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Progress. Updates. And questions.

68-500 said:
What timing chain set do you have?maybe it requires a Torrington bearing between spricket and thrust plate?
Click to expand...
So actually I have found the issue. It seems I had pushed the cam too far back into the block. So now I have it aligned. Waiting for the cup washer to arrive so I can keep it aligned and againsed the thrust plate.

20250714_140129.jpg


20250714_140137.jpg


20250714_140743.jpg
 
bm73charger said:
i haven't been able to find a detailed explanation yet on how to measure. Is there a specific set of steps involved? my idea was to set the measuring tool in there. expand it until there was 0 lash. and then rotate the engine to make sure it went through the full range of motion without looking like it was too strained or about to fall off. that just seems much too easy though. any help would be appreciated.
Click to expand...
Depending on what out come you desire it can be as simple as making sure cam is on base circle for the intake and exhaust for the cylinder your checking ( compression stroke TDC). Installing adjustable pushrod to zero lash. Then add whatever the desired preload to that length. I suggest at least.050 up to .100.
Being your build is a stroker you may want to read up on rocker arm geometry and really get things right. Which may require shims for rocker shafts. Then figure out pushrod length.
Edit: you should check the total preload range of your hydraulic lifters. Then I suggest a middle of the road preload.
 
bm73charger said:
i haven't been able to find a detailed explanation yet on how to measure. Is there a specific set of steps involved? my idea was to set the measuring tool in there. expand it until there was 0 lash. and then rotate the engine to make sure it went through the full range of motion without looking like it was too strained or about to fall off. that just seems much too easy though. any help would be appreciated.
Click to expand...
Fair warning: I'm not an experienced engine builder. The 408 I recently finished was only my second build ever; the first was over 30 years ago. So my experience has been learned over the last 7 months. Having said that, I now have about 200 miles on the engine with no issues, no strange noises, 80 psi oil pressure at cold idle.
I see you installed adjustable rocker arms; are the adjusters cup or ball? It makes a difference when dialing in the final pushrod length.
Regardless of cup or ball, rotate the each rocker's adjustment screw until the adjuster bottoms out against the underside of the rocker. Then counter-rotate 360° to drop the adjuster down one or two threads from the rocker. This gives wiggle room for any final adjustments when installing the pushrods.
Pick a cylinder, doesn't matter which one but most people default to #1. The cam lobe has to be on the base circle. With the rocker arms cinched down (don't have to be fully torqued), increase the length of the checker pushrod until it won't rotate by rubbing one finger against it. Now its at zero preload. Continued lengthening of the checker rod will only increase lifter preload. Now add your preload to the pushrod length, typically 0.030" - 0.060". During my build I talked to Dave Hughes at Hughes Engines, and Mike Beachel at B3 Racing, and each said that choosing a preload number isn't critical. A tighter preload may be a little noisier at cold idle.
If the pushrod is ball end, you're done. Cup end is a little tricky because you have to subtract the depth of the cup from your total length. I used PRW rockers with cup adjusters (ball end pushrods) so I was done. Using calipers you can try to measure the diameter of the ball.

I measured both intake and exhaust for both #1 and #2 cylinders to get a comparison. Remember to rotate the engine for each measurement so that you're always on the base circle.
When you're done, call up Smith Bros. pushrods; they were very helpful when I ordered.

I used a paint daub to help count the revolutions. I also painted one surface of the hold down brackets because they're offset and I wanted to make sure they were reinstalled in the correct orientation.
20250528_133454.jpg
 
CoronetDarter said:
Fair warning: I'm not an experienced engine builder. The 408 I recently finished was only my second build ever; the first was over 30 years ago. So my experience has been learned over the last 7 months. Having said that, I now have about 200 miles on the engine with no issues, no strange noises, 80 psi oil pressure at cold idle.
I see you installed adjustable rocker arms; are the adjusters cup or ball? It makes a difference when dialing in the final pushrod length.
Regardless of cup or ball, rotate the each rocker's adjustment screw until the adjuster bottoms out against the underside of the rocker. Then counter-rotate 360° to drop the adjuster down one or two threads from the rocker. This gives wiggle room for any final adjustments when installing the pushrods.
Pick a cylinder, doesn't matter which one but most people default to #1. The cam lobe has to be on the base circle. With the rocker arms cinched down (don't have to be fully torqued), increase the length of the checker pushrod until it won't rotate by rubbing one finger against it. Now its at zero preload. Continued lengthening of the checker rod will only increase lifter preload. Now add your preload to the pushrod length, typically 0.030" - 0.060". During my build I talked to Dave Hughes at Hughes Engines, and Mike Beachel at B3 Racing, and each said that choosing a preload number isn't critical. A tighter preload may be a little noisier at cold idle.
If the pushrod is ball end, you're done. Cup end is a little tricky because you have to subtract the depth of the cup from your total length. I used PRW rockers with cup adjusters (ball end pushrods) so I was done. Using calipers you can try to measure the diameter of the ball.

