Hey Charlie Chops.. speaking of louvers...Vapor lock?

[Dave]

Well it happened today.. Got to make a long trip in the 32 and it ran fine. The only problem is after a while it falls flat on its face when I hammer it. Actually it happens at full throttle. If I just drive the dam thing it runs good.. After sue and I got home i pulled the hood side pannels and took it out and beat the snot out of it and it ran fine so now I know its heat related.. This sucks cause i really like the smooth panels on the hood but if its not gonna work then i guess its soon to be louver time.. its funny that after our louver conversation at franks the other day I have trouble with heat. Im sure its got something to do with Vette Boy... He breaks things just thinking about em.. Oh ya I did replace the battery in my lectric fan ? I may have to get with ya and make a run up when you have time so we can punch some holes...................
Dave

[Charlie Chops 1940]

Dave, before ya start tearing her apart, make sure everything else is working correctly...proper timing, vac. advance, thermostat, fan(s) coming on, shroud....you know the drill. If none of that does it I suppose we're just gonna hafta let that bad air out.

Whenever you want. Strip the paint off both sides first. We can handle it from there. Might as well do the hood top while we're at it.....cheaper by the dozens ya know?

Charlie

[rumrumm]

I am concerned about this on my '32 as well, so I designed a cowl induction air scoop into the hood figuring not only would a little extra help but also thought it might release some heat from the engine compartment. The car is not running yet so I can't say if my theory works or not. I did not want louvers on the side of the hood because I am incorporating ghost flames, so this was my alternative.

[C9]

As a matter of interest, my 32's hood sides and top are liberally louvered.

I note when driving in city traffic - specially on a hot day - you can put your hand out the window and get a feel for the ambient temp.

Then lower your hand so you can feel the air on a level with the hood side louvers - bout 15-20 degrees hotter than the ambient.
Which goes to show the louvers are doing the job.

I would recommend against louvering the hood top if you have a cowl vent.
At slow speeds hot air from the engine compt. gets dumped into the cowl vent.
Highway speeds seem to create a pressure rise over the hood and the hood louvers don't seem to flow as much - if at all - hot air and the cowl vent works well then as far as bringing in cool air.

At highway speeds:
Over the hood air flow probably allows the louvers to exhaust air if the car has a fairly level stance.
With the rake most of us run, air flow over the hood is different due to the 'wedge' angle the hood is hitting the air at which creates a high pressure over the hood.

Slow speeds, the fan pressurizes the engine compartment and forces air out through the louvers.

Thin fender (A's, Deuces, etc.) cars have small engine compartments and engines put out a lot of heat.
Bigger the engine, both physically and in CID, the more heat.

Air flow in engine cooling is responsible for about 40% of the cooling, oil is about 20% and the radiator/coolant combo takes care of the remaining 40%.

Henry Ford put the louvers in hood sides for a good reason.

[Charlie Chops 1940]

Jay,

Good observations. It's been my experience that hood top louvers are just a part of the heat extraction. On my A Victoria 20 years ago I went louvered top, smooth sides and it never cooled in traffic like I thought it should have. I think louvered sides would have been helpful. A lot of guys don't like louvered hood tops because of rain getting in, and the usual cleanup problems. I just made washing the engine part of the routine. Never had any wet ignition problems with that car.

On my track roadster pickup the track nose opening is somewhat smaller then the area of the radiator so I have put some effort into closing off around the radiator with aluminum baffles and have fabricated a little air dam that slopes down and forward from the top of the front crossmember to about an inch below the shell...hoping I can scoop up a little more air through the radiator. Then a lot of hood top, side and belly pan louvers.

Again, ya never really know til you try it. There is so much anecdotal evidence about what works and doesn't, that one has to really pay attention and disect how ones guys experience relates to yours.

[Mikej]

A hood scoop might help. It could be more of a problem with the temp of the induction air.
If it is vapor lock, insulating the fuel line might help and an insulated spacer under the carb.

[Dave]

Ive already done the block under the carb thing so possibly moving the fuel line a bit or insulating it is the next option along with playing with the timing a little bit but it looks good. Man I hate to louver the sides cause it looks so good. Charlie I did some checking today and If i want i could go with new sides with 4 rows of louvers for about 150 bucks. That would save the ones I have and after fitting the new sides I would just have to drop em off to the painter. Its an option im looking at. I read an article in one of my manuals today that says vapor lock is more of a problem in the spring and fall. I wonder if thats still true today as its an older manual. They based it on the fuels but im thinking all the fuel is junk now so the problem is going to be there all summer.............
Dave

[purplepickup]

A lot of guys don't like louvered hood tops because of rain getting in, and the usual cleanup problems.

