forum.jdrace.com

Yes. Frankenstein is alive and runs, i did approx. 600 Miles and now there is something i would like to sort.

Facts First:
=========
Engine: 1964 Oldsmobile 330Cui (Now Bored Up to 350 Cui)
Heads: Olds 7A (1972 / 64cc)
Compression: 10.66 : 1
Pistons: Seald Power L2320F
Lifters: Elgin Hydraulic Flat Tappet Lifters
Push Rods: Comp Cams
Cam Specs: Dur@050 Int.224 / Exh 236, Lift Int. 504 / Exh. 512, 112 Lobe Separation, 45 Degree BANK ANGLE
Carburetor: Edelbrock AVS2 (1906) 650 CFM (+ Tuning Additional 0.04" Holes on all 4 Throttle Pates)
Intake: Edelbrock 2711 (Olds 350 Performer) + 1 x Adapter Plate
Vaccum Canister: by Comp Cams
Power Breaks with Dual Master Cylinder (all 4 Wheels / Drum Brakes)
Rockers: Harland Sharp Rockers (S50062A)
Lifters: Elgin HL1951S Hydraulic Lifters
Exhaustmainfolds: Thornton's Small Block JR Exhaust Manifolds
Exhaust: 2x 2.5" Dual (Left & Right/ No X-Pipe)
Transmission: TH350 Heavy Duty Build (Alto Parts, + Shift Kit)
Torque Converter: Assault Racing 3200 - 3500 Stall (Boss Hog)
Vehicle Weight: 1424 Kg / 3140 lbs
Rear End: 1964 Oldsmobile Cutlass, Typ: P 3.08 (3.08 Ratio)
Tire Size: 205 / 70 – R14

Timing:
I got the timing Set as following.
Base Timing (Setting without Vaccum Advance): 15 Degree @ 1200 RPM
If i connect the Vacuum (Point Distributor), i have 34 Degree @ 1200 Rpm

Problem:
My problem is that i have a Idle Drop from approx 1000 Rpm Idle
to 400. It not possible to adjust the Idle (with Vacuum Advance Connected)
between 1000 Rpm and 400 Rpm. i would love to have approx. 700 Rpm in Gear at a stop light.

Any input why or what i could do?
- Wrong Timing Advance?
- I have the Engine knocking under Load with 18 Degree @ 1200 Rpm (Base Timing) so more Advance aint the way.

As i didn`t had a Cam Card for the Camshaft (only a small Sticker on the Box), i set the Timing Chain to 0 Degree durring installation
and i didnt "Degree" anything.

Question:
Can i check if the Timing Gears / Chain degreeing is wrong if i go on TDC and use Air pressure thru Sparkplug of Cylinder Nr.1 with a valve Lifter Air Tool.

If the Pressure doesn`t build up (or stays) on TDC the valves aint closed, so i could turn the Crankshaft (BTDC o ATDC) and read the degree from the Balancer Scale. Right or totally wrong? So this would be the amount of Degree that would need to be Advanced or Retarded at the Timing Chain.

or could it be the additional holes on the Butterflys of the Edelbrock AVS2 (1906) 650 CFM (+ Tuning Additional 0.04" Holes on all 4 Throttle Pates)

Thanks for all your help

Greetings
Nic

Nic, Wow... sorry to hear your having a headache.
Well we see what we can uncover here.

First thing we noticed which is CRAZY most important thing in any motor is the distributor....
What are you running?
You have absolutely no info on this item in your thread.
Another thing is WHERE do you have your vacuum advance hooked up.

Vacuum advance is usually for engines that you want fuel mileage...
Most all our street vehicles that are built up only run mechanical advance. NO VAC ADVANCE.
we run the 6al box and MSD on just about every one of the street vehicles too.

Timing sounds fine 10-15 on the balancer at idle RPM to us sounds high 700- 1000 should be enough.
When you hook the vac advance the RPM will go up and your advance will too NOT IN GEAR

I do not understand the drill holes in the carb plates. For the set up you have you still should not need those in a carb. That is leaning out the idle and will cause you to fatten up the idle screws and a reason the car can not idle at lower rpm (likely)

Duration on the cam is just not that big to necessitate that drill option...that is for radical race cars.

So on the distributor... pull the cap and rotor and send a picture of the advance weights and springs for us here.

Lets get that info before doing anything to timing and taking anything apart...

Jim
JD Race

Lets just get the distributor info
then will get the car timed with out the vac advance to total timing set at 34-36 degrees

Get it to idle at 700 - 1000 and take it for a drive.

