NEW 489 BACKFIRING

[Shovelrick]

I also checked resistance on the Taylor Streetfire wires and they weren't consistant at all, I checked the #7 @ 1.038-1.04, #3 @ 1.5, #2@ 1.02 seems not so good for a U.S.A. made plug wire set but I don't know what's acceptable, I should have kept the MSD Super Conductors I had on the 454 I sold to my friend lol

 

[kmakar]

I also checked resistance on the Taylor Streetfire wires and they weren't consistant at all, I checked the #7 @ 1.038-1.04, #3 @ 1.5, #2@ 1.02 seems not so good for a U.S.A. made plug wire set but I don't know what's acceptable, I should have kept the MSD Super Conductors I had on the 454 I sold to my friend lol

I'd buy all new wires.

 

[Nashville Cat]

l put knew NGK BKR5E plugs gapped at .045 in today and the BF's gone, I couldn't get the mag base to stick anywhere since it's an alum top end so tried the steering shaft but it still moved but the rockers looked like they were moving same as others, the vac guage is still bouncing so next is the cigar test then Im going to try leaning out the carb, still running very rich

Make sure your timing isn't jumping up and down. That could happen if the vacuum can is dithering in and out; it should activate 2" below your normal idle vacuum.

 

[Shovelrick]

Make sure your timing isn't jumping up and down. That could happen if the vacuum can is dithering in and out; it should activate 2" below your normal idle vacuum.

The timing pointer does show it moving back and forth from around 37° to 39° but with the steering pump in the way and after market pointer its hard to tell, now I wonder if somethings up in the HEI Pertronix flame thrower III ? Hum

 

[Shovelrick]

I'd buy all new wires.

Been thinking about another set of MSD Supers

 

[Shovelrick]

Been thinking about another set of MSD Supers

I was looking at MSD Supers last night and only see adjustable spark plug ends? I use 135° and they clear the headers great, I'm assuming these adjustables Bend? to get whatever angle you want? Anyone using these and what do you think about them? I don't really care for bending a hard fitting but if it's bending the wire inside it seems it would spring back?

 

[68Chevele]

Is this a roller cam engine? if so recheck all the springs again, one may be weak and you don't want that with a roller cam. What type of ign do you run?

 

[Shovelrick]

Is this a roller cam engine? if so recheck all the springs again, one may be weak and you don't want that with a roller cam. What type of ign do you run?

It's a Lunati Voodoo line hyd roller 231/239 dur. @ .050, .600 lift both side, 110 lsa, installed 107 icl and 450 lbs. open spring pres., HEI Pertronix Flame Thrower III I'm taking a look inside dist. too but really thinking the problem is pig rich carb and with vac gauge bouncing either vac leak, valve adjustment ? I also called Lunati & Brodix they both said spring pres was fine for that cam, visually the springs look good but I don't have anything that checks pres but I think I could borrow something from the builder or have him check it but would like to do as much as I can before taking it to him

 

[68Chevele]

It's a Lunati Voodoo line hyd roller 231/239 dur. @ .050, .600 lift both side, 110 lsa, installed 107 icl and 450 lbs. open spring pres., HEI Pertronix Flame Thrower III I'm taking a look inside dist. too but really thinking the problem is pig rich carb and with vac gauge bouncing either vac leak, valve adjustment ? I also called Lunati & Brodix they both said spring pres was fine for that cam, visually the springs look good but I don't have anything that checks pres but I think I could borrow something from the builder or have him check it but would like to do as much as I can before taking it to him

I would run those springs @500 open if it were me if you are twisting it to 6500. You can get one of those on car spring pressure testers to check them out. Is that HP Holley a 1000? I know when I ran the last race with my 1000 M/D it was pretty blubbery on that engine but then I put my new FST 850 VS on the car it cleaned right up and ran a tenth and a half over the 1000. You might be right on the carb being to fat.

 

[cage2592]

I personally do not run vac. adv. on anything over 500hp to limit overall mech. timing to 36* at 2800rpm. My initial falls to 18* at 850rpm idle. I understand some swear by VAC adv, but every good builder I've talked to say you do not want a lot of timing on a high HP engine. Id at least try it. That and I run the same plugs as you but with 40 gap. Also an AED 750 HPHO.

