2x4 setup questions

[mac1]

Here's what I have. An 881 dual GM intake and two out of the box 500 cfm Edelbrock carbs. Electric choke on rear and choke removed on front. I'm using Showcars progressive linkage, fuel lines and adapter plates for the carbs.
This is my plan. Open both idle mixture screws 1 1/2 turns out, (both carbs), and turn both idle adjustment screws 1 1/2 turns in. Adjust the progressive linkage so that the front carb starts to open when the throttle in half way through it's travel. (although with this setup the front carb never opens all the way) Is this correct?? Any input is highly appreciated. Mac

[fatride]

Mac, I think your on the right track with your initial settings. Front and rear carbs should open all the way. Be sure you have the progressive linkage in the small hole on the front carb bellcrank. If no one else steps up, I have setup instructions for settting up the Edelbrock dual quads in the shop. I will post later.

[Ronnie Russell]

Mac, Rays instructions will probably provide you with information you need to finish the job. However, If you have tried everything and still front carb comes up short of full opeining, you can remove the small piece of linkage on the pass. side of the carb that links primary to secondary, and bend it a little to provide quicker opening of the secondaries. With a little trial and error, you will be able to have full opeining of front carb. This may not be neccessary, depending on linkage set-up. Good luck..........

[mac1]

Fatride and Ronnie thanks. The way the linkage is set up here, the front carb opens about 90% with the back carb at 100%, but the now front carb opens at 1/3 pedal travel instead of 1/2. I suppose I could get the front carb to open at 100% but then I would almost have a direct linkage setup?? Fatride, please post your startup instructions. :bow

http://img.villagephotos.com/p/2003-9/394748/KSHMX-10-30-06(48).JPG

[dq409]

I run my duals with direct linkage and love it !!!
I figure that with both carbs working evenly you don`t need as much peddle and the engine is working more efficient. JMO

With either linkage, after you get the engine fired and to running temps adjust both idle circuits, one carb at a time just as you would any single carb set-up.

With both carbs running idle circuits I believe the engine runs smoother and all cylinders get a better/equal fuel mix. ,,,dq

[Ronnie Russell]

For whatever it is worth,,,,, I share dq s opinion. I like the direct hook-up. :)

[mac1]

I do like the idea of using direct linkage. I may end up going that route. :brow
But with that much gas entering the intake, do you have any problems with flooding? Do you lean out the mixture screws to compensate?? Mac

[Skip FIx]

Man I had all 8 barrels of Holleys opening on my daily driver 09 in high school! Did the old screw in the secondary linakge and removed the secondary dash[pots to fit them sideways! But hen gas was .26 for 100 octane too!

[dq409]

I do like the idea of using direct linkage. I may end up going that route. :brow
But with that much gas entering the intake, do you have any problems with flooding? Do you lean out the mixture screws to compensate?? Mac
Nope!!! You don`t get more gas just a better mix,,, Front and rear carbs are feeding each of the front and rear four cylinder equal
where as IMO with progressive the front runs a tad lean,,,

TRY IT ,,,YOU`LL LIKE IT !!!

Check out my home made linkage,,,,
http://pic17.picturetrail.com/VOL847/1590826/4451335/55744137.jpg

[fatride]

Fatride and Ronnie thanks. The way the linkage is set up here, the front carb opens about 90% with the back carb at 100%, but the now front carb opens at 1/3 pedal travel instead of 1/2. I suppose I could get the front carb to open at 100% but then I would almost have a direct linkage setup?? Fatride, please post your startup instructions. :bow

http://img.villagephotos.com/p/2003-9/394748/KSHMX-10-30-06(48).JPG

Adjust each idle mixture screw out one turn and each throttle out 1.5 turns. Adjust each idle screw to obtain maximum manifold vacuum and then adjust throttle screws equally to obtain idle speed. If you do not have a vacuum gauge you will be guessing at best! "Every gear head must have a vacuum gauge". Adjust the progressive linkage so both front and rear carb open 100%. Do not worry about how much the rear carb is open before the front carb begins to open. I have my progressive linkage adjusted with front and rear open 100% when the juice is open all the way, I can cruise on the super slab at 75 mph + without getting into the front carb with 4.56 gears, don't sweat it! "For me" if you are planning on cruising your car on the street progressive linkage is the way to go.

