408 ideal rough

[340 man]

my 408 ideal rough it has a soild flat tappet cam cant find the problem can any one help me out. thanks

 

[jimjimjimmy]

what is your valve lash what is your timeing set at what kind of carb ect need more info

 

[340sFastback]

You need to post up the cam specs and did you degree the cam in?

 

[340 man]

cam spec.251/259 at .050 566/586 lift Damon at diamond back racing build the motor I am sure they degree the cam,timing at 34degree it has a 750 mighty demon.valve lash is 16/16

 

[fishy68]

That's a pretty healthy cam. It's gonna idle rough

 

[Abodybomber]

Better yet, what initial timing? Minimum 14-16 degrees initial 34-36 total at 3000. Don't be afraid, to go 18-22 initial. See if it smooths out. What distributor?

 

[moper]

How old is that carb? I've had to fix several Demons that had crap in them, or passages not completely drilled, or "hanging chads" from machining operations in the metering plates. IMO, if the combo is matched to the cam it should idle between 800-900rpm with a little romp to it. It's not that large.

 

[340 man]

16 degree msd dist.

 

[340 man]

carb. is not that old.

 

[MTmopars]

Got a video?

 

[Ted Carlson]

I have a 410 with a 232/237 @.050. The LSA or lobe centers are at 104 ground 4 degrees advanced. It idles very loppy at 800 RPM. Ask what the lobe center or LSA is. If it's 108 or less that will make the idle very choppy. Check for a vacuum leak. Spray some brake cleaner around the intake ports. If the idle changes, there is a vacuum leak. I have 16 degrees intial and 37 degrees at 2000. I live ar 4000' so I can get away with that. As stated before 34-36 total is very OK at at sea level. If you know anyone with a 600 or better known carb, put it on the engine and you will know right away if the carb is the problem. Hope this helps!

 

[Ted Carlson]

engine pic

 

[crackedback]

I'd run the initial in the 20-24 range.

You'll need a 10-14* bushing for the distributor.

 

[aaron68s]

I'd run the initial in the 20-24 range.

You'll need a 10-14* bushing for the distributor.

Where is the best place to acquire the distributor bushings?

 

[flyfish]

These might work:

http://www.summitracing.com/parts/msd-8464/overview/

If not, I would just lock out the timing....that's what I did with mine, works great (locked at 34°).

 

[crackedback]

I have a 14* bushing. Don't have any 10's

That MSD kit only has an 18 as the least amount of advance.

 

[fishy68]

There was a guy selling 10* bushings he makes himself a few weeks ago in the parts for sale section. Real cheap too. Found the ad, here it is, only problem is he might not have any left. worth a shot though

http://www.forabodiesonly.com/mopar/showthread.php?t=234991&highlight=msd+bushing