running a large engine
Team Owner
Joined: Feb 2003
Posts: 54,049
Likes: 9,390
From: Sitting in his Nowhere land Hanover Pa
2024 C2 of the Year Finalist - Unmodified
2015 C2 of Year Finalist
While the car is moving it's not bad. Coming to a stop is where it gets warm. But it all depends on out side temp.
Melting Slicks
Joined: Oct 2004
Posts: 3,345
Likes: 87
From: Northern MN
St. Jude Donor '13-'14-'15-'16-'17
I think it would depend on the exhaust. On my car with side exhaust it is not overly warm even in the summer months. I would think with the under car exhaust that the heat from the engine and exhaust would heat up the cabin fairly quickly, especially in the warmer weather conditions.
Melting Slicks
Joined: Feb 2015
Posts: 2,565
Likes: 1,115
From: Huntsville AL & Hills of Southern TN
Our '66 BB car is only used for pleasure so don't recall ever driving it when it's cooler than mid-60's and never with the top up. We're in the south so cruises with temps in the 80's to 90's are common. My wife and I usually drive with the vents almost turned to the max blowing air on our laps. Yes, it feels warm under the dash, but with the vents open not uncomfortable. Engine temps 180's when cruising so normal. Even when caught in traffic and closely watching temps creep up it's still not intolerable.... but you can definitely feel the engine heat rising. If it's so hot requiring AC we don't take the vette. Bottomline, not objectionable enough to discourage you from the BB. Cheers
CF Community Team
Joined: Oct 2004
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From: Cape Cod, Mass.
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More of an issue with coupes. The rear window creates a greenhouse effect. In the summer a convertible with the roof off makes it a non issue.
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
they are a larger heat sink than a sbc wouldnt worry too much unless you drive in the middle of summer. Can always add ac...small price to pay for having that brute torque...do it!
Instructor
Joined: Apr 2015
Posts: 114
Likes: 25
From: San Diego ca
Lots of articles on the forum about heat and noise reduction. Three twenty-seven owners
with a sea of silver on the floorboards trying to reduce heat and noise. I don't see it getting any better with a big block.
GJM
with a sea of silver on the floorboards trying to reduce heat and noise. I don't see it getting any better with a big block.
GJM
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Race Director
Joined: Nov 2003
Posts: 10,696
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From: Cottonwood AZ
C1 of Year Finalist (performance mods) 2019
The fiberglass firewall and floors absorb and let a lot of heat in the cockpit unlike steel that will reflect more of it. Another thing is that the 50 year old firewall grommets for things like speedo and tach cables dry up fall out and let a lot of heat in. Insulate the bottom side of the floors everywhere you can and also on the inside of the body everywhere you can. The original A/C in these cars is marginal at best and the cooling is as well with the radiator and A/C condenser laying in at an angle rather than standing up straight like in the C1s.
Instructor
Joined: Jul 2010
Posts: 112
Likes: 3
From: Redmond WA
I'm running a 454 LS6 as a driver engine in my numbers matching '66 convertible with factory side exhaust and there is minimal under floor heat. I also added a DeWitt custom aluminum radiator and Stewart stage IV pump with a 7 blade HD GM fan. No engine over heat and no objectionable cabin heat.
Melting Slicks
Joined: Sep 2010
Posts: 2,104
Likes: 701
From: Southern Illinois
We have a '66 L72 conv w/sidepipes and take some pretty lengthy trips in it. Top up/down, rain/shine, cold/hot and really can't imagine that it's much worse than a SB car under similar circumstances. I think the coupe would certainly feel hotter (either engine) but only due to the less airflow though. When stuck in traffic while cruising through Biloxi, Mississippi during the heat of summer, lacking AC is going pretty much suck no matter what you're in. 