I louvered my hood and am glad I did.  It is the one place you can admire your own louvers while you're driving.   A lot of the asthetics of a rod are only enjoyed by people outside the car when it is passing by.  I believe sights like this are best viewed over a louvered hood.


I have had problems because of the louvered top tho.  Twice the truck has sat in extreme thunderstorms (not running) when the wind was coming from the rear of the truck.  The rain went into the louvers and ran down the air cleaner element into the air cleaner base and down the carb then into the engine.  The first time I didn't even think about it and when I started the engine I immediately heard a CLINK followed by loud knocking.   Enough water got into # 7 cylinder to bend a rod when it started.  The second time I didn't take a chance and took the plugs out first and rolled it over.  Water shot out of a couple of plug holes.

I fixed that hassle tho by taking a piece of 1/8" aluminum sheet with a slight break in the middle to protect the engine from water.  I've never had any problems since.  An air cleaner base that didn't act like a funnel would work too.

[Dave]

Well im learning sumpin i think. I may change back to rubber fuel line because of its insulating properties. Thats on the carb side of the pump. Also insulating is a good idea but id rather not do it unless needed. Changing from a manual to an electric pump seems to help also.The engine seems to run cool but its the under hood temp from not enuff air flow thats mucking it up. I went out for a bit tonite and its fine but its also cooler than yesterday. I could also just drive it and never try to hammer it then id hardly know I have a problem ? NAH..... I did most of my research on the net tonite and found all these tips for curing the problem. Of course mine runs fine at slow speed and idle  which is a little different than a lot of vapor lock problems but it was covered on a few sites.. I dont mind the louvers in the side panels I guess but if I was going to do it I should have just bought the hood with the louvers. I thought about that but didnt.. I see a lot of rods in the mags with smooth panels so im not done yet...
Dave

[Charlie Chops 1940]

Dave,

I'm glad that you are looking at all the possible solutions as it is likely to be a combination of factors, not just louvers or no louvers. If you can get it to an acceptable level of cooling and no vapor lock problems without punching holes in a smooth car, then more power to ya. I'd hate to do a bunch of louvers and have it not do much good because of other problems.

Charlie

[Dave]

Dave,

I'm glad that you are looking at all the possible solutions as it is likely to be a combination of factors, not just louvers or no louvers. If you can get it to an acceptable level of cooling and no vapor lock problems without punching holes in a smooth car, then more power to ya. I'd hate to do a bunch of louvers and have it not do much good because of other problems.

Charlie

Well I went ahead and ordered the side panels from rootlieb today. Mainly cause the actually had em in stock. I sure hope they fit but I know ill have to do some trimming on the ends its the height to the bend at the top i worry about. I bought a herclues hood for the 34 and i had to put the bends in the side panels maybe ill get lucky and get panels this way but im not banking on it.. I changed my lines to braided stainless tonite to get rid of the heat build up in the aluminum line. I had a piece running from the carb down to the fuel filter. I also fabbed a new bracket to hold the line in position as the one I had mounted to the cylinder head and the filter attached to that and when I checked it tonite it was hot so i figured that was transfering heat to the filter also. Heres where I first screwed up. I went with the smooth side panels because I figured they were cheaper than the louvered ones?? Wrong answer .. They are the same price and i should have todl Michael to go with the louvers when I ordered the roller. I even got 4 row lovered instead of 3 for the same price.. I got thinking about it today and I decided for peace of mind and driveability id just buy the louvered sides and be done with it. I dont need any heat problems cause im having too much * fun driving it...
Dave

[river1]

dave, have you tried takin her (it is a her right?) out for a spin with the side panels removed? it might tell you you're looking for the wrong answer.

later jim

[Dave]

ya it ran good without em.. did that sunday when the problem first reared its ugly head.. its vapor lock...
Dave

[river1]

yeh figured you already tried that, but you know how it is sometimes we (ME) overlook the easy stuff.

later jim

[exsedan]

That sure does look like the road to 1FATGMC (Sumner)'s place......jb EXSEDAN