[mac1]

Thanks for the info. I'm getting ready to pull my engine tomorrow. It only took me 6 hours this time to remove the tranny and disconnect everything. I'm getting faster every time.:D I plan on replacing my leaking rear main seal with a felpro this time. I'll be changing out the intake as well. I noticed my T-10 has a small leak at the rear seal. How hard are these to R & R? Also what are you guys using on the T-10 fill and drain plug threads? It seems whatever I use, they always leak. Mac

[rstreet]

mac1
Are you using "zippers" anywhere:rofl :rofl
I am a firm believer in "fatrides" advice but I have an additional issue that has mine progressive. automatic..... Also a good adjusted vacuum advance helps a bunch....anyway good luck It does take a bit of "fiddling" to get 100% out of both:bang

[pauls63409]

I believe on the original carbs, the secondary carb does not have air fuel mixture screws. The air fuel mixture is adjusted with the primary carb only. I have two 600 manual choke carbs on mine and I have the air fuel mixture on secondary carb closed. These screws are only used in the Idle Circuit. With primary carb set correctly that is all you should need. Once you crack throttle you don't need idle circuit.

[fatride]

To each, his or her own. Smarter poeple than I insist that the secondary air idle bleed screws need to be adjusted to the highest vacuum and the curb idle adjusted for idle just as the primary carb when using Carter or Edelbrock carbs with the idle circut. This is how I did mine and anyone who has seen and heard my engine run can vouch that it idles and runs very well. :dunno Paul, you are correct, the original carbs did not have an idle circut for the secondary carb.

[Ronnie Russell]

Cannot comment on original carbs. No experience with them. Much experience with aftermarket Edelbrock and Carter. Fatride is correct on the set-up. Both brands will idle like a kitten, when adjusted properly.

[409z28]

Original front carb 3361 on 409 Doese have an idle circut,,Basically it is fixed so to speak. And you have to have it in play by setting the fast idle screw to open it . If it remains backed off all the way you can get a stumble as the blades fan past the transfer slots. Look at the carb and you can see the Idle transfer slots. Learned this from a Carter Rep. He's not alive now .but he sure schooled me on those old babys. Always go to a lean surge at cruise speed .then go .005 at a time on metering rods till the surge is gone. Voiala:) :p

[Ronnie Russell]

Not only does 409z8 know 3361s, he is bi-lingual!!!!!! Voiala :rofl

[dq409]

Not only does 409z8 know 3361s, he is bi-lingual!!!!!! Voiala :rofl

Voiala ???? I dated her once and ONLY once !!! man,,, wore me out !!:D

[mac1]

Well, got the 409 out of the car this morning and proceeded to replace the rear main seal. The two small rubber seals inside the rear cap where not there. This area was just filled in with silicone. The engine builder told me he put them in. :rolleyes: Installed new felpro seal WITH the two rubber strips in the cap. I had to loosen up the rear main caps to lower the crank a bit to slide the RMS out of it's groove. I tightened back up the caps bolts and put the pan back on.
I've got the dual four intake installed and both carbs on. I decided to follow Fatrides advice and go with progressive linkage for the time being. I'll take some pictures tomorrow and post them here. Mac

[skipxt4]

Mac: Now you know why the rear main seal was leaking. Those two rubber seals have to be there. Using Sillycone instead of Permatex, will let you down everytime. The other day you were saying you couldn't get the front carb to open all the way. In your picture, the linkage rod looks alot longer than what's on most 409 dual quad set-ups. The one on my engine is about 7 in. long. Also I noticed the linkage rod hole on the secondary carb. is higher up on your edelbrock, than on an afb. That could be another reason the front carb won't open up all the way. Check out an afb, and you'll see what I mean. Maybe you can drill a new hole in the linkage arm. Hope this helps you. Skip:)

[mac1]

Yea, lesson learned.:doh I should have picked this up when I got the long block back from the machine shop. It's easy to see if they installed them with the rear cap on. The two rubber strips extend out the side of the rear cap slightly.
I have to ask this question because it's been bugging me. When you loosen up all the bearing cap bolts and lift the rear crank slightly to replace the rear seal, after the seal is in and rear cap installed, do you just tighten back up all the bearing cap bolts? Or does the crank have to be "positioned" in some way before you tighten the bolts back up. Thanks Mac

[rstreet]

no indexing that I am aware of. I am getting ready to build a 409 so I am going to be looking at the same potential problem. I will be assemblying the rotating mass not the shop so maybe I can remember to do it right the first time!!!Isn't that the motor you "stole" from MD.?

