smelly exhaust gases

[sebastien]

Hi guys,need some input here,exhaust gases smell smell pretty strong on my 68 327.to the point that myself and other occupants in the car still stink like "bad exhaust smell" after riding in the car even  after just a short drive.There is no blue smoke coming out from exhaust pipe.

Here's my set up: 327-210,bore .030,40 000 miles since rebuilt,compresson all within 15psi ,mild cam I believe its a tp 236,new r45s spark plugs 035 gap,breakerless stealth edition electronic ignition in original distributor(engine use to smell with my old ignition accel system),Vacuum advance to full vacuum,new plug wires,
original carb 2gv (rebuilt),original intake manifold,original exhaust manifolds,Gardner exhaust sytem.

Where I live we need to pass an emission test to license your car.Wich I pass.Here's some numbers:
On Driving test,Hydrocarbons PPm 183,carbon Monoxide % .22,Oxide of Nitrogen PPm 771
On Idle test,Hydrocarbons PPm 711,carbon Monoxide % 1.25

Since then I adjusted the carb richer now the engine idles better and the smell is not as bad as it use to be but still bad.I don't think I can go any richer.

what timing do you recommend?

any suggestion?

thank you.

[JohnZ]

Do you have any open holes in the firewall or missing grommets that would allow engine compartment fumes to enter the cabin? Any floor pan plugs missing in the cabin or in the trunk floor or side drop-down panels?

[sebastien]

Good question,if I remember right I had hard time pushing some of the grommets in and I ponctured some of them during installaton of firewall insulation pad.That might just do it couldn't it?
Floors are fine.What do you mean by side drop-down panels?Kick panels?

what timing do you suggest ?

thanks for your reply John.

[JohnZ]

What do you mean by side drop-down panels?Kick panels?

what timing do you suggest ?

thanks for your reply John.

The side drop-downs are at the extreme right and left sides of the trunk, between the rear of the wheelhouse inner panels and the rear end of the car; they run vertically from the trunk floor level down to the weld joint along the bottom of the quarter panel.

Set the idle mixture screws using a vacuum gauge connected to a full manifold vacuum source; adjust them for highest steady vacuum. If the engine doesn't respond to idle mixture screw adjustments, the throttle plate is open too far and it's idling way rich on the transfer slot instead of the idle mixture orifice.

I don't have the '68 timing specs, but the '67 327/210 spec was 2* BTDC, with 32* of centrifugal advance in the distributor at 3950 rpm, for 34* total timing. That's pretty conservative - it'll probably run better at 6*-8*, but if you do that, you'll need to limit the centrifugal advance with a bushing to keep the total at 34*.

[sebastien]

Side drop-down panels have been replaced with the quarter panels and trunk floor should be fine.
I think it's engine related if you stand next to the car with engine running specially in a garage it's stinks.
I will check the carb again and timing as well.
How do you install a bushing to limit the centrifugal advance?

[JohnZ]

How do you install a bushing to limit the centrifugal advance?

There's a pin that protrudes down from the autocam on the mainshaft, into a slot on the weight plate (see photo below); that pin should have a bushing on it (rubber on original distributors, removed for clarity in the photo). A larger-diameter bushing will limit total centrifugal advance. It's best to pull the distributor and take it to a shop with a Sun machine so they can set it up properly if you're not familiar with setting up advance curves.

[sebastien]

o.k. I got few things to try hopefully I'll fix the problem.Once again thank you John for sharing your knowledge with us.