Carb spacer?

[burntorange70]

I have been having truble with heat soak with my 70 340. When it warms up fully it has a bit of a stumble of off idle. I have been thinking of going with a 1/2" 4 hole Phenolic carb spacer and mabby a heat shield. I was looking through the Jegs catalog and noticed a lot of the ones I was intrested in say. "Not for stock intakes with heat cross over"

Why is that? What should I use/get?

Thanks for your help.
Russell

 

[Rob R]

I pretty sure what your experiencing is a lean condition...adding a spacer is going to make your problem worse because your adding volume to the plenum...
I'd drill the shooter up by .004 and see if improves. just something I've come across many many times.

 

[burntorange70]

Thanks for the info rob. I am running an eddy 650 thunder series carb and have a jet kit for it. I have mesed around with different rods but have not changed any jets yet. I have never taken a carb apart. Can any one give me some advice on the what/how I need to be doing?

Thanks all for your help.
Russell

 

[Rob R]

Russ...

That carb is border line for a 340...I think it's a 600 if it's a thunder series.
What you can do is put a .101 main jet in it and leave the metering rod alone and see what happens.That should take most of the stumble out of it and then you can drill the shooter up .002 and see how it likes that.They usually like at least .005 or more but you'll get the idea when you see the improvement you get with just .002.

 

[burntorange70]

I will try that this week end. I have a set of .101's and a set of .104's. What ones you think I should try? Should I just shange out the main jets and leave the secondaries alone? How would I cang out the jets? I have never taken a carb apart so any thing you can tell me would be a big help.

Sorry for all the questions and thank you for all your help.

Russell

 

[Rob R]

Russ...
I wouldn't get too carried away with that large a jet (104) as your not going to be changing any metering rods...
If you have a 98 for the rear you can put it in but I wouldn't make too many changes at once.
Make sure that you have new spark plugs in the engine.
Taking off the top is no big deal...first remove the rods and pistons and then the 10 screws that hold the top of the carb down...they are around the outside of the carb with 2 on the inside F/R...Then the accelerator pump arm and off the top comes...

 

[burntorange70]

Sounds easy enouf. Thanks again Rob. I will let you know how it goes.

Russell

 

[AdamR]

Russ, You may try pulling the intake and blocking the heat crossover. Its not really needed in CA and should help cool the intake a bit.

 

[burntorange70]

Russ, You may try pulling the intake and blocking the heat crossover. Its not really needed in CA and should help cool the intake a bit.

I got an Eddy air gap I am going to put on when I rebuild the motor on of these days. That should help out a lot.

 

[burntorange70]

I changed the Jets today and went for a test drive. I think it did the trick. Stumble is gone off of idle even when the motor is hot.

Thanks for all your help!
Russell

 

[burntorange70]

Well my 340 has been running better than it ever has ever sence I put that Eddy on there. I was just thinking though. Do you think I should try messing with the rods and springs any? Or should I just leave it alone?

Thanks
Russell

 

[burntorange70]

Bump! Bump!

 

[burntorange70]

Any one have any ideas?

 

[AdamR]

You can try richening it up. I think Eddys are lean out of the box.

 

[burntorange70]

Thanks Adam. I think That is what I am going to do. Only way to learn is to do. So I am going to mess around with it a little.

 

[Mopar73340]

FWIW, Both of my 650 Eddies were RICH OOTB on 340's, So try a rod change each direction and see what seems to work best and go from there. If you don't have the manual for your carb, you can download it at the Edelbock web site. It lists rod and jet changes to calabrate the carb if you are unsure.

 

[burntorange70]

Thanks for the info.


Russell

 

[Rob R]

I'd just leave it alone...

 

[Chryco Psycho]

What is the plug color after cruising it ?

 

[burntorange70]

I got her all worked out now. She was on the lean side.
Thanks every one for your help.

Russell