Hope you have a total advance timing light...IF YOU DO NOT...BUY ONE... if you are into cars this is a necessity .

You will rev the car to 3000 rpm and the timing should stop advancing beyond that or the the distributor will need to be reworked or replaced with an adjustable distributor to get the advance curve in quicker.
Then once you get total timing in at 34-36 degrees... get the idle worked in... remember you may have to fatten the idle screws with those holes drilled in the plates.... see what the idle advance is at with the timing light -

I doubt the cam to crank timing is off as long as you lined up the correct timing marks... some timing chains have different triangle symbol and round symbol and square symbol... as long as you matched the symbols correctly ... you should be fine and it is not going to affect the trouble your having with idle.

Jim

Hi Jim
First of all Big Thanks for your time and first inputs on my Problem.

The Distributor is still "a new Points" Distributor, but i will change it to a
Small Cap OLDSMOBILE 330, 350,400,403,455 BLACK HEI Distributor w/45K Coil & PLUG WIRES.

i always connect the Vac Advance on the Ported Vac. (Above Throttle plate) Plug. On Edelbrock Carbs its the Left one.

I have a Timing Light and use it alot,
This is how i set Base Timing with a New Distributor.
1. 34 @ 3500 RPM & Set Lock Stud.
2. Idle down & Verfiy at 3500 (32 -34) Total Advance.
3. Idle again & Re-Check Initial Timing (Advance at approx 1200 Rpm). The Timing should be between 10 - 16 Degree BTDC.
4. Reconnect Vacuum Advance & Line with the Ported Vac. Plug of the Distributor (Timing Advance) & adjust Idle to apprix 800 - 600 Rpm
5. Total advance Setting is now complete!

When i did the Engine i got a Speedmaster PCE264.1016 Timing Chain
i didn`t gamble with any Retard or Advance settings. I set the "S" mark on the Camshaft Gear with the "dot" mark of the Crankshaft Gear.
now lets hope that Speedmaster Set, Crankshaft or the new Camshaft is not "Off" in any degree..

Yesterday 23rd of July i closed the 1.5mm holes on Primary Throttle Plates. The two 1mm Holes on the Secondary Plates are still.

About Idle Fuel Mixture, I have a "Emission Control Maschine" with %Vol CO & ppmVol. HC.
I adjusted the «idle» mix with approx. 4 %Vol CO on both sides but i can not remember the "ppm Vol. HC" value.
Its a fight to get any measurements with a connected VAC Adv. on Ported Plug of the Carb. between 1200 Rpm and Lower.. the Engine / Carb is so sensitive if adjusting Idle RPMs.

its like 1200 RPM solid or 380RPM chopping Solid.. all between is a random to have it solid.
I never had this in the beginning (during Engine Break-In Phase, first 600Miles)
Maybe somewhere around the Vac. Advance of the Distributor, Springs, Leak, damaged ?
Thanks for all your Inputs!

and here some more visuals

Ok things I see.
Carb primary throttle blades...open WAY too much in the picture for idle.
Engine - vacuum line to valve cover...is it one way valve? also do you really need that? We just put open breathers - do you have emmision checks in your area? try to plug that vacuum line to valve cover for now and see if you get a change too.
Were trying to find the draw here that is making your engine have to idle at too high of RPM. USUALLY a vacuum issue.
throttle spring- please find a dual throttle spring for your carb. Safety sake and also it will help your throttle not have soo much tug on the pedal... nicer for driving...
Distributor - advance springs. dump those springs unless your looking for terminal gas mileage. THEy need to be lighter. This will likely have NOTHING to do with idle...just launch and how fast your car will advance and ramp up to full advance for high performance stuff like burn outs and acceleration.

Points- Yah we really need to upgrade that...BUT do not throw that distributor away as if the SUN starts throw solar flares etc...points can be very useful...lol.

Have you played with the dwell on the points?

Vacuum advance.... Just dump it for now and tune the car with out vac advance...LIKE it will never be used. See if you can get it to idle that way and drive good and strong. You said your getting another distributor...it might be the pod playing games or the port in the carb just not playing with the throttle blade holes you have and the throttle slot being over exposed in the picture.

Remember I can only guess from here I am not there hearing and playing.
Trying to help the best I can from a distance. Bear with me. do not take offense to anything... remember this is your car and you can do what you want and try what you want. I am here to throw an extra set of eye and ears on the project.

Ok things I see.
Carb primary throttle blades...open WAY too much in the picture for idle.
- yes its WAY open maybe cause i needed that power to hold the Engine or cause of the Warm Up / Choke throttle adjustment Stud.