[Dond409]

yes, You have to set the thrust clearance. That is done either by hitting the crank with a dead blow hammer or using a huge screwdriver to move ths crank back and forth. You need a dail indicator too. I believe the spec is .005 to .008. If you don't set this or at least check to see if you are in spec, it will probably take out the trust bearing.

[rstreet]

oops!!! I was assuming that all rotating assembly items had been done prior to that Gasket step. Of course thrust bearing dimensions have to be checked. I haven't looked up in the old books on these but your numbers sound about correct.

[mac1]

Thanks Dan for that bit of information. Well, I didn't index or work the crank back and forth. Just tightened back down the cap bolts and torqued them all. No disrespect, but before I remove the pan again, I'd like to get another opinion. All the reading I did on this never mentioned indexing the crank when replacing the RMS. Mac

[Dond409]

You didn't do what I suggested the last time either.

[Ronnie Russell]

Mac, There are a couple of dozen guys on this website that offer suggestions based on much experience. Dond is one of those. Crankshaft should be " whacked" during assembly. Half of the people dont do this. Most dont have problems. If pan is already back on, I would forget about it. Dont know why so many ovrelook this procedure, only takes a few mnutes. Still, the odds are in your favor. Good luck.....

[mac1]

Sorry Don. Like I said no disrespect here. :bow My frustration level was pretty high. :mad: I'll pull the pan this weekend and check the thrust bearing clearance. I'd rather spend 90 minutes now than two or three days down the road. Also thanks Ronnie for that info. Mac

[models916]

you can check play without taking the pan off. Read from the flywheel flange. If it comes out wrong, then take the pan off.

[mac1]

you can check play without taking the pan off. Read from the flywheel flange. If it comes out wrong, then take the pan off.

I checked with a feeler Gage, (don't have a dial indicator), and I have .008 free play front to back travel on the crank flange. Does this mean it's OK?

[rstreet]

on the high side but still ok.. I assume you aren't going to put this as your daily driver

[mac1]

Got the 409 back in the car this weekend. I don't know if some of you remember, but I pulled it out to change out the RMS and install an 881 dual quad intake with dual 500 cfm Edelbrocks. I've got the intake matched up to 333 truck heads that had the intake runners ported and polished and 206/172 valves installed to breath better. It fired up after 20 seconds as the fuel line/filter were empty.
Adjusted the timing at 14 degrees and adjusted the four idle mixture screws for maximum vacuum which ended up being about 17 at 1500 rpm. Took it for a test drive with the progressive linkage and it ran good. Idle was good but throttle response was lacking a little. I switched it over to direct linkage and the throttle response was better. I think I'm going to use direct for the time being. I just have to learn to take it easy on the gas pedal. No leaks at the RMS. Thank you lord!:bow I posted some pics here. Show valve covers will be installed next week. . Thanks again for all your help! Machttp://www.villagephotos.com/pubbrowse.asp?folder_id=1781576

[Ronnie Russell]

No leak at RMS!! Aint life grand. Have a great time with it Mac..........:)

[fatride]

1500 rpm is way to much to adjust idle bleed screws for max vacuum. At that rpm I'm afraid you would be out of the idle circut. Try readjusting the idle bleeds at 700 rpm. If engine will not idle at 700 bump the timing to 20 dgs temporarily until you tune to highest vacuum. This should help off idle response also.

[mac1]

1500 rpm is way to much to adjust idle bleed screws for max vacuum. At that rpm I'm afraid you would be out of the idle circut. Try readjusting the idle bleeds at 700 rpm. If engine will not idle at 700 bump the timing to 20 dgs temporarily until you tune to highest vacuum. This should help off idle response also.

