank to let the system purge itself of the air. Things were going great. The car heated up past 195 (fans came on, great...they do move some air) and continued to 210 and stayed there...atleast by the gauge in the car. After a little longer, I put the 7 pound cap on the tank and within a minute water began pouring out of the radiator. About half way down on the driver's side the coolant trickled out of the fins. I removed the cap on the surge tank and the flow decreases quite a bit. I figure it's a bad weld. I'm just disappointed to have gotten a lemon from such a reputable name. I hope that things work out ok with Griffen or Dewitts because this could be a three week down :cry time b/c I'm only allowed to work on the weekends.
Well, there's my drama for the week. Hope ya'lls went a little better than mine. Even though I didn't get to drive the car with the new setup, I could tell that it was going to run much much cooler. The idle temp dropped 40-50 degrees without being pressurized.

Anthony

 

[69MyWay]

Yikes! What a pain in the butt. There has to be a major defect in that thing, because these radiators are tough and thick tubed.

The only reason I had to modify my upper is because with my belts and pulleys, my a/c is on the drive side with a long leg water pump driving too tight.


Those fans are nice though. They move enough air to push a small Honda down the road.

 

[Stingray74CC]

Websit updated with pics

I posted the pics on the website. They are on the left-hand side. Very sad to look at. If you scroll down toward the bottom, you'll see three pics of a couple beautiful 56 Chevy's that the guy had behind his house.

Black Cherry

 

[jsimpson]

By the way, NEVER use push-thru fan mounts when installing electric fans on a cross flow radiator. If you do, the weight of the fans will be carried by the coolant tubes instead of the fins. You will have a leaking radiator in no time at all!

 

[Stingray74CC]

Fan Mounting

jsimpson,

I think I'm ok with the fan mounts. They came from Dewitts already mounted on the Radiator with self-tapping screws on the upper and lower portions of the radiator. That would be a huge mistake by Dewitts if they screwed up by doing that.

 

[Stingray74CC]

Tom Dewitt is the MAN!!!

Tom Dewitt just replied to my email and here's what he had to say:

"Sorry to here you had troubles. I've been selling Griffin rads for over three years now and this is the first leaker that has been reported. I have a new one in stock and I will ship it monday. I will also put in a call tag with ups to pick up the old one so we can claim warranty with the factory. Thanks for your patience. td"

All-in-all I'm very impressed with his service even though I got a bum radiator.

 

[jsimpson]

Stingray74CC, if you have frame-mounted fans, your setup is OK. The kind of mounts I'm warning about are the long plastic thumbtack looking mounts that push through the fins and have push-on retainers on the opposite side to snug the fans up against the radiator!

 

[400hp_76]

I have a slight problem.

I have a 76 vette with a 19" by 31" griffin aluminum radiator. two tci electric fans that move 2200 cfm at 5 amps and a flex fan. I also have a 180 degree thermastat. The car was still runnin hot with all of this. I bought a new indy front spoiler and that cooled the car while i was cruisin, but in traffic it still wanted to run hot. And while i am talking about hot, before i could get the cooling situated the car caught on fire. The fire was the result of either tranny fluid or the carb was leaking. The motor had just been rebuilt from the bottom up. So while it is in the body shop i have removed the brand new powemax crane cam and i put a lunati with less duration and more lift. New manifold and ingnition. you name it i replaced it. The crane cam sucked, i mean it really sucked. I am thinking that i was not getting a proper vacuum and that my timing was way off, but something was just not right. comments

 

[jsimpson]

Your fans don't get it. A pair of Permacools will move 2900 each. Also, if your fans have shrouds, they block more airflow than they pull.

 

[69MyWay]

Re: I have a slight problem.

I have a 76 vette with a 19" by 31" griffin aluminum radiator. two tci electric fans that move 2200 cfm at 5 amps and a flex fan. I also have a 180 degree thermastat. The car was still runnin hot with all of this. I bought a new indy front spoiler and that cooled the car while i was cruisin, but in traffic it still wanted to run hot. And while i am talking about hot, before i could get the cooling situated the car caught on fire. The fire was the result of either tranny fluid or the carb was leaking. The motor had just been rebuilt from the bottom up. So while it is in the body shop i have removed the brand new powemax crane cam and i put a lunati with less duration and more lift. New manifold and ingnition. you name it i replaced it. The crane cam sucked, i mean it really sucked. I am thinking that i was not getting a proper vacuum and that my timing was way off, but something was just not right. comments

Wow-ouch!

Do you have a good quality water pump going the correct direction? If you have a C4 pump on the C3 it will run hot as the impellar is backwards on the newer ones. How about the pulley? Is it the correct size, or an under drive unit?

Did you put a good rubber seal between the radiator and the core support?

Are you sure you don't have a blown head gasket?

I would not suggest running both the flex fan and the electric as the spinning of both could cause a vortex that would actually decrease air flow.

