Hot under the Hood
Thread Starter
Racer
Joined: Sep 2002
Posts: 420
Likes: 1
From: SAN DIEGO CA
Hot under the Hood
Im sure this question has come up a few times but I couldnt find a post on "under hood temperatures". I have an 86 vette with a 383 stroker in it. I have the Lingenfelter intake and plenum. I also have TPIS coated headers and Dart Pro alum heads. After the car has warmed up I will sometimes open the hood only to find that it is as hot as an oven. If I stick my finger 1 inch from the header pipe I could seriously burn myself!!! My spark plug wire laid against the header for 10 minutes after warming up and it burned the wire to the core (my fault). Also, the hood gets very very very hot. Almost to hot to the touch. Im wondering if this is the reason the paint on the hood started to crack. Is there anything I can do to bring the temp down in the engine bay? 
Melting Slicks
Joined: May 2004
Posts: 2,524
Likes: 10
From: Lufkin Texas
St. Jude Donor '05-'06
Is it running ok?? Are your operating temps within reason?? You may be running lean which causes excessive heat. I've seen some glowing headers from a lean condition on an F body. Make sure your fuel pressure and delivery is up to snuff.
Burning Brakes
Joined: Feb 2001
Posts: 769
Likes: 0
From: Granbury TX
My 1987 burned last Thursday, after a year and a half of blood swet and tears. I have the same headers as you but I don't think brand is an issue. Several months ago, after I first installed my new engine, on initial start-up the old Mem-cal had the car running so rich that I was throughing flames out the exhaust and melting a nead-by hedge roll. The headers were glowing red within seconds and wiring and plastic components near the headers melted before I could shut the engine off.
After that, I corrected many tuning issues and installed insulation on cables, spark plug wires and starter. I thought all was well.
I went home for lunch Thursday and had some time to kill, so I took the Vette for a short 5 or 6 minute drive. I pulled back into the driveway and went into the house for lunch. About 20 minutes later, I left the house and began to clime into my van and head back to work. I looked up in the direction of my Corvette and was shocked to see flames shooting out above the right front wheel and along the windshield.
Take these "heat" issues serious. No one should have to feel the sick feeling as their car burns, the way I did.
After that, I corrected many tuning issues and installed insulation on cables, spark plug wires and starter. I thought all was well.
I went home for lunch Thursday and had some time to kill, so I took the Vette for a short 5 or 6 minute drive. I pulled back into the driveway and went into the house for lunch. About 20 minutes later, I left the house and began to clime into my van and head back to work. I looked up in the direction of my Corvette and was shocked to see flames shooting out above the right front wheel and along the windshield.
Take these "heat" issues serious. No one should have to feel the sick feeling as their car burns, the way I did.
Thread Starter
Racer
Joined: Sep 2002
Posts: 420
Likes: 1
From: SAN DIEGO CA
My car caught fire last Valentines because positive cable had somehow been scraped. In time it wore through enough to charge the block with power. It fried my stainless steel brakes lines causing them to ignite and it caused a fire under my Brake Master. Thats why I wanted to know what is too hot for a car. And if other people with 383 engines have this same problem. 
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Le Mans Master
Joined: Jan 2002
Posts: 9,036
Likes: 13
From: Edmonton AB
Originally Posted by PMARTINEZ92126
I would like to have another person check it out to make sure everything is fine.
in C4 Scan & Tune, as well as in C4 Tech.
.
Le Mans Master
Joined: Jan 2002
Posts: 9,036
Likes: 13
From: Edmonton AB
Originally Posted by stubbs
Where can you buy those?
also offer vents.
Here is a thread with those three and perhaps some other sources.
'who sells these hood scoops (GS977: 01-11-2006, 07:32 PM)'
I didn't look to see if it was covered in this thread but there has been
discussion about where the water goes when there is rain. Some of
the vents are reported to have more sophisticated arrangements than
others. Advanced searches on Greenwood and/or Mold Kraft will bring
back the threads.
.
Fixed timing and no more problem!
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Getting hot underhood air out from under the hood has always been an issue with header-equipped C4's. Engine timing plays a big part as the headers radiate more heat because they are typically larger and longer than the stock GM manifolds in either cast iron or steel tube.
