The stuff that drives you nutz is the stuff that you learn from Justin. Gotta take a breath and not take it personally...Its a machine it has no concept of (malice) The car Messing with your mind is all in your head. Patience young padawan...You'll get it.
NO..."that" backfire was probably because you were flooding the hell out of it. When you put the other carb on and "set the floats to the lowest level" (what possessed you to do that?) "That" backfire was most likely because you went to the complete opposite extreme. Others have already told you the likely reasons fuel was coming out the front horn...and it's not because it didn't have enough fuel! Go back and actually read ALL of the posts...digest them, and approach it methodically. Check your old carb...adjust it the way they've described...try it again and see if that helps. If you'd stop taking what you're getting from 15 different sites, and then only looking at the posts that steer you towards what you already think, and not necessarily what is actually wrong...you just MIGHT save yourself some aggravation. But hey, it's your car, do what you think. Maybe you just enjoy being aggravated.
Ok, if i was flooding the hell out of it with 2 1/2 turns out, then how come i didnt have this problem with the old heads? And they wern't seated properly! The motor ran great, it was a little noisy but it ran great. Dont come in here saying im not listening to everyone. Im getting a vacumm guage tonight to check if the valves are seating. I have tried adjusting the holley and with no luck (my holley) I will try adjusting his as soon as i get a timing chain gasket. I ended up pulling off my 1st carbs secondary bowl and the needle was perfect. My plan Check the comp If good then adjust carb and re gap plugs from 40 to 35 If i still have backfire then im going to pull the intake If i still have problems after that then i guess ill never know The machine shop would have let me know if the valves were not seating, they told me about the last pair. So i dont know hwat the hell is going on. Timing is right. seats in heads are good. Just keep checking things off the list.
yes you can. there are shims if the rocker arm screws down to far (over 1 turn according to those instructions i posted) or you have to use a shorter push rod if it doesnt go down far enough. right now i would guess that you are having to tighten them down over a turn. go check and see.
Justin,just a thought,I have read this entire thread and I'm wondering,are you sure your cam is for a 302? If you got one for a 351 you'll have to change your firing order. Check with the manufacturer and make sure it's for a 302. Been there done that,and played with mine for a month till I finally figured it out!
351 cam wired as a 302, but 180 out will run, idle "like a dragster", but backfire off idle also. Learned that one the hard way.
Ding Ding Ding! All the ford alphabet cams and the trick flows use the 351W firing order. 1-3-7-2-6-5-4-8
You have done so much changing around of the components it is hard to keep track so lets take it back to basics Distributor, set harmonic balancer to tdc take off valve covers and check to see that both the valves on number one---passengerside front are closed, if not then you need turn motor another 180 to get to tdc on compression stroke. Next turn the motor over by hand to next cylinder in firing order that you are using, those valves should now be closed, if they are not then you are not using the correct firing order. As a side note it is possible for the harmonic balacer to have spun due to the rubber being worn out and the degrees would be off. You can loosen the rocker arms and set the valve lash but you might as well pull them out and check them for straightness by rolling them on a piece of glass. Put them back in and tighten them until no play is felt, many people roll them until resistance is felt but others say to just wiggle them up and down is a better way, I do it by wiggliing them up and down as you can actually put a little preload on them before you can fell resistance. There has always been a debate on how far to tighten them 1/2 turn 3/4 turn but I have alays gone 1/2 and as you know some you just tighten down no adjustment is possible. Pushrod length needs to be looked at as well but you should be able to see by eye how the rockers arms are as far as hitting the center of valve stems. Intakes--- First of all throw the rubber or cork intake gaskets that go on the front and rear rails of the engine and use some rtv 1/4" bead with a little extra on the corner for this purpose, put a little around the water passages on both sides of gasket as well. Best method to check for vacuum leak is to have motor running and spray some carb cleaner around all the mating surfaces of intake,base of carb,vacuum ports. Increase in engine speed will occur if a leak is present. Dont forget to check the transmission modulator valve at transmission as well Spark plugs need to be gapped, cleaning them does not mean that they are working you need to read them and possible post a picture of them if you do not know how to tell if they are saying rich,lean,or ? Carb well I am not going to open a can of worms on this one other than the fact that you said that you turned screws all the ways in and it kept running so that tells me it is getting fuel with the metering turned off As you know there is a lot more to it than this but if all these items are correct than the engine should run correctly. I would do a compression test just to ease my mind, pull all the plugs and block carb open I know someone will flame me for some of this info, so be it as I am just trying to help
When in doubt do a running compression test. It will tell you if its a valve problem. Google it, if you havent done one before. You seem to be running around in circles. You have a vacuum gauge thats bouncing, unsure of the valve train components, back firing through the intake. Do the running comp. test.
