motor won't crank after shimmed and f cam.

dastang2

Active Member
Dec 11, 2003
2,020
0
46
tx
as you know, i put shims on the stock rockers because this motor has been milled or something before i got it. before it would not crank with them tight so if i loosen the bolts, it would fire up and run. so i shimmed them .090. that was enough to get the rockers loose.(off of the valves when closed.). i also put an f cam in it a couple days ago.it has blue spark, fuel and air.it is NOT 180 out and i tried both firing orders.i even loosened the rockers and nothing. not even a pop. but i turned the dizzy and the retarded ignition slowed the engine down while cranking. i am pretty sure i put the cam straight up. what gives. it is not even popping like it would if the distributor was out of sink or something. anybody got answers. stock rebuilt e6 heads, rebuilt roller engine stock valve springs, f cam, carbureted. i am stumped and it's pissing me off.
 
yes it is, i just had the motor out again to fix the gasket problem on the pump and i tested it. works and moves fine. i sprayed some starting fluid in it and it fired but through the intake. i know the distributor is in right but not so sure on the cam anymore. i am going to take the .030 shims out and see what .060 will do. i have them together right now.
 
well i guess it is not the cam since on tdc, the #1 valves are closed and the intake is about to open. the rotor is also pointing to 1. that would mean it has got to be my rockers, i still have not fixxed that, damn.
 
well i took the thin shims out which leaves it to .060. it cranks but runs like ass, i need to check the preload. do you think i will have enough piston clearance with the f cam. they are not hitting now.
 
What i did when i screwed with my heads, lay a straightedge across the top of all the valve stems, if theres any that are higher or below the rest at least u no they would require a different amount of shims, more or less, than the others. an easy to see if ur near the right area is do a compression test, (dont forget to open the throttle wide open, but u would prob do it with the upper intake off anyway so ignore that)....when i was doing mine, i had 9psi of compression in one of my cylinders lol and i added a shim and brought it up to 150 psi. if u do a search ull find a few long explanations on how to shim the stock rockers...First i would do a compression test, see if u even have enough compression to fire....but u have fuel and everything?, u hear the pump kick on etc..

BTW i MacGyvered my own shims lol dont do this. i got a few brass strips that fit perfectly in those rails and drilled a 1/2?? hole in them and cut them to size and that was my homemade shims lol i had no idea on the thickness but i drove it like that for 9 months lol and all had decent compression...i just did it cuz i had to drive to school and stuff, and actually i didnt even no they made shims for that purpose at the time lol
 
ok now what, i thought i fixxed my problem because i forgot to change the firing order to the HO spec so i did and hell. i made it worse. it only backfires. so i changed it back to the reg. 302 firing order and it fired up and it feels like it is lacking fuel when revved. running lean or something. i am out of ideas. it is an f cam is is stamped on the cam.
 
the F-303 cam has a firing order of 1-3-7-2-6-5-4-8 is this what you have it set at? I know when I put mine in I forgot about chaging the firing order and it would barly run and when it did it ran like dog crap. Hope this helps. But also make sure that when you set the distributor that you had the number 1 up on compretion before you put the distributor in. Good luck.
 
the distributor is right on where it is supposed to be with the intake valve about to open at tdc, both valves are closed. i know it is the HO firing order but it won't run that way. only the regular 302 firing order it will run. it is freaky. it is not 180 out. i checked that. i am going to do a compression test and see what i get.
 
dastang2 said:
i am dumb i did have it 180 out and it works now
We all make mistakes but to make yours better you hung in there 100% and kept at it to find what you did wrong. I'm not laughing at you by no means. Yes you will have some smartass probably will but atleast you learned something.I'm glad you found it and don't hammer it to much when you get it running