Solving V8 Conversion overheating, Exhausting out the HOOD is THE answer Options

[stewteral]

Hey V8 conversion 914ers,

I’ve been running my car for some 7 years now and chose to exhaust the radiator out the bottom of the car. It seemed to work fine, but in the 100 degree summer heat of Willow Springs, I was seeing water hitting 250 degrees with fans blazing.

We all know that from the 60’s, race cars have vented out to TOP of the hood and it worked well for a friend’s Corvair 327 Chevy we ran at Riverside (142 MPH on the short course back straight). However, I originally didn’t want the car to look too “radical.” When I got the car running it had 11” fender flairs, side scoops, roof scoop and a wing……Ya’ cops won’t notice my car!

With some time before my next event, I redid the whole radiator layout where I sealed the bottom of the trunk, HACKED a hole in the hood and fabricated radiator shrouding and an exhaust air dam. I upgraded my fans too.

This morning in 60 degree temps, I took the car for a drive AROUND town at low speeds to see if I could keep it from overheating in traffic, as it used to. What I found surprised me: I drove the whole run with NO fans and water temp at 140 degrees. When I was caught by a stop light, the temp went up to 160, but once moving again, it moved back down.

I jumped on the freeway and both oil and water dove down to 120 again. EUREKA, I have found my solution!

Conclusion:
-Of course 120 is lower than desired, in spite of the 180 degree T-stat, but I’m aiming at the right temp ON-Track in Summer. If I want to so some street driving, I can always tape off some of my intake opening.

-In the previous configuration, I would have had to run the radiator + oil cooler fans and worry about over heating, now with NO fans, the temps are on the low side.

-Before, the oil temp would exceed the water temp by some 30 degrees, now the oil matched the water temps, at least in street driving.

-The internal hood bracing defines the hole shape as a trapezoid, so I cut all the width I could get right to left. The back edge is defined by the rear wall of the trunk and from there I measured 12” forward, held my breath, and cut.

-If your V8 car is on the edge of overheating and big fans aren’t enough, give this a try. Mine is a pure “racer” design, but our friend byndbad914 came up with an attractive louvered approach that keeps his 500 HP small-block cool. In another design, AndyS created a very attractive molded “air dam” for his LS1 conversion.

Being pleased to see all the work was worth it, I wanted to pass it along.

Best,
Terry

[kyracedog]

What radiator is this in your car?
I am considering cutting the hood for more air as well. Good to see it works well.

Hey V8 conversion 914ers,

I’ve been running my car for some 7 years now and chose to exhaust the radiator out the bottom of the car. It seemed to work fine, but in the 100 degree summer heat of Willow Springs, I was seeing water hitting 250 degrees with fans blazing.

We all know that from the 60’s, race cars have vented out to TOP of the hood and it worked well for a friend’s Corvair 327 Chevy we ran at Riverside (142 MPH on the short course back straight). However, I originally didn’t want the car to look too “radical.” When I got the car running it had 11” fender flairs, side scoops, roof scoop and a wing……Ya’ cops won’t notice my car!

With some time before my next event, I redid the whole radiator layout where I sealed the bottom of the trunk, HACKED a hole in the hood and fabricated radiator shrouding and an exhaust air dam. I upgraded my fans too.

This morning in 60 degree temps, I took the car for a drive AROUND town at low speeds to see if I could keep it from overheating in traffic, as it used to. What I found surprised me: I drove the whole run with NO fans and water temp at 140 degrees. When I was caught by a stop light, the temp went up to 160, but once moving again, it moved back down.

I jumped on the freeway and both oil and water dove down to 120 again. EUREKA, I have found my solution!

Conclusion:
-Of course 120 is lower than desired, in spite of the 180 degree T-stat, but I’m aiming at the right temp ON-Track in Summer. If I want to so some street driving, I can always tape off some of my intake opening.

-In the previous configuration, I would have had to run the radiator + oil cooler fans and worry about over heating, now with NO fans, the temps are on the low side.

