Blown Chevy V8 with scoop through hood

[raoul reese]

Can a superchargered engine with a scoop in the hood be harmed by operation in rain?
I installed a Weiland supercharger 142 c.i.d. and new 350 Chevy crate engine in my 1975 FJ40. I am pleased with the performance; the math says about 400HP. I know it is much less at the wheels. The cruiser had a hole in the hood covered by pexiglass which the PO had installed; he may have had a scoop at one time before he stripped it for sale. I wanted to fill it because it looked lame. So I installed a Holley scoop through the hood. The scoop I installed has an installed filter but as you would expect provides a direct path through the supercharger to the engine. My mechanic cautioned me to avoid heavy rain and the possibility of ingestion. I am trying to detrmine how great a risk rain actually poses.

Yesterday while surfing the net I ran across a performance web site. This site indicated that this set up, scoop and supercharger, should not pose a risk of rain ingestion during street use; moreover they stated that water was sometimes introduced in supercharged drag racers to cool the compressed air. So now I have conflicting view points and this forum seems to be the perfect place to resolve an issue with conflicting views.

I attached a pic even though I know it doesn't show the installation very well. I keep the cruiser at a remote site which I will not be able to go to for the next three weeks so this is the best I can do.

I know you guys are likely to have the answer. Tahnks for the help.

 

[VTFJ40]

I'd avoid the heavy rain. Too much water would be bad. How much I don't know.

It's probably different for each application. I wouldn't compare it to the drag cars. The amount of air and fuel they're consuming is a whole different world.

Good luck!

 

[chuglife]

i am thinking when they say drag cars are introduced to water to cool down the air, they mean they have an air/water intercooler, not actually putting water in the comb. chamber

sounds like a sweet setup though

 

[raoul reese]

This is the quote from the website "Scoop and supercharger IN THE RAIN:

Rain is no problem, because most driving is done at part throttle and the butterflies will be pretty much closed.

The only thing you would have to take care of is to shield the distributor from getting water on it, as per any open hood situation, otherwise there would be no other major considerations.

The scoops come with standard Hi-Perf paper filter elements but you can also run up to a 2 3/4" x 10" diameter (a lot bigger than other single street scoops) high quality K&N filter element which will not be affected by the weather.

K&N claim that there filters will still flow the full amount of air even if they are wet.

If you did hit wide open throttle it wouldn't make any difference anyway even if a small amount of water entered any engine, on some blown engines on the street, they inject water into the engine to cool the charge and resist the possibility of detonation. "

Maybe different scoops have different ingestion risks?

Has anyone got info on this. Thank you

 

[fsusteve]

I'm not really sure why you would run this setup, unless you compete in mudbog racing or something. The few times I've seen those guys run they usually run some type of cowling over the carbs, but obviously it can't be water/air proof or the motor wouldn't run. Maybe look there for the answer.

 

[cahilc]

What you have is very similar to the setup I will be migrating to in the future. I like the Weiland setup with Chebby 350. Gonna try and go small block 400(same block size). Current 2F is fine but when she goes ...

Water injection has been used to lower combusitons temp. Lot's of places have played with this for effciency in fuel economy to performance. The main stumbling block have been maintenance. The water injection systems corrode like crazy.

Hydrostatic loading ??? Fancy buzz word ?

Me *thinks* you would be *ok* in the rain as long as your start dry from under shelter(scoop not full of water) and finish dry under shelter(engine cools slowly and evenly).

Problems will occur when you get to much water through the intake(starting, running, or stopped hot) which could either radically increase compression or quickly cool the interior of the motor too rapidly ... sorta like a big splash of water dousing a fire.

My thoughts, hope it helps,
Cahil

 

[raoul reese]

Thanks sounds like you know what you are talking about.

 

[cahilc]

I'm sorta a newbie to this forum. There is a *wealth* of knowledge in the folks who read & post here. Very impressive. Your in the right place.

Sent ya' PM with more info.

Cheers,
Cahil

 

[Halogrinder]

Simple Answer If You Are Really Scared About It. Turn The Scoop Around.....actually, It Will Get Plenty Of Air In It Going Down The Freeway, Cause Of The Pressure Built Up In Front Of The Windshield Will Be Going Right In It....i Wouldnt Worry At All Though.... I Can Take A 350 Engine, Hold It Wide Open, And Turn A Milk Jug Upside Down Over The Carb To Clean Out The Valves And Combustion Chambers With No Problems, Thats Way More Than You Will Ever See Driving

 

[TJDIV]

Simple Answer If You Are Really Scared About It. Turn The Scoop Around.....actually, It Will Get Plenty Of Air In It Going Down The Freeway, Cause Of The Pressure Built Up In Front Of The Windshield Will Be Going Right In It....i Wouldnt Worry At All Though.... I Can Take A 350 Engine, Hold It Wide Open, And Turn A Milk Jug Upside Down Over The Carb To Clean Out The Valves And Combustion Chambers With No Problems, Thats Way More Than You Will Ever See Driving

That's hard to read.


But your point is good. Our shop Yukon has a Weiand 175 on a SBC355 and I run in very, very heavy rain in FL. NO problems. Scooped as well.

Good Luck.