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New 351 wont run worth a st timing

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andrewmaeyaert

Contributing Member
"also, back to one of the thin

"also, back to one of the things i originally suggested: "tight valves"

when i put the engine together, i did not know how to tighten down the rockers, so i just snugged them all. is that right?"
 
I have a 75' block from tr

I have a 75' block from truck. It is old firing order 1-5-4-2-6-3-7-8. Year of crank is definitley more important than year of block as the blocks did not change. I think the firing order changed in 78' but not sure. You may have to replace cam if the 74' crank is old firing order. The rockers should be 22lb torque but double check...important to use torque wrench for this...different torque will alter the position of the push rod even slightly which will affect your valve lift...
 
"not that this is Andrews prob

"not that this is Andrews problem and not that I did this personally but, accidently putting washers under the carb gasket at one end then installing the carb, there by causing an air gap will cause a similar issue, causing the engine not to idle at all. (Vacuum Leak)

I think the firing order change was to help balance the engine more and produce a little more HP, but I think it was only done by changing the cam and not the crank.

Also shims under valve springs is also used to tweak and balance and blueprint the spring pressure."
 
"When you set up the timing ch

"When you set up the timing chain was it installed correctly ? Did you bye chance set one sprocket, 180 degrees in the wrong direction ?

Timing chain tight?

I like the running motor method of setting the lash on valves, and yes that could be the problem to tight valves.

One more thing, when you installed the dizzy, did you maybe install that, 180 degrees in the wrong direction?"
 
"Compression test would be the

"Compression test would be the easiest way to see if valve timing and lash are good or not.

If comp test ok, then move on to ignition system."
 
"thanks guys. when i installed

"thanks guys. when i installed the timing chain, i put the dot in the crank up, and the dot on the cam down, how do i adjust the valves while running?"
 
"figured it out!!! you guys wi

"figured it out!!! you guys will laugh your asses off when i tell you. It was f-ing spark plugs!!!!!! put new plugs in, and it ran like a top!
the bad news: after call to the local machine shop, i learned the "book" i used to put the engine together told me the wrong torque specs for the rod caps. i didn't torque them down enough, so that is where my "knock" is coming from. do you know if i can drop the oil pan enough to get at the rod caps w/o pulling the engine?"
 
"great news, if you have enoug

"great news, if you have enough room to drop the pan(doubt you do), no reason I know why you can't and get to the rod caps.."
 
"depending on what you torqued

"depending on what you torqued them too and how much you ran it, what the clearances are like... maybe. Instead of just torqueing them down, take each off and have a look at the bearing."
 
"hey guys. i yanked the motor,

"hey guys. i yanked the motor, dropped the pan and found that all 16 bolts were finger loose!!!. no crank or bearing damage. torqued them down to spec. threw the motor back in. runs like a dream!!!. i want to say thanks to all of you guys for your help. i really appreciate it!!"
 
HOLY BOAT !!! wow.. I think th

HOLY BOAT !!! wow.. I think the mechanic needs some talking to.. Congrats !!!

Did you put the timing back? or is it OK now ?
 
"I had the same kind of thing

"I had the same kind of thing happen to me last season. The final solution was too stupid to speak of it here. I took the boat out, wouldn't get over 2000 RPM even at full throttle. Boat would run ok in Neutral.Idled smooth and revved right up to 4000 RPM. Kept thinking....fuel problem. Replaced fuel filter, NO good. Replaced sieve screen in primary fuel filter, STILL no good. Tore down fuel pump, found the bottom part full of rust flakes, STILL no good. Gave up, went home and found I had the plug wires on in wrong order.
Instead of 4 then 3, I had it the other way around. BOY...did I feel stupid.LOL."
 
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