Wow.. heres a dilemma. I've been doing shake downs in the Indy car and the 3x2 has been a dream. Went to start her the other day- nothing- no fire. Checked spark- yes, now to fuel... Ok- plugs gas fouled mid motor to back. I pulled the top of the center carb- voila, a cracked float- problem solved right? Ordered CP floats (gr8 guy- had em to me quick and we even knew people in common)..... adjusted float to 1 11/32. and replaced fuel needle and seat to rubber tip. Engine would not fire... checked plugs- fouled again! Pulled the carb from base and had fuel in the power valve chamber. Checked the other two carbs- same thing!! Heres my dilemma- the car has been running like a raped ape for about 5 test runs. The motor is seasoned. Could all of the power valves operate fine for the first runs and then all fail? Secondly, it had stock power valves in all carbs with progressive linkage (folks say this wont work), but it ran great- plugs looked a bit rich though, but it would scream at about 5000 rpms. Should I look into running 3.5 power valves in all when I buy them, or go the route many suggest and plug the two outer model 59's while running a 3.5 or stock PV in the center 91-99 model with my current progressive linkage and make secondary dumpers with no PV and idle screws all the way in? It's hard for me to figure... it was running good, but this motor was built for a hydroplane boat originally by Clay Smith, so it may need to come down a bit for the street... Any suggestions? (I'm obviously not versed in my multi carb applications! - Any help greatly appreciated). -Rick
Id say look into running 3.5 power valves but thats just me. Maybe just try 2 94s instead of the three..
I don't think running power valves in all 3 carbs is really necessary w/progressive linkage. Maybe just a 65? pv (depending on your vacuum at idle) in the center carb and no pv's in the end carbs w/larger jets to make up for the lack of enrichment. As far as your pv leakage goes, pull them all, aside from checking the diaphragms, also look to see if the gaskets are sealing right and if they are hanging up for any reason. You can find more on this by doing a H.A.M.B. search. I'm not necesarily an expert on multi carb setups myself, but I've also heard that you may have trouble getting your idle down to a reasonable level w/out some air fuel adjustment on the end carbs, unless you can close the throttles completely, which may require new plates cut at a different angle so that they don't stick in the bores. Hope any of this helps and i'm sure there are more experienced 3 bolt types that will chime in.
over on fordbarn a lot of guys are finding new powervalves dont like the gas you guys get and the gas destroys the diaphram in the powervalve - not sure if thats your issue? might also be worth mentioning that the new powervalves you get dont really fit (the base is too big on them) like the old ones do and unless you put two washers on they dont seal even though they look like they do.
Get rid of the F&R power valve-Go up a jet size in the F&R then experiment with the center carb as to size power valve needed. You can actually rejet and dump all the power valves if its the ethanol creating the problem.
Hey guys- thanks for all the response. It seems like most are fans of blocking the power valves.... my dilemma seems to lie with the fact that before the valves went bad, the car started straight up and ran like a banshee and really broke loose on the top end which made it really fun. They are the old style stock powervalves. So what make me bonkers is witnessing the motor run like this with 3 powervalves and 3 idle circuits without problems- maybe just a bit rich at the plugs which I could run hotter plugs as it would not smoke or load up, even while idling for a while. Does anyone have experience running all three stock vaccum powervalves with idles circuits without issues as it seemed my motor had prior to the valves going bad? The idles circuits were set up at 1 1/4 out in center, and 1/2 out on the end carbs all with progressive linkage. I assume the valves were 7.5 stock as well.
Ok - heres an interesting new turn. I found one good powervalve - I tested it on a sheet of newspaper overnight with a full float bowl. No leak from the gasket or diaphram. Good news. I made carb block plates for the front and rear carbs and installed them with 2 gaskets. So now we effectively have a single carb engine with a good stock powervalve in it, new float set to 1 11/32 and new needle and seat. Turned her over- dead! Pulled the plugs (center engine)... soaked in gas!!! what the heck??/ Pulled the body and the power valve bowl was wet..... where is the gas coming from????
Two checks: Get hold of one of the vac pump testers made for 4150 PV's...several speed companies make them. If gasket surfaces don't match, stick an O-ring in to seal it...then pump up a bit of vac and see if it holds. This will tell you if diaphragms are the souce of the leak, Next, flip over carb body and eyeball the ring right around the hole for PV that is the gasket surface. Look at your PV's...if they are wito rather than AA1 types, gasket ring will lie exactly outboard of where you want it. Proper AA1 gasket will jam into the tapered area and kindamaybe almost seal. 4150 gasket will be totally on its own with no place to sit down. I just noticed that NAPA kits, formerly OK, have started coming through with wrong valves. You should get better results with PV's, in general, becuse without carbs are going to be wrong at some part of their range no matter what. It ran well, so gettit back to there!
