Keep in mind that the timing technique I suggested is for the passenger car damper not a

t-bird. Let us know how the holley 390 cfm works after the original power valve is reinstalled.

-Gary Burnette-

The Edelbrock you have is also for use with cams that have less than 220 @.050. Try the demon if you have the cash to spend.


Lawrenceville, GA

The Road Demon Jr. uses a jet plate in the secondary side in lieu of standard jets.  Not a big deal as the carb is jetted reasonably close on the secondary side as supplied.   If stepping up to an equivalent sized Road Demon instead of a Road Demon Jr., then you’ll require a dual feed fuel line but you’ll also have conventional jets in the secondary side if you like to fiddle with them.  I’ve run both the 625 Road Demon and 525 Road Demon Jr. on my 272 with the Isky E4 camshaft and the 525 carb definitely gets my vote.  Previously to using the Demon carbs, I ran a myriad of Holley and Carter carbs with a 500 cfm Carter carb being the carb of choice until using the 525 Demon Jr.  The air cleaner requirements for the Road Demon Jr. are similar to those for a Holley List #1850 (600 cfm).  I also used the same air cleaner for the 500 cfm Carter for what its worth.

Lorena, Texas (South of Waco)

so in researching, they say the 525 is for cams less than 220 deg duration @ .050.  Should this deterr me from making the switch?  Also, any thoughts on demon vs. demon jr?  I think the Jr has a single inlet - would be my preference with smaller float bowls, etc. if it would perform as well for my application...

Thanks!

Ron Grove

Wauconda, IL

Yup.... im thinking that if/when I get this fixed, id likely put a small mark in the pulley even with the 0 deg mark. 

Ron Grove

Wauconda, IL

While I am not sure about how pass. dampers are constructed (T-Bird parts have the timing marks on the pulley, not the weight ring, and thus cannot vary), it would seem to me to be a good idea to mark new ones in such a way that any shifting could be easily detected, and timing could thus always be set fairly close, though the balance would still be off until the damper was replaced/repaired?

Such an obvious advance alert might prevent serious engine damage. I could not be the first one to think of this (?), yet have never seen it mentioned!






6 VOLTS/POS. GRD. NW INDIANA

Gary, you are right again!  it is amazing how much knowledge is on this site....

So a while ago I used a whistler to try to confirm TDC was correct; but as mentioned, timing light said it wasnt quite right.  I just checked per Garys recommendation, and sure enough the marks are wrong!  I never would have known, as the whistler I used obviously wasnt precise enough....so I think timing for right now is ok, but I will have to fix that over the winter so that I can really get it dialed in properly....

THANKS!

Ron Grove

Wauconda, IL

ha ha ha!  Not sure what I would do with a carb that worked!

I actually already own the edelbrock - it was the first carb I bought with the blue thunder, but it always seemed a bit "sloppy" on throttle response, so i tried the holley.

More folks I talk to seem to endorse the demon jr.  I need to figure out how it would sit/fit under the original air cleaner.  I gutted the oil bath part and converted it to a hi-po paper type filter, but I like it to appear mostly stock for shows, etc......

Ive seen rebuilt ones on line for not tons of cash....   any idea if they work as good as new?

Thanks again for the help!

Ron Grove

Wauconda, IL

Ron,

   I vote for the Demon unless somebody gives you the Edelbrock. Lotsa guys like them, but I am extremely happy with my Demon. I think Ted runs one also and will tell you the same thing. They do use Holley style Jets and power valves. The biggest problem with the Demons is that they work and don't leak! Kinda boring!

Frank/Rebop

Bristol, In ( by Elkhart) 

Frank,

Thanks for the reply!  I think I will not mess with it much beyond putting the 6.5 PV back in and trying it.  It really runs pretty well now.... the higher PV should help smooth it out a little under acceleration, if i understand correctly.  I may also try leaning the main jets a little, as Im sure that need has changed a bit since I fixed the loose baseplate, etc. and solved the vaccuum leak.  I initially went up from a 51 to a 56 or 58 main jet when i was chasing the main problem.

Overall the carb is working pretty darn well now.... and best of all it responds the way that it should to tuning changes, which makes it much easier to sort out/fine tune.

Next up after this one is put to bed is to start working on the Edelbrock.  Car doesnt like to idle nearly as well with the edelbrock, and it is a little harder to start.  Throttle response isnt quite as crisp either.  Ill need to do some reading up on how to tune that one.  Alternately I was contemplating a demon jr. 525 - can you use holley jets, PV, etc. on the demons?

Ron

Ron Grove

Wauconda, IL