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schrick 284 valve clearance?


chrisrouse
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I recently rebuilt a motor for a friend's 1600 restoration. It's kind of a hot motor, with mahle 9.5/1 pistons, a schrick 284 cam, weber 40mm sidedrafts, and an IE reproduction 008 distributor with pertronics ignitor. I've got the timing set at ~4 degrees BTDC @ ~ 900rpm, up to `24 degrees BTDC @ 2500 rpm.

The thing doesn't run great, and I can't seem to get any adjustment of the #3 idle screw. It idles rough, doesn't have the power it should, and it backfires (popping from the tail pipe) on deceleration (engine braking).

I did not rebuild the carbs, the owner of the car did (yes, i know ;).

Here's my questions for all you FAQ gurus:

Do the schricks require a different valve clearance than the stock cams?

AND...

Why does the car run like muff cabbage cold ( and i mean really poorly )?

AND...

Why does it pop from the exhaust on deceleration (engine braking)?

Should I be looking mostly at the carbs, or could the valve adjustment be affecting things?

Thanks,

Chris

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well...

yes, sounds like you have problems.

Why does the car run like muff cabbage cold

because the cold run circuits on the Webers aren't hooked up?

Popping can be timing OR lean carbs- I'd start with setting timing to

36 BTDC total with ALL advances in (4500rpm+) and see what happened

then.

Then I'd check the float levels.

Then I'd look to see what chokes were in the carbs, and if they were

over 32's, I'd go to the bar.

If I found myself NOT at the bar, I'd look at jetting just for S&G, and if

the mains were over 135, I'd go to the bar.

If again I had the bad fortune to not be at the bar, I'd probably check the

throttle shafts to make sure they weren't bent,

check the progression jets to see if they were in the 45-55 range,

and look at the spark plugs to see if they had anything to add.

If none of that came up odd, I'd set valve lash to .007 cold, and try

it again.

Then I'd definately go to the bar.

I forgot what happened next...

t

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