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Old 10-31-2012, 07:08 AM
Dajerseyrat Dajerseyrat is offline
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Quote:
Originally Posted by F-BIRD'88 View Post
Your cam is pretty much what I suspected.
Valve lash: you can chcek this your self. You do not need to adjust it, right now , just check it using a feeler gauge. As long as the lash is aceptable range its good for now.
( you probabily don;t know how to R and R the stud girdles so.....)
As you know I am very particular on correct engine ignition timing on racey engines especially when you want it to idle well and run well on the street.
( SET up for Racing) usually indiates its only set up to run well at WOT without specific attention to race engine idlling etc etc. Lots of improvment there usually.
So replace the plugs , drain all the fuel and replace, and get er fireed back up.
Need to know inital base timing,, Max timng when you rev it up....
Power valves when the diaphram is blown ruptured the power valve leaks fuel ( internal) is always rich
,, fouls plugs oftem caused by a backfire thr the carb ,
Check both PV's diaphram. (stick it in your mouth and suck on it to see if it leaks and operates)
replace if suspect.
Once yu get it up and running ans set up it wouls be nice to take it for a good long hiway run to
"clean it out" ( blow the carbon out) Legal speed hiway driving is good enough.
Get an extra set of new spark plugs and bring them and a plug wrench in case they refoul.
You can run it on 92+ octane pump gas but reduce the timing a bit ( 32 to 34deg max)
with 11:1 cr and full power timing 36-38deg you need 100 octane gas.

It is very likely that this motor does not have enough idle spark timing. ( distributor curve not set up correctly)
Racey engines with 260+deg cams need a ton of timing at idle. as much as 38deg BTDC at idle.
If it don;t have at least 26deg base timing at idle ( more is better) you need to fix that
or it will load up and foul again.

2. because you do not have vac advance the motor wil really like locked out timing
full timing at idle (32 to 34deg for street pump gas) It wil idle much cleaner, not load up and drive much better on teh street. Its a easy set up change on most race distributors.

power valve must stay closed at idle. idle manifold vacuum/power valve vac rating...
power valves must not be leaking/blown diaphram.

That carb body don;t look like a 850. Looks like a 650-700 and the jetting corisponds with that.
Measure the throttle bores diameter and the pri and sec.venturii diameter on the carb body.
You can compare that to the dimentions shown on the holley model list number list (PDF)
This will tell you can mee a lot about what carb body it is and get it dialed in better so it runs clean all the time..
As opposed to "set up for racing".... ( I define that as not set up well at all)

If you have it apart post some picks of the metering blocks. Looks like Percy or...
Probily has removable metering orifices 9 emulsions, idle feed restriction. PVCR etc) idle and hi speed air bleed sizes?
the specs of al this really helps determine the carbs present setup.

which means it may not be right (except for WOT racing) and you can fix that and make it a beauty carb
if you are willing.

When you drive this car do no lug the motor at low rpm. These motrs with this size camashft are not real happy driving at less than 2500rpm. Hi wat cruaising at 3000+rpm is where they like to live. (with 3.08's Id cruise in 3rd gear (4speed)) its not a taxi. It want to run and rev. The usalbe power band of that cam is 4000 to 7000+ rpm keep that in mind.
Avoid needless idleing and low rpm lugging.
Once its set up correctly and cleaned out ( carbon in combustion chambers)) it will run well on the street.


Since the car was sitting replace the fuel filter.. The carb needle seats may need to be replaced too (they go hard and don;t seal) Power valves too,,, don't like to sit. Blow out carb air bleeds with compressed air.

Thanks will do, I replaced the needle and seats and all the carb seals, new accelerator pump diaphragms, but the power valves seemed to be ok so I reused them cause the rebuild kit came with much larger ones. Also my pump shot squirters were .28 and .31, not .21 and .22 ( they were hard to see until I removed them. The metering blocks looked like the ones I had in my old 4150 Dominator.

How do I measure the carb bowls, do I need a caliper? or will a ruler suffice?

Also from what Im getting from your post, the base timing will be higher than the WOT timing? So it will actually be retarding timing as you accelerate?
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