Blower carb power valve help please

hey geo.

I FOUND MY VAC. WAS ACUALLY HIGHER THAN I THOUGHT (ABOUT 10 AT IDLE) I PUT IN THE 6.5 VALVES AND MADE SURE THEY WERE INDEXED

AS IT TURNED OUT THE ANGLIA (AS DE-TUNED AS I COULD GET IT) WAS TO MUCH FOR THE STREET (AND NEIHBORS)

THE ANGLIA IS NOW STRICKLY A DRAG CAR

MORE THAN LIKLY YOU HAVE A BUNCH OF LITTLE PROBLEMS

I AM NO EXPERT BUT THESE ARE THE THINGS I DID TO MAKE MINE RUN GOOD.

-MAKE 100% YOU HAVE NO VAC LEAKS
- RECOMEND LOCKING OUT THE TIMING (MINE IS AT 28DEGREES
- MAKE SURE CARBS ARE THE KIND THAT HAVE AN INDEXING PORT AND INDEX THEM
(IN ADDITION MAKE SURE YOU DONT HAVE A DIST W/ VAC. ADVANCE
- SET ALL FLOAT LEVELS WITH THE ENGINE RUNNING
- MAKE SURE FUEL PRESURE IS NOT TOO HIGH (I RUN 8-9 PSI)
- MAKE SURE PLUGS ARE CORRECT RANGE (I LUCKED OUT WITH A RECOMENDATION FROM EDELBROCK, I HAVE EBROC. HEADS
- DO YOU HAVE THE CORRECT CAM FOR A BLOWER MOTOR
- IS YOUR COMP RATIO CORRECT (8-8.5 TO 1)
- ARE YOU UNDERDRIVING THE BLOWER BY 10%ISH (AT BEST ALL YOU CAN RUN ON PUMP GAS)
- WHAT STALL SPEED CONVERTOR ARE YOU RUNNING
(STOCK STALL SPEED COULD BE A PROBLEM)

AGAIN I AM NO EXPERT BUT THESE ARE THE THINGS I LEARNED

 

Haven't driven that much , just short bursts

427, Aries blower pistons(8:5to1), scat rods, steel crank , Merlin rect. Port open chamber heads, comp cam, hydraulic non roller,
Duration= 284/305
Lift= 575/595 Prt# nx284h
Th350= TCI nitrous converter 8" (3500-4500 stall) mine stalls in the car on foot at 3000, 389 gears
Running magneto, I not sure on timming , set it to where it starts easy when hot , and cold, takes all gas I give it, just runs rich idling
6lbs boost

 

What heat range plug you running?

 

again, not an expert....

at face value of what you said i think you need to get some more knowledge of engine tuning.
not knowing what advance you are running both static and full advance (and curve if not locked out) is a no-no

i would be suspect of the mag and its set-up for a street rod.
what size is blower? 6.71 or 8.71?

are you running it under driven? (pully sizes will determain)

seems to me cam is not enough for the blower and heads you have
i believe a blower cam should have (what i believe is ) a split overlap
on the duration. i believe that helps clear the cyls. after a power stroke has taken place (posibly with your cam that there is too much unburned fuel left over causing the load up)

my can is a comp cam (again) matched for the heads, blower, intake and carb size)
int. duration 300, exh. duration 308 with a 652 lift

my blower is an 971 bds, the heads are ebroc 24 degree 119 cc open chamber (made for blown applications)

i would check the compatabillity of your componants to make sure they are a good match for a blower motor

if you want to chat 207.252.3744 geo.

 

No expert for sure
Ronco mag is locked out at 7 deg. Adv.
No advance built in, the cam and the carbs are components built with a blower in mind. Running a crank hub . Need to put some tape on the husband make a timming marker for the Weiand timming cover. Plugs are black, can't be running too bad. If I remember the pulley sizes I think I am 6% under driven .i have to go look at chart again. Thanks for the help though, gonna just try bumping the primary jets to 74,s then open up the idel mixtures screws to let more air in
Thanks again

 

Idle mixture screws let more fuel in. Seat them and back out about 5/8 to 3/4 turn. Plugs should not be black. What is your idle rpm? Changing jets will have no effect on idle richness.

 

On the idle , can't tell ya, do not have my mechanical tach hooked up yet. I thinking around 800 on the idle. Will post a video soon as I get the chance.

 

abone 1930;

mag locked out at 7? That won't work. You mean initial at 7 right? You want between 24-34 total if locked out, typically. But iin my experience, idle speed may be unstreetable without a curve in the mag.

 

Don't laugh has an exhaust leak on the right side, fixed now
Car runs fine just loads up now and then http://s69.beta.photobucket.com/use...2-64157135BAFB-8557-00000ABA34B56ADB.mp4.html

And sorry don't usually talk alot about this car not Hamb friendly , just need advice

 

It has 7 deg. Advanced built into mag, so then I need to set timming around 25 deg advanced?

 

F%&*&^#$%*ck, I'm getting a head ache. Throw those carbs away and bolt on a set of Hilborns, problem resolved............

 

So you're saying it has 7 degrees of centrifugal in the mag, by way of weights and springs? Then start with about 20-23 degrees initial (at balancer, with timing light.) Look very closely at plugs for tiny balls of melted metal on plug porcelain, or missing strap material. If none, advance timing a degree at a time, test drive it hard, check plugs and keep going up up to about 27 degrees initial max. At some point it will get hard to start as you run that much initial timing. 7 plus 27 = 34 degrees total. Thats as far as I'd go with this set up.

 

Thanks for all the ideals everyone
Instead of boost referenced power valves , does any blower guys out there just delete the power valves, run a plug and bump the primary jets up?

 

Yes, my current blower motor is that way. Less street friendly, more racy. Runs lean up a hill, rich down a hill, on a/f monitor.

 

7 at distributor is 14 at crank!

 

My blown big block Anglia had a rolling Idle where the rpm would roll up and down a couple hundred , I put A/F sensors in and found Idle A/f was around 9.8 to 10.5 to 1 . I could lean out the carbs (idle screws ) to 13.5 -13.8 and the roll stopped . I ran 84 jets with 2.5 power valves . The carbs where 780 vac secondaries on 454 , 6-71 , Mag @ 30 deg not locked out . Comp blower cam 7.5 compress . 2800 converter 3.55 gears , very streetable . I ended up riching up the system abit just on the idle screws so it would sound alittle more racey.
Mike

 

With an 8-71 and two 750s on a BB chevy, I'd be more concerned with making enough vacuum at high rpm WOT to pull them closed, with catastrophic results. This is one of the few cases where I would probably plug them and go up on the mains.