Thanks Fatride, I'll check it again tonight. :)
Does anyone have a problem with the showcars stock dual quad air cleaner coming into contact with the distributor? (Using a stock Delco cap on an MSD ready to run) Mine really mushes down the front half of the cap wires. Might need to get some right angle ends.

[dq409]

Mac, I believe the MSD is a little taller then the stock dist.
Ray should know this.

Speaking of Ray,, I would follow his advice then after you have dialed in the idle jets read your manual that came with the carbs.
Adjust the metering (?) rods and springs acording to the graphs and you should be headed to a great running engine,,
Then you can play with the main and secondary jets,,,dq

[mac1]

Mac, I believe the MSD is a little taller then the stock dist.
Ray should know this.
Speaking of Ray,, I would follow his advice then after you have dialed in the idle jets read your manual that came with the carbs.
Adjust the metering (?) rods and springs acording to the graphs and you should be headed to a great running engine,,
Then you can play with the main and secondary jets,,,dq

That would explain the air cleaner contact. :eek:
I haven't had a chance to recheck the air mixture screws yet. Hope to do it tomorrow. Damn, I hate when we go to standard time. As far as changing the rods and springs, it's something to study up on over the next few months. Thanks DQ

[fatride]

When you get the idle speed low enough to keep the carb in the idle circut and set the idle bleeds for max vacuum you can check the manifold vacuum. Idle vacuum is where you will pick the step up springs for the metering rods. Let me know the idle vacuum at 750 rpm and I (or others) will let you know what step up spring to use.

[mac1]

When you get the idle speed low enough to keep the carb in the idle circut and set the idle bleeds for max vacuum you can check the manifold vacuum. Idle vacuum is where you will pick the step up springs for the metering rods. Let me know the idle vacuum at 750 rpm and I (or others) will let you know what step up spring to use.

I had a chance to check it again today. I'm using two out of the box 500 cfm Edelbrock performer carbs. At 750 rpm, I'm getting 15 inches of vacuum. This is with a pcv valve run off the rear carb front center nipple to the draft tube opening.
Idle mixture screws all set two full turns out. Timing 14 initial with idle rpm set at 800 to 900. Seems to idle good and throttle response is good.
I still have it hooked up to direct linkage. I've noticed with direct linkage, I have to be very careful not to give it allot of throttle off idle. If I do, the engine stumbles a bit.
The gas pedal has to be "babied" more then my single quad. I'd like to hear from you guys running direct linkage and what your experience with it has been.

[Ronnie Russell]

Mac, Im using 2 600 cfm Carters. On Offy intake. Direct linkage.. No hesitation, no stumble, everything smooth. My memory is bad, but arent you using modified 333s and modified 881 intake? Not sure this has anything to do with it, just remember others experiencing similar problems. Probably something minor that you will work out. good luck.......:)

[mac1]

Mac, Im using 2 600 cfm Carters. On Offy intake. Direct linkage.. No hesitation, no stumble, everything smooth. My memory is bad, but arent you using modified 333s and modified 881 intake? Not sure this has anything to do with it, just remember others experiencing similar problems. Probably something minor that you will work out. good luck.......:)


Ronnie, your memory is good. I thought the mismatched intake runners would only effect the higher RPMs? over 3000?? I think everything will be OK. I just have to re-learn how to work the gas pedal. Like my High School driving instructor said, "make believe you have an egg under it." :brow

[fatride]

With 15" of vacuum the step up springs supplied with the carbs should do the trick for you. There should be no stumble off idle. Is the 14dg timing at idle obtained with the vacuum advance connected? What is the timing with the vacuum pot disconnected? Connected?

[Ronnie Russell]

Mac, Another suggestion that may or may not be a benefit. By adjusting throttle linkage so firewall lever is as far forward as possible will give maximum pedal travel. Might help with low speed throttle control. Lousy weather gives me too much time to think about things. Good luck;...........

[mac1]

With 15" of vacuum the step up springs supplied with the carbs should do the trick for you. There should be no stumble off idle. Is the 14dg timing at idle obtained with the vacuum advance connected? What is the timing with the vacuum pot disconnected? Connected?