Also, if possible, get kit from NAPA or a serious rebuilder so there's at least some connection to a real company...I see lots of kits that are sold in an unmarked plastic bag. Who makes'em? Where do they come from? Must be great stuff!
Bruce- Thanks- that was exactly my dilemma. I figured, if it worked once- why fix it or change it? The gaskets are all proper etc. I'll have to get a tester and check- just so I can sleep at night- thanks for the info- I just found one online. I also just ordered some 4.5 pv's from CPrice ... I figured I would run all three and maybe allow some "breathing room" with the lower numbers. It's hard to imagine it being anything but the PV's as the amount of fuel dumping in is incredible- and the carbs aren't leaking when they are on the bench and full of fuel. I'm going to spend my retirement if I gas foul any more plugs! Now I'm learning to put the old plugs back in just to test for wetness!
Neat stuff available from your repro parts guy now to fit your 94: Power valves that cannot possibly seat on the body Accerator pumps that are the wrong length, taken from some 50's Merc application Viton needles that stick to their seats rebuild kit instructions showing float level as 1 1/8"...glug...glug...glug... Whyinhell can we no longer buy any parts that we can actually use without lengthy investigation?? How does a normal human being without a 50 year collection of Ford data even figure out which nice looking part is totally incompatible with function??!?
I couldn't agree more.... thats why I'm looking forward to buy my Chinese made American car in 2011 !!
I'm fit to be tied.... I'm at a total loss. I replaced floats- set to 1 11/32, seats all good. Changed to 3.5 PV's all the way around using stock gaskets (they all seal well)... buttoned everything up and it still wont start. Great spark from magneto- no gas in engine (turned engine without spark plugs in), new plugs, et al. It sparks runs about 2 seconds and signs off... almost like it is starved for gas. I wont hit the throttle pedal as this floods my plugs. I tried turning the idle screws out 1/4 turn to richen the idle circuit- nothing... tried leaning out... nothing.. same symptoms. Tried idle set screw at barely engaging throttle plate (no choke) to a couple screws in ... nothing.... Am I missing something? I feel absolutely limp!
Oh yeh- this will blow your mind... I didn't kill the mag when I was purging the cylinders from any excess gas... it started and ran with only 4 plugs in the engine. What can cause an engine to run with 4 plugs in and 4 out but not run with all 8 in???
Maybe you want to go here.......... http://www.jalopyjournal.com/forum/showthread.php?t=383390&highlight=haunted Terry
I just read with interest your post , I was really interested when you said it ran for 2 secs & cut out , I had the same thing a month ago on a flathead running a 500cfm Edelbrock , built flatty. I suspected carb, then coil then ign, then realizing it was a Mallory dual point I whipped out the points, put in a Petronix unit Voila , a runner. Get the Mag checked properly or try a disi real quick. A mag will spark at athmosphere but not under compression if the coil is going away. I had a simillar thing with my Anglia Gasser GMC 302 2 Hollets & a mag, 1 day no run , bad Mag coil !!!. It seems you've exhausted the carb issues , maybe wet plugs = weak/no spark. Worth a try before you have less hair than me Steve
I have a Holley 94 3+2 set up on the 55.. I dont have much of a fuel problem.. but man do these thing whistle.. gasket leaks.. they each sing a different tune.. its hard on the ears.. Im with a few others.. Do you have spark??
After reading all posts I tend to look at another issue and favor Limeysteve's advice. If this is a points controlled mag with a bad condenser it will exhibit similar low, iratic or no spark. Because you indicate that you have plenty of fuel it then reverts to poor spark as the problem, the rich fuel charge is due to the engine not firing the fuel mixture as it is cranked over thus soaking the plugs and the appearance of a flooding condition.. Change the condenser in the mag first.
Thanks much guys.... I'm thinking you guys nailed it... I have worn my scalp thin with much scratching.... given all the options and although the mag sparks good with my tongue on it... I have to wonder if it's not on its way out.... at least it seems like a very viable option... will look here and get back with a post and follow up on results. I wasn't aware that under compression, it will give.... this could be it......
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