-Before, the oil temp would exceed the water temp by some 30 degrees, now the oil matched the water temps, at least in street driving.

-The internal hood bracing defines the hole shape as a trapezoid, so I cut all the width I could get right to left. The back edge is defined by the rear wall of the trunk and from there I measured 12” forward, held my breath, and cut.

-If your V8 car is on the edge of overheating and big fans aren’t enough, give this a try. Mine is a pure “racer” design, but our friend byndbad914 came up with an attractive louvered approach that keeps his 500 HP small-block cool. In another design, AndyS created a very attractive molded “air dam” for his LS1 conversion.

Being pleased to see all the work was worth it, I wanted to pass it along.

Best,
Terry

[stewteral]

[quote name='kyracedog' date='May 1 2010, 05:44 PM' post='1312252']
What radiator is this in your car?
I am considering cutting the hood for more air as well. Good to see it works well.



[quote name='stewteral' post='1308505' date='Apr 24 2010, 09:00 AM']
Hey V8 conversion 914ers,

I’ve been running my car for some 7 years now and chose to exhaust the radiator out the bottom of the car. It seemed to work fine, but in the 100 degree summer heat of Willow Springs, I was seeing water hitting 250 degrees with fans blazing.

We all know that from the 60’s, race cars have vented out to TOP of the hood and it worked well for a friend’s Corvair 327 Chevy we ran at Riverside (142 MPH on the short course back straight). However, I originally didn’t want the car to look too “radical.” When I got the car running it had 11” fender flairs, side scoops, roof scoop and a wing……Ya’ cops won’t notice my car!

With some time before my next event, I redid the whole radiator layout where I sealed the bottom of the trunk, HACKED a hole in the hood and fabricated radiator shrouding and an exhaust air dam. I upgraded my fans too.

This morning in 60 degree temps, I took the car for a drive AROUND town at low speeds to see if I could keep it from overheating in traffic, as it used to. What I found surprised me: I drove the whole run with NO fans and water temp at 140 degrees. When I was caught by a stop light, the temp went up to 160, but once moving again, it moved back down.

I jumped on the freeway and both oil and water dove down to 120 again. EUREKA, I have found my solution!

Conclusion:
-Of course 120 is lower than desired, in spite of the 180 degree T-stat, but I’m aiming at the right temp ON-Track in Summer. If I want to so some street driving, I can always tape off some of my intake opening.

-In the previous configuration, I would have had to run the radiator + oil cooler fans and worry about over heating, now with NO fans, the temps are on the low side.

-Before, the oil temp would exceed the water temp by some 30 degrees, now the oil matched the water temps, at least in street driving.

-The internal hood bracing defines the hole shape as a trapezoid, so I cut all the width I could get right to left. The back edge is defined by the rear wall of the trunk and from there I measured 12” forward, held my breath, and cut.

-If your V8 car is on the edge of overheating and big fans aren’t enough, give this a try. Mine is a pure “racer” design, but our friend byndbad914 came up with an attractive louvered approach that keeps his 500 HP small-block cool. In another design, AndyS created a very attractive molded “air dam” for his LS1 conversion.

Being pleased to see all the work was worth it, I wanted to pass it along.

Best,
Terry


Hey kyracedog,

If you live anywhere that gets hot, I think it is the only way to go. Our bud, byndbad914, with the tube-frame V8 car, has a very attractive louvered exhaust that is hardly noticeable. You can check out his approach on his website: http://www.negativereinforcementracing.com/ . The outlet louvers are standard pieces from Summit Racing and readily available. byndad914 has a race-prep 355 SBC that puts out 500 HP at an insane RPM....he's a real engine builder.

Speaking of Summit Racing, that's where I got my radiator. It is a lower-cost ($270 current price) unit for a Camaro and measures 30-5/8" X 18-1/2". The Summit Racing number is SUM-380455. You can also chase eBay for a better price. I've run the stock radiator for 7+ years and simply put a high-pressure cap on it while relying on my header tank in the engine bay to purge the air from the system. The cap arrangement began to weep a bit, so just welded the filler neck over with a bleed hole for the initial fill up.