I checked initial with vacuum disconnected, (manifold vacuum right port) and plugged. I'll check initial again with the vacuum connected. I'm using an MSD with the light blue springs. All my timing should be in at 3000 rpm. Not sure if I made this clear, but it only stumbles a little bit when I give it a quick pedal starting out from a standstill., (direct linkage) I think its getting to much fuel. Just need to learn to go easy on the pedal. Learning curve :dunno

[mac1]

Mac, Another suggestion that may or may not be a benefit. By adjusting throttle linkage so firewall lever is as far forward as possible will give maximum pedal travel. Might help with low speed throttle control. Lousy weather gives me too much time to think about things. Good luck;...........

Good idea Ronnie. I'll check that to.
If that dosn't work, I'm going to take the pedal out and work the lever with my bare foot.:brow

[dq409]

Not sure if I made this clear, but it only stumbles a little bit when I give it a quick pedal starting out from a standstill., (direct linkage) I think its getting to much fuel. Just need to learn to go easy on the pedal. Learning curve :dunno


Once you have checked and made sure your timing is correct you should not have to go easy on the pedal!!!

You should be able to MASH it to the floor and have to hang on !!!

You can try different springs on your metering rods.
One other problem with the Edelbrocks can be the secondaries opening too fast and this will cause a stumble or flat spot.

This is why I recommend going with the AVS Thunder Series that have adjustable secondaries for more tunability.

Hang in there and you will get it right,,dq

[fatride]

Like Ronnie say's we got time on our hands! Having the timing come in full at 3000 rpm is cool if you have a high comp. engine with a small cam and 3.08 gears. I think we can help you a little but will need your engine specs. I looked at your previous posts but could have missed something. Would you please run the engine specs past me again plus gear ratio, tire diameter and the weight of the car. I think we can dial you in.

[mac1]

Like Ronnie say's we got time on our hands! Having the timing come in full at 3000 rpm is cool if you have a high comp. engine with a small cam and 3.08 gears. I think we can help you a little but will need your engine specs. I looked at your previous posts but could have missed something. Would you please run the engine specs past me again plus gear ratio, tire diameter and the weight of the car. I think we can dial you in.

OK Fatride, here's what I have:
1965 656 truck block bored 30 over
Ross forged pistons 10.5 to 1 (engine net 9.5 to 1 with reliefs)
333 truck heads ported and polished to line up better with the HP intake runners
206/172 stainless valves
881 stock intake with two 500 cfm Edelbrock performers, front no choke rear
elec choke using 91 octane gas W/15" of vacuum @750 rpm
Scorpion roller rockers with screw in studs
The cam I flat out don't know fur sure. The builder said it was a corvette grind??
engine does have a slight lope but nothing to radical. I made him write down what he thought were the cam numbers and he wrote 270 degree, 450 lift 108-110. But don't know if these are accurate.
MSD ready to run distributor set at 14 initial, using manifold vacuum, stock delco cap. No detonation, with light blue springs
Stock 2 1/2 exhaust manifolds with magnaflow mufflers
Four row desert cooler radiator
308 posi traction with 27.5" tall tires (225 70R 15)
BW T-10C 4-speed wide ratio trans (2.52 1st gear ratio)
Car weighs about 3900 Lbs with driver (estimated)

Like I say, engine runs strong, just seem to "load up" after warmed up hard acceleration. I have to be very careful on the pedal or I get what I think could be an over rich condition. I don't smell fuel though, but do see black smoke coming out the exhaust pipes when it happens.
That's all I can think of, so have at it. I appreciate any help. Mac

Just a side note, I very seldom ever go over 3000 rpm. Just once in a while when the I play my Jan & Deans Drag City CD. :brow
http://www.youtube.com/watch?v=w8v-oX2_iGA

[Ronnie Russell]

