hi, i have a 1970 maverick, i just rebuild a 1979 302, but it doesnt run well. -it have flat top pistons # TRW-8KH120CP30 hypereutectic -COMPS CAMS 280 MAGNUM, .512 LIFT, 230 DEGR. duration -1990' something 5.0 heads whit comps cams springs, exaust ported only -offenhauser tunnel ram intake, one carburetor ( manual choke holley 600 vacum sec.) - points distributor the first problem is that i cant check the timming because the pointer and damper doesnt even come close when i put the light on, maybe because i use a 1969 damper on a 1979 engine? i installed a doble rolling timming chain cca- 2120 and aligned the "o" marks right the car starts right away, but i cant push the accelerator to fast,i have to do it very slowly it feels powerless, like if you removed a couple of sparkplugs, and the engine shakes all the time it have some sounds in the valvetrain, maybe because i use the old pushrods, they are getting worse! i accelerate and i hear some litle explotions coming out of the carb what im going to do right now is change all the pushrods, put and electronic distributor, and see what happen. do you think that the intake is just too big?
Timing, firing order or timing chain/camshaft installed wrong ... Most Ford cars are have dampers setup to have the timing pointer on the drivers side of the car ... so they may not work with the ponter on the passenger side like a Maverick ..
Did you break in the cam properly? Also, the tunnel ram has a very large plenum and needs a large 'pump shot' to get the main circuit going. I am not saying the pump and/or squirter are the root of your problems, but if you didn't put serious thought into tuning them, you will have serious problems with bogging on takeoff. The low vacuum signal could also cause your secondarys to open too soon. You may need a different spring also. Certainly you need to do a proper break in run and then get timing dead on, then check the carb. Dave
First, the combination is poor for street use. The cam will not idle smooth. You need to find top dead center for #1 cylinder then identify the zero point on the damperd so you know what you have for a timing reference and time from that reference. Is the cam/timing chain installed correctly? Late heads! do you have the correct length push rods? When all these things are under control then you can start to tune. It takes airflow to open the secondaries. Open to soon and the engine falls flat. This is where secondary springs have to be tried to get the right tip in. and on and on.
break in the cam? well the car didnt start right away. i spend one day trying to get the engine running, (well it started but just for 7 seconds), i drained two batteries. maybe I put to much gasoline in it. the next day it started but shaking all the time. i dont think that was a good " break in", maybe I wipe the ****of the cam, because those springs have too much pressure, (300 something lbs) for break in. tomorrow i will change the pushrods, let me see how it work. i dont want to torn the engine apart yet. let me do some adjustments first, install the electronic distributor, and check the carb and timming issues. how do you know the cam is damaged? does it make a weird sound? thanks Nelson Etienne
check the fratistat it could be out of timing fluid.j/k its sounds like timing or firing order...just my $.02
I'd start with the basic #1 piston at TDC, checking the rotor seeing where it's pointing, checking the firing order, etc.
The piston will be at TDC 2 times in the firing cycle. You need to have the valve cover off so that you can watch the valves and make sure you are in time with the cam. Short... get TDC on the compression stroke. Otherwise you will be 180 degrees out of time. Dave
So many things can cause what you describe. Did you use a 351W or 302 cam? Firing order is different. Just reversing the two small wires on the ignition coil will cut down power.
you don't have to remove the valve cover just put your finger in the plug hole,,,,bump it over till your finger gets blown off j/k but it will push your finger then use a plastic staw put it in the hole move it back and forth till its at its high point
bad news. a mechanic checked my car, he says that the pushrods in the cylinders No. 2 and No. 7 are way too loose, probably because the cam is wipe out. maybe he is right. i will take it out and see, but not tomorrow, i will do this in the weekend.
check the balancer also thay will spin on themself and the timing mark will be off as much as it can turn. Try to set it by ear and see what happens.
had the same issue recently/ in the past 3 years the zinc level in the oil has dropped significantly ( source of emmissions). all new cars have roller cams so zinc ( anti-shear additive) could be reduced with no ill effects. This is unstated ( so far) but it is HIGHLY reccomended that rotella -T or some other diesel oil be used during break in ( has lots of zinc and promotes lifter spin ) DO NOT USE SYNTHETIC oil to break cam in / it is too slick to make the lifters spin to polish the cam lobes. ONCE worn in...ANY oil is fine as the cam has been polished and it has hardened during break in...hope this helps...dont ask me how I know. I dont type too well
If the camshaft has any wiped lobes, the motor really needs to be thouroughly disassembled, cleaned and inspected. It sounds like you are using a flat tappet camshaft. If so, burning up two batteries to start the motor will probably be responsible for the damage. Cams require splash oil from the crankshaft to lubricate the lobes. The crank is not spinning fast enough to sling oil onto the camshaft when you are trying to start the motor. There are several things that need to be done to give a flat tappet a good chance of survival. First, you must apply cam assembly lube (or an equivalent moly paste) to the lobes and lifters when you install the cam. Second, you must have the correct preload on the lifters. Too much or too little can easily destroy a camshaft. Finally, proper break in must be done. That means immediate start up and running the engine at > 2,000 rpm for no fewer than 20 minutes. In order to ensure immediate start up, I set the initial timing in the motor w/o the plugs in it. Then I put the plugs in and fire it up. This step really reduces the amount of grinding the starter (not to mention angst) on initial start up. Another step I would recommend is degreeing the camshaft. Not only will it tell you where the cam is timed in but it requires you to find true TDC. Once I have the cam where I want it, I turn the motor to TDC on the degree wheel. The motor does not get turned again until the timing chain cover, balancer and timing tab are on and I mark true TDC on the balancer. You would be surprised how far off timing marks can be on a balancer. Just a few suggestions that will hopefully get you headed in the right direction.
