Letting heat out

Running a 19t on 90plus manifold in a 240. Anyone come up with any ideas of a vent on the hood that looks good? On muscle cars they would raise the back of hood a couple of inches. Not sure if that would look right on a 240? Any ideas? Or pics?

not necessary. 240 turbo cars came with hood blankets to keep the heat and noise in.

If you really care about thermal issues from a turbo, Get ceramic coatings for the manifold and turbine housing. Keep the heat in, where its useful.

do you have the belly pan on?

90volvo said:

Running a 19t on 90plus manifold in a 240. Anyone come up with any ideas of a vent on the hood that looks good? On muscle cars they would raise the back of hood a couple of inches. Not sure if that would look right on a 240? Any ideas? Or pics?

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As Ben mentioned, it's not super necessary on a street car unless you are driving it really hard for extended periods of time.

But this is what I did on my stage rally car that gets run hard for 15+ minutes at a time sometimes in places where the ambient temp is already 100 degrees. I also have a giant skidplate under the entire enginebay, so it's a must. I am also running my turbo with a blanket and some wrapping on the downpipe.

For the coffin hood, I really am satisfied with what I came up with because I got to avoid cutting any structure from the hood.





The side vents are cheap ebay pieces while the center piece is from a Jeep Wrangler. The placement of it is good as it pulls heat coming out from the radiator (can feel it after a hard run with the fan on.) The side vents are good for getting everything else out. It's worked great so far, I watched a lot of teams having to pull their hoods off at Oregon Trail last year [even some that were already vented] but I had no such issues.

https://www.amazon.com/Daystar-Wran...=1549223690&sr=8-5&keywords=daystar+jeep+vent

I also like Tuff240's old car which had a 300zx hood scoop, pointed backwards directly above the turbo

I was more concerned with underhood heat following the turbo LS swap on my car, and I got a junkyard hood. Planning on putting some extractor vents on either side above the headers. Something on either side of the central raised coffin:


But I haven't bothered to do so yet. The car doesn't overheat in use, and I have the e-fans wired so they can do a couple of brief cool down runs (if needed, controlled by a dumb temp switch on the top rad hose).

my top mount turbo was bubbling my new paint under the hood but a bunch of DEI adhesive heat shield took care of that.

I always open my hood up when it's back in the garage after a spirited drive so everything can cool down, also makes the engine bay less attractive to mice while it sits around. I have thought about some very low profile ventilation over the turbo, though. Too bad we don't have any old saab 900 hoods left around.

I think Pat and I did the same thing. Rally racing is a basically a non-stop dyno run for 5-25min with a ~40mph air speed. Turbo cars get hot (like really hot), but NA cars are generally OK. The more radiator you can have exposed to air, the better. Once you put a stock sized intercooler in front, that’s when the temps go up.
The only car I know of that doesn’t have this issue is the ex-John Lane turbo v6 car, but that’s using a radiator that’s nearly double the core area of a stock 240.

My radiator is huge and does a good job keeping temps at bay. I also have blanket on turbo and part of my downpipe wrapped. Just seems like alot of heat coming from turbo area. Thanks for all the input.

Found a picture a while ago of someone who reverse mounted an early 80s 300ZX hood scoop to act as a heat extractor. Thought it might work pretty well on a brick.

Alan29 said:

Found a picture a while ago of someone who reverse mounted an early 80s 300ZX hood scoop to act as a heat extractor. Thought it might work pretty well on a brick.

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I had that scoop as air inlet on the flat hood driver side. The base of the 300ZX scoop is curved so it would look really tilted on the passenger side.

280Z hood vent that was fitted about where the turbo is in this thread: http://forums.turbobricks.com/showthread.php?t=136136

blkaplan said:

not necessary. 240 turbo cars came with hood blankets to keep the heat and noise in.

If you really care about thermal issues from a turbo, Get ceramic coatings for the manifold and turbine housing. Keep the heat in, where its useful.

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Yeh in stock form that they designed everything works great. But, you change somethings and start making some big power, like running 24lbs boost. Things are gonna get hot. Heat kills alot of stuff under the hood. But yes, I still have my hood blanket and belly pan. When I put the vents in Im gonna remove the blanket. Next time I pull things apart Ill look into the ceramic coating. Thanks

I set the back of the hood 1/2 higher than stock on my V8 wagon. I have never had a problem with the motor running hot, but I had a custom radiator built for the car.

You all are forgetting the history of the PenisHood.
#freebrettwillis

90volvo said:

Yeh in stock form that they designed everything works great. But, you change somethings and start making some big power, like running 24lbs boost. Things are gonna get hot. Heat kills alot of stuff under the hood. But yes, I still have my hood blanket and belly pan. When I put the vents in Im gonna remove the blanket. Next time I pull things apart Ill look into the ceramic coating. Thanks

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I flogged the crap out of my car with a 19T @ 24 psi with no problems, my hood was not vented hood.

Alot of it comes down to driving conditions and environmental conditions. These cars are not prone to having issues that hood venting fixes even with modified cars but in certain instances, it definitely can help.

Pat posted an excellent example of rally cars running at low speeds with high loads for long durations, this is a scenario when it helps.

The easiest thing to try would be a turbo blanket, also a SS downpipe will put less heat into your engine bay than mild steel.

On my turbo I never had problems with the engine coolant running hot. Heat damage to other 'stuff' on the turbo side of the engine was a greater issue. If you run only with an electric fan, air temperatures can spike in the engine compartment when the fan cycles off (depending on how fast you are going). A viscous clutch fan is directly affected by engine compartment ambient temperatures so may be more effective at controlling under hood temperatures at lower speeds.

The most effective way to prevent damage is probably to wrap any wiring and hoses on the turbo side of the engine with thermal barriers. Those woven glass jackets with a shiny foil external surface look trick; but, once the foil gets dirty it looses a lot of its effectiveness. McMaster Carr and a lot of other vendors sell stretchable silicone rubber tubing which has a fairly heavy woven glass thermal barrier underneath the silicone jacket. Available in lots of sizes . This is my preferred 'stuff' for protecting wiring and hoses from ambient heat and thermal radiation - also protects wiring from oil (high heat + oil exposure = early death for electrical insulation).

The turbo blanket mentioned by blkaplan - if that means a tight fitting thermal jacket around the turbine that would also be my first vote in terms a high effectiveness/(effort and cost) ratio. Jacketing the down pipe will also help; but, exhaust gas temperatures exiting the turbine are much less than up stream temperatures. Jacketing the exhaust manifold should have a high thermal management benefit (and a potential performance benefit); but, can be really difficult to do well depending on the manifold design. This is a case where a simple view block heat shield to block sensitive parts from direct thermal radiation exposure from the manifold may be most effective (much like the simple heat shield used on the B230 FT to protect the spark plug wiring from manifold radiation).

thanks for all the advice. My car always runs cool with the big radiator I installed. I ordered couple of vents, and some wrap, and sleeves. Also plan to build a shield other than the stock plug wire ones. Thanks again.

Put AC in the bay.