Mac. Guess I misread earlier. thought your main problem was at normal take off during normal driving. Did not notice you had a WOT problem.. Sounds like a great engine. Lots of good parts. The cam specs you show seem very small. Often you dont get full advertised lift so maybe even less than the figure you posted. Not sure if a cam with such little lift and duration can handle 2x4s. I guess first you should try re-jetting 2 stages lean. You might try going back to progressive linkage and adjusting so front carb is only opening 1/2., and seeing if the black smoke disappears. Did the single 4 bbl show black smoke? Dont know if you can use 1,000 cfm with a small cam and stock manifolds without being too rich. It would be much better if you could positively identify camshaft. Im sure others will have more ideas and suggestions. :)

[mac1]

Mac. Guess I misread earlier. thought your main problem was at normal take off during normal driving. Did not notice you had a WOT problem.. Sounds like a great engine. Lots of good parts. The cam specs you show seem very small. Often you dont get full advertised lift so maybe even less than the figure you posted. Not sure if a cam with such little lift and duration can handle 2x4s. You might try going back to progressive linkage and adjusting so front carb is only opening 1/2., and seeing if the black smoke disappears. Did the single 4 bbl show black smoke? Dont know if you can use 1,000 cfm with a small cam and stock manifolds without being too rich. It would be much better if you could positively identify camshaft. Im sure others will have more ideas and suggestions. :)

Sorry if I said wot, it happens after the motor has been run awhile and warmed up. It does not happen at all when the motor is warming up, (10 minutes) Choke problem??? If I give it to much throttle to quickly, it stumbles, like it's running on 6 cylinders. If I ease into the pedal, then all is fine. Didn't have any black smoke with 463 intake, (single) and 650 thunder Edelbrock previously. In fact that setup was very nice. No problems at all. I'm not sure of those cam numbers. Damn, I wish I knew. I'll try running the progressive linkage again. Just had a thought, isn't there an adjustment on the Edelbrock for the accelerator pump travel? Maybe I can set it in one of the higher holes so I get less of a squirt. Mac

[Ronnie Russell]

Mac, If you have black smoke at Wide Open Throttle, then the accelerator pump rod posistion will not cause the problem. It appears that you need to change from .086 primary jets to .083 and from .095 sec. jet to .089 and use your .065x.052 meteering rods. This may not be the only problem, but would have to do much better. You could check net valve lift with a dial indicator, but what is done, is done. First try the jets, then check symptom for improvement. Be glad to mail you some jets if you want to PM your address.

[rwagon57]

Mac,

Here is what I understand...when warmed up to normal operating temperature, the engine idles clean, but in order to prevent a stumble and black exhaust you have to squeeze the throttle gently.

Before you do anything else, make sure that the choke is completely open (off), then I would try moving the accelerator pump lever to a smaller shot and see if that helps before you change any jets or springs.

[mac1]

Mac,

Here is what I understand...when warmed up to normal operating temperature, the engine idles clean, but in order to prevent a stumble and black exhaust you have to squeeze the throttle gently.

Before you do anything else, make sure that the choke is completely open (off), then I would try moving the accelerator pump lever to a smaller shot and see if that helps before you change any jets or springs.

You got it John. Will do the accelerator pump adjustment first and see if that helps. If not, then it's time to learn how to change out the jets and rods. Thanks Ronnie for those numbers. I plan on installing my show valve covers, (if I ever get my gaskets from showcars), and I will check cam lift with a dial indicator
at that time as suggested. Where is a good place to buy one?

[Ronnie Russell]

Mac, Summit, Jeggs, many sell them. Maybe someone near your location. Finding valve lift will give you a rough idea of the cam you have, but changing cam to get rid of rich condition is not neccessary. You should be able to tune out black smoke.

[dq409]

I`d have to agree that it is a choke problem. I would start there and leave the accelerator pump alone.
From the description you gave it all points to that,,,black smoke until it is fully warmed up.

But I am confused in your description,, after rereading it,,

it happens after the motor has been run awhile and warmed up. It does not happen at all when the motor is warming up, (10 minutes)

Hummmm,,,

It sounds like you choke is coming on AFTER your engine warms up,,,
OR,,, check and see if the metering rods are stuck.
I would bet that you have one that is stuck.
Remove the small caps over the rods and check them,,,


Try one thing at a time so you know what the problem is.
If you try more then one change at a time you will not know what the problem was/is.

