What do I do now?....again

[Phalen409]

Long story shorter. I replaced the intake gasket on my 409 stroker. Replaced my worn bronze distributor gear with a new one. (Same as the old one). All back together O.K.

Started right up. Intermittent single back fire. Played with timing till back fire went away. Motor is sluggish and not responsive. Checked the timing with my digital light and it reads 28+.!!!! When I try to bring it back to my original 11.5 degrees....the backfiring starts and the motor dies. I have checked TDC and am comfortable that I have the wire in the right order.

I am determined to learn what I need to know about these "W's", but I'm not doing so well.

What do I do now?

Thanks again,
Dennis

 

[Bub6le 2op]

Go on a set the timing at 32 to start and there is a good wiring diagram in the thread right under yours titled Mallory distributor with 6AL shows you the firing order and diagram of where the cylinders are located in the engine and where the wires go on the cap, the timing is why you are sluggish

 

[Phalen409]

Thanks for the lead on the other post. Read thru it...., thought that I had done most of the suggestions, but went back thru it again. Pulled valve cover off and plug from #1 to confirm that I was on the compression side of #1. Checked position of rotor and it was correct. Even though I had changed plugs recently, I pulled them all again. #2 & #4 fouled badly and wet. #3 was fouled but not so wet. All other plugs looked fine to maybe a little lean looking. Changed all the plugs.....Slowly went thru the plug wiring and low and behold, #'s 2 & 4 were crossed. Made sure that all others were correct, and the damn thing cranked up with no issue. Timing set to 12* BTDC with no spitting or popping this time. My vacuum now measures 12 (up from 9) and needle fairly steady considering the cam.

Took it for a test spin. It was awesome and ran like a bat out'a hell with partial throttle. Now I need to figure out my metering rod chatter to get it all to work together.

I was getting really down on this car, but one fix on the ignition side has got me fired up again!

 

[Donny Hammond]

Way to go......Donny

 

[blkblk63ss]

Well glad my posting helped you find your miss and back fire. Now what the heck is a metering rod chatter?????? Are you talking carb metering rod?????

 

[Phalen409]

Yea,
These Edlebrocks have been a pain in the ass for a while. I have been hesitant to work on them and have let other folks do the work. Springs and rods have been changed since new when Jack Gibbs found they were wrong from the Manufacturer. I am now going to start doing the work myself. Never have done carb work, but it's time to learn. With so many of this forum's members knowledge, it's a little embarrassing to admit that I'm not the mechanic I want to be on these cars, but I will learn. One guy claims cam, one claims vacuum. etc. I'll find out for myself. Jack built this great motor, and all it wants to do it run. I just need to learn to help it get there!

 

[Don Jacks]

Phalen409,What do you mean by "chatter",and when does it occur? What are the spec's on your cam,and what is your compression ratio? 12 inches of vacuum at an idle sounds low.Are you using a vacuum advance? What is the engines total advance at 2500-3000 rpm,vac.advance disconnected?

 

[scott hall]

Mine chattered because of a cam change. Vac was right at spring rate. If you have 12" of vac try 8 or 10's. I had to go down to 5's.

 

[SSpev]

Glad you got it working wouldn't wish my pain on anyone.

 

[blkblk63ss]

I understand what you are saying now.I have never had metering rod clatter problem's as i have had more vacuum on my engine's and left original metering rod's and spring's in.Getting 21.9 mpg on a edelbrock carb on a 350 engine, 350 turbo tran's in my son's 1969 camaro, with a slightly above stock cam. It's also a tire fryer.
Did they dyno your engine and get it all set up correctly after it was built????

 

[Phalen409]

Phalen409,What do you mean by "chatter",and when does it occur? What are the spec's on your cam,and what is your compression ratio? 12 inches of vacuum at an idle sounds low.Are you using a vacuum advance? What is the engines total advance at 2500-3000 rpm,vac.advance disconnected?

Cam: Isky H-636 Pistons: Ross 10.5 Pertronix Dist.Flame thrower II - No vacum advance
Duration 305 Degrees
Valve Lift .617
overlap 85 Deg.

You can here the machine gun like metal on metal "tinkle" over each metering rod position at any idle under 900 RPM.
Vacum measured from the front carb is around 10 mm and that RPM. At 1200 RPM the tinkling goes away. I will have to go in and find out what folks other the Jack did after the motor arrived to me in CT. I feel that there has been to many cooks in the kitchen and have changed what the motor from Jack came with.

Given the above information; is the measure vacuum from this position need to be more the 12 mm? I am confident that after changing the intake gaskets that there is no leak from the intake. Car cranks and idles at 1200 RPM beautifully. Falls on it's face if you bring the secondaries into play.

 

[yellow wagon]

This engine with that cam should run like a raped ape. It should be a handful to drive, throw you back in your seat and nuke the tires from a slow roll without even trying. If it doesn't do that, something is very wrong. It also should idle below 1000rpm. Mine idles 900-950rpm. Anything less and it idles like garbage. Keep the idle as high as possible while still being in the idle circuit. This will help your idle oil pressure.

I've never heard of metering rod clatter and no way I would be able to hear anything like that under the hood of my car. Its loud! How the heck can you hear a metering rod?

 

[blkblk63ss]

Well ,i thought maybe i was the only one with bad hearing. But if you suspect metering rod 's you could block them down with something between cover and top of rod to see if that's what the noise is for sure, just at idle only.If they are jumping up and down it would keep it from going into power {rich} mode. Then you could experiment with spring's to prevent that. Have you checked your pcv valve or any or all possible vacuum leak's???? Who ever is smarter than me on cam spec's as to to what vacuum would be on that cam can chime in.

 

[Don Jacks]

Well,I think Scott's right about the springs,the 5 inch of vacuuum will get rid of the "clatter".You really should get a dist. with a vacuum advance on it.With it hooked up to a vacuum source,you should see between 14 and 15 inches at about 900 rpm.Jack usually dyno's his engines,so the build sheet may provide you with the jets and rods that he used.Keep in mind that engine dyno numbers are generated at WOT,so some minor part throttle changes may be needed.Get your total timing around 34-35 degrees at 2500,dont worry about the inital timing,as it will be hard to read [it'll dance around] acuarately at idle speed anyway.Jason's right,this thing will rip once you get this tuning dialed in.

 

[Phalen409]

Jack has been very helpful and I've bugged him so much about these 409's, (and these carbs), he's has to be tired of hearing my voice. Rest assured, I'll get'er done. This spring I twisted 3rd gear and the drive shaft out of the thing going from 2nd to 3rd when it was running half assed. This is a super build and it will reach it's potential (in spite of me) before it's put away for the winter. All you guys are very helpful and I truly appreciate hearing from you.
Dennis