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With adjustable valve train you adjust each rocker arm so the pushrod just touches the lifter plunger then give the adjusting nut a half turn (which is about .060" preload). On non-adjustable valve train you use a shim under the rocker pedestal and/or change pushrod lengths to get this preload.
Too loose the rockers clatter and you don't get full valve lift, too tight and the valve may be held open a little once the lifter "pumps up" that can cause poor performance and loss of compression and even cause the valve to burn up if its an exhaust valve.
With adjustable valve train you adjust each rocker arm so the pushrod just touches the lifter plunger then give the adjusting nut a half turn (which is about .060" preload). On non-adjustable valve train you use a shim under the rocker pedestal and/or change pushrod lengths to get this preload.
Too loose the rockers clatter and you don't get full valve lift, too tight and the valve may be held open a little once the lifter "pumps up" that can cause poor performance and loss of compression and even cause the valve to burn up if its an exhaust valve.
What engine are you working on?
Damn i just torqued it to spec. And it was a 351m but now a 400
Damn i just torqued it to spec. And it was a 351m but now a 400
also i have the harness to my old distributor. The advance timing had 3 wires. But all the d
new distributors im looking at only have 2
My stock harness
the black/orange im assuming is power
black/gray ???
and black is ground correct ????
Damn i just torqued it to spec. And it was a 351m but now a 400
Well, it may be okay - but the "proper" way to do it is to check the pre-load on each lifter.
If you just replaced the OEM cam and lifters with the same OEM parts you are pretty safe to just torque the rocker arms down (although a pro shop will/should still check) but when replacing with aftermarket parts where parts tolerances may be different, you just don't know what you have. It's your choice.
Well, it may be okay - but the "proper" way to do it is to check the pre-load on each lifter.
If you just replaced the OEM cam and lifters with the same OEM parts you are pretty safe to just torque the rocker arms down (although a pro shop will/should still check) but when replacing with aftermarket parts where parts tolerances may be different, you just don't know what you have. It's your choice.
CB, you got it! I was wondering what the others were reading about cam/crank dots and TDC?
If you line the dots up on a small chevy timing gearset and leave it there, you will be 180 out. I didn't know about the 400 and can't remember any of the other Ford engines.
If you line the dots up on a small chevy timing gearset and leave it there, you will be 180 out. I didn't know about the 400 and can't remember any of the other Ford engines.
OK I just checked my Haynes book = Ford pick-up & Bronco 1980 - 1996 / 2wd & 4wd /Full-size / F-100 thru F-350 / gasoline engines
1997 2wd & 4wd Full-size / F-250 & F-350 Gasoline engines:
It said for ALL v8's to line the 2 dots up crank @12 / cam @6.
I can check my motor manuals but I am sure they will say the same.
And even if 180* out, 1 turns 2 times as fast as the other (cant remember if it is the cam or crank?) so it would line up after 2 turns or so.
If you were to drop the dist. in like that on a SBC then yes the dist. would be 180* out but we are talking SBF.
BTW the OP has a lot more going on with this motor than the timing gear marks. Last I saw he has needs to check his valve train as he has a mix of parts that may not play nice together.
Dave ----
And even if 180* out, 1 turns 2 times as fast as the other (cant remember if it is the cam or crank?) so it would line up after 2 turns or so.
If you were to drop the dist. in like that on a SBC then yes the dist. would be 180* out but we are talking SBF.
The crankshaft makes two revolutions for every one of the camshaft.
I don't know about the Chevy timing setup - those guys are backwards.
OK I just checked my Haynes book = Ford pick-up & Bronco 1980 - 1996 / 2wd & 4wd /Full-size / F-100 thru F-350 / gasoline engines
1997 2wd & 4wd Full-size / F-250 & F-350 Gasoline engines:
It said for ALL v8's to line the 2 dots up crank @12 / cam @6.
I can check my motor manuals but I am sure they will say the same.
And even if 180* out, 1 turns 2 times as fast as the other (cant remember if it is the cam or crank?) so it would line up after 2 turns or so.
If you were to drop the dist. in like that on a SBC then yes the dist. would be 180* out but we are talking SBF.
BTW the OP has a lot more going on with this motor than the timing gear marks. Last I saw he has needs to check his valve train as he has a mix of parts that may not play nice together.
Dave ----
I believe you guys, but that description you gave from the book says nothing about where the engine actually is when the dots are lined up. Yes you line the marks up to get the crank gear and the cam gear in synch, but on a small chevy that is not tdc #1.
I say mix because you said you replaced the cam, did not say if stock or not.
You also hinted you did not check the valve train set up that should be done if stock or not.
Now if pre-load is not right as said either the right push rods to be used with the non-adjustable rockers OR swap out the rocker nuts/studs for adjustable ones.
Wait I am wrong on that last part you still need the right push rods for the valve train to be right.
See it is not so easy to just swap cams and be done even stock.
Originally Posted by Franklin2
I believe you guys, but that description you gave from the book says nothing about where the engine actually is when the dots are lined up. Yes you line the marks up to get the crank gear and the cam gear in synch, but on a small chevy that is not tdc #1.
It makes no difference where the engine is because on a FORD it puts it at TDC.
Besides this is a FORD forum and he is working on a FORD.
Dave ----
I say mix because you said you replaced the cam, did not say if stock or not.
You also hinted you did not check the valve train set up that should be done if stock or not.
Now if pre-load is not right as said either the right push rods to be used with the non-adjustable rockers OR swap out the rocker nuts/studs for adjustable ones.
Wait I am wrong on that last part you still need the right push rods for the valve train to be right.
See it is not so easy to just swap cams and be done even stock.
It makes no difference where the engine is because on a FORD it puts it at TDC.
Besides this is a FORD forum and he is working on a FORD.
Dave ----
well i guess the only thing i can do is hope for the best haha
