Thanks for the replies...  Manifold vacuum at idle is 11.5" @ about 500 rpms.  I will try tightening up the lash a teeny bit too, but the issue im trying to improve upon has been existant since the car got on the road, so...

 

As for the damper, I had it rebuilt last year, so it should be good for timing marks.

 

And Ive thought about a spacer, but Im reluctant to use one....Im pretty sure it wont fit under the hood.  I have the BT intake, with either the holley or edelbrock carb, and I am using a gutted out oil bath air filter, so it takes up a LOT of height under the hood.  im just not sure I could move everything up 2" and still close the hood.  We show the car a lot, so I dont want to ditch the air filter assy.

 

Originally, I was thinking of putting on a demon JR 525 to clean up some of the response over the edelbrock.  More research, however, led me down the path of thinking I could improve with a different manifold first, see how that works, then try the other carb if needed; a lot of variables........man, I wish i were smarter!!

Ron Grove

Wauconda, IL

Yes, my Blue Thunder intake has modifications for more flow and that was done in response for the aluminum heads I'm waiting for. I jetted my 390 cfm holley up to 58s in the primary side and pulls easily thru 4500 rpms. I am running the 390 carb on the 56 sunliner, and the Blue Thunder on the tbird. The intake on the sunliner is an extrude honed 57 intake flowing something close to the BT. I like the BT better and may put one on the sunliner at a later date.

-Gary Burnette-

If the camshaft was not degreed in when it was installed, then that will remain a question until it is degreed in.  Simply counting the pins between the marks doesn’t classify as degreeing in the camshaft.  However, installing a 2” four hole spacer under the carb will improve the vehicles performance right off of idle with the Blue Thunder intake.  Have you checked the manifold vacuum at idle?  That will give a clue as to look at the camshaft or go elsewhere.  Something else you can try in the short term is add 0.003"-0.004" of clearance at the tappets and see if this improves both the manifold vacuum and the off idle acceleration.

 

If the car responds positively with more intial timing without any signs of detonation, then run it there for awhile and see if that’s where you’d like to leave it.  If you haven’t checked the damper lately for an exact TDC mark, then there’s always the chance the damper has slipped which is leading you down a false trail.

Lorena, Texas (South of Waco)

Actually, my car liked even more advance than that as a base.  However, I backed it off to 12 degs because the exhaust is so loud I was afraid I wouldnt hear pinging, although the plugs looked decent.

Ive messed around with a holley 390 carb.  It was a little better, but had much less as the revs climbed than the 500 cfm carb.  Bigger carb just worked a bit better.

Im not sure i understand your comment about "the BTs we are running are bigger"....  I think I was one of the first ones to get one (around 2002, IIRC); have they changed over the years?  Or have you done additional work to yours?

Thanks!!

Ron Grove

Wauconda, IL

Im as sure as I can be without a degree wheel.  Used a service manual and eickmans book during the rebuild.

Again, the car isnt terrible; just trying to see if there is a way to get it incrementally better....

Thanks!

Ron Grove

Wauconda, IL

When the cam was installed was it set to the correct degree or did you use a rollmaster timing set. Advancing the cam gives more low end torque and retarding it gives more high end torque. are you sure it didn't get in retarded a tooth or something?

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

rgrove, You should be ok with the cam you have, it's for a stock converter. The BT intake in stock form should be ok as well with an average of 264 cfms per runner. The BT intakes we're running are considerably higher in cfms than the one you've got. Set the timing 12 too 14 degrees GET a smaller carb in the cfm range of 390 - 410 and see if that want make a difference. That's a LOT cheaper AND alot quicker than pulling out a mild street cam.

-Gary Burnette-

Howdy; I think PWH42 is correct on using a ECZ-B intake. I was told they were for a 292 truck motor for more torque. And some times electronic ignition does not work as well as a 57 to 59 distributor with both vacuum and centrifugal advance. I have had very good luck with this combo on a 292 with 389 rear gears. It is reasonable to do also. Also would not go higher than a 550 cfm carb.

at this point im not going to change the cam, and not looking to monkey with different rear gears.  Just not worth the headache, especially for a car that gets 3-4k miles/year.  Im looking for incremental improvements here, as it drives "ok" as is.  like most guys, just looking for a little more.... ha ha ha..

And yes, Im familiar with FOM weird 1st gear programming (now THAT would be a great mod/change!  Figure out how to get it to start in 1st EVERY time!!!!)

WHen I was messing with carbs over the summer, IIRC, vac was around 12.5 in gear at about 500 revs at idle.

Someday if I ever get around to either rebuilding this engine or putting together a higher performance oriented mill (better heads, higher CR, etc.) Ill use a different cam, etc.  And at that point Id consider a different trans, too....but that is all a looooonnnngggg way off, if ever.

Thanks!

Ron Grove

Wauconda, IL

About your lack of low RPM torque and drivabilty issues I think you nailed it as a combination of heavy convertable, FOM transmission and a too big cam. Either change the cam or put in a lower rear gear ( higher numerical axle ratio). You are using manual low to get a first gear start are you not? Put a vacuum gage on it and tell us what you read in gear and stopped and what RPM.

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