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Comp Roller Lifters Problem |
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73XBGT
AMC Apprentice Joined: Jan/28/2010 Location: Huntsville, AL Status: Offline Points: 123 |
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Posted: Jun/15/2010 at 9:56pm |
Would appreciate some advice guys.
I bought a new Comp Cam solid roller (.608/.614 valve lift) and their 861-16 roller lifters a few months back. I did not bush the lifter bores in my block (my mistake). I just assumed Comp's re-design of the AMC lifters had fixed the oil pressure bleed-off problem due to the "eyebrow" at the bottom of the lifter skirt being exposed at max lift. I talked with Nick Alfano last night and thank goodness he told me to check for this. I checked, and the bottom of the lifter skirt is exposed in the oil passage when the cam is at max lift.
Now, what to do?? Bushing the bores means disassembling my partial buildup, getting the machine work done, and reassembly. I'm not even sure if the local speed shops here in Alabama are set up for bushing an AMC V8. If they are, I think typical cost is $400-$500, plus bushings.
Does anyone else make a roller lifter that will work for AMC yet? If I can get my money back from Comp, I would even consider getting Crower or somebody to build some custom lifters with a long enough skirt. Anyone have connections with a company that will do custom lifter work? This option might be less expensive and less trouble than bushing the bores.
What would some of you experienced engine builders do at this point? This is my first engine build, so I'm having to learn the hard way
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Red Devil
AMC Addicted Joined: Jul/10/2007 Location: Canada Status: Offline Points: 1743 |
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Have you tried priming to check the leakage? Maybe get the cam re-ground with a small base circle if it's only an issue at max lift? If Comp said the cam and lifters would work without bushing the bores, maybe they will do the regrind at no cost? Crane 86518-16 lifters seem to work, but don't know if you can still get them? Pretty disappointing that Comp didn't fix the problem. Could you please post a photo or two of the new lifters? Maybe you got old stock (old design)?Edited by Red Devil - Jun/15/2010 at 11:55pm |
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73XBGT
AMC Apprentice Joined: Jan/28/2010 Location: Huntsville, AL Status: Offline Points: 123 |
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[QUOTE=Red Devil]
Have you tried priming to check the leakage? I did not try priming. I figure if I can see a gap, then there's no point - it's a long sad story, but I have .003" main bearing clearance, so I need all the oil pressure I can get. I know .003" is too much for a street engine, but I went through two different crank grinds and purchased .010" and .020" bearings. The first crank grind was .0045"!! After the second guy missed the tolerances on .020", I just decided to run it like it is with 20w50 and some good cooling capacity.
Maybe get the cam re-ground with a small base circle if it's only an issue at max lift? If Comp said the cam and lifters would work without bushing the bores, maybe they will do the regrind at no cost?
Actually, I sent the cam back to Comp for a re-grind last month, because I didn't like the DCR number that I was getting with a 10.5:1 compression ratio. Right now the base circle is almost the same diameter as the cam's shaft diameter, so I don't know if they could make the base circle any smaller.
Pretty disappointing that Comp didn't fix the problem. Could you please post a photo or two of the new lifters? Maybe you got old stock (old design)?
The lifters are definitely the newer design. I need to figure out how to post pics. In the meantime, I'll attach a pic that I borrowed from a forum member's older post. They look just like this:
They have the taller shoulder above the oil groove.
They do not look like the older short shoulder version, like this:
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forest
AMC Addicted Joined: Nov/14/2008 Status: Offline Points: 2114 |
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I have talked with Crower Cams about this issue and can get custom made lifters with a big shrouded roller if you like... I am a dealer for Crower and am on the phone with them every week, several times a week... PM me for more info if you want.. Forest
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setting guys out by car lengths....
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Red Devil
AMC Addicted Joined: Jul/10/2007 Location: Canada Status: Offline Points: 1743 |
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Hey forest, any chance of getting Crower to develop an off-the-shelf AMC solid roller lifter, since Comp doesn't seem to be making progress ... and one that gets decent street life? Edit: Is Crower 66384H-16 a viable option?
Thanks! RD. Edited by Red Devil - Jun/15/2010 at 11:29pm |
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73XBGT
AMC Apprentice Joined: Jan/28/2010 Location: Huntsville, AL Status: Offline Points: 123 |
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Yeah, or perhaps Crower could set up and do a limited (minimum order) production run. Maybe there are enough AMCers and vendors that would make it worth their while, especially since they would own the market, albeit small. Forest, can you pull some strings??
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SKeown
AMC Addicted Joined: Jul/30/2009 Location: Texas Status: Offline Points: 3085 |
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Call Barry Allen and discuss what you're concerned about, he tested the new Comp design and gave his blessings. Something aint right, I compared the origional Comp lifters to Crane's and found that the Crane lifters allowed only about .040 cam lift than Comp's before starting to bleed off at the bottom too. Some people are running much more lift than you without modifying the lifter bores. If I remember correctly, you should be able to run you're cam with the old style Comp lifters, particularly with a reduced base circle camshaft.
SKeown
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amx39068
Supporter of TheAMCForum Joined: Feb/21/2008 Location: Arizona Status: Offline Points: 11576 |
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This is the same #$%#$% problem that I had with my Comp solid roller lifter cam that I fixed with Crane solid rollers. Take forest up on his offer and get a set of the Crower lifters and your problem will be solved. Based on your experience here, I am through with Comp. There is no excuse for getting it wrong the second time around and they don't deserve our business as a result.
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Dan Curtis-Owner and CEO AZ AMC Restorations; Facebook: https://www.facebook.com/amcmusclecars/ & Curtis Real Estate Development
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forest
AMC Addicted Joined: Nov/14/2008 Status: Offline Points: 2114 |
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Skeown, obviously he can see a gap between the bore and lifter... what does he have "wrong"? did he somehow install things wrong and get this problem,? no, its pretty straightforward, too much lift = comp sucks... Ill call Crower today about it and see what it will cost for a set of shrouded roller lifters to be made.
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setting guys out by car lengths....
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amx39068
Supporter of TheAMCForum Joined: Feb/21/2008 Location: Arizona Status: Offline Points: 11576 |
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Forest, I'll sign up for a set as well as I really liked the solid roller I had the bad lifters on but will look for Crower to make me a similar grind rather than comp
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Dan Curtis-Owner and CEO AZ AMC Restorations; Facebook: https://www.facebook.com/amcmusclecars/ & Curtis Real Estate Development
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