Best way to seal up cowl vents?

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Re: Best way to seal up cowl vents?

Postby dindin » Wed Feb 10, 2016 2:20 pm

I would seal up any exhaust leaks first, have you looked into an oil catch can setup??

Al
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Re: Best way to seal up cowl vents?

Postby EVL VEGA » Wed Feb 10, 2016 6:42 pm

dindin wrote:I would seal up any exhaust leaks first, have you looked into an oil catch can setup??

Al


I have looked into a catch can.
A catch can won't work without a source of vacuum. (right?) I'm not going to send it back into the intake and under WOT..where my biggest blowby problem is..you won't have any vacuum anyway.
The problem with the header style evac kits is most people say it will only work with open headers which i use at the dragstrip or cruising up and down the main drag at the car shows.
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Re: Best way to seal up cowl vents?

Postby spencerforhire » Wed Feb 10, 2016 9:20 pm

I would image that the pan evac system can be made to work on the street, especially is you have minimal muffler/tailpipe restriction. Actually it would be easy to test; go ahead and take the leap to weld in the tubes as far back as possible(maybe even behind the mufflers?), install the check valves and measure vacuum in the hose at idle. At the very least, it will keep the valve covers cleaner and hopefully gain you a bit more power at the track.
My drag car has the typical setup, and I can pop out one breather at a time and feel the other side pulling vacuum at the hole in the valve cover.
These pan evac systems are cheap- Under $50(plus hose)-
http://www.summitracing.com/int/parts/mil-85700
The "fleet"-
72 Vega HB Drag Car -383/'Glide/9"(9.35@146.19)(5.94@117.28 1/8th)
77 Vega Estate wagon- project(someday)will have TPI305/T-5, S-10 spindles/axles
76 Vega GT- 400/4spd/9" retired from active duty(rusty)
06 Silverado 2WD ex.cab daily
03 Silverado 2WD ex.cab (retired)
06 Haulin' 20ft enclosed car transporter
06 GMC Canyon Shop truck
07 Colorado project( 5.3 4L60e swap)
99 Saturn SL1- wife's car
01 Saturn SC2- son's project
07 Saturn Ion Redline project
and 4 more Saturn "parts cars"
Note- the very act of listing all of these has made me realize I have some kind of problem.....

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Re: Best way to seal up cowl vents?

Postby zeke » Wed Feb 10, 2016 11:11 pm

I had problems with my pcv system, on my Chevelle, with it pulling oil back at high rpms. (shifted at 7200) I made a pcv filter from a plastic half pound peanut butter jar. Put hose barbs in each end of it and put some foam insulation inside of it. Tucked it up under the fender out of sight. Worked great.
Chris

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Re: Best way to seal up cowl vents?

Postby ol55 » Thu Feb 11, 2016 12:47 am

How would you get air to the inside if the vents were sealed?


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Re: Best way to seal up cowl vents?

Postby EVL VEGA » Thu Feb 11, 2016 12:52 am

ol55 wrote:How would you get air to the inside if the vents were sealed?


Larry

The windows?
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'73 Vega Hatchback (former Super Gas car)
406 SBC, AFR 210 Eliminator Heads, 9:1 comp, pump gas, 328RWHP/412RWTQ (old heads, no N2O 1/17/04), 6.86 @ 100.8 in 1/8th (No N20 9/4/16), Mike's Trans TH400 (reverse manual), 5000 stall, 12 bolt, 35 spline strange axles, 4.33 gears, spool, hipster transbrake, linelock, backhalved, Alston 3 link, 100 shot NX Hitman+ kit, LC1 Wideband sensor, 31x18.5 MT Sportsman Pros, "Plum Ugly"™ Purple paint.
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Re: Best way to seal up cowl vents?

Postby dindin » Thu Feb 11, 2016 11:12 am

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Re: Best way to seal up cowl vents?