Engine - vacuum line to valve cover...is it one way valve?
Yes its has a steel ball in it, i think under higher Vacuum it will suck it upwards and get unburned Gas back in.

also do you really need that? We just put open breathers
i don`t need it, i just rebuild it like the original engine had it. on all other cars i have breathers.

do you have emmision checks in your area
Yes we have. max 4.5 %CO thill 1983 Cars.

try to plug that vacuum line to valve cover for now and see if you get a change too.
i will do that again. but i don`t think was a big deal as far i remember that.

Were trying to find the draw here that is making your engine have to idle at too high of RPM. USUALLY a vacuum issue.
yes.. thank you so much.. i thing its something between "Distributor, Vacuum Adv. Can, springs, and things"
i think i need something that the Vacuum Adv. Can don`t react under 8 In/Hg (different Vac. Can?) or that the Vac Ad. doesn`t jump in under 1000RPM. (tougher springs?)

i think the timing & RPM adjustments & readings are by FAR easier without connected VAC Advance.. so i will drive it tomorrow without connected VAC Adv. and see how pure mechanical Advance is to drive.

throttle spring- please find a dual throttle spring for your carb
do you mean a Thottle Return "pulling" spring?
if so.. i really thought about that.. "if these horses can`t return.. your done" it happend once with my 1978 Cutlass..

Distributor - advance springs. dump those springs unless your looking for terminal gas mileage. THEy need to be lighter. This will likely have NOTHING to do with idle...just launch and how fast your car will advance and ramp up to full advance for high performance stuff like burn outs and acceleration.

Uff.. okay.. i thought i need much Stonger to sort that RPM vs Vac Adance struggle.
i have a MSD spings kit somewhere.. so i go softer.

Points- Yah we really need to upgrade that...BUT do not throw that distributor away as if the SUN starts throw solar flares etc...points can be very useful...lol.
I`m a keeper.. hahahaha shi**

Have you played with the dwell on the points?
never! i just keep the newest part of the old engine and swapped it into this new engine.. its a refurbished "AUTOLINE D243"

Vacuum advance.... Just dump it for now and tune the car with out vac advance...LIKE it will never be used.
See if you can get it to idle that way and drive good and strong.
You said your getting another distributor...it might be the pod playing games or the port in the carb just not playing with the throttle blade holes you have and the throttle slot being over exposed in the picture.
yes i will test and let you know!

do you think a MSD Dist. Part # 8529 is a good way to go? its very expensive if i calculate shipping & Taxes etc. on top..
it looks like there a few good options to make adjustments if needed.


Remember I can only guess from here I am not there hearing and playing.
Trying to help the best I can from a distance. Bear with me. do not take offense to anything... remember this is your car and you can do what you want and try what you want. I am here to throw an extra set of eye and ears on the project.
of corse! and i`m sooo glad & happy for different inputs, help or point of views..

Finally.. about Total Timing.
should i rev 3500Rpm w/ 32-34 Degree or 3000 Rpm w/ 32-34 Degree ? is it about that type of Camshaft?

Thanks & i will come with updates.

Throttle Return spring...YOU NEED 2... absolutely. If that one breaks YOU ARE SCREWED... lol
Plus with 2 you will not need that hard of a return spring.
Please for your safty and others on the road...They sell one inside of another type spring
run a metal arm off the intake bolt or off the carb base bolt (holley carb)
The totally advance can only be determined when you keep going up the RPM scale until it stop going up.
With those advance springs you have it could be 3500- 4000 for all we know. try the middle of the road MSD springs...or you can go one light one medium....THEY DO not need to be the same load on each weight. We mix them quite frequently to get the right curve for the size and cube and wants of the car driver.
Try it with the stocker springs and mechanical...go for a drive then ONLY switch out those springs and see the difference.
DO only one thing at a time so you can see the difference the items make. same with timing etc.

DWELL: so where is the dwell set? Or did you just pull it from the box and install? Hope not...That is like installing a spark plug right for the box and installing. especially the way parts are these days...lol.

Just ditch the vacuum advance for now.
Can you open the rear plates a little on a edelbrock carb and close the primaries more?
how many turns out are the idle screws?
screw them in and turn them both out the same 1.5 - 2 turns
try this video.... even if you know everything sit through it anyway.
https://video.search.yahoo.com/yhs/sear ... ction=view

I really have to wonder about those throttle blade drilled holes and the extra idle amount of fuel your going to need to make the idle be steady down under 1000 rpm.
I really feel that is RACE car stuff only.
we have a 10.20 1/4 mile car and we do not have any drilled holes for idle on that...
Jim

Hi Jim,
thanks for all of this so far!
i will start further tests and i would like to show you what i found in the
Edelbrock Carburetor Manual on Page 8.

