At A Loss On Timing - Page 3

benshere · #31 (**permalink**) 05-06-2008, 03:37 PM

Hate to keep bringing it up, but if you do a cam, do not forget about the exaust valve rotators!! Our 79 bronco w/400 and a crane cam had .500 lift and with the rotators would break pushrods because of coil bind. Whatever cam you use, be sure to read the material on that. Sorry it didnt work and you are having to do all this stuff

dobber97 · #32 (**permalink**) 05-06-2008, 10:07 PM

Hey guys ol dobber again. I just wanted to let you know that I put the old cap back on and seemed to be better. Although still didn't seem to want to start, it would fire but just wouldn't go on over and run. So didn't seem to help in my eyes. I set the balancer back to TDC and pulled off the intake. I decided to pull the #1 intake rocker off and when i loosened the rocker stud I noticed the valve closed some more. Is this right? I pulled the lifter and decided to measure compared to the one that was there before. The old one had an overall length of 1.962, and the new one measured 1.984 is this enough to keep the valves open enough to keep causing the backfiring. So I hope i am on to something. thanks guys.

brthevio · #33 (**permalink**) 05-07-2008, 03:34 AM

Sounds to me like you just found your problem. Unless you just want to put a new cam and everything in, I would say buy a new set of lifters (measure before you install them to make sure they match your originals) and run with it.

danlee · #34 (**permalink**) 05-07-2008, 05:48 AM

Get a pushrod length checker, and find the right length pushrod. Then order a set of pushrods in the correct length, or shim the rockers to get the right height.

benshere · #35 (**permalink**) 05-07-2008, 08:45 AM

80broncoman · #36 (**permalink**) 05-08-2008, 08:40 AM

There are many engines that when you set the markes on the timing gears ar 6 O'clock for the cam and 12 O'clock for the crank gear you are on TDC overlap.
NOT TDC compression. Be sure to check that. with a stock type cam valves MAY actully be closed on Both of the TDCs.
Measuring the outside body of a lifter will tell you,.....the outside body size of the lifter. Which has nothing to do with lifter preload. If you need to use shims under the rocker pedesals Crane Cams has part number 99170-1.
Valves will not close all the way with Too much lifter preload.
Lifter preload explained in detail here:
CraneCams

scroll down the page to : What is Hydraulic Lifter Preload?