Author Topic: Hydraulic Flat Tappet Spring Pressure  (Read 4475 times)

Offline Topcat

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Re: Hydraulic Flat Tappet Spring Pressure
« Reply #15 on: December 09, 2016 - 09:44:24 PM »
My engine is back together now but Winter has hit. It will be a while until I get a chance to see if these lifters will hold. But I will check back in when I find out.
 Thanks everyone.

If the engine is going to sit for a long time, back off the spring pressure on the valves by loosening the valve train bolts.
This was recommended on my build by my machinist.
« Last Edit: December 09, 2016 - 09:46:20 PM by Topcat »
Mike, Fremont, CA.





Offline 734406pk

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Re: Hydraulic Flat Tappet Spring Pressure
« Reply #16 on: December 09, 2016 - 10:08:51 PM »
If the engine is going to sit for a long time, back off the spring pressure on the valves by loosening the valve train bolts.
This was recommended on my build by my machinist.

 :iagree: That's a great idea! Why have several valve springs/lifters under tension all winter for no reason?? Thanks Mike!! :2thumbs:
1973 Challenger 440 6 pack auto 3.91 rear
2012 Dodge Ram 3500 dually 6.7 Cummins Fleece EFI Live
1973 Challenger 318 2bbl auto 2.73 rear 22.5 mpg RIP
1970 Challenger TA 340 4bbl auto-Sold and sad
1999 Dodge Ram 3500 dually 5.9 Cummins Fleece tuned VGT-sold
1995 Kawasaki ZX1100E & still alive

Offline YO7_A66

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Re: Hydraulic Flat Tappet Spring Pressure
« Reply #17 on: December 09, 2016 - 11:10:05 PM »
 I need to fire it up for a few minutes to get the moisture out of it  and to get the oil pressure up enough to recheck lifter preload. Once I have done that, then I may loosen up the shafts until Spring.
 Thanks again!

Offline YO7_A66

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Re: Hydraulic Flat Tappet Spring Pressure
« Reply #18 on: December 17, 2016 - 01:59:49 PM »
 I finally got around to getting it fired up. I was a little worried about the 150+ seat pressure on these older Comp lifters, but it idled great with no noises up to 1500rpms on the first startup.

 The valve train actually seemed to be quieter now than it did with the 120lb springs. No ticking like before and blipping the throttle even seemed to have a quicker response. My cam card shows 135lbs seat pressure (1.5 rockers), so maybe the 120lb springs were just too light especially with my 1.65 rockers that I have now.
 I still need to recheck the preload one more time after the next startup (lifters pumped up), but then I will need to wait until spring to see if these lifters actually hold up or not.

 Thank you all!
« Last Edit: December 17, 2016 - 02:01:36 PM by YO7_A66 »

Offline 734406pk

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Re: Hydraulic Flat Tappet Spring Pressure
« Reply #19 on: December 17, 2016 - 04:34:49 PM »
Good info! I hope it works for you! :2thumbs:
1973 Challenger 440 6 pack auto 3.91 rear
2012 Dodge Ram 3500 dually 6.7 Cummins Fleece EFI Live
1973 Challenger 318 2bbl auto 2.73 rear 22.5 mpg RIP
1970 Challenger TA 340 4bbl auto-Sold and sad
1999 Dodge Ram 3500 dually 5.9 Cummins Fleece tuned VGT-sold
1995 Kawasaki ZX1100E & still alive