Long Duration Camshaft

does that mean that, if i wanna drive it without "Vacuum Advance", only with Mechanical Advance, then i need that very soft springs (Mechanical Curve) inside of the Distributor to have more "Advance" at early RPMs like 500 RPM? (right?)

Is this aswell the reason why i need 2 1/4 Turns on the "Idle Speed Screw" (that opens the Throttle Plates) to have a minimum Rpm that can start the Engine and hold it. (400 RPM)

Okay, Todays Journey was as following.

I went to the Car and reset the Edelbrock AVS 2 Carburetor to «Lets say, out oft he Box Settings». I took of all Vacuum user from the Car band closed these ports.
(Vacuum Advance, PCV, Manifold Vacuum)

So i turned the Idle Mix Screws (Left & Right) clockwise back in till Stop and then 2 Turns Out again for the beginning.

I did the same with the Idle Speed Screw.

I Turned that Screw «outward» till the end of the Screws Tip barely touches the Throttleplate Linkage and checked aswell if the «Fast Idle Linkage» is not holding the Throttleplates open.

Then i Turned the Idle Speed Screw 1 Turn In.

I changed the Distributor Springs to the Lightes possible setting (MSD Springs - Silver Light & Silver Light)

Then i gave it the first try and i could not start the Engine with the «Idle Speed Screw - 1 Turn» . So i tweaked the «Idle Speed Screw for 1 more turn = 2 Turns Total»

I Started the Engine and it was on the Edge of holding on. So i gave it a little ¼ Turn more on the «Idle Speed Screw = Total 2 ¼ Turns» and it Startet and kept holding on, on a very very low of 380 RPM.

1st. Fact - The Car did not Start & Hold under 2 ¼ Turns of Idle Speed Screw.

So to get a bit more RPM i needed again more «Idle Speed Screw Turns» .
At around 850 RPM i was checking if some Idle Mixture Screwings would help me now.. But there was nothing, No reaction of The Engine or Vacuum. I turned them «Inwards» till Stop and the engine was still running with no signs of anything. I turned them Out again, each up till 4 Turns.. Nothing...

2nd Fact - Idle Mixture Screws don`t react at 2 ¼ to 3 Turns of Idle Speed Screw Turns anymore. Cause of the exposed Transfer Slots by the Primary Throttle Pates.

3rd Fact – Not possible to adjust a solid Idle.

So i took the Carburetor off and checked the Primary Throttleplates set with (2 ¼ Turns) by far to wide open! Then i opend the Carburetor to check all 4 Jets, Rods, Step Up Springs, Pump & Re-Adjusted the Floater Levels and cleaned it.

I put it back on the engine again.. and there was no change.

Question:
what causes this problem that i can not get the Engine running without «Bypassing» the Idle System with approx. 3 Turns of the Idle Speed Screw.

- Carburetor Damaged?
- More Advance Timing? False Timing

Thanks for your Inputs!

Well I have to say it has a lot to do with the holes in your throttle plates and or something is leaking air from somewhere?
Do you have a car friend you can borrow a GOOD known running carb from?
The distributor springs should not need the LIGHTEST spring just something below what you have there. Medium would have been fine.

SO you ditched all the vacuum hook ups and you still can not get the idle under 1000RPM steady?

The car should run with 1.5-2 turns out on the idle jet screws and the throttle transfer slot should not be highly exposed...
Do you have any adjustment in the rear throttle plates to crack a hair open to help some?

I really deal in Holley carbs more than Q jet based carter based cars like edles ... They are great gas mileage metering carbs. We are more STOMPERS of the gas on the carbs here and holley parts can be gotten at any basic auto store.

I have to keep pointing to this carb not working correctly...BUT the only way to be sure is to get someones that does work good and install it to KNOW that this is your headache. At least that would help you feel better about everything else in the motor and timing...
Remember we said to try and do only one thing at a time to keep track of stuff that makes changes. You do multiple changes and you do not know what cause what?

Jim
JD

avs2 1906 carb is a square bore carb...YOUR picture is a spread bore carb....??? So what carb do you really have?
Jim

Did those drilled holes come factory in the carb?
If not
Why did they get drilled?

They are calling this carb on summit site a SQUARE bore...BUT it is not it has front primaries smaller than the secondaries...THIS IS A spread bore carb. BUT that really is a moot point in the trouble your having...I am just trying to look up specs on the carb you are using. Jim