Inline dual fours

[Zoom This]

I believe that any motor with a high lift cam and long duration will never pass a smog test. Motor is way too lumpy at idle to be clean. I had my 418W sniffed by the smog police when I lived in California (a requirement for record purposes only) and was told that at 2500 rpm the motor was clean enough to pass as a 1965 Ford. At idle I was told that I was a gross polluter. The best you can do, in my opinion, is to set the carbs so the motor runs at its best at idle, transition to the high speed circuits, and full throttle. If you are required to clean up the motor to pass a smog test you could have trouble. Has your car been on a chassis dyno with a sniffer up the exhaust? Your plugs will always tell you what's going on inside your motor. Clean up the plugs by proper jetting and you're good to go.

[Gaz64]

Originally Posted by Zoom This

I believe that any motor with a high lift cam and long duration will never pass a smog test. Motor is way too lumpy at idle to be clean. I had my 418W sniffed by the smog police when I lived in California (a requirement for record purposes only) and was told that at 2500 rpm the motor was clean enough to pass as a 1965 Ford. At idle I was told that I was a gross polluter. The best you can do, in my opinion, is to set the carbs so the motor runs at its best at idle, transition to the high speed circuits, and full throttle. If you are required to clean up the motor to pass a smog test you could have trouble. Has your car been on a chassis dyno with a sniffer up the exhaust? Your plugs will always tell you what's going on inside your motor. Clean up the plugs by proper jetting and you're good to go.

All good advice.
High rpm cams will not pass emissions with carbs, period.

Sequential EFI or milder cam with less overlap.

I'd be throwing the 1850s in the bin, fit a pair of 600 Edelbrocks.

[lovehamr]

Originally Posted by Gaz64

I'd be throwing the 1850s in the bin, fit a pair of 600 Edelbrocks.

Huh?! Mike, run from this man!

[YerDugliness]

Originally Posted by Gaz64

All good advice.
High rpm cams will not pass emissions with carbs, period.

Sequential EFI or milder cam with less overlap.

I'd be throwing the 1850s in the bin, fit a pair of 600 Edelbrocks.

Originally Posted by lovehamr

Huh?! Mike, run from this man!

Not quite sure why you'd say that, Lovehamr--I bought an already running Cobra replica with a Holley carb, and despite having been fiddling with these beasts for decades I just couldn't bring it to its knees.

I bought an Edelbrock, just for grins, and the thing pulls hard from idle to redline........much better than any Holley I've ever had.

Having said that, though, I feel a case of GAS (gear acquisition syndrome) for a 600 CFM double pumper, center hung floats Holley.....would love to see if I could get one of those to run like the current Edelbrock. Gotta love the looks of a good Holley!!!

Cheers from Dugly