I disagree that the two 500cfm (1000 cfm) carbs are too big.
A dual quad set-up fools the engine in believing it only has one carb and it does not act like a combined CFM number of the two carbs.

I just don`t understand how your engine builder can`t give you the cam specs and calls it a Corvette cam ???:takethat

What the h*ll is that crap ????:dunno

Where do these guys come from,,,,dq

[models916]

Back barrels are manifold activated. If the engine does not need the secondaries they wont open. I have run 800 series on my offy intake as a test and noticed no difference from the 600 carbs. Engine pulls the secondaries open as needed. Both sizes ran perfect. Full mechanical 1:1 linkage.

[models916]

On the Performer series carbs, the PCV should ONLY be connected to the front center port on either carb. NOT in the back of the carb which is used for power brakes. This info is from an Edlebrock tech memo. If connected in the rear it will cause calibration problems in that carb.

[mac1]

Models, pcv connected to rear carb front center port.
DQ, motor ran fine for the first ten minutes. Only after warmed up did it have a problem. Engine builder is Fernando at El Inca Racing cams in Los Angeles. He's been building W motors since he was a kid. I don't know where he got this cam.
I talked to the him again today and he said it was a corvette grind with 450 or lift. :dunno

I checked the plugs today and they were all black, so I think we can all conclude this motor is just getting to much fuel. With this small of a cam, I'm going to have to run progressive linkage. That's OK. Lot's of guys running progressive. Maybe a cam change down the road??? Mac

[fatride]

Something just isn't right. Start turning in the idle bleeds in, try a 1/4 turn in on the front carb. If all is well turn in the rear carb the same. It kinda sounds like you are fat at idle. Let's lean the idle out by turning the idle bleeds in untill the engine starts to lose rpm then turn out untill idle is steady.

[models916]

My Carter Competition pump overpowered the stock needle and seat. I went to off road replacement needle and seat from Edlebrock and cured the flooding and leaking throtle shafts.

[mac1]

Cleaned all the spark plugs up and took it for a test drive running progressive linkage. Front carb was not used as I drove conservatively. NO problem until warmed up, maybe 10 minutes, then again noticed the hesitation and smoke when I gave it gas off idle, (goose the pedal) Again no front carb engaged yet. Got home and found # 1 plug had some oil on it and was black. I think I may have a leak in my intake gasket and it's sucking in oil from the valley area. I can say I never had a problem with the single 463 HP intake that I had on this motor before the swap, the plugs were always light brown before. So I think I'll pull the intake this weekend. Why it only happens after warmed up to operating temp, I don't know. Mac

[dq409]

"I talked to the him again today and he said it was a corvette grind with 450 or 460lift."
__________________
Mac

Thats the point I don`t understand,,,:dunno

It means nothing,,, A Corvette grind??? Small block? big block? Duration?? Center line?

If indeed he is a good engine builder I`m surprized he even uses phrases like that,,, It just don`t mean diddily squat !!:doh

AND,, What the rickin` frikin` ratin`fractors is a Corvette grind anyway,,, even in a Corvette engine it would mean nothing,,,,and in a W engine it means even less then less,,,

OK ,,, I`ll stop,,,

Back to your fouled plugs,,, CHECK THE METER RODS !!!!! If either one or both are stuck this will be the symptom.

It sure is easier then pulling the manifold,, and needs to be checked,,dq

I like the 3/4 race cams myself !!!!:rofl :rofl :rofl

[Ronnie Russell]

Mac, Sucking oil through intake gasket leak would cause blue smoke, not black. 15 in. vacuum indicate no vacuum leak. I would guess you have a carb. problem. You can check the metering rods , as dq suggested, by simply removing the caps and gently pressing down on the rods to see if they move down freely against spring pressure. If they are free, you need to find help from someone with a little experience . Pull the airhorns off and find the problem. Have you still got the 650? Might try it on rear, see if problem persists. If so, try it on front. Would at least isolate which carb is the troublemaker. And by the way, your engine builder leaves a little to be disired. Building w heads since he was young? If so.,,, why did he leave out the little rubber seals from rear main cap? Dont know any engine builder that doesnt save cam cards or at least knows how to acquire the correct one from whoever be ordered from. Something does not add up. I wish you luck.

