Hot Rods Eliminating crankcase gasses inside the car

OK guys, I'll try and summarize.

Engine
Fresh rebuild (500 miles) 1994 350 with New Edelbrock Carb 600 cfm, PCV valve in driver side valve cover routed to the base of the carb, Open breather in p*** side valve cover. Generic 14" chrome air cleaner.
HEI
Car
63 Nova Wagon
All holes sealed up, inside and outside of floorpans sprayed with bedliner, fat mat installed on all floor pans, firewall etc. Carpet even has m*** backing on it, new firewall seals around heater core and new insulation blanket installed on firewall, new exhaust and gaskets, no leaks.

I still get an exhaust smell inside the car. It makes you smell like you have been working in the shop all day after a 10 minute drive. We are wanting to drive this thing cross country this summer, but the old lady is not gonna go for smelling like a mechanic.

What can I do to reduce the smell inside the car?
I have pondered going to a more modern style air cleaner to capture some of the g***es.

 

exhaust smell is probably a leak in the ex system rather than a PCV problem. Unless the PCV valve is too small to handle the volume & it's backing up & out the breather.

 

Where does the exhaust exit? Make sure it exits out from under the body, ( I'm sure it does ) if out the back, make sure the end gate and windows etc are sealed up


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Chris ..... did you exit the exhaust behind the rear wheels?

 

Give us some pics of the rear of the car, so we can see which way the tailpipes point. Sideways at the very back of the car seems to work best.

It isn't easy to seal up a car like that, even when they were new it wasn't easy, so you have to do what you can to point the exhaust out in a way that it won't get ****ed back in

 

There is a low-pressure area created behind the rear window and tail gate of station wagons. If this area of the car is not sealed well exhaust g***es will be ****ed into the p***enger compartment. Be sure your exhaust is exited to the rear of the rear axle and to the side of the car. This will minimize the problem.

 

Here is how I made my exhaust on my Chevy II Wagon .

 

......another angle

 

As noted above, exhaust has strange dynamics. You can't even guess which way it is actually going after it leaves the pipe. Aside from the tailgate area noted up there, there are all sorts of potential low pressure traps under the car where stray tailpipe exhaust or exhaust from minor leaks under car can find failed seams and enter.
Also, on the side, worry about the PCV breather...it is supposed to be an inlet, of course, but often serves as an outlet. Try mocking up a stock aircleaner with that hole routed up to the cleaner and see if life improves from that.

 

>>>>>>Eliminating crankcase g***es inside the car>>>
>>>Open breather in p*** side valve cover. Generic 14" chrome air cleaner.>>>

OK, which is it. Crankcase smell or exhaust smell? If the former, your problem is an open breather. You need this kinda breather cap with tubing to a fitting on your aircleaner canister. If the canister doesn't have one, you need to get another one with the fitting.

Jack E/NJ

 

The crankcase breather may or may not be the problem. With a fresh rebuilt engine, it should not have so much blowby that the PCV system can't control it. But with a worn out engine, it could.

 

Wonder if there might be an easy way to distinguish between crankcase fume(s) and exhaust?
One of the foggers, sprayed into the air filter?

 

Did the engine get a fresh paint job? Maybe it's the paint burning in, that can smell a lot like petroleum vapors.

Also-- make sure you have no fuel leaks. That can certainly stink up a p***enger compartment.

 

A PCV valve doesn't **** much when significantly off idle when there likely to be some stinky blowby even in a fresh rebuild.

Jack E/NJ

 

Seems years ago, chrome rings took time to seat, over the moly types. For What It's Worth

 

Maybe you could just drive faster than the fumes?

 

Yup. 8^)

Jack E/NJ

 

I still get an exhaust smell inside the car. It makes you smell like you have been working in the shop all day after a 10 minute drive. We are wanting to drive this thing cross country this summer, but the old lady is not gonna go for smelling like a mechanic.