If you think of the motor as a giant heat sink, there is a lot of heat stored under the hood. Coolant temps also play a part in heat build-up. Having the coolant at 180 instead of 295 to 210 helps keep underhood temps down.
A number of years ago, Corvette Fever ran an article about a company that developed a set of exhaust fans that installed in the fender wells to help extract hot air. They looked like PC fans and were small enough to fit up to 3 per side depending on how much of a heat problem there was. You could wire them to a temp sensor for automatic operation or just a toggle switch.
Don't know what happened to the company but it seemed like a great idea.
If you think of the motor as a giant heat sink, there is a lot of heat stored under the hood. Coolant temps also play a part in heat build-up. Having the coolant at 180 instead of 295 to 210 helps keep underhood temps down.
A number of years ago, Corvette Fever ran an article about a company that developed a set of exhaust fans that installed in the fender wells to help extract hot air. They looked like PC fans and were small enough to fit up to 3 per side depending on how much of a heat problem there was. You could wire them to a temp sensor for automatic operation or just a toggle switch.
Don't know what happened to the company but it seemed like a great idea.
Le Mans Master
Joined: Jan 2002
Posts: 9,036
Likes: 13
From: Edmonton AB
An 80mm PC case fan (3.14" fan) is typically capable of 30-35 CFM flow.
These are not typically designed for use in harsh, external conditions.
Derale Tornado fans flow between 400 CFM for the 7 & 8" (4.8A) up to
2175 CFM for the 16" (18.4A). Spal fans are well known for their flow
characteristics, too.
I've haven't seen it done on a C4 but I believe it is Superformance's
version of the Cobra Daytona Coupe that uses Derale-like fans to
pull air out of the engine compartment.
.
These are not typically designed for use in harsh, external conditions.
Derale Tornado fans flow between 400 CFM for the 7 & 8" (4.8A) up to
2175 CFM for the 16" (18.4A). Spal fans are well known for their flow
characteristics, too.
I've haven't seen it done on a C4 but I believe it is Superformance's
version of the Cobra Daytona Coupe that uses Derale-like fans to
pull air out of the engine compartment.
.
Thread Starter
Racer
Joined: Sep 2002
Posts: 420
Likes: 1
From: SAN DIEGO CA
any thoughts on wrapping the headers in that header wrap i see at the hot rod shop? Its like a cloth in a roll that comes in about 10 to 15 foot rolls. I just ordered some of those boot guards for each plug wire. I see them advertised for 40 -60 bucks for a set of 8 but I found them for 27 dollars online. Hopefully I wont burn any more wires. I do believe its time to get the Headers recoated because the ceramic coating is flaking off. Should I go with the same coating or try something else?
Le Mans Master
Joined: Jan 2002
Posts: 9,036
Likes: 13
From: Edmonton AB
Header wrap is what you use after you make sure everything else is
as it should be. There are pros and cons but let's hold off on those
for now.
Start by looking into the basics of a tune-up (parts in good condition
and all settings within parameters) which you can pretty much do
yourself. Then see someone local or gather the knowledge and
equipment necessary to work with a remote tuner.
Use the Advanced Search to find several recent threads about
'Headers' or 'Exhaust glowing red hot' to read about others who have
experienced what 'skateparkdave' posted about above and how they
solved this problem.
.
as it should be. There are pros and cons but let's hold off on those
for now.
Originally Posted by PMARTINEZ92126
The company "Fastchip" did it about three years ago. I would
like to have another person check it out to make sure everything is fine.
like to have another person check it out to make sure everything is fine.
and all settings within parameters) which you can pretty much do
yourself. Then see someone local or gather the knowledge and
equipment necessary to work with a remote tuner.
Use the Advanced Search to find several recent threads about
'Headers' or 'Exhaust glowing red hot' to read about others who have
experienced what 'skateparkdave' posted about above and how they
solved this problem.
.
Racer
Joined: Sep 2005
Posts: 484
Likes: 0
From: Germany
I do believe its time to get the Headers recoated because the ceramic coating is flaking off. Should I go with the same coating or try something else?