I liked the radiator because it was the BIGGEST I could fit in the car. To get it in between the headlight boxes took a bit of "massaging" of the boxes with a big hammer and in it went. Since I'm running a BUILT 383 SBC with 500+HP, I wanted the biggest I could get!

I'm a firm believer that there is no such thing as TOO much cooling and my new layout IS actually running the engine too cold (120 Deg.) However, as I said, I can easily block off parts of the intake to bring the temp up, if necessary.

My very smart bud AndyS advised me that the exhaust opening MUST be at least 1.7 times the intake area to ensure good pressure differential for good cooling. Carroll Smith advises that the INTAKE opening must be >40% of the radiator area, so I'll leave you to do all the calculating! (IMG:style_emoticons/default/smile.gif) The bottom line is that it works GREAT!

Good luck,
Terry

[rickthejetman]

.
"If you live anywhere that gets hot, I think it is the only way to go. Our bud, byndbad914, with the tube-frame V8 car, has a very attractive louvered exhaust that is hardly noticeable. You can check out his approach on his website: http://www.negativereinforcementracing.com/ . The outlet louvers are standard pieces from Summit Racing and readily available. byndad914 has a race-prep 355 SBC that puts out 500 HP at an insane RPM....he's a real engine builder."

ok so maybe i'm blind i looked all over the summit racing site for functional hood louvers and no joy. can you point out exactly where i might find some like the ones on byndad914's car? that is exactly the thing i have been searching for. i like the big hole in the hood look(as long as it has the proper ducting to go along with it) but i think the louvers are more my speed

[byndbad914]

ok so maybe i'm blind i looked all over the summit racing site for functional hood louvers and no joy. can you point out exactly where i might find some like the ones on byndad914's car? that is exactly the thing i have been searching for. i like the big hole in the hood look(as long as it has the proper ducting to go along with it) but i think the louvers are more my speed

I have the Genesis louvers - I can't recall if I got them from HRP specifically but I think that was the case. It wasn't Summit tho'. I think some circle track places had 'em but not as cheap as I ended up finding. Have smaller ones in my roof as well.

Nonetheless, here is a link and you can search away on the net to find if there is better pricing elsewhere

http://www.hrpworld.com/index.cfm?form_pro...;action=product

[rickthejetman]

ok so maybe i'm blind i looked all over the summit racing site for functional hood louvers and no joy. can you point out exactly where i might find some like the ones on byndad914's car? that is exactly the thing i have been searching for. i like the big hole in the hood look(as long as it has the proper ducting to go along with it) but i think the louvers are more my speed

I have the Genesis louvers - I can't recall if I got them from HRP specifically but I think that was the case. It wasn't Summit tho'. I think some circle track places had 'em but not as cheap as I ended up finding. Have smaller ones in my roof as well.

Nonetheless, here is a link and you can search away on the net to find if there is better pricing elsewhere

http://www.hrpworld.com/index.cfm?form_pro...;action=product

thank you very much thats exactly what i have been looking for. but i promise i won't copy your car all the way (IMG:style_emoticons/default/KMA.gif)
p.s. i used to go to school at jefferson county airport. loved living in broomfield

[byndbad914]

p.s. i used to go to school at jefferson county airport. loved living in broomfield

weather is getting nice again so a few of us roll over to JeffCo and have lunch periodically and watch the planes come and go on the patio. And I lived in SoCal (LA and OC) 'til 3 yrs ago so we just traded states... my tube chassis was built in Orange in '06 and that shop is now in Corona.

I have a dyno sheet that shows 460hp at the rear wheels at 6000rpm.

I was just spoofing on that you stated FWHP which would be front wheels (IMG:style_emoticons/default/happy11.gif) I now realize you meant at the flywheel, or BHP (brake HP).