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  #46 (permalink)  
Old 10-29-2012, 09:54 PM
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Valves springs usually do not fatiguge or go bad from sitting but they do have a limited service life and need periodic inspection and replacement on racey motors. with roller cams. Same with the roller lifters.
Inspection is key...

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  #47 (permalink)  
Old 10-29-2012, 10:00 PM
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If you plan on keeping this car and will be cruising more than racing and want a more drivable car
you could downsize the camshaft o something that suits how you use your car, a lot better.
You can install a much more streetable less racey cam that will idle much better, drive much better on the street
etc. It will still sound cool and Go like hell.
("street roller" )
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  #48 (permalink)  
Old 10-29-2012, 10:04 PM
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As for assuming that the previous owner set it up right. That is very very unlikely...
The fact that its all loaded up and carbon fouled,, tells all. I have been doing this for some 35+ years. Seen it all.

Trust me, it ain't set up right. details on the carb will reveal a lot.
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  #49 (permalink)  
Old 10-29-2012, 10:49 PM
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Heres what i see. Go ahead and borrow an on head spring tester. Check em.If it is a solid roller,even 220 seat psi is ok on the street. Take the carb apart and soak it. Make sure all your bleeds are clean. I see it doesnt have screw in idle bleeds, so you can take a pin vise and a number bit and increase the idle bleeds a little,just check the existing size.Check the primary butterflies for position and make sure they aren't covering the idle wells i guess you call em, if they are you can drill the butterflies for more air so they can be closed down. Get the jetting down where its not washing the engine and a low power valve that is 3 or so in. below the idle vacuum so it wont be tipping in. Put a hot enough plug in it to keep the tips clean, like a - 6 ngk.tune the squirters after you get it idling and driving correctly. Make sure you have adjustment on your idle mixture screws, if you can close em down and it keeps running,its too rich idle mixture wise. Just basic get it running stuff. You can worry about cam timing and such until after you get it to respond. It will take a great ignition to keep it going. Lots of initial timing, but before it is hard to start and trys to detonate. Let the engine tell you want it wants, not the neighbors. The cam is a little large on .050 duration for the street and thats what makes em soggy on the bottom(no cylinder pressure at low rpms) That can be somewhat fixed by cam timing,but later on you will porb find out that a more up to date cam is in order
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  #50 (permalink)  
Old 10-31-2012, 07:08 AM
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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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  #51 (permalink)  
Old 10-31-2012, 07:11 AM
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Quote:
Originally Posted by F-BIRD'88 View Post
As for assuming that the previous owner set it up right. That is very very unlikely...
The fact that its all loaded up and carbon fouled,, tells all. I have been doing this for some 35+ years. Seen it all.

Trust me, it ain't set up right. details on the carb will reveal a lot.
Gotcha, as soon as we are back to normal here in NJ I will proceed to get gas and start her up and set the base timing, might be a few days cause gas is in high demand with al the power outages here from the hurricane..I will post the results when i do get her fired up..Oh and I picked up the Champion plugs you recommended.
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  #52 (permalink)  
Old 10-31-2012, 08:01 AM
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FYI here is the distributor I have, and I cant find within the instructions how to set the timing curve.

Chevy Crab Cap Crank Trigger Distributor - 8489
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  #53 (permalink)  
Old 10-31-2012, 08:24 PM
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Quote:
Originally Posted by Dajerseyrat View Post
FYI here is the distributor I have, and I cant find within the instructions how to set the timing curve.

Chevy Crab Cap Crank Trigger Distributor - 8489
That's a distributor used for racing so the distributor itself contains no mechanical or vacuum advance capabilities. If you want an ignition "curve", you will need an ignition box that is programmable. It's not unusual for the timing to be set to the max power setting and then an ignition timing retard is used to crank it up.
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  #54 (permalink)  
Old 10-31-2012, 08:37 PM
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Nothing better for the street than a vacuum secondary 780 Holley - like the old 3310 model used in Z-28s; 425 HP 427s and 454s. Easy to tune and can make a good bit of power.
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  #55 (permalink)  
Old 10-31-2012, 08:37 PM
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badban,read what the engine is? Its not a stock 355
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  #56 (permalink)  
Old 10-31-2012, 09:50 PM
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Ok i read way more on this post then intended.. doesnt look like money is an issue.. dont be offended but the carb looks like junk. Call Willy's Carbs in the morning and they will hook you up with something nice.. the carb looks mismatched and i havent seen bowl bolts like that in a long time.. also every carb I have ever had on and engine like this had the primary throttle blades drilled..
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  #57 (permalink)  
Old 10-31-2012, 10:34 PM
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Vinnie: You said that your 355 isn't stock. I had to use the vac. sec. 780 on a 425 hp 454 in NHRA Super Stock and we made 806 hp in Super Stock trim 20 years ago. I NEVER liked the non vacuum secondary on the street for streetability and every time I made the 780 so that the secondaries were manual, it always sounded better, but didn't run as fast. I suppose I might have made more power if I could have used an 800 or 850 cfm. Do they make one with vac. secondaries. My point is, you can make good horsepower with a vac. sec. smaller carb that is more streeable and doesn't foul plugs or hesitate. The car ran 9.40s 142mph at 3650 lbs, with a Turbo 400 20 years ago. The trick was to have the right size nozzles in the accelerator pump system and the correct stroke in that system (add the larger pump capacity) - and let the vac. secondaries come in relatively quickly, but not instantaneously.
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  #58 (permalink)  
Old 10-31-2012, 10:43 PM
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bad banana.. you sound like a super stocker friend of mine//LOL (add the larger pump capacity) word for word.. I always do this now...never looked back!
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  #59 (permalink)  
Old 10-31-2012, 11:09 PM
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no, I was noting that the op has what appears to be a race car with a race carb. We ran 2 wcfb s on an 11 second 265 powered 56,,,it too was a race car.The op does not have to use a vac carb and the rest of the car is race looking.
yes a 750 vac would work,so would a 750 carter

It just looks like you skipped over the original post,,,
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  #60 (permalink)  
Old 10-31-2012, 11:18 PM
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Yeah. "Back in the day" we couldn't add the Rio pump in Stock or Super stock; but we got around that by stacking gaskets on the stock pump housing to increase the volume. Also used a Cadillac pump plunger and cut some off the end of the pump rod shaft to pull it all the way up to the top of the housing for the longest usable plunger stroke. We needed to do that because we didn't have a secondary pump. We also ran relatively lean jets like 75s (primary) and 76s (secondary). If you need mush more (like in the 80s), then your induction and exhaust are working together correctly. Stepped headers that were properly tuned with the intake, head ports, and cam, pulled more fuel and required that we use the smaller jets. I really can't remember what size the needle and seat was, but it was larger than stock, and about 6 to 6.5 psi fuel pressure at idle. Floats were set just slightly on the low side of the inspection windows of the float bowls with the larger seats and that much pressure. As per the original question of a streetable carb - start small (780 or 800) vacuum sec.; get it running good asnd then throw on that big carb and see if it is any better. Flat top piston (9to1 comp ratio) a good timing starting point is about 34 to 36 degrees total.
Large piston dome and compression in the 12 to 12.5 to 1 range should theoretically require more total timing 38 to 42. I guess this car is somewhere in between. I guess I'd start about 36 or 38 degrees total.
Just Sayin'
Dave
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