I measured both intake and exhaust for both #1 and #2 cylinders to get a comparison. Remember to rotate the engine for each measurement so that you're always on the base circle.
When you're done, call up Smith Bros. pushrods; they were very helpful when I ordered.

I used a paint daub to help count the revolutions. I also painted one surface of the hold down brackets because they're offset and I wanted to make sure they were reinstalled in the correct orientation.
View attachment 1886257
Click to expand...
https://www.jegs.com/i/PRW/228/3231812/10002/-1

These are the rockers i bought. so I'm assuming they're very similar to the ones you have.

I have seen a few mentions of being on base circle. Im unsure of what that means though.
 
RemCharger said:
Excellent advice. There's so many great books out there a guy needs to read!
Click to expand...
i have a book on rebuilding a small block Mopar but there's nothing in it on measuring pushrod length. it is really based off of rebuilding an existing engine not adding different parts. Any recommendations on good literature would be appreciated. @RemCharger @68-500
 
Geoff 2 said:
Sure don't like the severely bent guide plate on those lifters...
Click to expand...
can you elaborate? im not in front of the heads right now and in the pictures im not seeing anything out of place. but again im a novice and could be overlooking things. which is why i post here asking for tips tricks and advice.
 
bm73charger said:
https://www.jegs.com/i/PRW/228/3231812/10002/-1

These are the rockers i bought. so I'm assuming they're very similar to the ones you have.

I have seen a few mentions of being on base circle. Im unsure of what that means though.
Click to expand...
Those look like the rockers that I have. Cup style lifters, ball type pushrod ends. That's good, takes one variable out of the equation.
Base circle is the bottom of the cam lobe. If you measure your pushrods while on the ramp or at the peak, they'll be too short.
 
CoronetDarter said:
Those look like the rockers that I have. Cup style lifters, ball type pushrod ends. That's good, takes one variable out of the equation.
Base circle is the bottom of the cam lobe. If you measure your pushrods while on the ramp or at the peak, they'll be too short.
Click to expand...
ooooooh. so it dosent matter about top dead center or anything. just that the cam lobe is at its lowest point when starting to make sure its long enough all the way through the lobes stroke?
 
bm73charger said:
Are you referring to this. That bar that connects the two lifters? This is how it came out of packaging from the kit. The lifters and cam came as a kit together. Posting below to see if that helps.

https://www.jegs.com/i/Howards-Cams/466/CL718005-09/10002/-1

View attachment 1886929
Click to expand...
The threaded bosses in the lifter valley are for the lifter hold-down (commonly called a 'spider'), which implies that its a roller cam block. I have a Magnum block, which has some differences from an LA block.
In the magnum, the lifters are held down by the 'dog bone', and the dog bone in turn is held down by one of spider arms. I thought the LA roller blocks had the same setup, but I could be mistaken.
Here's a close up of the spider arm holding down the dog bone, with the checker rod in place.
20250513_103429.jpg
Bird's eye view of the lifter valley with the spider in place.
20250509_134548.jpg
 
bm73charger said:
ooooooh. so it dosent matter about top dead center or anything. just that the cam lobe is at its lowest point when starting to make sure its long enough all the way through the lobes stroke?
Click to expand...
Correct. Determining TDC is the first thing you do when you're degreeing the cam.
 
CoronetDarter said:
The threaded bosses in the lifter valley are for the lifter hold-down (commonly called a 'spider'), which implies that its a roller cam block. I have a Magnum block, which has some differences from an LA block.
In the magnum, the lifters are held down by the 'dog bone', and the dog bone in turn is held down by one of spider arms. I thought the LA roller blocks had the same setup, but I could be mistaken.
Here's a close up of the spider arm holding down the dog bone, with the checker rod in place.
View attachment 1887043
Bird's eye view of the lifter valley with the spider in place.
View attachment 1887045
Click to expand...
yes i have this piece in my parts pile that came with the engine when i first got it. the old lifters came with it to and the dog bone connector is a circle that the lifter rides in connected to a straight piece connected to another circle the other lifter rides in. those lifters sit loose in the dog bone and the spider holds it all in place. the Howards lifters are attached to each other with that v shaped bar. i can still put the spider on as i still have it and its in solid shape. however i was told that with 1.6 rocker ratios the spider may not work and it might be better to not use it.

any input would be helpful.
 
CoronetDarter said:
Those look like the rockers that I have. Cup style lifters, ball type pushrod ends. That's good, takes one variable out of the equation.
Base circle is the bottom of the cam lobe. If you measure your pushrods while on the ramp or at the peak, they'll be too short.
Click to expand...
awesome. im thinking about getting oil through pushrods as well. i figure it cant really hurt to have even though it oils through the shaft. any thoughts on that?
 
bm73charger said:
awesome. im thinking about getting oil through pushrods as well. i figure it cant really hurt to have even though it oils through the shaft. any thoughts on that?
Click to expand...
Oiling through the shafts means you have the LA engine block. No need to provide additional oiling through the pushrods. Too much oil on top means less oil down low, where its needed most.
 
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