Postby Kenova » Thu Feb 11, 2016 11:48 am

Awesome car, but I'm sure the problem with the fumes takes some of the fun out of it and reduces the amount
of time you want to spend in it, restricting the length of trips you may want to take. I think you would be even
happier with the car if you adopted some of the suggestions made.
I would definitely run some sort of PCV system. It would be better for both the engine and you. There are even
some (somewhat) economical vacuum systems made for street engines. You could seal up the interior panels
with a high density foam tape. Check with a RV shop or a truck accessory store. The tape is commonly used to
seal up truck caps, windows, and vents. You may need to change the length of your fasteners but keeping the
fumes out would be worth the effort.
I have always felt that uni-body cars have some of the ugliest inner fenders on the road. My suggestion would
be to take a stock hood and cut out a big honkin' hole in the middle. You want the hole big enough to showcase
the engine but still partially hide things like the inner fenders and rad. You would also have enough of the hood
at the rear to cover and seal your cowl vents. Do a little sheet metal work around the cut edge to clean things
up. You would have cleaner air and the ugly holes in the cowl would be covered. I have seen this done on other
cars and at first glance you really don't notice the hood, you just see the engine.
Every car is a work in progress, so if you keep chipping away at all of the little problems it can only get better.

Ken
My other car is a Nova.
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Re: Best way to seal up cowl vents?

Postby EVL VEGA » Thu Feb 11, 2016 1:02 pm

Kenova wrote:Awesome car, but I'm sure the problem with the fumes takes some of the fun out of it and reduces the amount
of time you want to spend in it, restricting the length of trips you may want to take. I think you would be even
happier with the car if you adopted some of the suggestions made.
I would definitely run some sort of PCV system. It would be better for both the engine and you. There are even
some (somewhat) economical vacuum systems made for street engines. You could seal up the interior panels
with a high density foam tape. Check with a RV shop or a truck accessory store. The tape is commonly used to
seal up truck caps, windows, and vents. You may need to change the length of your fasteners but keeping the
fumes out would be worth the effort.
I have always felt that uni-body cars have some of the ugliest inner fenders on the road. My suggestion would
be to take a stock hood and cut out a big honkin' hole in the middle. You want the hole big enough to showcase
the engine but still partially hide things like the inner fenders and rad. You would also have enough of the hood
at the rear to cover and seal your cowl vents. Do a little sheet metal work around the cut edge to clean things
up. You would have cleaner air and the ugly holes in the cowl would be covered. I have seen this done on other
cars and at first glance you really don't notice the hood, you just see the engine.
Every car is a work in progress, so if you keep chipping away at all of the little problems it can only get better.

Ken

Thank you. (and everyone else for their input on this..i appreciate it :th: )

I'm thinking of a catch can setup.

I don't have the stock hood. It came with a pin on style fiberglass short cowl hood (that i still have) and a HUGE snorkel that i gave away years ago. Car wasn't set up for that hood anymore..didn't have attachment points.
The first thing i did at every car show was take the hood off and put it on the roof. The guy i bought the car from used it for street racing and didn't use an air filter. The carb barely fit under the cowl hood. I added the tall K&N and haven't put hood on since.

I for sure will look at sealing cowl vents, firewall holes, floor pan holes, etc. I might even have some of that high density foam tape from a previous construction project..think it's like 3" wide.

The very nature of the car limits it's long distance potential: 8 gal fuel cell, spool, 18.5" wide tires, 4.33 gears, locked distributor, reverse manual TH400, non adjustable race seats with vinyl covers, no front sway bar, extremely loud, full cage, cooling system on the edge of being too small.
However that very nature also makes it awesome for street driving at the same time. :mrgreen:

This is how the car looked when the guy i bought it from bought it. He got it as a roller with no motor but complete otherwise. He took all the stickers off and threw the mild 406 in that currently resides between the fenders. I've made it my own over the past 13+ years upgrading, changing, modifying.
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Re: Best way to seal up cowl vents?

Postby cjbiagi » Thu Feb 11, 2016 4:56 pm

Have you ever made any attempt to check the A/F ratio? Too lean can cause a lot of fumes by causing misfires that you may not even notice. Obviously too rich can cause some excessive smells as well. Your car is obviously more race oriented than street so I can understand some compromises need to be made. I guess it's a matter of priorities.....
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Re: Best way to seal up cowl vents?