[rstreet]

Mac, I may have missed it but what fuel pump are you running. There are issues with "too much" fuel pump so that could be part of an issue

[dq409]

Mac, I may have missed it but what fuel pump are you running. There are issues with "too much" fuel pump so that could be part of an issue


Good point !!! If you have too much pressure it will keep the needle and seat open and flood your carb/engine.

I still think you have a stuck M Rod,,,,dq

[DennisK]

This maybe a shot in the dark, but I had a very similar problem. I tried a lot of things and it turned out to have been a bad coil. It was brand new but bad. It started up and ran fine untill it warmed up. Then started missing and fouled #1 plug. It might be wouth a try. Dennis.

[mac1]

I like the 3/4 race cams myself !!!!:rofl :rofl :rofl

dq, you crack me up.:rofl Actually Fernando was recommended by someone on these boards. I asked him about the two rear main cap seals today and he told me he couldn't find them, and thought silicone would be OK. :mad: Anyway, thats water over the bridge now.
Ronnie, I still have the 650 thunder. I'll try putting it on this weekend. Have to get some new gaskets. Speaking of gaskets, On my 463 HP single intake showcars sent me a carb spacer that was 1/2" thick to mount my 650 on. For the 881 intake they sent me two spacers that are very thin maybe a 1/16". Is that correct? Not positive the intake gasket is leaking. Not sure reading plugs. # 1 plug was very black, obviously from the rich condition, almost wet. I dry fitted intake to block before install and it was a perfect match. All mating surfaces were good. Running a stock fuel pump. Pump worked OK with previous carb so don't think that's the culprit but will check. I like Ronnie's idea installing the 650. Will let you know.

Edit: Thanks for that info Dennis. Will keep that in mind.

[dq409]

Shoot Mac,,, If you already have one 650 get another one !!!

A much better carb then the AFB`s and they have the adjustable secondaries!!:brow
But why change the carbs out now? These carbs are very dependable and easy to work on.

Ya know ,,, the coil could be a problem like mentioned,,

But why haven`t you checked the meter rods yet?:takethat
Only takes literally a minute or two,,, Common problem,,

The thin carb plates are the right ones,,,

What you have is a minor problem with an easy fix ,IMO,,,
You just have to find the problem.

Go back to the basics and test everything,, one at a time.

AND START WITH THE METER RODS,,,,dq

PS,,, I`m going to hammer on the metering rods until I hear you say you checked them,,,,

[mac1]

I played around with the rear accelerator pump settings for a while and it did run better at the least shot, (furthest hole). This is with progressive linkage. I went one step further and lengthened the pump arm which limited the pump travel even more to lessen the shot more and I got the hesitation to go away completely, but I had a hard time starting the motor. I called Edelbrock support and the tech said to switch over to ported vacuum as I was running manifold vacuum to my MSD. I asked him why, and he said that with manifold vacuum, when you give it a quick throttle, the vacuum drops and the engine retards, which will cause a " momentary stumble". Made sense to me, so I hooked the accelerator pump back in the bottom hole and switched it over to ported and it got rid of the hesitation. I also think the motor idles a little better with ported vacuum. I dunno, comments??

[Ronnie Russell]

Mac, No need for comments. Are you happy with the run characteristics? Are you happy with performance? If you are happy-------we are happy. :)

[mac1]

1775 hits on this thread. :cheers Hopefully someone has learned something from all this. Thanks to everyone for their help. :bow Now I'll have to find something else to worry about. :rofl :rofl :rofl

[MileHiSS]

1775 hits on this thread. :cheers Hopefully someone has learned something from all this.

I have. Thanks.

[rwagon57]

Every time I visit I learn something, once in a great while I get to share useful information. Of the several car forums I frequent, I believe this one is the most useful to me. There are lots of smart people here and lots of wisdom.:bow :clap :clap :clap

[Ronnie Russell]

John, I agree. I cant speak of other sites, this site and e-bay are the only two I log on to. We are so fortunate to have so many with so much knowledge on this site. Every day I learn something new is a great day, and I have had so many great days because of this web-site. Ole Bob sure knew what he was doing when he put this site together. Can't thank him enough. :clap