This probably gives you a nasty headache too and is why my buddy, a L O N G time mopar fan and racer sold all of his old stuff and bought a new challenger. (Some really cool stuff too) It's Not that there's anything major wrong with your car or that it wasn't fine in its day- it's that the new ones are just so much better at that stuff.

Any air, fresh or contaminated will move from high pressure area to low pressure area. Extensive wind tunnel and aero dynamic testing will show the areas. Could just be heading into the vents and the designed natural airflow thru the car.

 

The hood to cowl seal is important, too. And how the hood fits.

 

>>>New Edelbrock Carb 600 cfm>>>

Floats may be set too high. Common problem with 1406s outta the box. Especially stinky out the tailpipe at or near idle when you're not moving.

Jack E/NJ

 

All of the suggestions are good ones for a change. The exhaust should exit the wagon as AHotRod showed in posts 7 & 8 as they should on any wagon. Plus the tips need to be out enough to make sure the exhaust g***es get out from under the car.
There is usually a spot on most chrome 14 inch air cleaners bases where you can put a hole through and attach a fitting (such as a Mr Gasket 2079) designed to hook a hose to to connect to the breather that Jack E/NJ showed in post 10 so the crank case is drawing fresh air from the air filter. That should help keep any blowby fumes contained.
I'd think any fumes coming in are being drawn in though the tailgate/back window area though as that is usually the fume entry area on wagons.

 

unless his rings are not seated yet, the goodwrench engines they use a hard chrome ring for long life and fine pattern finish , he might have to romp ( or what my neighbor cop calls a spirited take off ) on it a few times to get it to seal , we often do this at the local entrance ramp to the interstate and theres a blue trail behind us .4-5 times and the trail disapears .

also if its exhaust gas you might have to put a extension on the pipe to get it into the air stream away from the body , remember in the 70's they had to put spoilers on the luggage racks as people were g***ing themselves from riding with the rear window opened , the back of the wagon is like the back of a semi trailer and is a big low pressure spot that collects everything .

also the breather in the air cleaner might help too , but also check your PCV as they do have different weights for different vacuum opening /closing vacuum numbers , the heavy truck ones are low numbers ( big cams ) p***enger cars of the 70's are higher . look in the bottom and there
is a letter or number stamped on the weight that differentiates them .

 

I was just going to mention the spoilers.
Could always try one out of cardboard and duct tape.

Also the old school back yard wind tunnel testing was done with streamers attached to the car and driven or towed while being filmed.

 

Is this driving with the tail gate window down?

 

even with the window up they had problems from all the air leaks back there ( astroventing )

 

Wow, you just brought back some memories of me as a kid getting car sick from riding in the wayback with the window open. Exhaust backwash. So true.

 

We always had the same problem with carbureted engines until we put catalytic converters in the exhaust. New fuels have different makeup than the old fuels. Exhaust to the rear, side exit, and cats. That will get you to a livable odor.

 

Could the fat mat, undercoating be giving off an odor?

 

Had this problem many years ago with a 55 Chevy hardtop that was our main driver. On long trips it would give us headaches. It had duals out the back with tips. A clue was the residue/film on the trunk lid and rear bumper after a 3-400 mile trip.Changed it to turndowns at rear corners of bumpers like stock 57 dual exhaust cars had. No more issues after that and we drove it for 6-7 years after-sometimes on 1000 mile trips. Do my 40's the same way.

 

Wow, this thread has really taken off. Sorry guys, I was in meetings all day.

The exhaust exits about 4" past the back bumper.
The rear gate window is up 99% of the time. It's worse when it's down.
The hood fits good.
It does give me a nasty headache over time.
The motor is new and painted, but this smells like exhaust or crankcase g***es
The floats are dead on. Just reset them.
The carb is tuned to max vacuum at idle
There is a small gap on the top of the rear window that appeared after installing new gl***. I plan on sealing that up soon.
The fresh air vents have all new seals.
The undercoating is a catalyzed bed liner that dries hard. It shouldn't be off g***ing.