The Dewitt assembly is on my car as well. It has a shroud with 12 rubber flapper doors. The shroud is the key to keeping it cool. It directs the air and channels it at low speed to come right through the radiator and pass on. At speed, the pressure of the air in the shroud will force the flapper doors open allowing for a natural air flow through the system. Many new cars including the full size impala SS, the last generation C4, and the C5 use this same flapper door shroud technology to stay as efficient as possible without causing interferance.

 

[400hp_76]

HEY

How much is a Dewitt setup. water pump is fine. it is a stewart components. it is new just like everything else(new). one thing you said struck my interests though. most 76 corvettes had long water pumps. so when i called to order my water pump, i said i need a stewart components water pump for a 76 vette. well when i got my pump and compared it to the old one. i came to find out that i have a short water pump and pulley setup. maybe its like you said and the pulleys could be causing the prob.

 

[Stingray74CC]

Dewitt Setup

400hp_76,

The Dewitt Setup isn't cheap, but from what I could tell before the radiator began spewing coolant, it lowered my idle temp 40-50 degrees. I would suggest you call and talk to him and see what he can do for you. Here's the site: www.Dewitts.com
and his number is: 810-220-0181.

He sent me another radiator, no questions asked. It should be here tomorrow.

Good Luck,
Anthony

 

[400hp_76]

Thanks alot

I would just like to tell you that you have a sweet corvette. Black is the best. You have some interesting body work done and i am sure you enjoy the 427. I am looking for a 427 small block, for a motorswap this summer. I am planning on getting the heads worked on my 357 and have the manifold worked to match so i can put them on the 427. You may not know the answer to this, but can you get a 427 out of a 400 small block. i have heard several people say that with 6" rods you can. im not saying you can but i was just not sure. thanks, "T"

 

[Stingray74CC]

Thanks

T,

The 427 is unbelievable. I thought it was black at first too, but it's called Black Cherry. The appraiser told me that it's a 1979 GM color. Speaking of, I need to get some touch up paint.

As far as making a 427 out of a 400, don't start me lying. There are more than a few engine builders around here that can tell you the best way to get what you want. I'm here learning as much as I can. I've picked up alot so far. The best way is to take part in every part of the repair/rebuild that you can. You will not pick up more experience any other way.

Good Luck with your engine build

 

[Bullitt]

Hello T. I was just looking through my PAW book again, and they have what's called a Super Gorilla small block. It can be had in 420 (.030 over) or 426 cubic inches (.060 over). The bore is 4.125+, 3.875 stroke and a 5.700 connecting rods. This is with a 400 block and a custom ground 5140 forged crank.The total is $3700 for a short block assembly. I'm sure that there are other ways to get a big cubed small-block, as this one does.

Following up on the heating problem. Are you sure that there are no restrictions/clogs in the radiator or the coolant passages of the block? Just wondering aloud here.

--Bullitt

 

[400hp_76]

Bullitt and stingray 74cc

Thanks for the info on the 400 sb. If you dont mind , if you find out anymore please let me know.and as for my cooling problems. I am leaning more towards a bad engine setup. I mean i had so much trouble with the cam and components matching up. it was extremely hard to get timing correct and have it idle right. The funny thing about the timing is that it ran cooler when i had the timing high(which it is usually the opposite). I think that was because it was idling higher at a stop and the flex fan was pulling more air or possibly it was burning the fuel better , instead of burning the excess fuel off in the headers(super comp.hookers). 74cc, I dont just take part in the rebuild which i have done twice already i do the rebuilds,haha. My dad used to drag race. So working on cars is pretty natural to me. I love working on cars keeps me out of trouble, that is until the car runs again(cops hide behind every corner). thanks alot ,P.S. my bad on the black cherry color.

 

[jsimpson]

Retarded timing causes engine overheat, possibly because of slow burn. Mnay people retard their timing to enable their high compression engines to handle lower octane fuel. Then they end up with overheating problems. Advanced timing causes preignition. Neither are good.

 

[jsimpson]

999 times out of a thousand, a C-3 overheating is caused by not adequately channeling air through the radiator. the faster a C-3 goes, the more the slanted rdiator starts acting like a wedge and sliding air over it instead of through it. Two things are paramount in C-3 cooling. An adequately installed lip spoiler that channels air from below the bumper up through the radiator, and a sealed area infront of the radiator that allows NO air to escape around the radiator. Even if your fan clutch is practically freewheeling, if the radiator is properly sealed off, you won't overheat in South Florida with the air on!

 

[Stingray74CC]

Update

The new radiator is in and working fine. I'm still running above 200 but no where near as hot as I was. I ran her hard to and didn't come near over heating. I know that my timing is off some.....Pings a little when I stomp on it at lower RPMs. I'm pretty sure it's the timing, along with that vacuum advance thing I was talking about in the other thread.

I now have a nice factory shroud, an electric fan and an original radiator if anyone is interested in any of these things. I'm not sure why someone would want the radiator, but I haven't thrown it away yet.

 

[jsimpson]

If your timing is too far advanced, you can expect the engine temp to rise after you set the timing back.