I think Taylor wires have resistance listed on their website. I just looked and yes the Spiros I have say 350 ohms per foot. I just checked my new Taylors this past weekend when tuning up the truck 454 and they were all very close. Straub is selling wires as well. Those will be my next as I already had the Taylors though.

Just my quick thoughts Sir.

Mike

 

[cage2592]

Just reading over your post on the other site now.

Mike

 

[Shovelrick]

I'm either going to buy a kit for the 850 dbl pumper and put it in myself or take it to a carb shop for a rebuild, I'm sure the AED 1,000 is great on this engine for the strip but prob a little too much for the street? I'm still going to try adjusting the rear mix screws today though, I lightly seated all 4 then backed out 1.25 turns for a starting point but haven't touched the 2 rear mix screws yet, I'm going to get another vac gauge too

 

[68Chevele]

For me I give the engine what it wants in timing as it's the compression and chamber design that makes the magic happen there. My 406 last year with Vortec heads like 31° and the 461 peanut port engine liked 40-44° of timing. Just have to watch the plugs for signs of detonation.

 

[kmakar]

For me I give the engine what it wants in timing as it's the compression and chamber design that makes the magic happen there.

Just have to watch the plugs for signs of detonation.

I must admit that sounded elegant.

 

[Shovelrick]

My 454 with vac adv hooked up was around 52° or maybe more above 3,500 and ran very strong and plugs looked great too

 

[Nashville Cat]

My 454 with vac adv hooked up was around 52° or maybe more above 3,500 and ran very strong and plugs looked great too

I bought this 850 carb because it has the same throttle bore size as a 750 (1.688) but gets the 850 rating
by eliminating the choke and contouring around the venturis.

Maybe a carb like this could boost your torque without costing you top end power ?

I bought mine for $400 refurbished; it looks brand new.

Holley FR-82851SA 850 CFM Aluminum Street HP Carburetor-Factory Refurbished

This is an official Holley Performance Factory Refurbished Carburetor listing. Factory Refurbished carbs are NOT old worn-out carbs that have been rebuilt. They are brand new carbs that were returned under warranty. When these carbs are returned, we check them out and most of the time there...

www.holley.com

IMHO, if you eliminated the vacuum advance, you would get miserable mileage on the interstate.
You do have an overdrive trans ?

 

[Shovelrick]

I bought this 850 carb because it has the same throttle bore size as a 750 (1.688) but gets the 850 rating
by eliminating the choke and contouring around the venturis.

Maybe a carb like this could boost your torque without costing you top end power ?

I bought mine for $400 refurbished; it looks brand new.

Holley FR-82851SA 850 CFM Aluminum Street HP Carburetor-Factory Refurbished

This is an official Holley Performance Factory Refurbished Carburetor listing. Factory Refurbished carbs are NOT old worn-out carbs that have been rebuilt. They are brand new carbs that were returned under warranty. When these carbs are returned, we check them out and most of the time there...

www.holley.com

IMHO, if you eliminated the vacuum advance, you would get miserable mileage on the interstate.
You do have an overdrive trans ?

OD is something I'd like to add at some point, thinking hard about a GV unit, that 850 you bought is a VERY nice carb and a heck of a good deal, I do want to stay with vac adv

 

[cage2592]

Just reading your update 'over there'. Too bad were not a little closer as Id let you use my AED 750HPHO on my 70 now. Its dialed in to my MJ406. Don't know what shipping from me to you would be but should be quick for only 4 hrs.

Have you called AED to hear what they would suggest to get that 1000 dialed in for the engine?

Mike

 

[Shovelrick]

I ordered a Lisle vac/fuel test gauge and good old Amazon dropped it off yesterday so I went today and got it a little better with a steady 12 Hg at an 1100 rpm idle but getting closer, had the vac gauge outside windshield, might keep it there lol, Oh and my timing was at 12° btdc so I moved it to 18-19° I'd sworn it was there a few days ago and dist was down tight

 

[cage2592]

It sounds like it coming together !