New rebuild....but tic..tic...tic

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megavites

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So, I have a fresh rebuild on a 75 318 with 70 heads. Unknown if they were previously milled.
Running a Hughes Whiplash hydraulic cam with their lifters and springs.
Heads were rebuilt and stems were equal with a straight edge when I checked.
All new stock valvetrain, rockers, shafts and push rods (7.5")
A quick check with feeler guages shows .035-.045" stem to rocker clearance.
Not sure why all stock valvetrain would be off..but it is.
I'm trying to get hold of an adjustable pushrod to get better measurements.
At that point, I'm assuming I just find longer pushrods based on my measurements?
Would I just measure to zero lash and add in the recommended preload of .080-.085?
Am I missing anything?
BTW..Hughes does state their cam ar not as quiet as stock cam.
 
if I understand properly you need longer pushrods maybe the new lifters are a little shorter on the on the plunger or the body . and no doubt a little geometry issues also .
check and measure everything and also check the sweep pattern on the valve tip .
 
megavites said:
So, I have a fresh rebuild on a 75 318 with 70 heads. Unknown if they were previously milled.
Running a Hughes Whiplash hydraulic cam with their lifters and springs.
Heads were rebuilt and stems were equal with a straight edge when I checked.
All new stock valvetrain, rockers, shafts and push rods (7.5")
A quick check with feeler guages shows .035-.045" stem to rocker clearance.
Not sure why all stock valvetrain would be off..but it is.
I'm trying to get hold of an adjustable pushrod to get better measurements.
At that point, I'm assuming I just find longer pushrods based on my measurements?
Would I just measure to zero lash and add in the recommended preload of .080-.085?
Am I missing anything?
BTW..Hughes does state their cam ar not as quiet as stock cam.
Click to expand...
Don't think you are missing anything, longer pushrods.
 
megavites said:
So, I have a fresh rebuild on a 75 318 with 70 heads. Unknown if they were previously milled.
Running a Hughes Whiplash hydraulic cam with their lifters and springs.
Heads were rebuilt and stems were equal with a straight edge when I checked.
All new stock valvetrain, rockers, shafts and push rods (7.5")
A quick check with feeler guages shows .035-.045" stem to rocker clearance.
Not sure why all stock valvetrain would be off..but it is.
I'm trying to get hold of an adjustable pushrod to get better measurements.
At that point, I'm assuming I just find longer pushrods based on my measurements?
Would I just measure to zero lash and add in the recommended preload of .080-.085?
Am I missing anything?
BTW..Hughes does state their cam ar not as quiet as stock cam.
Click to expand...
Don't run it anymore.

Check lifters for signs of cam failure. If all checks out...get push rods .075 longer than you have.
 
So you have actual valve lash?
And the lobes are still all there?
I highly recommend a set of adjustable arms, and it might as well be 1.6s; if there's room for the extra 6% lift. I realize that these are pricey. But in the long run, you're probably gonna need them.Plus you might be able to set them up with minimum preload and buzz your engine up a few hundred rpm higher. 273 stuff works pretty good, and can be had for a reasonable price.

I would also check the clearance from the underside of the stamped rockers to the retainers. Those springs require the 340 rockers, which are factory clearanced for the 340 springs and retainers which are of a larger od than the OEM teener stuff.
 
Last edited:
Take your valve stem to rocker clearance then divide that clearance by 1.5. THEN add it to the desired preload.

Example: .045" stem to rocker clearance / 1.5 = .030"
.030" + .070" preload = .100" longer pushrod
 
nm9stheham said:
Take your valve stem to rocker clearance then divide that clearance by 1.5. THEN add it to the desired preload.

Example: .045" stem to rocker clearance / 1.5 = .030"
.030" + .070" preload = .100" longer pushrod
Click to expand...
-did not measure new cam vs old (seems reasonable I have a stackup tolerance issue)

-.075 longer?

nm9…I see your calc dividing by stock 1.5 rocker ratio, so if my adjustable pushrod is adjusted to ZERO lash and I get the same approx.. .040” longer /1.5 + .080(recommended) =.106 longer pushrod =(7.606)

Based on above theoretical example, I could get a set of 5/16” -7.605 (Ford 302) pushrods and I’m good to go.

Should I measure every pushrod or can I just go with one intake and one exhaust?
 
The recommended procedure is to measure at all 4 corners, in case you have some deck slope front-to-rear on either side. Then average the 4 numbers. I would not expect intake and exhaust to be any different, unless something was up with the valves and how the heads and valves were worked. If you lay a good straight edge across the valve tips with the rockers off, and look for tip-to-tip variations, that will give you direct read on any valve tip-to-tip variations.

IMHO, see where you end up with .060" preload as well as .080".... that is near the middle of the common lifter movement range that I think will usually be in most lifters. (common... think.... usually... most.... Boy, I put I put a lot of qualifiers in that sentence! LOL) Not saying .080" is not a good number.... it's just that .060" has been in my wee brain for years.

And check that the ball size is the same on any pushrod.
 
hey mate I had the same ticking noise in my motor.... I swapped over to 273 adjustable valve train into my 318 and also zero decked the block...this caused the valvetrain to ever so slightly touch the baffles inside the rocker covers causing a tick, gave it a *gentle massage* now its all sweet
 
**UPDATE**
so I used a feeler gauge to measure each valve, I also noticed a slight diff. in stem height. I'm going to have to accurately measure that. Measurements as follow and bump starting to base circle:
Intake Exhaust
#2(0) #8(0)
#1(.003) #4(0)
#8(.003) #3(.017)
#4(.006) #6(.043)
#3(0) #5(0)
#6(0) #7(.011)
#5(.012) #2(.014)
#7(0) #1(0)
Car idled fine, no popping or spitting, but I'm not running it until I resolve. Exhaust lobe on #6 chewed up? Next step is to pull intake.:BangHead:
 
Lets' hope that 6E has something amiss with the valve stem length or the rocker or pushrod has something wrong with it. You could pull out the 6E lifter and look at the bottom for a quick 'preview of coming attractions' like at the movie theatre....

Also, it could be that the 6E lifter is not right.
 
Just take the rockers off and lay a straight edge across the valve tips. If it is out that far, it will be obvious and measureable.

Just keep in mind that if a lifter is weak/not holding oil, that may be the cause the large gap you had on 6E. With that lifter on the base circle, where you measured the lash, push down on the pushrod side of the rocker. If it is squishy, then the lifter has lost oil.
 
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