Postby EVL VEGA » Thu Feb 11, 2016 5:35 pm

cjbiagi wrote:Have you ever made any attempt to check the A/F ratio? Too lean can cause a lot of fumes by causing misfires that you may not even notice. Obviously too rich can cause some excessive smells as well. Your car is obviously more race oriented than street so I can understand some compromises need to be made. I guess it's a matter of priorities.....


I have an Innovate LC-1 wideband on the car. Have a digital A/F gauge on the dash and sometimes hook up a laptop for logging.
At WOT I'm running right at the sweet spot for power in the 12-13 range.
EVL VEGA
'73 Vega Hatchback (former Super Gas car)
406 SBC, AFR 210 Eliminator Heads, 9:1 comp, pump gas, 328RWHP/412RWTQ (old heads, no N2O 1/17/04), 6.86 @ 100.8 in 1/8th (No N20 9/4/16), Mike's Trans TH400 (reverse manual), 5000 stall, 12 bolt, 35 spline strange axles, 4.33 gears, spool, hipster transbrake, linelock, backhalved, Alston 3 link, 100 shot NX Hitman+ kit, LC1 Wideband sensor, 31x18.5 MT Sportsman Pros, "Plum Ugly"™ Purple paint.
"Pound to fit..paint to match"
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Re: Best way to seal up cowl vents?

Postby cjbiagi » Thu Feb 11, 2016 7:26 pm

Where is it at when you are cruising around town?
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Re: Best way to seal up cowl vents?

Postby EVL VEGA » Thu Feb 11, 2016 7:35 pm

cjbiagi wrote:Where is it at when you are cruising around town?


From what i remember 13-14 ish.
I'd need to do some logging to know for sure.
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Re: Best way to seal up cowl vents?

Postby EVL VEGA » Tue Feb 16, 2016 5:23 pm

Did some work on the Vega since my last post. Some related to the sealing vents and fumes issue..some not.. Had some ups and downs. Drove it quite a bit this weekend.
1. removed 1 quart of oil so that it was on the low end of full instead of the high end.
a. This really helped the blowby and oil on the windshield. Haven't seen a puff of oil burning on headers yet
2. fixed the exhaust leak on driver side middle header piece.
b. Bought a cheap mr gasket white header gasket set. Left my remflex in place against heads. Cut out just the middle two cylinders of the new gasket. coated both sides with copper rtv. Waited for it to tack up and installed.
This made a huge difference on the leak. I think it's gone. I'll continue to tighten after heat cycling.
then proceeded to poke a little hole in header when i was tightening bolt. Had my buddy throw a tack weld on it to seal it up. Might also swap for the smaller headed header bolts my buddy gave me. Then there is more room to get a wrench in there.
3. Swapped out old parts store 160 thermostat with a Mr Gasket high flow 180 thermostat. I drilled in some weep holes since i have an electric waterpump that is on a toggle. That didn't help so much. Almost overheated after a freeway run. I got off the freeway and right into stop and go traffic and got up to 225 or so. Pulled into the place i was heading and let the waterpump/fan run and it cooled right down. It has started running much hotter since i got the new heads. It makes sense since aluminum heads strip more heat away from the cylinder than iron heads do. I'm going to pull thermostat tonight and see how that works for a bit.
4. Was on a spirited drive with my wife on VDay and I think my fuel pressure (set to 9.5 psi for nitrous) overwhelmed my secondary needle valve. I've been driving this way for about 10 years. Well this time It puked gas through air filter and on to windshield at about 80MPH. Let it cool down and evaporate some gas. It started right up and i limped home. No problems since then. Gonna keep an eye on it.
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Re: Best way to seal up cowl vents?

Postby ol55 » Fri Mar 11, 2016 10:07 am

Does the air go in the cabin inside of the fenders? If so, can the space near at the outer cowl/inner fender area be filled (foam block) to prevent the air coming in?


Thanks,
Larry
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'76 Cosworth
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